JP2008072886A - Power converter, dc power transmission system utilizing same, and power storage system - Google Patents

Power converter, dc power transmission system utilizing same, and power storage system Download PDF

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JP2008072886A
JP2008072886A JP2006251962A JP2006251962A JP2008072886A JP 2008072886 A JP2008072886 A JP 2008072886A JP 2006251962 A JP2006251962 A JP 2006251962A JP 2006251962 A JP2006251962 A JP 2006251962A JP 2008072886 A JP2008072886 A JP 2008072886A
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magnetic flux
magnetic
winding
iron core
superconducting
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Kiyotaka Ueda
清隆 植田
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Kiyotaka Ueda
清隆 植田
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    • Y02E40/66
    • Y02E40/67
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E70/00Other energy conversion or management systems reducing GHG emissions
    • Y02E70/30Systems combining energy storage with energy generation of non-fossil origin

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power converter that has a function as an AC/DC transformer, a function as a circuit breaker, and a function as a frequency converter while reducing loss by suppressing heat generation along with suppressing enlargement in size, an inexpensive DC power transmission system having high power-transmission efficiency, and a power storage system. <P>SOLUTION: The power converter is provided with a DC-side iron core 3 wound around with a DC-side winding 30, an AC-side iron core 2 wound around with an AC-side winding 34, and magnetic-path switching elements 41, 42, 43, and 44 which are respectively arranged at each magnetic connection part between the DC-side iron core 3 and the AC-side iron core 2 and switch the magnetic-path connection part by controlling cutoff and passing of a magnetic flux at each magnetic connection part so as to periodically and alternately form two types of magnetic-flux flows A, B that flow in the same direction at a part of the DC-side winding 30 of the DC-side iron core 3 and whose flow directions are opposite to each other at a part of the AC-side winding 34 of the AC-side iron core 2. A magnetic-flux flow, generated with an AC current or a DC current made to flow into the AC-side winding 34 or the DC-side winding 30, is switched by each magnetic-path switching element. Consequently, it is possible to execute power conversion while generating a DC current or an AC current in the other winding 30 or 34 with magnetic induction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power converter, a DC power transmission system using the power converter, and a power storage system. More specifically, the present invention is an apparatus that converts AC power into DC power or DC power into AC power, and is suitable as an AC / DC converter incorporated in a DC power transmission system, and a transformer, The present invention relates to a power converter that can have functions of a circuit breaker, a power storage device, and a frequency converter, a DC power transmission system using the function, and a power storage system.

  Currently, AC / DC converters are used in power transmission systems, solar power generation, wind power generation, battery power storage facilities, electric vehicle motor power supplies, fusion magnets, accelerator magnets, medical diagnostic MRI magnet power supplies, homes. It is used in a wide range of applications from large capacity to small capacity in various fields such as industrial equipment and lighting power supplies. All of these converters are semiconductors using silicon crystals, and a combination of silicon semiconductors that allow current to flow only in one direction is used to convert alternating current into direct current or direct current into alternating current. This converter is used in combination with a transformer for a converter that transforms an AC voltage to a value suitable for the converter (Patent Document 1). Moreover, since a ripple is accompanied at the time of rectification, a smoothing reactor for eliminating this is provided.

  Further, as shown in FIG. 32, for example, a conventional DC power transmission system includes a step-up transformer 103 provided in an AC line between a generator 101 and a load 102 (or substation) such as a consumer. , Forward converter 104 using thyristor valves, etc., smoothing reactors 105 and 106, DC line 107, reverse converter 108, step-down transformer 109 provided in the AC line, and harmonic filter circuits at both ends of each transformer. (Patent Document 2).

JP-A-9-233833 JP 2000-253582

  Conventional converters using silicon semiconductors require a transformer for converting the AC voltage to a value suitable for the converter, and in addition to leakage that does not exceed the allowable current tolerance of the semiconductor element in preparation for an arm short circuit accident. Since an impedance transformer must be employed, the operating current level must be operated in a small range compared to the current withstand capability of semiconductors. Further, even if a current limiter using a superconducting conductor that is activated when an arm short-circuit failure occurs and prevents a failure current from becoming large is used, the allowable current withstand capability of the silicon semiconductor is limited. For this reason, it is not suitable for large-scale power conversion with a single facility, and for example, many stages of power conversion facilities have to be interposed between a power plant and a power consumer.

  Moreover, the combination of the transformer of the room temperature winding and the converter using the silicon semiconductor involves loss. For example, the main loss of the equipment used at present is the highest efficiency among the large capacity equipment with low loss, and the transformer including the step-up transformer 103 and the step-down transformer 109 and the smoothing reactors 105 and 106 Each copper loss and iron loss is about 0.5% of the rated capacity, and the loss in the forward converter 104 and the reverse converter 108 is about 1% of the rated capacity, which is about 1.5% or more in total. Appear, and this is over 3% for low voltage. The loss value of 1.5% or more is the most efficient case among the devices of the large-capacity DC transmission system. For example, in the case of a 500 MW class large-capacity transmission system, this loss is reduced as described above. Even if it can be suppressed to 1.5%, the amount of loss is extremely large. In addition, since the loss in a normal large-capacity device does not fall within 1.5%, there is a possibility that more loss may occur. In addition, although the amount of loss in a small-capacity device is smaller than that in a large-capacity device, the loss is generally twice that of a large-capacity device in terms of the ratio to the rated output. Therefore, there is a demand for further reducing power loss as much as possible in both large-capacity devices and small-capacity devices.

  Further, in the case of a large-capacity transmission system, the equipment is inevitably increased in size due to an ultra-high voltage and a large current. Also, there is a problem in that each of the devices of the inverse conversion device 108 and the smoothing reactors 105 and 106 has a limit in miniaturization.

  Further, in addition to the semiconductor conversion element, a transformer, a DC smoothing reactor winding, and the like are required, which increases the size and weight of the device, and requires the manufacturing cost, transportation cost, and construction cost of the device.

  Further, in order to transform a DC voltage, it is necessary to convert it to AC once, transform it with a transformer, and then convert it again into DC, so that a transformer and a converter are duplicated.

  An object of this invention is to provide the power converter device which can reduce a power loss and can accelerate | stimulate size reduction. Moreover, this invention aims at provision of the power converter device which has a function as a direct current or alternating current transformer. Moreover, an object of this invention is to provide the power converter device which has a function as a circuit breaker. Moreover, this invention aims at provision of the power converter device which also has a function as a frequency converter. Another object of the present invention is to provide a direct current power transmission system and a power storage system with high power transmission efficiency and low cost.

  In order to achieve such an object, the power converter of the present invention includes a DC side iron core that winds a DC side winding and an AC side that forms a closed magnetic circuit between the AC side winding and the DC side iron core. The DC side of the DC core is switched by switching the magnetic path connection by controlling the interruption and passage of the magnetic flux at the magnetic connection location, which is arranged at the magnetic connection location between the iron core and the DC side iron core and the AC side iron core. A magnetic path switching element that periodically and alternately forms two magnetic flux flows that flow in the same direction in the winding portion and that flow in opposite directions in the AC side winding portion of the AC side iron core; By switching the flow of magnetic flux generated by the alternating current or direct current flowing in the winding or the direct current side winding by the magnetic path switching element, the direct current or the alternating current is generated by magnetic induction in the other winding. To convert It is.

  Here, in order to periodically and alternately form two kinds of magnetic flux flows between the DC side iron core and the AC side iron core, four magnetic connection points are necessary in principle. However, since the magnetic flux flows in the same direction in the DC side winding portion, the entrance side or the exit side of the magnetic path can be shared and reduced to one location, and there are at least three magnetic connection locations, that is, magnetic flux gate portions. All you need is enough. Further, by sharing a part of the magnetic connection portions, it is not necessary to control the interruption and passage of the magnetic flux at the magnetic connection portions. Therefore, in this case, there are two magnetic connection portions for controlling the interruption and passage of the magnetic flux. It's enough at the point.

  Therefore, in the power conversion device of the present invention, the DC side iron core has four inner magnetic flux gate portions, two at each end of the iron core leg, and the AC side iron core is disposed opposite to the inner magnetic flux gate portion, respectively. And the magnetic flux switching element is formed between the inner magnetic flux gate portion and the outer magnetic flux gate portion. Is arranged.

  Further, in the power converter of the present invention, the DC side iron core includes the inlet side inner magnetic flux gate portion and the outlet side inner magnetic flux gate portion at both ends of the iron core leg, and the inlet side inner magnetic flux gate portion and the outlet side at the center of the iron core leg. It has a common internal magnetic flux gate part that also serves as an internal magnetic flux gate part, and has a core leg between the common internal magnetic flux gate part and the entrance-side internal magnetic flux gate part, and between the common internal magnetic flux gate part and the exit-side internal magnetic flux gate part. DC side windings are wound around the iron core legs of the DC core and are coupled to each other in order, and the AC side iron core is disposed opposite to the inlet side inner magnetic flux gate portion, the outlet side inner magnetic flux gate portion and the common inner magnetic flux gate portion of the DC side iron core. The outer side magnetic flux gate part, the outer side magnetic flux gate part, and the outer side magnetic flux gate part, which are magnetically coupled to each other, and the outer side magnetic flux gate part and the common outer magnetic flux gate part. Part or outlet side outer magnet The AC side winding is wound around the iron core leg between the gate part, and the magnetic path switching element is arranged at the magnetic connection point formed between the magnetic flux gate part on the inlet side and the outlet side. There are two types of magnetic fluxes: a magnetic flux passing between the inlet-side outer magnetic flux gate portion and the common outer magnetic flux gate portion through the iron core legs of the iron core and a magnetic flux passing between the common outer magnetic flux gate portion and the outlet-side outer magnetic flux gate portion. Magnetic flux flows are alternately formed.

  In the power conversion device of the present invention, the DC side iron core is magnetically connected to the center of the yoke portion and the yoke portion each having an inner magnetic flux gate portion on both ends on the inlet side or the outlet side, and the inner side on the outlet side or the inlet side is provided. 2 having an iron core leg having one magnetic flux gate portion and winding the DC side winding, and the AC side iron core is arranged to face each of the three inner magnetic flux gate portions of the DC side iron core, and is magnetically coupled 2 The external magnetic flux gate portion on one inlet side or the outlet side and the outer magnetic flux gate portion on the one outlet side or the inlet side are provided, and the outer magnetic flux gate portion on the two inlet sides or the outlet side has an iron core leg and a mutual output respectively. Two AC side windings connected in an inverted relationship are provided, and between the outer magnetic flux gate portion at the end of the core leg that winds the two AC side windings and the corresponding inner magnetic flux gate portion. At the magnetic connection By arranging a path switching element, two types of magnetic flux flows alternately, ie, magnetic flux passing through one AC side winding and DC side winding or magnetic flux passing through the other AC side winding and DC side winding. Try to form.

  Further, the power conversion device of the present invention can be established only by using a winding made of a normal conducting conductor in a normal temperature environment, or can be established only by using a winding made of a superconducting conductor in a cryogenic environment. However, the use of a superconducting conductor is more preferable in terms of reducing loss, although it can be established under any environment and using a conductor.

  Therefore, in the power conversion device of the present invention, the DC side iron core is placed in a heat insulating container in which a cooling medium is enclosed, and the DC side coil made of a superconducting conductor is wound, and the AC side iron core is placed outside the heat insulating container. It arranges and winds the AC side winding which consists of a normal conductor. Furthermore, in this power converter, it is preferable that the DC side winding is a low voltage winding and the AC side winding is a high voltage winding. In this case, the voltage is low and a large current can flow.

  In the power conversion device of the present invention, the magnetic path switching element controls the interruption and passage of magnetic flux between the DC side iron core and the AC side iron core, and the DC side winding portion of the DC side iron core has the same direction. As long as it forms two types of magnetic paths in which the flow direction is opposite in the AC side winding part of the AC side iron core that flows, there is no particular limitation on the material and structure, and any magnetic flux shielding principle or mechanism Alternatively, it is possible to use a means for limiting the amount of magnetic flux passing through, but it is particularly preferable to use diamagnetism having a high magnetic shielding effect.

  Therefore, the power conversion device of the present invention includes, as a magnetic path conversion element, a rare earth superconducting element that is disposed at a magnetic connection location in a heat insulating container and blocks the passage of magnetic flux by the Meissner effect, and an AC side winding or a DC side winding. And a control winding that generates a control magnetic flux in which the magnetic field generated by adding the main magnetic flux generated in the magnetic path by the current flowing in the wire is equal to or higher than the critical magnetic field or less than the critical magnetic field. It is preferable to use a magnetic field based on the main magnetic flux and the control magnetic flux that can be switched between the superconducting state and the normal conducting state by causing the superconducting element to transition by alternately switching to or below the critical magnetic field.

  Here, the fluctuation of the magnetic field at the magnetic connection point can be performed by, for example, a combination of the directions of the main magnetic flux and the control magnetic flux or an increase / decrease in the control current. That is, the magnetic path switching element in the power conversion device of the present invention is configured to increase or decrease the control current flowing through the main magnetic flux or the control magnetic flux as a direct current and the other as an alternating current or a control winding at a certain period. It is preferable that the magnetic field applied to the connection location is alternately switched over to the critical magnetic field or less than the critical magnetic field, and the superconducting element is changed to be switched between the superconducting state and the normal conducting state.

  Further, the magnetic path switching element in the power conversion device of the present invention increases or decreases the control current flowing to the control winding at a constant period, so that the magnetic field generated by adding the main magnetic flux is greater than or less than the critical magnetic field. It is preferable that they are alternately switched to cause a transition in the superconducting element and can be switched between a superconducting state and a normal conducting state.

  Furthermore, the superconducting element is not particularly limited to the above-mentioned rare earth-based superconductor as long as the transition to the normal conducting state or the return to the normal conducting state can be performed instantaneously, but the use of the rare earth superconducting film is not limited. The use of a laminate of a plurality of rare earth superconducting films formed on an insulating layer is preferred.

  Here, the control current supplied to the control winding is preferably a current that gives a critical magnetic field to the rare earth superconducting element alone or a current that generates a critical magnetic field in the rare earth superconducting element by applying a main magnetic flux.

  When a superconducting element is used as the magnetic path switching element, the function of the power converter and the frequency conversion can be easily implemented by controlling the control current flowing through the control winding. That is, in the power conversion device of the present invention, the control winding is energized with a control current that maintains all the rare earth superconducting elements below the critical magnetic field and maintains the superconducting state, or the control current is set to zero current. A function as a circuit breaker can be provided by blocking the road. Further, in the power conversion device of the present invention, when the control current flowing through the control winding is alternating current or direct current whose current varies periodically, the frequency of the alternating current or the variation period of the direct current is variable. Thus, when converting DC power to AC power, it can be converted to an arbitrary frequency.

  Further, the control winding only needs to be wound around one of the iron cores constituting the magnetic path, and is required to be wound only on one of the DC side iron core and the AC side iron core or at a specific location. Although not necessarily done, it is preferable to wind around the core leg of the DC side iron core through which the magnetic flux always flows or the connecting yoke arranged outside the heat insulating container for a simple structure. Furthermore, the control winding may be either a superconducting conductor or a normal conducting conductor, but when it is composed of a superconducting conductor, a control current having a magnitude required for maintaining a critical magnetic field can be passed without loss. However, since a current lead is required to flow a control current from the outside, there is a problem of heat loss and an external resistance circuit is required. Although there is a large loss when a control current of the magnitude required to maintain the critical magnetic field is flowed, the energy saving effect by eliminating the problem of heat penetration through the current lead by arranging it outside the heat insulation container Since it has an appropriate resistance, it has the advantage of being excellent in responsiveness and easy to control.

  In addition, the magnetic path switching element is not limited to the one that uses the transition of the superconducting element, and a substance that easily passes magnetic flux and a substance that does not easily pass through a magnetic connection point between the DC side iron core and the AC side iron core at a certain period. By alternately inserting the magnetic flux at the magnetic connection point, it is also possible to realize switching that alternately switches the passage and interruption of the magnetic flux flow at a fixed period. In this case, it is preferable that the substance through which the magnetic flux easily passes is a magnetic body, and the substance through which the magnetic flux does not easily pass is a diamagnetic body. More preferably, the magnetic path switching element is disposed in the heat insulating container. Is to use a superconducting element that interrupts the flow of magnetic flux due to the Meissner effect as a substance that is difficult to pass through, and a magnetic element as a substance that easily passes through the magnetic flux. Moreover, it is also possible to use a magnetic material that fills the air gap as a substance that is difficult for magnetic flux to pass, and a gap formed between the magnetic flux gate portions of the DC side iron core and the AC side iron core as a substance that easily passes the magnetic flux. .

  In this case, the magnetic path switching element realizes switching of the magnetic path by moving a substance that easily passes through and a substance that does not easily pass through the magnetic path. Therefore, the magnetic path switching element is not limited to being placed in the heat insulating container. It is also possible to apply the magnetic path switching at room temperature without using the heat insulating container itself.

  That is, the magnetic path switching element in this case is a non-magnetic material that surrounds the DC side iron core and alternately arranges a substance that easily passes magnetic flux and a substance that hardly passes magnetic flux in the circumferential direction at positions facing the inner magnetic flux gate portion. And a drive source for rotating the movable support in one direction. By rotating the movable support with the drive source, a magnetic flux is generated between the inner magnetic flux gate portion and the outer magnetic flux gate portion. It is preferable to control the flow of magnetic flux by alternately arranging substances that are easy to pass and substances that are difficult to pass.

  Further, the magnetic path switching element is a non-magnetic disk-shaped movable support body arranged in the circumferential direction so as to alternately pass a substance that easily passes through and a substance that hardly passes through at a position facing the inner magnetic flux gate portion. And a drive source that rotates the movable support in one direction, and a material that allows magnetic flux to easily pass between the inner magnetic flux gate portion and the outer magnetic flux gate portion by rotating the movable support by the drive source. Are preferably alternately arranged at a constant period to control the flow of magnetic flux.

  In addition, the rotating cylindrical body of the magnetic path switching element does not necessarily have to rotate in one direction. At least a pair of magnetic flux easily passing materials and difficult to pass materials are arranged in the circumferential direction, and a movable supporting body is movable. A drive source that swings the support at a constant angle, and a material that easily passes magnetic flux and a material that hardly passes between the inner magnetic flux gate portion and the outer magnetic flux gate portion are alternately generated at a constant cycle, and the flow of magnetic flux You may make it control what.

  Further, the magnetic path switching element is a non-magnetic material in which at least a pair of magnetic flux easily passing materials and difficult passing materials are arranged in the axial direction parallel to the core leg of the DC side iron core at a position facing the inner magnetic flux gate portion. A movable support and a drive source that reciprocates the movable support, and a material that allows magnetic flux to easily pass between the inner magnetic flux gate portion and the outer magnetic flux gate portion by reciprocating the movable support by the drive source; It is also possible to control the flow of magnetic flux by alternately generating a substance that is difficult for magnetic flux to pass through at a constant period.

  And, when switching dynamically by alternately inserting a substance that is easy to pass magnetic flux and a substance that is difficult to pass as a magnetic path switching element at a constant period, by controlling the movement of the drive source, Synchronization and frequency conversion can be easily performed. That is, in the power conversion device of the present invention, the drive source is preferably a motor that drives the movable support in synchronization with the frequency of the alternating current flowing through the low-voltage alternating current bus. In particular, the motor is preferably a canned synchronous motor in which a permanent magnet rotor is disposed in a heat insulating container and an armature winding is disposed outside the heat insulating container.

  Furthermore, since the power conversion device of the present invention realizes power conversion by switching the flow direction of magnetic flux flow and magnetic induction, the voltage change according to the turn ratio between the DC side winding and the AC side winding is simultaneously performed. However, by providing the AC side winding with a plurality of switching voltage taps, or by forming an air gap into and out of the magnetic path formed by the AC side iron core, the magnetic element The magnetic element insertion / extraction mechanism for voltage adjustment that increases the amount of magnetic flux flowing through the magnetic path when the magnetic field element is inserted and reduces the amount of magnetic flux flowing through the magnetic path when the magnetic element is extracted can further increase the voltage. Adjustment or fine voltage adjustment can be made possible. The magnetic element insertion / extraction mechanism can finely adjust the voltage regardless of whether it is provided on any magnetic path. Preferably, the magnetic element insertion / extraction mechanism preferably has a magnetic path composed of an AC side iron core that can be easily installed and operated. More preferably, it is provided at a position closer to the connecting yoke than the connecting yoke or the outer magnetic flux gate portion.

  Furthermore, the power converter of the present invention includes two power converters, and the normal conducting windings of the converter are connected to each other and the turn ratio of the superconducting winding and the normal conducting winding of at least one of the converters. Thus, the direct current input to the superconducting winding of one power conversion device is boosted or lowered from the superconducting winding of the other power conversion device to output a direct current. Since the conversion device itself of the present invention also has a transforming function, when the input direct current is converted into alternating current and when returning from alternating current to direct current, it can be transformed, and can be output as direct current of different voltages.

  The power converter of the present invention can convert power between AC power and DC power regardless of single phase or three phase. For example, three power converters are prepared, and these DC side windings are prepared. Are connected in series with each other, and any one of the U-phase, V-phase, and W-phase can be connected to the AC-side winding to be compatible with three-phase AC.

  In addition, the power conversion device of the present invention includes three sets of DC side iron cores in which a common DC side winding is wound in one heat insulating container, and each AC side winding is wound outside the heat insulating container. The three AC side iron cores are arranged opposite to each other, and a magnetic path switching element is arranged between each pair of DC side iron cores and AC side iron cores, and the current flowing through each AC side winding is 120 ° in electrical angle. Each phase is given to be compatible with three-phase AC.

  In addition, the power conversion device of the present invention arranges three sets of DC-side iron cores around which a common DC-side winding is wound in one heat-insulating container and is shifted by 120 ° in the circumferential direction by a mechanical angle. 3 sets of AC side iron cores each wound with an AC side winding are arranged opposite to the DC side iron cores, and the magnetic flux of the movable support between each pair of DC side iron cores and AC side iron cores Magnetic path switching elements in which the positional relationship between a substance that easily passes through and a substance that hardly passes through magnetic flux are shifted from each other by 120 ° in electrical angle are arranged, and the alternating current supplied to each AC side winding is expressed in electrical angle. It is designed to be compatible with three-phase AC with a phase of 120 °.

  Furthermore, the direct current power transmission system of the present invention comprises two power conversion devices using the superconducting conductor of the present invention, and the superconductivity in which the DC side windings composed of the superconducting conductors in the heat insulating container of the conversion device are drawn into the heat insulating container. A cooling medium is circulated in the insulated container and the superconducting cable by connecting with cables.

  Furthermore, the power storage system of the present invention includes two power conversion devices using the superconducting conductor of the present invention, and connects the superconducting windings in the heat insulating container of the conversion device with a superconducting cable drawn into the heat insulating container, A cooling medium is circulated in the heat insulating container and the superconducting cable, and electric power is accumulated in the superconducting winding itself or a smooth winding provided in a connecting portion between the superconducting windings and the superconducting cable.

  The power conversion device of the present invention according to claim 1 converts the flow of magnetic flux between the AC side iron core and the DC side iron core into DC magnetic flux or AC magnetic flux by the magnetic path switching element, and then converts the power by magnetic induction. As a result, the transformer does not require a transformer or current limiter that transforms it to a voltage suitable for the allowable current withstand capability of the semiconductor rectifier, and the superconducting winding for electromagnetic conversion itself is a smooth winding. Therefore, since the structure does not require a smooth winding, the device can be made more compact than the conventional AC / DC converter.

  In addition, since the number of windings of the superconducting winding with respect to the number of windings of the normal conducting winding becomes the transformation ratio of the DC half-wave voltage with respect to the AC half-wave voltage, a transformer function can be provided by these turns ratio. Depending on the turn ratio, it is possible to convert power at step-up, step-down or equal pressure.

  Further, according to the power conversion device of the present invention as set forth in claim 2, since the magnetic path switching element controls the interruption and passage of the magnetic flux flow at the four magnetic connection points, the forward conversion is performed only by switching the input. Thus, it is possible to easily construct a dual-purpose power converter that can perform reverse conversion.

  Further, according to the power conversion device of the present invention described in claims 3 and 4, the iron core structure is simplified by partially sharing the inner and outer magnetic flux gate portions, and the magnetic flux flow is interrupted at two magnetic connection locations. Since it is sufficient to control the passage, the structure of the magnetic path switching element can be simplified. Therefore, the power converter can be made compact.

  Furthermore, according to the power conversion device of the invention according to claim 5, wherein the superconducting conductor is used as the DC side winding in a cryogenic environment, the conventional AC / DC converter is a combination of a transformer using a normal conducting winding and a silicon rectifier. The problem of the conversion device can be eliminated.

  That is, the AC / DC converter of the present invention accommodates a superconducting winding, a superconducting element as a magnetic path switching element, and an iron core that becomes a magnetic path in a cryogenic environment in a heat insulating container, and magnetically couples without using a current lead. Since the superconducting environment isolated from the external circuit is obtained as a structure for transmitting and receiving power energy to and from the room temperature side circuit outside the heat insulation container, to the cryogenic part in the heat insulation container via the current lead It has a structure that eliminates heat intrusion and heat generation from the current lead part and contains the heat loss source in a cryogenic environment. A significant loss reduction of 60 to 70% is expected compared to the loss to be made.

  In particular, in the case of the power converter according to the invention of claim 6, in which the DC side winding made of a superconducting conductor capable of flowing a large current is a low voltage winding and the AC side winding is a high voltage winding, a low voltage and large current is allowed to flow. Therefore, it is possible to transform with a large capacity. That is, as the output capacity from the superconducting winding increases, an ultrahigh voltage and low current can be input to the normal conducting winding, and it is possible to convert ultrahigh voltage power into a direct current for transmission. For this reason, it is suitable for large-scale power conversion with a single facility, and for example, the power conversion facility between a power plant and a power consumer can be reduced. In addition, a large current can be transmitted without loss, and insulation is easy at a low voltage. Therefore, heat generation is small, and no increase in the size of the winding is necessary, and the power converter itself becomes small.

  Furthermore, according to the power conversion device according to claims 7 to 14, the rare earth superconducting element that undergoes a transition in a short time is used, and the transition of the rare earth superconducting element is controlled by the fluctuation of the control magnetic flux, so that the AC side iron core and the DC Since switching of the magnetic path between the side iron cores is performed, loss due to heat generation at the time of transition is slight, but it is slight, and there is a mechanical drive unit for switching the magnetic path Therefore, since there is no mechanical loss, the loss due to heat can be greatly reduced compared to the loss generated in the conventional AC / DC converter, and the conversion efficiency is improved.

  In addition, since the superconducting winding side that can flow a large current is a DC circuit, insulation is easy even when a large current flows, the superconducting winding itself is compact, and heat insulation is performed in a heat insulating container to further reduce the loss. Can be reduced. Furthermore, when the control winding is composed of a superconducting conductor, a control current having a magnitude required for maintaining a critical magnetic field can be passed without loss.

  In addition, in the case of superconducting elements using rare earth superconducting thin films, the magnetic field is instantaneously switched by instantaneously shielding the magnetic flux flow by the Meissner effect because it immediately returns to the superconducting state by removing the critical magnetic field. it can. In particular, the invention according to claim 10 in which the thin film is a multilayer enables the interruption of a large magnetic flux and the conversion of a large electric power.

  Furthermore, in the invention according to claim 8 or 9, the magnetic field applied to the magnetic connection point is greater than or equal to the critical magnetic field by increasing or decreasing the constant period of the control current flowing to the AC or control winding of either the main magnetic flux or the control magnetic flux. Since the switching is alternately performed below the critical magnetic field, the input voltage waveform can be converted forward or backward efficiently and without distortion.

  According to the invention described in claim 13, it is possible to provide a circuit breaker function that isolates the failure of the external circuit by magnetically shutting off the inside of the heat insulation container from the outside when the external circuit fails.

  According to the invention described in claim 14, by changing the frequency of the alternating magnetic flux of the control winding during the reverse conversion from direct current to alternating current, the alternating current of any frequency, for example, 50 Hz or 60 Hz can be applied. Furthermore, it is possible to perform inverse conversion directly to other frequencies.

  On the other hand, according to the power converter using the magnetic path switching element according to any one of claims 15 to 22, the superconducting element and the magnetic element, which are always maintained in the superconducting state, are connected to the wall surface of the heat insulating container and the inner magnetic flux gate portion. Since the magnetic flux flow is interrupted and passed by arranging them alternately in between, the influence on the life due to repeated quenching of the superconducting element is greatly reduced and more stable operation is expected. it can. Further, the control winding is not required, and the structure is simple with only two types of windings for input and output. In addition, since the superconducting element is always maintained in a superconducting state, it is not necessary to use a rare earth superconducting element that can be transferred in a short time, and a cheaper superconducting conductor can be employed. Moreover, the conversion efficiency of this power conversion device is accompanied by AC loss due to the Meissner current, iron loss of the magnetic element, and mechanical loss of the drive source for switching between the superconducting element and the magnetic element, but both losses are small. This can greatly improve the conventional AC / DC converter. Furthermore, since the switching of the magnetic path is not digital but analog, the output is inverted every half cycle during inverter operation and can be extracted as a sinusoidal AC voltage.

  In particular, in the case of the power conversion device according to the sixteenth or seventeenth aspect of the present invention, the shield of the magnetic flux flow by the complete diamagnetism of the diamagnetic material or the superconducting element and the passage of the magnetic flux by the magnetic material are realized dynamically and reliably. it can. In addition, since the magnetic flux flow is blocked and passed instantaneously, the magnetic path can be switched instantaneously.

  Further, in the case of the power converter according to the eighteenth aspect of the invention, the magnetic flux is shielded and passed by the gap formed between the DC side iron core and the AC side iron core and the magnetic material filling the gap. Since it is controlled, it does not require any special materials or environment, and can be realized inexpensively and easily.

  In addition, according to the power converter using the magnetic path switching element according to any one of claims 19 to 22, the magnetic flux can be passed and blocked by changing a speed at which the movable support is rotated, rocked or reciprocated. It is possible to provide a frequency conversion function. For example, by changing the rotational speed or moving speed of the movable support during the operation of the reverse converter, it has a frequency conversion function, and the input DC power can be changed to any frequency, for example, 50 Hz or 60 Hz. Can be directly inverted to other frequencies.

  According to the invention of claim 23, the switching of the magnetic path synchronized with the frequency of the alternating current flowing through the low-voltage alternating current bus can be easily realized, so that the conversion efficiency is good.

  According to the invention of claim 24, by adopting a canned synchronous motor, the armature winding outside the heat insulation container is synchronized with the external AC system, so that the heat can be rotated without entering the heat insulation container. The cylinder can be rotated.

  According to the power converter of the invention described in claim 25, since the normal conducting winding is provided with a plurality of switching voltage taps, the voltage can be roughly adjusted simply by switching the taps. As a result, it is possible to obtain a device that can adjust the AC voltage, can cope with a large voltage fluctuation, and has little impact.

  Furthermore, according to the power converter of the invention of claim 26, the magnitude of the passing magnetic flux can be controlled by changing the magnetic resistance of the magnetic path by adjusting the amount of insertion of the magnetic element into the magnetic path. Therefore, when operating as a rectifier, the DC voltage is finely adjusted to increase or decrease the DC load current to increase or decrease the flow to the DC transmission system. When operating as an inverter, the AC voltage is finely adjusted to change the AC load current. By increasing or decreasing, the power flow to the AC transmission system can be controlled individually. In addition, in the case of the invention of claim 27, a voltage fine adjustment mechanism is provided in a portion closer to the coupling yoke than the coupling yoke or the outer magnetic flux gate portion. Therefore, the voltage can be finely adjusted with a single voltage fine adjustment mechanism.

  Further, according to the power converter according to the invention of claim 28, since the power converter itself has a transforming function, the current transformer connecting the combination of two sets of transformers, semiconductor rectifiers and smooth windings with a cable. DC power can be transformed with a simple and compact structure. Moreover, since the conversion device itself of the present invention also has a transforming function, it is possible to transform the input direct current when converting it into alternating current and when returning from alternating current to direct current, as well as the semiconductor rectifier and its allowable current withstand capability. Compared to current equipment, which requires the use of transformers that are limited in size, it is possible to perform large-scale transformation at once, and it is easy to construct a DC distribution network or a DC transmission network that connects different voltage classes. It becomes.

  Further, according to the power conversion device according to the invention of claims 30 and 31, since one power conversion device is provided with three pairs of alternating current side circuits and direct current side circuits, each circuit has a three-phase alternating current circuit. By connecting the U, V, and W phases, it is possible to convert a direct current into a three-phase alternating current, or to convert a three-phase alternating current into a direct current. In addition, even in the case of the invention according to claim 29, in which the normal conducting windings of the three power converters described above are coupled to the respective phases U, V, and W of three-phase alternating current, the electrical angle is shifted by 120 degrees A half-wave rectified voltage is generated in the superconducting winding of each converter. If the superconducting windings of the three converters are combined, a half-wave rectified voltage with little pulsation fluctuation can be obtained.

  Further, according to the superconducting DC power transmission system according to the invention described in claim 32, since the DC portion is placed in the superconducting environment, the heat loss can be greatly reduced, and this superconducting environment can be applied to a large-scale DC power transmission system. For example, the loss reduction amount is extremely large. In addition, since transformation according to the turns ratio can be performed simultaneously when converting from AC to DC, DC transmission can be performed after a large current and low voltage, which is suitable for superconducting DC transmission and distribution. Furthermore, when converting from direct current to alternating current again, it is possible to return to a large voltage and low current by transformation according to the turn ratio. Moreover, since it is superconducting DC power transmission, the voltage is low and a large current can flow, so the insulation can be made compact.

  According to the power storage system of the thirty-third aspect of the present invention, the DC permanent current without electrical resistance loss or AC loss is generated in the cryogenic side magnetic circuit portion and the smooth winding or superconducting cable connected thereto. Since the mode can be formed, magnetic energy can be stored by the sum of the inductances of the superconducting winding and the superconducting cable. The superconducting winding and the DC cable connected to it have inductance, and both the forward conversion device and the reverse conversion device are superconducting, so that a permanent current can flow between them, proportional to the inductance of the current path. Electric power can be stored.

  Hereinafter, the configuration of the present invention will be described in detail based on embodiments shown in the drawings. The power conversion device according to the present invention includes a transformer, a circuit breaker, a power storage function, a frequency conversion function as well as a power conversion function from AC to DC (forward conversion: rectifier) and DC to AC (reverse conversion: inverter). However, first, the configuration / function as a power conversion apparatus will be described, and then other functions will be described.

  FIG. 1 shows a first embodiment of a power conversion device of the present invention using the transition of a superconducting element. In FIG. 1, both configurations of the forward conversion device and the reverse conversion device are shown at the same time. Here, the configuration of only the forward conversion device alone or the configuration of only the reverse conversion is omitted, and FIG. 1 will be described as the configuration of a general-purpose forward / reverse simultaneous conversion device including both.

  The power conversion device of the present invention includes a DC side iron core that winds a DC side coil, an AC side iron core that forms a closed magnetic circuit between the AC side coil and a DC side iron core, and a DC side iron core. It is located at the magnetic connection point between the AC side iron core and switches the magnetic path connection by controlling the interruption and passage of the magnetic flux at the magnetic connection point, so that the DC side winding part of the DC side iron core is in the same direction. The AC side winding portion of the alternating current side iron core includes a magnetic path switching element that periodically and alternately forms two magnetic flux flows whose flow directions are opposite to each other, and the AC side winding or the DC side winding. By switching the flow of magnetic flux generated by an alternating current or a direct current flowing through the magnetic path by the magnetic path switching element, a direct current or an alternating current is generated by magnetic induction in the other winding to convert power.

  More specifically, in the power conversion device of the present embodiment, the heat insulating container 1 in which the cooling medium 4 is enclosed and the direct current side winding 30 made of a superconducting conductor are wound and arranged in the heat insulating container 1. A side iron core 3, an AC side winding 34 made of a normal conducting conductor is wound, and the AC side iron core 2 disposed outside the heat insulating container 1 and magnetically coupled to the DC side iron core 3, Magnetic field which switches the magnetic flux flow which flows between AC side iron core 2 and DC side iron core 3 by controlling interception and permeation of magnetic flux between AC side iron core 2 and DC side iron core 3 which were magnetically coupled in a cryogenic environment The other winding, that is, the DC side by switching the flow of magnetic flux generated by the AC current or DC current flowing through the AC side winding 34 or the DC side winding 30 by the magnetic path switching element. Magnetic induction in winding 30 or AC side winding 34 It is intended to power conversion by causing the current of the direct current or alternating current. The magnetic path switching element covers the end surfaces of the four inner magnetic flux gate portions 5, 6, 7 and 8 formed at both ends of the core leg 20 of the DC side iron core 3, and covers the inner magnetic flux gate portions 5 and 6 by the Meissner effect. , 7, 8 and four rare earth superconducting elements 41, 42, 43, 44 that block the passage of magnetic flux between the outer magnetic flux gate portions 15, 16, 17, 18 of the AC side iron core 2 facing this, and superconductivity When the elements 41, 42, 43, and 44 flow in the same direction as the main magnetic flux generated in the magnetic path by the current flowing through the AC side winding 34 or the DC side winding 30, the magnetic flux combined with the main magnetic flux is critical. A superconducting element 41, 42, 43, based on the mutual direction of the main magnetic flux and the control magnetic flux passing through the inner magnetic flux gates 5, 6, 7, 8. 44 causing a transition You have to switch to the state and the normal conducting state.

  That is, this power conversion device includes the AC side iron core 2 and the AC side winding 34 constituting the AC side magnetic circuit as a whole, and the DC side iron core 3 and the DC side winding 30 constituting the DC side magnetic circuit. The four superconducting elements 41, 42, 43, and 44 constituting the magnetic path switching element are arranged between the AC side iron core on the AC side and the DC side iron core on the DC side, and the AC side magnetism is obtained by the Meissner effect of the superconducting element. The connection relationship between the circuit and the DC magnetic circuit is selectively connected or shielded. The main magnetic flux and the control magnetic flux, one of which is direct current and the other is alternating current, are combined and applied to a switching element composed of a superconducting element as a magnetic field that is less than the critical field or greater than the critical magnetic field. By controlling the flow of magnetic flux passing through the circuit, AC power is converted into DC power or DC power is converted into AC power. Note that the power conversion device of the present embodiment has a configuration in which two magnetic circuits and an electric circuit that are magnetically coupled to a switching element composed of a superconducting element are combined. Expressions such as a magnetic circuit and a DC side magnetic circuit are used for convenience to help understanding, and do not specify the input side of power or limit the presence or absence of voltage transformation. In addition, the case where the number of windings is the same and no voltage change is included, and strictly speaking, it does not have the configuration of the transformer itself.

  The DC side iron core 3 is disposed on both ends of the iron core leg 20 and the iron core legs 20 to form the outlet side yoke 21 that forms the inner magnetic flux gate portions 5 and 6 and the inlet side yoke 22 that forms the inner magnetic flux gate portions 7 and 8. And formed into an I shape. Then, magnetically between the outlet side yoke 21 and the AC side iron core 2 disposed outside the heat insulating container 1 via the four inner magnetic flux gate portions 5, 6, 7, and 8 at both ends of the inlet side yoke 22. The iron core leg 20 is wound around the iron core leg 20 with a DC winding 30 and a control winding 31 composed of a superconducting conductor. The DC side iron core 3 is mounted on and supported by the gantry 10.

  Furthermore, superconducting plates (superconducting bulk) or superconducting films (deposited thin films) are formed on the exit side yoke 21 at both ends of the iron core leg 20 and the inner magnetic flux gate portions 5, 6, 7 and 8 of the entrance side yoke 22 so as to block each end face. ) Superconducting elements 41, 42, 43, and 44 are arranged respectively. Specifically, superconducting elements 41, 42, 43, 44 are directly attached to the respective end faces of the inner magnetic flux gate parts 5, 6, 7, 8 with an adhesive or the like, or on the inner peripheral wall surface side of the heat insulating container 1. I am trying to paste it. The superconducting elements 41, 42, 43, and 44 are formed of a rare earth superconductor such as a superconducting bulk of Y (yttrium) -based superconductor or a thin film deposition material because it is necessary to complete the transition rapidly in a short time. And it forms in square or circular plate shape according to the end surface shape of each inner magnetic flux gate part 5,6,7,8.

  The heat insulating container 1 is a so-called cryogenic vessel or cryostat in which a double wall structure is formed of, for example, FRP or a polymer insulating material, and the space between the double walls is evacuated. Therefore, the inside and the outside of the heat insulating container 1 are placed in a vacuum heat insulating state. Inside the heat insulating container 1, liquid nitrogen or slush nitrogen (see Japanese Patent Application Laid-Open No. 2006-52921) is sealed and circulated as the cooling medium 4, and kept at a cryogenic state of, for example, 65K. Therefore, the DC side winding 30 and the superconducting elements 41, 42, 43, and 44 are placed in the superconducting state by the cooling medium 4, the electric resistance becomes zero, and it has a completely diamagnetic property.

  Here, the DC side winding 30 and the control winding 31 are formed of, for example, a Bi (bismuth) -based superconductor. As shown in FIG. 2A, the Bi-based superconductor has a configuration in which a Bi wire 91, which is a superconducting material, passes through an Ag wire 90. In the superconducting state, Bi (bismuth) has an electric resistance of zero. As shown in the characteristic diagram of FIG. 2B, for example, when the normal state is exceeded beyond the critical state, Bi becomes a resistance value depending on the electric resistance of Ag instead of the insulator, The resistance value gradually increases with the increase.

  On the other hand, it is preferable to use a Y-based superconductor for the superconducting elements 41, 42, 43, and 44. In particular, as shown in FIG. 2C, a superconducting element having a structure in which a Y (yttrium which is a rare earth) thin film 93 is deposited on an insulating CeO2 (ceria) plate 92 (Japanese Patent Nos. 1778693 and 1778694). ) Is preferred. As shown in the characteristic diagram of FIG. 2 (d), the Y-type superconductor element having this structure exhibits complete diamagnetism with zero electrical resistance in the Y thin film 93 in the superconducting state, exceeding the critical state. When the normal conducting state is reached, the CeO2 plate 92 abruptly increases the electric resistance to increase the resistance and allow the magnetic flux to pass. The state of the transition of the Y-based superconductor is extremely steep as compared with the transition of the Bi-based superconductor. In addition, this Y-based superconducting element has a characteristic of returning immediately when the critical magnetic field is removed even if quenching occurs, and exhibits excellent responsiveness as a magnetic path switching element. In particular, as the Y-based superconductor thin film, a multi-layered film of, for example, 5 to 10 layers of Y (yttrium which is a rare earth) thin film 93 formed on an insulating CeO2 (ceria) plate 92 by a coating method or the like is laminated. Use is preferred. At this time, the ceria insulating layer is 0.5 mm, for example, and a Y-based superconductor film of about 1 μm is formed thereon. In this case, a superconducting element whose complete diamagnetism does not break even when a high magnetic flux is applied can be formed, and a large voltage can be applied. However, the superconducting elements 41, 42, 43, 44 are not limited to the superconducting elements of these thin film layers, and can be used in bulk superconducting elements, and particularly maintained in a superconducting state. In the case of switching the magnetic path by switching the position while moving, it is sufficient to use a bulk superconducting element, and in some cases, a diamagnetic material other than the superconducting conductor is used to reduce the flow of magnetic flux. You may make it interrupt.

  As for the cooling medium 4 in the heat insulating container 1, slush nitrogen is used in addition to liquid nitrogen. This slush nitrogen is a cooling medium in which liquid nitrogen and solid nitrogen are mixed as disclosed in JP-A-2006-52921. For example, even if heat is transferred from superconducting to normal conducting, the solid to liquid is converted into liquid. It excels in the characteristics of absorbing heat by phase change and maintaining a constant cryogenic state. Since superconducting elements 41, 42, 43, and 44 frequently generate heat due to transition due to repeated superconducting state and normal conducting state, the use of slush nitrogen for this heat absorption is very convenient, and slush nitrogen and In order to keep the temperature at 65K regardless of which liquid nitrogen is used, circulation for cooling the cooling medium is necessary. In addition, since the magnetic field in the superconducting elements 41, 42, 43, 44 may change due to the temperature change due to the normal conducting transition, the critical magnetic field of the superconducting elements 41, 42, 43, 44 is maintained by controlling the current to the control winding 31. Like that. Since the control winding 31 is a superconductor housed inside the heat insulating container 1, a control current having a magnitude required for maintaining a critical magnetic field can flow without loss.

  Furthermore, outside yokes 23 and 24 constituting the AC side iron core 2 are disposed outside the heat insulating container 1. The outer yokes 23 and 24 are provided so as to bridge the outlet side yokes 21 and 22 at both ends of the core leg 20, and the outer magnetic flux gate portions 15, 16, 17, and 18 are separated from the heat insulating container 1. It is provided so as to face the inner magnetic flux gate portions 5, 6, 7, 8 of the side yoke 21 and the inlet side yoke 22. The outer yokes 23, 24, the outlet side yoke 21, and the inlet side yoke 22 are not mechanically coupled to each other because the heat insulating container 1 is interposed therebetween, but are magnetically coupled to form a closed magnetic circuit. In FIG. 1, the inner magnetic flux gates 5 and 8 on one side of the outlet side yoke 21 and the inlet side yoke 22 are magnetically coupled to the outer yoke 23, and the inner side magnetic flux gate on the other side of the outlet side yoke 21 and the inlet side yoke 22. The parts 6 and 7 can be magnetically coupled to the outer yoke 24. The AC side iron core 2 is provided with a connecting yoke 25 straddling between the outer yokes 23 and 24 outside the heat insulating container 1. For example, it is provided so as to connect the end portions of the outer yokes 23 and 24 on the outlet side yoke 21 side, and the yoke outer magnetic flux gate portions 15 and 16, a part of the outer yokes 23 and 24 connected thereto, and the outlet side yoke 21 A closed magnetic circuit can be formed. Thus, the iron core leg 20 → the inner magnetic flux gate portion 5 → the outer magnetic flux gate portion 15 → the outer yoke 23 → the connecting yoke 25 → the outer yoke 24 → the outer magnetic flux gate portion 17 → the inner magnetic flux gate portion 7 → the first iron core leg 20 is passed. Route A and the iron core leg 20 → the inner magnetic flux gate portion 6 → the outer magnetic flux gate portion 16 → the outer yoke 24 → the connecting yoke 25 → the outer yoke 23 → the outer magnetic flux gate portion 18 → the inner magnetic flux gate portion 8 → the iron core leg 20 Two closed magnetic paths with the second route B can be formed.

  The iron core leg 20, the outer yokes 23 and 24, and the connecting yoke 25 are each wound with a winding. Among these, the iron core leg 20 is disposed in the heat insulating container 1 and coupled to an external DC circuit, and is connected to an external DC circuit and receives a DC power at the time of rectification or inverter. A control winding 31 composed of a DC side winding for controlling the interruption with the circuit is wound. The direct current winding 30 and the control winding 31 are wound in opposite directions so as to have opposite polarities so as to maintain the critical magnetic field of the superconducting element even when the exciting magnetic flux due to the current passing through them is superimposed. . The control winding 31 is connected to a DC power source (not shown) so as to excite DC magnetic flux. The direct current generated by the control winding 31 is set to a value such that the direct-current magnetic field does not exceed the critical magnetic field of the superconducting elements 41, 42, 43, and 44. In this embodiment, the control winding 31 is made of a superconductor so that a large current can flow. However, in some cases, the control winding 31 is an alternating current composed of a normal conductive conductor disposed outside the heat insulating container 1. It may be a side winding. Furthermore, the control winding 31 only needs to be wound around one of the iron cores constituting the magnetic path, and is not required to be wound around either the DC side iron core 3 or the AC side iron core 2. However, it is preferable to wind around the core leg 20 of the DC side iron core through which the magnetic flux always flows or the connecting yoke 25 arranged outside the heat insulating container 1 for a simple structure.

  The outer yokes 23 and 24 are coupled to each other in series and coupled to an external AC circuit to supply AC power to the external AC circuit. Two inverter windings (also referred to as second AC side windings) 32 and 33 are provided. Are wound respectively. The second AC side windings 32 and 33 are windings for outputting the converted AC when used as an inverse conversion device. Further, a winding (also referred to as a first AC side winding) 34 made of a normal conductor is wound around the connecting yoke 25. The first AC side winding 34 is an input winding connected to an AC power source (not shown) for a rectifier that receives AC power from an external AC circuit when used as a forward conversion device. In addition, when this first AC side winding 34 is used as an inverse conversion device (inverter) for converting DC to AC, the superconductivity of the superconducting elements 41, 42, 43, 44 receives AC power from an external AC circuit. It is used as a control winding for generating a control magnetic field for switching between a state and a normal conducting state. These first and second AC side windings 34, 32, 33 are formed of a normal conductor made of, for example, copper or aluminum. Each of the AC side windings 32, 33, and 34 is provided with a plurality of switchable voltage taps (not shown). Depending on the target voltage or in order to mitigate the impact at the time of transition, the high voltage to low voltage It is provided so that the voltage class up to can be switched and adjusted.

  In such a structure, the forward conversion operation will be described with reference to FIG. FIG. 3 is a circuit diagram showing a configuration necessary for the forward conversion operation of the configuration of FIG. In the forward conversion operation, the winding 34, the DC side winding 30, and the control winding 31 are used, and an AC current flowing through the AC side winding 34 is converted into a magnetic flux current, and then converted from the DC side winding 30 as a DC current. Take out. The control winding 31 is energized with an exciting current to excite a DC magnetic field Φc that passes a critical magnetic field through the superconducting elements 41, 42, 43, 44, while an AC to be rectified is input from the AC winding 34. Thus, the alternating magnetic field Φac is excited in the connecting yoke 25. In the case of the rectifying operation, the second AC side windings 32 and 33 wound around the outer yokes 23 and 24 are not used, and therefore it is desirable to insert a high resistance to make a short circuit.

  Here, as shown in FIG. 3A, an AC magnetic field Φac in the arrow direction that becomes the main magnetic flux generated in the AC side winding 34 and a DC magnetic field Φc in the arrow direction that becomes the control magnetic flux generated by the control winding 31 are obtained. When the superconducting elements 42 and 43 act in opposite directions, the superconducting elements 42 and 43 maintain the superconductivity without exceeding the critical magnetic field, exhibit the Meissner effect (complete diamagnetism), and block the magnetic flux (FIG. 4). (Refer to (f)). On the other hand, in the superconducting elements 41 and 44 in which the AC magnetic field Φac and the DC magnetic field Φc are superposed in the same direction, a magnetic field exceeding the critical magnetic field acts, so that the transition to normal conduction occurs and the complete diamagnetism is broken and the magnetic flux is broken. (See (e) of FIG. 4). As a result, the closed magnetic path interlinking with the first AC side winding 34, the DC side winding 30, and the control winding 31 is connected yoke 25 → outer yoke 24 → outer flux gate portion 7 → inner flux gate portion 7 → iron core. It is formed by the path of the leg 20 → the outlet side yoke 21 → the inner magnetic flux gate part 5 → the outer magnetic flux gate part 15 → the outer yoke 23 → the connecting yoke 25. In this way, a voltage applied to the AC half-wave magnetic field Φac is induced in the DC side winding 30.

  Further, as shown in FIG. 3B, an AC magnetic field Φac in the arrow direction that becomes the main magnetic flux generated in the first AC side winding 34 and a DC magnetic field Φc in the arrow direction that becomes the control magnetic flux generated in the control winding 31 In the superconducting elements 41 and 44 acting in opposite directions, the superconductivity is maintained without exceeding the critical magnetic field, and the magnetic flux is interrupted by the Meissner effect (complete diamagnetism) (see FIG. 4 (f)). On the other hand, in the superconducting elements 42 and 43 in which the AC magnetic field Φac and the DC magnetic field Φc are superposed in the same direction, a magnetic field exceeding the critical magnetic field acts, so that the transition to normal conduction occurs and the complete diamagnetism is broken and the magnetic flux is broken. (See (e) of FIG. 4). As a result, the closed magnetic path interlinking with the first AC side winding 34, the DC side winding 30, and the control winding 31 is connected yoke 25 → outer yoke 23 → outer flux gate portion 18 → inner flux gate portion 8 → iron core. It is formed by the path of the leg 20 → the outlet side yoke 21 → the inner magnetic flux gate portion 6 → the outer magnetic flux gate portion 16 → the outer yoke 24 → the connecting yoke 25. In this way, a voltage applied to the remaining AC half-wave magnetic field Φac is induced in the DC side winding 30.

  The forward conversion operation shown in FIG. 3 is shown by waveforms in FIG. 4A shows a waveform in which the AC magnetic field Φac of the AC side winding 34 is superimposed on the magnetic field Φc of the control winding 31, for example, the positive half wave indicates the direction of Φac shown in FIG. The negative half wave indicates the direction of Φac shown in FIG. 4B shows a positive half-wave induced magnetic flux to the DC side winding 30 in the state of FIG. 3A, and FIG. 4C shows the direct current in the state of FIG. This is a negative half-wave induced magnetic flux to the side winding 30. Therefore, the induction magnetic flux of the DC side winding 30 has the waveform shown in FIG.

  As a result, the AC half-wave magnetic field linked to the DC side winding 30 in FIG. 3A and the AC half-wave magnetic field linked to the DC side winding 30 in FIG. Therefore, a DC voltage as shown in FIG. 4D is induced in the DC side winding 30. That is, the AC input of the first AC side winding 34 can be converted into the DC output of the DC side winding 30. In addition, in this case, the ratio of the number of turns of the DC side winding 30 to the number of turns of the AC side winding 34 becomes the transformation ratio of the AC half-wave voltage, so that the transformer function can be provided by these turns ratio. Depending on the turn ratio, step-up, step-down transformation, or even equal pressure conversion can be performed. In the present embodiment, when direct current power transmission is intended, a request to output a low voltage and large current from the direct current side winding 30 using a superconducting environment with low loss and easy insulation occurs, so this transformation function is indispensable. As the output capacity from the DC side winding 30 increases, an ultra-high voltage and low current is input to the AC side winding 34. Therefore, the AC side winding 34 requires a number of windings corresponding to the voltage. Become. However, when the transformation function is not required, the number of windings of the first AC side winding 34 and the number of windings of the DC side winding 30 are made the same.

  Here, a current flows by connecting the DC side winding 30 to an external DC circuit (not shown). However, since the DC side winding 30 itself has an inductance corresponding to the number of windings, The side winding 30 itself functions as a smoothing winding, and half-wave ripples are removed and smoothed by the DC side winding 30. Accordingly, a sufficient smoothing effect can be obtained without providing a smoothing winding for pulsating the DC current after rectification, and therefore cost reduction and compactness can be achieved by omitting the smoothing winding. Of course, it is also possible to insert a smoothing winding between the DC side winding 30 and the external DC circuit. Since a half-wave rectified voltage is induced in the DC side winding 30, a load current flows in the external DC circuit. For this reason, the magnetic field applied to the superconducting elements 41, 42, 43, 44 increases by the load current. Therefore, the reverse polarity of the superconducting control winding 31 and the DC / DC side winding 30 is used to reduce the current of the control winding 31 so that the magnetic field applied to the superconducting elements 41, 42, 43, 44 maintains a critical magnetic field. It is preferable to control.

  In the above-described forward conversion operation of this power conversion device, it is desirable to perform the following preparatory operation and control during the initial operation of the device. First, liquid nitrogen or slush nitrogen is injected into the cryogenic space in the heat insulating container 1 and cooled to 65K. Excitation current is applied to the control winding 31 so that the superconducting elements 41, 42, 43, and 44 have a critical magnetic field. At this time, the state of magnetic flux at the position of the superconducting elements 41, 42, 43, 44 is measured with a gauss meter or the like, and the energization current is set in advance. In this state, the DC side winding 30 is coupled to an external DC circuit composed of a cable, a power transmission line or a load, and an AC voltage is applied to the tap having the minimum turns ratio of the AC side winding 34. Thus, a half-wave rectified voltage is induced in the DC side winding 30, and a DC current is passed through the external DC circuit. At this time, the magnetic field of the iron core leg 20 is increased by the amount of direct current passing through the direct current side winding 30, so that the reverse polarity of the direct current side winding 30 and the control winding 31 is utilized. The conduction current is decreased to maintain the critical magnetic field of the superconducting elements 41, 42, 43, and 44 necessary for switching. Note that the critical magnetic field may not be maintained due to a change in the current of the control winding 31 or a change in the direct current to the direct current load at the time of start-up or transition. In this case, the half-wave waveform generated in the DC side winding 30 becomes unbalanced every half cycle. However, even if the conversion efficiency is reduced, a DC current can be obtained by the smooth winding. Further, during steady operation, the DC current to the external DC circuit can be increased or decreased by switching the voltage tap of the AC side winding 34. In this increase or decrease, the iron leg 20 is changed by the DC current change of the DC side winding 30. Since the magnetic field changes, the current of the control winding 31 needs to be adjusted in order to maintain the critical magnetic field.

  Next, the inverse conversion operation will be described with reference to FIG. In this reverse conversion operation, the first AC side winding 34, the DC side winding 30, the control winding 31, and the second AC side AC windings 32, 33 are used, and a DC current that flows through the DC side winding 30 is used. Is converted into a magnetic flux current and then taken out as an AC voltage in the second AC side windings 32 and 33. A direct current flows through the direct current side winding 30 to excite a direct current magnetic field Φdc as a main magnetic flux in the iron core leg 20 and a pulsed alternating current magnetic field using the first alternating current side winding 34 of the connecting yoke 25 as a control winding. Is excited as a control magnetic field Φa to form a control magnetic flux. In this case, the control winding 31 of the iron core leg 20 is energized with a current that excites the DC magnetic field Φc that increases or decreases the DC magnetic field Φdc in order to obtain the critical magnetic field of the superconducting elements 41, 42, 43, 44. That is, here, as shown in FIG. 5A, a pulsed AC magnetic field Φa in the arrow direction by the first AC side winding 34, and a DC magnetic field Φc in the arrow direction by the control winding 31 and the DC side winding 30. And Φdc act in directions opposite to each other, the superconducting elements 42 and 43 maintain superconductivity without exceeding the critical magnetic field, have complete diamagnetism by the Meissner effect, and block the magnetic flux. On the other hand, a superconducting element 41 in which a pulsed AC magnetic field Φa in the direction of the arrow by the AC side winding 34 and DC magnetic fields Φc and Φdc in the direction of the arrow by the control winding 31 and the DC side winding 30 act in the same direction. , 44, a magnetic field exceeding the critical magnetic field acts, and transitions to normal conduction (complete diamagnetism is broken) and passes magnetic flux. As a result, the closed magnetic path interlinking with the DC side winding 30 and the AC side windings 34 and 33 is the iron core leg 20 → the inner magnetic flux gate part 5 → the outer magnetic flux gate part 15 → the outer yoke 23 → the connecting yoke 25 → the outer yoke 24. → The outer magnetic flux gate portion 17 → the inner magnetic flux gate portion 7 → the core leg 20 is formed. Thus, an AC half-wave voltage that is applied to the DC magnetic field Φdc is induced in the AC-side winding 33 along with the pulsed positive AC half-wave.

  Further, as shown in FIG. 5B, the pulsed AC magnetic field Φa by the AC side winding 34 and the DC magnetic fields Φc and Φdc in the arrow direction by the control winding 31 and the DC side winding 30 are mutually connected. The superconducting elements 41 and 44 acting in the opposite direction hold the superconductivity without exceeding the critical magnetic field and block the magnetic flux by the Meissner effect. On the other hand, a superconducting element 42 in which a pulsed AC magnetic field Φa in the direction of the arrow by the AC side winding 34 and DC magnetic fields Φc and Φdc in the direction of the arrow by the control winding 31 and the DC side winding 30 are superposed in the same direction. 43, the magnetic field exceeding the critical magnetic field acts and transitions to normal conduction, so that the complete diamagnetism is broken and the magnetic flux is passed. As a result, the closed magnetic path interlinking with the DC side winding 30 and the AC side windings 34 and 32 is the iron core leg 20 → the inner magnetic flux gate part 6 → the outer magnetic flux gate part 16 → the outer yoke 24 → the connecting yoke 25 → the outer yoke 23. The outer magnetic flux gate portion 18 → the inner magnetic flux gate portion 8 → the iron core leg 20 are formed as a path. Thus, an AC half-wave voltage that is applied to the DC magnetic field Φdc is induced in the AC-side winding 32 along with the pulsed negative AC half-wave.

  Accordingly, the respective half-wave voltages are alternately induced in the second AC side windings 33 and 32. Therefore, the AC side windings 33 and 32 are connected to each other so that their outputs are reversed, and can be taken out from the output terminal 50 as an AC voltage. In this case, since the number of windings of the second AC side windings 32 and 33 with respect to the number of windings of the DC side winding 30 becomes a transformation ratio, the transformer function can be provided by these winding ratios. Depending on the voltage, step-up or step-down voltage transformation or even equal pressure conversion is possible.

  In this way, a power conversion device having a transformation function can be obtained. In addition, since the winding corresponding to the primary winding when providing the transformation function is the DC side winding 30 and switching uses the transition of the superconducting elements 41, 42, 43, 44, the loss due to heat is greatly reduced. The DC side winding 30 can be easily insulated even when a large current flows and is compact in itself, and can be further shielded by heat shielding in a heat insulating container. In addition, according to this power converter, the switching function using the Meissner effect of the superconducting elements 41, 42, 43, and 44 is added to the magnetic joint portion that is the magnetic coupling portion between the DC side iron core 3 and the AC side iron core 2. Therefore, the direct current can be converted into alternating current power at a frequency of a cycle for switching the superconducting elements 41, 42, 43, and 44 between the superconducting state and the normal conducting state. That is, the power is converted into an alternating current having the same frequency as the frequency of the alternating current power source for generating the control magnetic flux to be applied to the first alternating winding 34 that determines the switching period of the superconducting elements 41, 42, 43, and 44, and is output. And function as a frequency converter.

  In the reverse conversion operation of this power conversion device, it is desirable to perform the following preparatory operation and control during the initial operation of the device, as in the above-described forward conversion operation. First, liquid nitrogen or slush nitrogen is injected as a cooling medium 4 into the cryogenic space in the heat insulating container 1 and cooled to 65K. Next, the energization of the control winding 31 is adjusted so as to obtain a DC magnetic field Φc that increases or decreases the DC magnetic field Φdc in order to obtain a critical magnetic field in the superconducting elements 41, 42, 43, 44. That is, a direct current is passed through the DC side winding 30 wound around the iron core leg 20 and a direct current is passed through the control winding 31 so that a critical magnetic field is generated at the position of the superconducting elements 41, 42, 43, 44. The direct current of the control winding 31 is adjusted. Thereafter, the control current that generates the control magnetic field Φa with a slight alternating current sufficient for the superconducting elements 41, 42, 43, and 44 to repeat superconductivity and normal conduction with the tap ratio of the first AC side winding 34 minimized. Energize as. For example, by combining with the AC bus on the inverter side, the magnetic field of the superconducting element increases or decreases by about several percent around the critical magnetic field every half cycle, and a small AC signal current that can repeat the transition return of superconducting and normal conducting is obtained. It is supplied via the first AC side winding 34. By the control magnetic field Φa supplied from the first AC side winding 34, each superconducting element 41, 42, 43, 44 is magnetically shielded every half cycle by the Meissner effect, and the left and right second AC side windings 32, Since the magnetic flux is alternately switched to 33, half-wave intermittent rectified voltages having different directions are generated in the second AC side windings 32 and 33. And since these two 2nd alternating current side windings 32 and 33 are connected in series, a sine wave voltage is induced. Therefore, if the taps of the second AC side windings 32 and 33 are minimized and coupled to an external AC circuit (cable, power transmission line, generator, load, etc.), the magnetic flux flowing in the left and right outer yokes 23 and 24 is demagnetized. AC load current flows in the direction of Here, the AC voltage induced in the second AC side windings 32 and 33 is a magnetic flux Φc + Φdc interlinked with the second AC side windings 32 and 33 (magnetic flux generated by the DC side winding 30 and the control winding 31). The voltage tap ratio between the AC side winding 34 and the AC side windings 32 and 33 is determined, and a large voltage adjustment is performed by switching the taps, and a fine adjustment is performed by adjusting the current of the control winding 31. When the magnetic field (magnetic flux Φc + Φdc) of the superconducting element due to the sum of the current of the DC side winding 30 and the current Ic of the DC control winding 31 deviates from the critical magnetic field at the start-up or voltage adjustment transition, the left and right outer yokes (iron core legs) ) The magnitude of the magnetic flux shunting 23 and 24 becomes unbalanced, and the induced voltage of the second AC side windings 32 and 33 becomes an unbalanced voltage. Therefore, the magnetic field of the superconducting element is always made critical by the current of the control winding 31. Control to keep in a magnetic field. Further, during steady operation, the voltage can be adjusted by switching the voltage taps of the AC side windings 32, 33, and the external AC current can be increased or decreased. The current adjustment of the line 31 is required.

  The above-described simultaneous forward / reverse conversion device shown in FIG. 1 can function as a forward conversion device or an inverse conversion device, depending on selection of windings and control currents to be used in actual use. That is, when used as a forward conversion device, the AC side windings 32 and 33 are not necessary and can be omitted. The AC side winding 34 of the connecting yoke 25 is supplied with a very high voltage and low current in the forward conversion operation, and is applied with a pulse voltage waveform that causes a transition of the superconducting elements 41, 42, 43, and 44 in the reverse conversion operation. Therefore, when the same winding is used as the AC side winding 34 for both forward and reverse conversion, the use of the voltage tap is indispensable.

  Next, the case where the power converter of the present invention is used as a circuit breaker will be described. That is, the power conversion device of this embodiment further cuts off by adjusting the control magnetic flux when a failure occurs in the external AC circuit connected to the second AC side windings 32 and 33 or the external DC circuit connected to the DC side winding 30. Can be used as a container. The current flowing to the control winding 31 is controlled to make the DC magnetic flux Φc zero or extremely low so that the critical magnetic field is not reached. By eliminating any transition, it is possible to isolate the DC magnetic circuit inside the heat insulating container 1 from the AC magnetic circuit outside the room temperature and stop the output of voltage and current to the outside. After the failure is removed, the power conversion device can be restarted by energizing the control winding 31 or by increasing the energization amount. Note that when executing this shut-off function, if the voltage tap of the AC side winding is switched to the minimum, it will be completely stopped. The occurrence of a failure in the external AC circuit or the DC circuit is detected by a protection relay, and energization control of the control winding 31 is performed by cutting off the current to the control winding.

  FIG. 6 shows another embodiment. In the power conversion device of this embodiment, the control winding 31 of the superconductor disposed on the cryogenic side in the power conversion device of FIG. A normal conductor control winding 31 is wound around the leg 20. The operation of this power converter is the same as that of the power converter of FIG. In other words, in addition to the power conversion function from AC to DC (forward conversion: rectifier) and DC to AC (reverse conversion: inverter), it also has functions such as transformer, circuit breaker, power storage function, frequency converter, etc. In the figure, both configurations of the forward conversion device and the reverse conversion device are shown at the same time. However, the forward conversion device and the reverse conversion device may be configured as separate independent configurations. It is described as a configuration.

  FIG. 7 shows still another embodiment. The power converter of this embodiment is different from the power converter of FIG. 1 in that it includes two heat insulating containers 11 and 12 for the AC side winding 320 made up of one AC side iron core 2 and a normal conductive conductor, and is DC. The side iron core 3 is divided into two parts and configured as a forward conversion device in which DC side windings 301 and 302 each made of a superconducting conductor are wound. That is, two heat insulating containers 11 and 12 are provided, and one heat insulating container 11 is provided with an iron core leg 201 and inner magnetic flux gate portions 211 and 221 and a DC side winding 301 is wound around the iron core leg 201. In addition, the other heat insulating container 12 is provided with an iron core leg 202 and inner magnetic flux gate portions 212 and 222, and a DC side winding 302 is wound around the iron core leg 202. Between these two heat insulating containers 11 and 12, outer magnetic flux gate portions 311, 321, 312, 322 and iron core legs 230 that are magnetically coupled to the inner magnetic flux gate portions 211, 221, 212, and 222 on the cryogenic temperature side. The I-shaped AC side iron core 2 having the shape is arranged, and the AC side winding 320 is wound around the iron core leg 230. A connecting yoke 25 is provided outside the heat insulating containers 11 and 12 and magnetically connects at least one end of the iron core legs 201 and 202 to each other. A control winding 31 for generating a DC control magnetic field is wound around the connecting yoke 25. The end faces of the inner magnetic flux gate portions 211, 212, 221, 222 are shielded from the end portions of the inner magnetic flux gate portions 211, 212, 221, 222 coupled to both ends of the iron core legs 201, 202 of the DC side iron core 3. Thus, superconducting elements 41, 42, 43, and 44 made of a Y-based bulk or a Y-based thin film are arranged.

  In this structure, the forward conversion operation is as follows. FIG. 8 shows the configuration of FIG. 7 as a circuit diagram necessary for the operation. The forward conversion operation is an operation for taking out the AC voltage of the AC side winding 320 as a DC voltage via the DC side windings 301 and 302. From the control winding 31, a DC magnetic field Φc, which is a superconducting critical magnetic field, is excited in the connecting yoke 25, while from the AC side winding 320, an alternating current to be rectified is input and an AC magnetic field Φac is excited in the iron core leg 230. Is done. Here, as shown in FIG. 8A, the AC magnetic field Φac in the arrow direction by the AC side winding 320 and the DC magnetic field Φc in the arrow direction by the control winding 31 are opposite to each other in the superconducting elements 41 and 44. When it acts, the superconducting elements 41 and 44 do not act on the critical magnetic field, maintain superconductivity, have complete diamagnetism by the Meissner effect, and block the magnetic flux. On the other hand, when the AC magnetic field Φac in the direction of the arrow by the AC side winding 320 and the DC magnetic field Φc in the direction of the arrow by the control winding 31 act in the same direction in the superconducting elements 42 and 43, the superconducting elements 42 and 43 are critical. The magnetic field acts and transitions to normal conduction, and the complete diamagnetism breaks and passes the magnetic flux. As a result, the magnetic flux generated in the AC side winding 320 is the iron core leg 230 → the outer magnetic flux gate portion 312 → the inner magnetic flux gate portion 212 → the connecting yoke 25 → the iron core leg 201 → the inner magnetic flux gate portion 221 → the outer magnetic flux gate portion 321 → A closed magnetic circuit is formed which flows through the iron core leg 230 and interlinks with the DC side winding 301. In this way, a voltage applied to the AC half-wave magnetic field Φac is induced in the DC side winding 301.

  Further, as shown in FIG. 8B, the AC magnetic field Φac in the direction of the arrow by the AC side winding 320 and the DC magnetic field Φc in the direction of the arrow by the control winding 31 act in opposite directions on the superconducting elements 42 and 43. Then, in the superconducting elements 42 and 43, the critical magnetic field does not act and superconductivity is maintained, and it has complete diamagnetism by the Meissner effect, and interrupts the magnetic flux. On the other hand, when the AC magnetic field Φac in the direction of the arrow by the AC side winding 320 and the DC magnetic field Φc in the direction of the arrow by the control winding 31 act in the same direction on the superconducting elements 41 and 44, the superconducting elements 41 and 44 are critical. The magnetic field acts and transitions to normal conduction, and the complete diamagnetism breaks and passes the magnetic flux. As a result, the magnetic flux generated in the AC side winding 320 is iron core leg 230 → outer magnetic flux gate part 322 → inner magnetic flux gate part 222 → iron core leg 202 → connection yoke 25 → inner magnetic flux gate part 211 → outer magnetic flux gate part 311 → A closed magnetic circuit is formed which flows through the iron core leg 230 and is linked to the DC side winding 302. In this way, a voltage applied to the AC half-wave magnetic field Φac is induced in the DC side winding 302.

  Therefore, a DC magnetic field corresponding to a half wave is induced in each of the DC side windings 302 and 301, and a DC voltage can be taken out from the output terminal by inverting and connecting the DC side windings 302 and 301 to each other. it can.

  Furthermore, a superconducting DC power transmission system can be constructed using the power converter of the present invention. For example, as shown in FIG. 9, the forward conversion device shown in FIG. 3 and the reverse conversion device shown in FIG. 5 are combined, and the DC windings 30 that are the DC windings of both devices are directly connected by the superconducting cable 40. A superconducting DC power transmission system is configured by connection. Although the detailed structure of the superconducting cable 40 is not shown, in general, a hollow former formed of a copper stranded wire is used as a core material, and a superconducting conductor (core wire) 39, an electric insulation layer, and a superconducting shield 38 are formed on the outside. And covering with a protective layer composed of copper braided wire, and further opening a space that becomes a liquid nitrogen channel outside the protective layer, and heat insulating inner tube, vacuum heat insulating tube, heat insulating outer tube, and polymers such as vinyl chloride A heat insulating pipe made of a resin anticorrosive layer is provided. And it is provided so that liquid nitrogen may flow using the space inside the former and the space between the protective layer and the inner tube of the heat insulating tube as a liquid nitrogen channel. Therefore, the heat insulating tube portion is connected to the superconducting core wire lead-out port 9 of the vacuum heat insulating container, the superconducting core wire 39 covered with the superconducting shield 38 is drawn into the heat insulating container 1, and then from the superconducting core wire 38 and the superconducting conductor. By directly connecting the DC side windings 30 with indium solder, a DC power transmission system can be constructed without using normal conducting leads. And if the direct current side windings 30 are connected to each other by the superconducting cable 40, DC power can be transmitted in the superconducting state, converted into alternating current under the power consumer, and fed. The cooling medium in the heat insulating containers at both ends of the direct current power transmission system and the cooling medium flowing in the superconducting cable are circulated between the cooling medium supply source via the liquid nitrogen channel of the superconducting cable. In addition, it has already been described that the DC side winding 30 functions as a smoothing winding during AC / DC conversion. However, separately arranging a DC smoothing winding between the DC side winding and the superconducting cable, It is more effective in realizing DC transmission with better quality. Thus, an energy-saving high-quality new power supply system having a power storage function can be realized.

Further, in this direct current superconducting environment, it is possible to store electric power by the inductance of the direct current winding 30 and the smooth winding or the superconducting cable separately arranged in addition to the direct current winding. This power storage system (SMES) has the same basic configuration as the superconducting DC power transmission system, and the DC windings 30 of the forward conversion device shown in FIG. 3 and the reverse conversion device shown in FIG. By connecting them directly, or by connecting them directly with a superconducting cable with a smoothing winding interposed as necessary, it is possible to connect a smoothing winding and a superconducting cable provided in the DC side winding itself or a connecting portion between the DC side windings. Electric power is stored. That is, the power storage system includes a cooling system that cools the DC side winding, a cryostat that stores the cooled DC side winding, and a power converter (rectifier and inverter). According to this power storage system, in any operation of AC / DC or DC / AC, a DC permanent current mode having no electrical resistance loss or AC loss can be formed by the entire superconducting DC circuit configuration. If the control magnetic field applied to the superconducting elements 41, 42, 43, and 44 by applying a current once is smaller than the critical magnetic field or zero, the flow of magnetic flux between the AC side iron core and the DC side iron core is interrupted. A direct current flows permanently in a closed circuit composed of a DC side winding and a superconducting cable connecting them, and power can be stored as magnetic energy by the sum L of inductances of the superconducting winding 30 and the superconducting cable. Stored energy amount at this time, Em ≦ LI 2/2, and the upper limit is determined by the critical current value of the cables and smooth winding. For this reason, even in various operating conditions, protection monitoring control is performed so that the current of the DC winding of the rectifier does not exceed the critical current, and when the critical current approaches the critical current, the control winding current of the rectifier is immediately made zero and emergency stop is performed. Must. In addition, when supplying electric power to an electric power grid | system, the magnetic energy stored in the direct current | flow side coil | winding is converted into alternating current with a power converter device. Electric power storage and supply is achieved by controlling the magnetic path switching element to completely block or selectively allow the flow of magnetic flux between the DC side magnetic path and the AC side magnetic path, for example, the superconducting element 41, All of 42, 43, and 44 can be set in a superconducting state or selectively in a combination of a superconducting state and a normal conducting state.

  Furthermore, in the inverse conversion device (inverter) of the present invention, the frequency of the inverter output (AC output) is determined by the output frequency of the AC signal current that is supplied to generate the control magnetic flux in the first AC side winding 34. Therefore, in the above-described reverse conversion device or superconducting DC power transmission system, the AC signal current for switching the superconducting elements 41, 42, 43, 44 applied to the first AC side winding 34 by the voltage frequency of the AC bus on the inverter side. If the output frequency is determined, AC power having an arbitrary frequency is output.

  In any system, the voltage, current, and power of DC transmission are controlled by adjusting the voltage tap of the first AC side winding 34 on the forward converter (rectifier) side shown in FIG. 3, and the inverse converter shown in FIG. The voltage, current, and power of AC transmission are controlled by tap switching of the second AC side windings 32 and 33 on the (inverter) side. During this period, it is necessary to control the magnetic field of the superconducting elements 41, 42, 43, 44 of both converters to be a critical magnetic field, that is, to control the current of the control winding 31 with respect to fluctuations in the load current. In the case of a superconducting direct current power transmission system, the direct current output of the rectifier and the alternating current output of the inverter are equal, and are converted into voltage, current, and electric power required by the electric power consumer to be fed. As for power storage, the difference power between the direct current output and the alternating current output is stored as magnetic energy in the inductance of the direct current side winding, the smooth winding, and also the superconducting cable, and is released as necessary. It should be noted that, regardless of whether the electric power is stored or the superconducting DC transmission, current control of the control winding 31 is necessary so as to maintain a critical magnetic field in the superconducting element. Care must be taken so that the current of the side winding does not exceed the critical current, and when the current approaches the critical current, the DC current of the control winding 31 must be set to zero and stopped.

  10 and 11 show another embodiment. In this embodiment, the static magnetic shield type power converter shown in FIGS. 1 to 8 is further provided with a voltage adjustment function, and the transition of the superconducting elements 41, 42, 43, and 44 is used. Since the basic configurations of the magnetic path switching element and the magnetic circuit inside and outside the heat insulating container 1 are the same, detailed description will be omitted. In the static magnetic shield type power converter shown in FIGS. 1 to 8, the transformer function is uniquely determined from the turn ratio of the AC side winding 34 or 32, 33 to the number of turns of the DC side winding 30. However, in the structure in which the transformation ratio is determined only by the difference in the number of windings between the high voltage side and the low voltage side, once the number of windings is determined, the step-up ratio or the step-down ratio is uniquely determined. Therefore, in the case of the AC / DC conversion device of FIG. 10, a winding with a tap having a plurality of taps capable of changing the turns ratio is adopted as the AC side winding 34 and a tap changer 35 is provided. The voltage can be roughly adjusted by switching. In the case of this power converter, the AC magnetic flux generated by the AC current input to the AC side winding 34 and the DC control magnetic flux generated by the control winding 31 wound around the iron core leg 20 are superconducting elements 41, 42, 43. , 44 causes the superconducting element to transition depending on whether it flows in the same direction or in a different direction, thereby switching between the superconducting state and the normal conducting state.

  In the case of the DC / AC converter of FIG. 11, tapped AC side windings 32 and 33 are employed between the outer magnetic flux gate portions 15 and 16 of the outer yokes 23 and 24 and the outer magnetic flux gate portions 18 and 17. In addition, a tap changer 35 is provided so that the voltage can be roughly adjusted by switching the taps. In this case, the left and right outer yokes 23 and 24 serve as core legs around which the tapped AC side windings 32 and 33 are wound. The AC side winding 34 wound around the connecting yoke 25 functions as a control winding for generating a control magnetic flux for switching the transition of the superconducting elements 41, 42, 43, 44, and is connected to the low voltage AC bus. Yes. Therefore, the superconducting elements 41, 42, 43, and 44 are alternately switched between the superconducting state and the normal conducting state in synchronization with the alternating current of the AC bus. In the figure, reference numeral 36 denotes an insulator and 37 denotes a frame.

  Furthermore, the AC side iron core 2 is provided with a voltage fine adjustment mechanism 26 that allows the magnetic element 27 to be taken in and out, so that the voltage can be further finely adjusted. As shown in FIGS. 10 and 11, the voltage fine adjustment mechanism 26 is provided with a slit 29 constituting an air gap between a part of the AC side iron core 2, for example, between the connecting yoke 25 and the outer yoke 24, and the slit 29 The amount of magnetic flux flowing through the connecting yoke 25 is adjusted by controlling the amount of insertion of the magnetic element 27. The magnetic element 27 can be inserted or extracted by using a linear motor 28, and the magnitude of the passing magnetic flux is controlled by changing the magnetic resistance of the magnetic path. When operating as a rectifier, the output DC voltage is used as an inverter. When operating, adjust the output AC voltage. In this embodiment, an actuator such as the linear motor 28 is used. However, in some cases, a moving mechanism such as a feed screw mechanism that is manually rotated may be used. In the present embodiment, the voltage fine adjustment mechanism 26 is arranged in the AC side iron core 2 that is easy to control. However, the present invention is not limited to this, and depending on the case, it may be arranged in the DC side iron core 3. Anyway.

  Here, in the embodiment of the AC / DC converter of FIG. 10 and the embodiment of the DC / AC converter of FIG. 11, the connection yoke 25 or the outlet side yoke 21 through which the magnetic flux always passes regardless of the direction in which the magnetic flux flows, and the magnetic field. However, it is possible to control by one voltage fine adjustment mechanism 26 by providing it at a position closer to the connecting yoke 25 than the externally connected magnetic flux gate portions 15 and 16. It may be provided at any position on the magnetic path to be provided, for example, between the outer magnetic flux gate portions 15 and 16 and the outer magnetic flux gate portions 18 and 17, either at the outlet side yoke 21 or at the inlet side yoke 22. In this case, a portion where the magnetic flux does not flow is generated depending on the direction of the magnetic flux. Therefore, the voltage fine adjustment mechanism 26 is provided at an arbitrary position on the switched magnetic path, so that the passing amount of the magnetic flux can be controlled.

  Furthermore, FIG.12 and FIG.13 shows embodiment of the power converter device with which a magnetic path is switched mechanically. The power conversion device of this embodiment includes an interchangeable magnetic path switching element 50 that mechanically switches a magnetic path between the AC side iron core 2 and the DC side iron core 3.

  The basic structure of the power conversion device is the same as that of the embodiment using the switching element utilizing the transition of the superconducting element of FIGS. 1 to 11, and the DC side core for winding the DC side winding and the AC side winding are wound. A magnetic path switching element that controls the interruption and passage of magnetic flux is provided at the magnetic connection point between the rotating AC side iron core and flows in the same direction in the DC side winding portion of the DC side iron core by switching the magnetic path connection point. In both of the AC side windings of the AC side iron core, two types of magnetic flux flows whose flow directions are opposite to each other are periodically and alternately formed. More specifically, a heat insulating container in which a cooling medium 4 is enclosed. 1 includes a DC side iron core 3 having a total of four inner magnetic flux gates 5, 6, 7 and 8 at both ends of the iron core leg 20, and a DC side winding 30 made of a superconducting conductor for passing a DC current. On the other hand, the DC side iron core 3 outside the heat insulating container 1 An AC side winding comprising an AC side iron core 2 having four outer magnetic flux gate portions 15, 16, 17, 18 magnetically coupled to the inner magnetic flux gate portions 5, 6, 7, 8 and a normal conducting conductor for passing an AC current. 34.

  The DC side iron core 3 includes an inlet side yoke 22 and an outlet side yoke 21 that are magnetically coupled to both ends of the iron core leg 20, and inner magnetic flux gate portions 7, 8, 5, 6 at both ends of the yokes 22, 21. To make up. On the other hand, the AC side iron core 2 is opposed to the four inner magnetic flux gate portions 5, 6, 7, 8 of the DC side iron core through the wall of the heat insulating container 1, and is formed with four cores for forming a closed magnetic circuit with the iron core leg 20. The outer magnetic flux gate portions 15, 16, 17, 18 are magnetically coupled to the two outer yokes 23, 24, and the outer yokes 23, 24 are directly magnetically coupled outside the heat insulating container 1 so that the outer magnetic flux is obtained. A connecting yoke 25 that connects the gate portions 15, 16, 17, and 18 outside the heat insulating container 1 is provided. Therefore, the outer magnetic flux gate portions 15 and 18 and the outer magnetic flux gate portions 16 and 17 of the AC side iron core 2 distributed to the left and right around the DC side iron core 3 are magnetically coupled by the connecting yoke 25 outside the heat insulating container 1. In addition, a closed magnetic path is provided between the AC side iron core 2 and the DC side iron core 3 that are arranged to face each other with the heat insulating container 1 interposed via the connecting yoke 25.

  Here, the winding of the power conversion device of the present embodiment includes an AC side winding 34 disposed in the connecting yoke 25 outside the heat insulating container 1 and a DC side winding 30 disposed in the heat insulating container 1. It consists of two windings. The AC side winding 34 functions as a rectifier winding that receives AC power from an external AC circuit or an inverter winding that supplies AC power to the external AC circuit. Also, the DC side winding 30 functions as a winding that exchanges DC power when coupled with an external DC circuit and during rectification operation or inverter operation. In addition, in the power converter device of this embodiment, the winding with a tap provided with the some tap which can change turns ratio is further employ | adopted as AC side winding 34, and the tap switch 35 is provided, Tap switching Thus, the voltage can be roughly adjusted. Further, a slit 29 constituting an air gap is provided between the connecting yoke 25 and the outer yoke 24 of the AC side iron core 2, and a voltage fine adjustment mechanism 26 that allows the magnetic element 27 to be taken in and out is provided in the slit 29. By adjusting the amount of magnetic flux flowing through the yoke 25, the voltage can be further finely adjusted. In the present embodiment, the DC side winding 30 is a movable body that is a cylindrical body by being supported by a bracket protruding from the inner wall of the heat insulating container 1 outside the cylindrical movable support body 51 and inside the heat insulating container 1. Although the rotation of the support 51 is not hindered, the present invention is not particularly limited to this, and wiring inside the movable support 51 by wiring the lead wire so as to be hidden in the mount 45 that supports the movable support 51. It is also possible to directly wind the DC side winding 30 around the iron core leg 20.

  Further, a superconducting element 53 and a magnetic plate (hereinafter referred to as a magnetic element) 52 are arranged at a constant period between the heat insulating container 1 and the inner magnetic flux gate portions 5, 6, 7, 8 of the DC side iron core 3. By alternately inserting the magnetic flux gates 5, 6, 7, and 8 through the inner magnetic flux gates 5, 6 and 7, the magnetic flux gates 5, 6, 7, 8, 15, 16, 17, and 18 are alternately switched. , That is, a magnetic path switching element 50 that switches between a magnetic path constituted by the AC side iron core 2 and a magnetic path constituted by the DC side iron core 3 alternately between a superconducting state and a normal conducting state at a constant period is disposed. Has been.

  The magnetic path switching element 50 includes a cylindrical movable support 51 formed of a non-conductive and non-magnetic material such as FRP that encloses the iron core leg 20 and the inlet-side and outlet-side yokes 21 and 22, and the movable Superconductivity arranged alternately in a strip shape in the circumferential direction around the inner magnetic flux gate portions 5 and 6 at both ends of the outlet side yoke 21 of the support 51 and the inner magnetic flux gate portions 7 and 8 at both ends of the inlet side yoke 22. An element 53 and a magnetic element 52 are included. This magnetic path switching element 50 synchronizes the superconducting bearing 57 for rotatably supporting the bottom of the movable support 51 to the bottom 45 of the heat insulating container 1 and the frequency of the alternating current flowing through the low-voltage bus. And rotating the movable support 51 to alternately cover the end faces of the inner magnetic flux gates 5, 6, 7, and 8 with the superconducting elements 53 and the magnetic elements 52, While the AC side iron core 2 and the DC side iron core 3 are magnetically shielded by the Meissner effect of the superconducting element 53, the magnetic coupling between the AC side iron core 2 and the DC side iron core 3 is maintained by the magnetic element 52. It is configured to allow transmission of magnetic flux.

  That is, the power conversion device of the present embodiment can convert from alternating current to direct current or vice versa, and only by switching the input current, the half-wave rectified voltage is applied to the direct current side winding 30 by alternating current. An alternating voltage is generated in the side winding 34 and functions as an AC / DC converter or a DC / AC converter. For example, a DC motor is preferably used as the motor 56 as a drive source for synchronizing the AC frequency of the low-voltage bus and the rotation of the movable support 51, but a synchronous motor can also be used. In this case, synchronization can be easily achieved by pulling in the low-voltage bus.

  Here, the superconducting element 53 and the magnetic element 52 are when the superconducting element 53 is arranged in one magnetic flux gate portion of the entrance side yoke 22 with respect to the four inner magnetic flux gate portions 5, 6, 7, and 8. The magnetic element 52 is disposed in the opposite magnetic flux gate portion, and at the same time, the outlet side yoke 21 opposite to the iron core leg 20 has an opposite positional relationship, and the magnetic element 52 is disposed in one magnetic flux gate portion. The superconducting element 53 is disposed in the opposite magnetic flux gate portion. Specifically, according to the schematic diagram shown in FIG. 12, the magnetic flux gate portions 5, 7 are paired with the inner magnetic flux gate portions 5, 7 and 6, 8 arranged diagonally across the iron core leg 20. When the magnetic element 52 is disposed on the magnetic flux element and the magnetic flux is allowed to pass therethrough, the superconducting element 53 is disposed in the magnetic flux gate portions 6 and 8 to block the magnetic flux. Superconducting element 53 and magnetic element 52 are respectively arranged. Therefore, the inner magnetic flux gate portions 6 and 8 and the inner magnetic flux gate portions 5 and 7 alternately block and transmit the magnetic flux of the yoke portion by the rotation of the movable support 51, so that the magnetic flux flows in the same direction in the iron core leg 20. While passing, the magnetic path on the entrance side and the exit side of the magnetic flux reaching the iron core leg 20 can be switched alternately. When the magnetic paths are alternately switched, a half-wave rectified voltage is generated in the DC side winding and an alternating voltage is generated in the AC side winding. In this embodiment, the movable support 51 is provided with five pairs of superconducting elements 53 and magnetic elements 52 in a strip shape so as to pass through positions facing the inner magnetic flux gate portions 5, 7, 6, and 8, respectively. .

  By utilizing this principle, the AC current of the AC side winding 34 of the connecting yoke 25 magnetically induces a half-wave rectified electromotive force in the DC side winding 30 of the iron core leg 20, thereby enabling a rectifier operation from AC to DC. Furthermore, the inverter operation can be performed from direct current to alternating current by directing the direct current of the direct current wire 30 of the iron core leg 20 to the connecting yoke 25 by magnetic induction of an alternating electromotive force having a frequency corresponding to the rotational speed of the movable support 51.

  As the synchronous motor 56, in the case of the present embodiment, the permanent magnet field 55 is canned in the cryogenic temperature, that is, in the heat insulating container, the armature winding 54 is installed in the room temperature portion, and the cryogenic current lead is omitted. Like that. Specifically, for example, the bottom of the movable support 51 is rotatably supported on the bottom 45 of the heat insulating container 1 by the superconducting bearing 57, and the movable support 51 is movable and supported in the heat insulating container 1 on the upper end side of the movable support 51. A canned synchronous motor composed of a permanent magnet rotor 55 disposed on the rotation center axis of the body 51 and an armature winding 54 disposed in the room temperature portion is employed. The armature cable 54 in the room temperature section is connected to an external AC system, that is, a low-voltage three-phase AC bus, and is provided to rotate synchronously at a commercial frequency. The movable support 51 may be supported by using a guide rail wheel instead of the superconducting bearing 57.

  The superconducting element 53 may be any element that does not need to actively induce a phase transition and can maintain the Meissner effect. Therefore, the use of the rare earth superconducting element used in the switching element shown in FIGS. Although preferred, other superconducting materials such as bulk materials or thin films of common superconductors can also be used. In order to keep the Meissner effect constant, it is desirable to cool with slush nitrogen that can maintain a constant temperature of 65K. In the case of liquid nitrogen cooling, since the change in the Meissner effect of the superconducting element due to the temperature change affects the magnetic shielding amount and changes in the induced voltage of the winding, voltage adjustment control is performed for correction.

  The terminal of the DC side winding 30 is connected to the superconducting cable 40 via the superconducting lead-out port 9, and the superconducting core wire 39 and the superconducting shielded wire 38 are drawn into the heat insulating container 1 and directly joined with indium solder or the like. It is combined with a DC current smoothing winding or the like according to This structure can eliminate the current lead between the cryogenic temperature and the room temperature, and since there is no heat penetration into the cryogenic temperature part, the cooling loss can be greatly reduced. In the present embodiment, the DC side winding 30 is arranged outside the movable support 51 and wound around the iron core leg 20 so as not to hinder the rotation of the movable support 51. The wire 30 may be disposed inside the movable support 51. At this time, the lead wire of the DC side winding 30 is taken out from the bottom and soldered to the superconducting core wire 39 on the superconducting cable 40 side.

  According to the replaceable power converter configured as described above, DC / AC conversion and AC / DC conversion can be realized as follows.

  FIG. 13 shows the relative positional relationship between the superconducting element and the magnetic element when the magnetic path switching element 50 is rotated by the rotation of the movable support 51 and the electrical angle changes by 360 degrees in one cycle. Show. First, when the superconducting element 53 is entirely inserted into the inner magnetic flux gate portions 6 and 8 in the initial stationary state (see (a)), the inner magnetic flux gate portions 6 and 8 are magnetically shielded by the Meissner effect, and the inner magnetic flux Since all the magnetic flux passes through the gate portions 5 and 7, the magnetic flux is connected to the connecting yoke 25 of the AC side iron core 2 → the outer yoke 24 → the outer magnetic flux gate portion 17 → the magnetic element 52 → the inner magnetic flux gate portion 7 as shown in FIG. → Inlet side yoke 22 → iron leg 20 → outlet side yoke 21 → internal magnetic flux gate part 5 → magnetic body element 52 → external magnetic flux gate part 15 → connecting yoke 25 and a magnetic flux flow A are formed. At this time, if the alternating current flowing through the AC side winding 34 of the connecting yoke 25 flows in the counterclockwise direction at the maximum value, the direction of the magnetic flux acting on the DC side winding 30 wound around the iron core leg 20 becomes upward. A half-wave voltage in the direction is induced.

  As shown in FIG. 13 (e), after a half cycle in which the current is reversed, the inner magnetic flux gate portions 5 and 7 are covered with the superconducting element 53 and are magnetically shielded by the Meissner effect. Covered with a magnetic element 52 to allow passage of magnetic flux. As a result, a magnetic flux flow B centering on the right outer yoke 23 is formed, but the alternating current flowing in the alternating current side winding 34 is reversed and the direction of the magnetic flux is clockwise. As described above, an upward magnetic flux flows, and a voltage in the same direction is induced. Thus, since the main magnetic flux of the iron core leg 20 is always in the same direction regardless of the direction change of the magnetic flux generated by the AC side winding 34, a continuous half-wave rectified voltage is induced in the DC side winding 30. In this state, the DC side winding 30 can be coupled to a DC external circuit to perform power conversion as a rectifier from AC to DC.

  On the contrary, a DC current is applied to the DC side winding 30 of the iron core leg 20 so that a magnetic flux flow in the upward direction is always generated in the iron core leg 20, and the movable support 51 is synchronized with the AC current flowing through the low voltage AC bus. Then, as shown in (i) to (p) of FIG. 13, the magnetic flux flows A and B in the AC side iron core 2 are switched according to the switching period between the superconducting element 53 and the magnetic element 52. As a result, an AC current is induced in the AC side winding 34 of the connecting yoke 25. That is, when the superconducting element 53 is disposed in the inner magnetic flux gate portions 6 and 8 and the magnetic element 52 is disposed in the inner magnetic flux gate portions 5 and 7, the magnetic flux flow of the upper yoke 21 is maximized and the counterclockwise magnetic flux flows. An induced voltage is generated in the positive direction. Further, when the movable support 51 rotates and the inner magnetic flux gate portions 6 and 8 become the magnetic element 52 and the inner magnetic flux gate portions 5 and 7 become the superconducting element 53, the magnetic flux flow of the upper yoke 21 becomes the maximum. Since the direction is clockwise, a reverse voltage is induced in the AC side winding 34. In the AC side winding 34, ± alternating pulse magnetic flux is linked every half cycle to generate a voltage, and if this is combined with an external AC circuit, power conversion as an inverter from DC to AC can be performed.

Next, a description will be given of a method for starting / stopping and controlling a DC output during a rectifying operation from AC to DC.
First, slush nitrogen is injected into the cryogenic space in the heat insulating container 1 to cool the superconducting element 53, the magnetic element 52 and the DC side winding 30 disposed on the movable support 51 to 65K. Then, the movable support 51 of the rotating magnetic path switching element 50 is fixed so that the period in which the pair of the superconducting element 53 and the magnetic element 52 passes through the inner magnetic flux gate portions 5 to 8 is synchronized with the period of the external AC voltage. If an alternating current is applied to the AC side winding 34 while controlling the permanent magnet type canned motor 56 so as to rotate at a rotational speed of, a half-wave rectified voltage is induced in the DC side winding 30. If the DC side winding 30 is coupled to an external DC circuit (DC reactor, cable, power transmission line, load, etc.), a load current flows through the external DC circuit by the induced half-wave rectified voltage. This current is smoothed by the inductance of the DC side winding of the converter and the inductance of the reactor of the external circuit to become a DC current. In the rectifier operation during steady operation, coarse voltage adjustment is performed by the winding tap ratio of the AC side winding 34, and fine voltage adjustment is performed by driving the linear motor 28 and the magnetic element 27 is taken in and out of the slit 29. Control the voltage / current and power flow.

Next, a description will be given of a start-up and an AC output control method during DC-to-AC inverter operation.
First, the slush nitrogen 4 is injected into the cryogenic material space, that is, the heat insulating container 1, and the superconducting element 53, the magnetic element 52 and the DC side winding 30 disposed on the movable support 51 are cooled to 65K. Next, a direct current is applied to the DC side winding 30 wound around the iron core leg 20. The rotational speed of the movable support 51 of the magnetic path switching element 50 is constant so that the period in which a pair of the superconducting element 53 and the magnetic element 52 passes through the inner magnetic flux gates 5 to 8 and the period of the external AC voltage are synchronized. The permanent magnet type canned motor 56 is controlled so as to be rotated. For example, in FIG. 12, five pairs of superconducting elements 53 and magnetic elements 52 are arranged on the upper and lower sides of the movable support 51. Therefore, in order to synchronize with an external AC system of 50 Hz, the speed is 10 revolutions per second. Use a synchronous machine that rotates at. As this synchronous motor, for example, a 20-pole permanent magnet rotor type synchronous machine is suitable. As a result, a synchronous 50 Hz alternating magnetic field is induced in the AC side winding 34. In the rectifier operation during steady operation, coarse voltage adjustment is performed by the winding tap ratio of the AC side winding 34, and fine voltage adjustment is performed by driving the linear motor 28 and the magnetic element 27 is taken in and out of the slit 29. Control the voltage / current and power flow.

  Furthermore, according to the power converter of the present embodiment configured as described above, the operation can be stopped as follows to function as a circuit breaker. For example, in the case of a failure of the connected DC system in both the rectifier operation and the inverter operation, the rotation of the movable support 51 is stopped to stop the AC / DC conversion function, the induced voltage is set to zero, and the DC circuit is interrupted it can. When the AC system fails, the AC line is interrupted by an AC circuit breaker as in the prior art, and the DC system is stopped by the above method as necessary. Furthermore, when restarting at a high speed, since the superconducting element 53 and the magnetic element 52 of the rotating magnetic path switching element 50 are held at 65K, the operation is resumed by immediately rotating the synchronous motor to the synchronous speed. be able to.

  14 and 15 show an embodiment in which the present invention is applied to a three-phase AC power converter. The power converter of this embodiment includes three DC-side iron cores 3U, 3V, 3W and one superconducting winding 30 wound over these iron core legs 20U, 20V, 20W in one cryostat. The AC side windings 34U, 34V, and 34W wound around the three AC side iron cores 2U, 2V, and 2W and the respective connecting yokes (iron core legs) 25U, 25V, and 25W are disposed outside the cryostat. Outside magnetic flux gates 5U, 5V, 5W, 6U, 6V, 6W, 7U, 7V, 7W, 8U, 8V, 8W and the AC side iron cores 2U, 2V, 2W of the paired DC side iron cores 3U, 3V, 3W The magnetic flux gate portions 15U, 15V, 15W, 16U, 16V, 16W, 17U, 17V, 17W, 18U, 18V, and 18W are arranged to face each other. Here, the three DC side iron cores 3U, 3V, 3W and the AC side iron cores 2U, 2V, 2W are arranged so as to be shifted in the circumferential direction by 120 ° in mechanical angles, respectively, and in the cryostat 1, the DC side iron cores 3U, 3V, Ten superconducting elements 53 and magnetic elements 52 are alternately arranged on a movable support 51 made of a nonmagnetic material surrounding 3 W. That is, the superconducting element 53 and the magnetic element 52 are alternately arranged as plates having a mechanical angle of 18 ° with respect to the center of rotation. At this time, a half-wave rectified voltage that is shifted by 120 degrees in electrical angle corresponding to the three-phase AC U, V, and W phases is generated in the DC side winding 30. Conversely, if a DC current is applied to the DC side winding 30 and the movable support 51 is rotationally controlled by a synchronous motor so as to have a predetermined period, the AC side windings 34U, 34V, and 34W are electrically angled. A three-phase 50 Hz alternating magnetic field with 120 ° phase is induced. In the figure, reference numeral 54 is a canned synchronous motor armature winding, 55 is a canned synchronous motor permanent magnet field, 56 is a canned synchronous motor shaft, 57 is a superconducting magnetic bearing, and 58 is a frame.

  FIG. 16 shows still another embodiment. The power converter of this embodiment is a modification of the interchangeable power converter shown in FIG. 12, and two heat insulating containers 11 are provided for one AC side iron core 2 and an AC side winding 320 made of a normal conductive conductor. , 12 and the heat insulating containers 11 and 12 are accommodated in a DC side core 3 and a DC side winding 301 and 302 made of a superconducting conductor, and are configured as a forward conversion device. That is, one of the two heat insulating containers 11 and 12 is provided with the iron core leg 201 and the inner magnetic flux gate portions 211 and 221 and the DC side winding 301 is wound around the iron core leg 201, and the other heat insulating container. 12 includes an iron core leg 202 and internal magnetic flux gate portions 212 and 222, and a DC side winding 302 is wound around the iron core leg 202. Between these two heat insulating containers 11 and 12, an I-shaped AC side iron core 2 in which an AC side winding 320 is wound around an iron core leg 230 is disposed, and a central I-shaped AC side iron core 2 is interposed. Thus, two closed magnetic paths are formed between the DC-side iron cores 3 in the cryogenic environment in the left and right heat insulating containers 11 and 12. In addition, the AC side iron core 2 has outer magnetic flux gate portions 311, 321, 312, 322 that are magnetically coupled to the inner magnetic flux gate portions 211, 221, 212, 222 on the cryogenic temperature side at both ends of the iron core leg 230, respectively. In addition, an AC side winding 320 is wound around the iron core leg 230.

  And in each heat insulation container 11 and 12, as a switching element which controls the flow of the magnetic flux which passes between between the alternating current side iron core 2 and the direct current side iron core 3, for example, the exchange type magnetic path switching element 50 shown in FIG. Is provided for each of the heat insulating containers 11 and 12. Since this magnetic path switching element 50 has the same basic configuration as that shown in FIG. 12, its detailed description is omitted, and the magnetic path switching element 50 housed in the heat insulating container 11 is taken as an example. A schematic structure will be described. That is, the FRP movable support body 51 that surrounds the iron core leg 201 and the inner magnetic flux gate portions 211 and 221 and the portions surrounding the inner magnetic flux gate portions 211 and 221 of the movable support body 51 are alternately arranged in a strip shape in the circumferential direction. The superconducting element 53 and the magnetic element 52, the superconducting bearing 57 for supporting the bottom of the movable support 51 by the bottom of the heat insulating container 11 or a frame (not shown), and the alternating current flowing through the low-voltage bus bar. A synchronous motor 55 for rotationally driving in synchronization with the current, and by covering the end surfaces of the inner magnetic flux gate portions 211 and 221 with the superconducting element 53 and the magnetic element 52 by the rotation of the movable support 51; The AC side iron core 2 and the DC side iron core 3 are magnetically shielded by the Meissner effect of the superconducting element 53, while the AC side iron is interposed by the magnetic element 52. 2 and retains the magnetic coupling is configured to allow transmission of magnetic flux between the DC side core 3.

  Here, the superconducting element 53 or the magnetic element 52 is simultaneously disposed with respect to the inner magnetic flux gate portions 211 and 221 at both ends of the iron core leg 201, and the DC side iron core 3 in the heat insulating container 11 is connected to the AC current. A magnetic path is formed with the side iron core 2, or it is cut off and separated from the AC side iron core 2. At this time, the magnetic path switching element 50 of the other heat insulating container 12 has a reverse relationship to the heat insulating container 11. That is, when the magnetic path switching element 50 of the heat insulating container 11 is arranged with the superconducting element 53 with respect to the inner magnetic flux gate portions 211 and 221, for example, the magnetic flux switching portions 50 are magnetic with respect to the inner magnetic flux gate portions 212 and 222 at both ends of the iron core leg 202. The body element 52 is disposed.

  Accordingly, the magnetic flux in the inner magnetic flux gate portions 211 and 221 and the inner magnetic flux gate portions 212 and 222 are alternately blocked and transmitted by the rotation of the movable support body 51 of each of the heat insulating containers 11 and 12, so Magnetic flux gate portion 211 → external magnetic flux gate portion 311 → core leg 230 of AC side iron core 2 → external magnetic flux gate portion 321 → internal magnetic flux gate portion 221 → iron core leg 201 and a closed magnetic path through which magnetic flux passes, and iron core leg 202 → internal magnetic flux Two closed magnetic paths of the gate part 222 → the outer magnetic flux gate part 322 → the iron core leg 230 of the AC side iron core 2 → the outer magnetic flux gate part 312 → the inner magnetic flux gate part 212 → the iron core leg 202 and the closed magnetic circuit through which the magnetic flux passes are alternately arranged. It is formed. In other words, the power conversion device of the present embodiment can convert from alternating current to direct current or vice versa, and only by switching the input current, the half-wave rectified voltage is applied to the direct current side winding 30 by alternating current. An alternating voltage is generated in the side winding 34, and it can function as an AC / DC converter or a DC / AC converter simply by switching the input / output relationship.

  For example, in this structure, when functioning as a rectifier, the magnetic path switching element 50 of each of the heat insulating containers 11 and 12 rotates in synchronization with the reversal of the alternating current flowing in the alternating current side winding 320, so that the direct current side A voltage corresponding to an alternating half-wave magnetic field Φac is alternately induced in the windings 301 and 302, and a direct-current magnetic field corresponding to the half-wave is induced in each of the direct-current side windings 302 and 301. , 301 can be reversed and connected to each other to extract a DC voltage from the output terminal. Also, when functioning as an inverter, a direct current is passed through the direct current windings 301 and 302 of the two direct current iron cores, and the alternating current iron core 2 is switched by alternately switching the passage and interruption of the magnetic flux. Magnetic flux flows having different directions are alternately generated in the iron core leg 230, and in the AC side winding 320, ± alternating pulse magnetic flux is linked every half cycle to induce an AC voltage, and an AC current flows. If this is combined with an external AC circuit, inverter conversion from DC to AC can be performed.

  FIG. 17 shows still another embodiment. The power conversion device of this embodiment employs a magnetic path switching element 50 in which a superconducting element 53 and a magnetic element 52 made of a magnetic plate are annularly arranged on a single disk-shaped movable support 51. It is a thing. The power converter according to the present embodiment is different in mechanical configuration from the above-described embodiments in that a disk-shaped replaceable magnetic path switching mechanism 50 is employed. However, the magnetic circuit and the electric circuit are basically the same. Since the configuration is the same, detailed description thereof is omitted.

  In the power conversion device of this embodiment, the DC side iron core 3 around which the DC side winding 30 is wound is accommodated in the heat insulating container 1 in which the cooling medium 4 is enclosed, and the AC side winding 34 is outside the heat insulating container 1. Is arranged, and a magnetic connection portion between the DC side iron core 3 and the AC side iron core, that is, inner and outer magnetic flux gate portions 5, 6, 7, 8, 15, 16, 17, 18 A magnetic path switching element in which magnetic elements 52 and superconducting elements 53 are alternately arranged in an annular shape is disposed on a movable support 51 made of a rotating disk. More specifically, an outlet side inner magnetic flux gate part 5, 6 and an inlet side inner magnetic flux gate part 7, 8 are provided at both ends of the core leg 20 of the DC side iron core 3, while the AC side iron core 2 has a heat insulating container. Four outer magnetic flux gate portions 15, 16, 17, and 18 opposed to the four inner magnetic flux gate portions 5, 6, 7, and 8 through one wall are provided magnetically by the two yokes and the connecting yoke 25. Are connected. In the present embodiment, the structural stability is increased by arranging the heavy connecting yoke 25 at the bottom. However, the present invention is not limited to this, and as shown in the above-described embodiments. In addition, the connecting yoke 25 may be disposed above the heat insulating container 1. Further, in the present embodiment, one outer yoke of the AC side iron core 2 is disposed in close contact with the heat insulating container 1, and a part of the outer yoke is provided so as to function as the outer magnetic flux gate portions 16 and 17, and separate parts are provided. The outer magnetic flux gate portions 16 and 17 are not configured, but the magnetic connection locations are established by the corresponding inner magnetic flux gate portions 6 and 7, so that there is no particular problem.

  In the power conversion device of this embodiment, a winding with a tap and a tap changer 35 that can change the turns ratio of the AC side winding 34 are provided, and the voltage can be roughly adjusted by switching the tap. Further, the connecting yoke 25 of the AC side iron core 2 is provided with the above-described fine voltage adjusting mechanism 26 composed of a slit and a magnetic element inserted therein, and adjusts the amount of magnetic flux flowing through the connecting yoke 25. The voltage can be further finely adjusted. Of course, these voltage adjustment mechanisms may be omitted if not necessary.

  The magnetic path switching element 50 of the present embodiment includes a disk-shaped movable support 51 made of FRP in which superconducting elements 53 and magnetic elements 52 are alternately arranged in a ring on a single plane, and the disk-like shape. The movable support body 51 is composed of a canned synchronous motor 56 and a superconducting bearing 57 for supporting the movable support body 51 rotatably in the heat insulating container 1. The movable support 51 is supported at the center by a motor shaft 58 that passes through the core leg 20 and is supported so as to be rotatable in a plane orthogonal to the magnetic flux passing between the DC side iron core 3 and the AC side iron core 2. ing. The front end portion of the motor shaft 58 is rotatably supported by a superconducting bearing 57 provided in the heat insulating container, and a permanent magnet rotor 55 constituting a canned synchronous motor 56 is mounted on the base end side. This permanent magnet rotor 55 constitutes a canned synchronous motor 56 with an armature winding 54 arranged outside the heat insulating container 1, and the armature winding 54 in the room temperature section is connected to an external AC system, that is, a low-voltage three-phase motor 56. It is connected to the phase alternating current bus and is provided to rotate synchronously at a commercial frequency.

  As shown in FIG. 29, the movable support 51 has a diameter large enough to simultaneously cover the end faces of the inner magnetic flux gates 5, 8 or 6, 7 on both the inlet side and the outlet side. 53 and magnetic elements 52 made of magnetic plates are alternately arranged in an annular shape, and the superconducting elements 53 and the magnetic elements 52 are alternately arranged at fixed intervals on the end faces of the inner magnetic flux gate portions 5, 8, 6, 7. By inserting it in front, the end surfaces of the inner magnetic flux gate portions 5 and 8 or 6 and 7 are alternately covered with the superconducting element 53 and the magnetic element 52 by the rotation of the movable support member 51, thereby obtaining the Meissner of the superconducting element 53. The magnetic connection between the AC side iron core 2 and the DC side iron core 3 is magnetically shielded by the effect, while the magnetic coupling between the AC side iron core 2 and the DC side iron core 3 is maintained by the magnetic element 52 interposed. Allow transmission of magnetic flux Is constructed sea urchin.

  Here, the magnetic element 52 and the superconducting element 53 of the two movable support members 51 are arranged such that when the superconducting element 53 is disposed in the inner magnetic flux gate parts 5, 7, the magnetic element is formed in the inner magnetic flux gate parts 6, 8. 52 are combined in the relationship in which they are arranged. That is, the superconducting element 53 of the same movable support 51 is arranged in the inner magnetic flux gate portion 5 on the side from which the magnetic flux flows out when the magnetic element 52 is arranged in the inner magnetic flux gate portion 8 on the side in which the magnetic flux flows in. At the same time, the superconducting element 53 is disposed in the inner magnetic flux gate portion 7 on the side where the opposite magnetic flux flow flows in with the iron core leg 20 interposed therebetween, and the same movable support 51 is disposed on the inner magnetic flux gate portion 6 on the side where the magnetic flux flow flows out. Are provided in such a relationship that the magnetic elements 52 are arranged. Therefore, the magnetic flux passes through the iron core leg 20 in the same direction by alternately interrupting and passing the magnetic flux flow in the inner magnetic flux gate portions 6 and 8 and the inner magnetic flux gate portions 5 and 7 by the rotation of the movable support 51. However, the magnetic path on the inlet side and the outlet side of the magnetic flux reaching the iron core leg 20 forms two magnetic flux flows A and B that are alternately switched in the AC side winding 34 portion. When the magnetic paths are alternately switched, a half-wave rectified voltage is generated in the DC side winding and an alternating voltage is generated in the AC side winding. In the present embodiment, seven pairs of superconducting elements 53 and magnetic elements 52 are annularly arranged on one disk-shaped movable support body 51, but there is no particular reason for this logarithm, and one magnetic interruption switching is performed. It is important that the rotational speed of the movable support 51 and the frequency of the applied voltage are synchronized with each other in a relationship that coincides with the timing at which the voltage on the AC side is inverted. Further, even between the two movable supports, when the magnetic element 52 is disposed in the magnetic flux gate portions 5 and 7 and the magnetic flux is allowed to pass therethrough, the superconducting element 53 is disposed in the magnetic flux gate portions 6 and 8 so that the magnetic flux is transmitted. The blocking relationship needs to be synchronized. In the present embodiment, two movable support bodies 51 that respectively cover the end surfaces of the inner magnetic flux gate portions 5 and 8 or 6 and 7 are provided, but depending on the case, the inner magnetic flux gate portions 5, 6, 7, It is also possible to provide four disc-like movable supports 51 that cover the respective end surfaces every 8 and to rotate and synchronize these to control the interruption and passage of the magnetic flux flow at each magnetic connection location.

  According to the interchangeable power conversion device configured as described above, the AC side winding and the DC side winding must be passed, and the DC side winding portion must pass in the same direction and to the AC side iron core. Thus, two magnetic flux flows A and B that pass alternately in opposite directions are formed. Therefore, it is possible to convert from alternating current to direct current or vice versa, only by switching the input current, a half-wave rectified voltage is applied to the direct current side winding 30, and an alternating voltage is applied to the alternating current side winding 34. Is generated and functions as an AC / DC converter or a DC / AC converter.

  First, the rectification operation will be described. In a state where the superconducting element 53 is entirely inserted into the inner magnetic flux gate portions 5 and 7 of the pair of disk-shaped power conversion elements and the magnetic element 52 is entirely inserted into the inner magnetic flux gate portions 6 and 8. When an alternating current is passed through the side winding 34 and magnetic flux is generated upward, the inner magnetic flux gate portions 5 and 7 are magnetically shielded by the Meissner effect, and the inner magnetic flux gate portions 6 and 8 pass all the magnetic flux. A is the outer magnetic flux gate portion 18 → the magnetic element 52 → the inner magnetic flux gate portion 8 → the iron core leg 20 → the inner magnetic flux gate portion 6 → the magnetic element 52 → the outer magnetic flux gate portion 16 → the outer yoke → the connecting yoke 25 → the AC side winding. It flows to the core leg (connection yoke 25) around which the wire 34 is wound. Next, as the disk-shaped movable support plate 51 rotates in synchronization with the voltage change, the magnetic element 52 starts to cover the inner magnetic flux gate portions 5 and 7 and the inner magnetic flux gate portions 6 and 8 are connected to the superconducting element. 53 begins to cover. Therefore, as the alternating current flowing in the alternating current side winding 34 is reversed, the magnetic flux begins to pass through the direct current side iron core 3 via the internal magnetic flux gate portions 5 and 7, while the direct current passes through the internal magnetic flux gate portions 6 and 8. The magnetic flux passing through the side iron core 3 begins to decrease. When the magnetic element 52 completely covers the inner magnetic flux gate portions 5 and 7 and the superconducting element 53 covers the inner magnetic flux gate portions 6 and 8, the alternating current flowing through the alternating current side winding 34 peaks in an inverted state. The connecting yoke 25 → the outer magnetic flux gate 17 → the magnetic element 52 → the inner magnetic flux gate 7 → the iron core leg 20 → the inner magnetic flux gate 5 → the magnetic element 52 → the outer magnetic flux gate 15 → the outer yoke → the AC side Only the magnetic flux flow B flowing to the iron core leg (the connecting yoke 25) around which the winding 34 is wound is provided. Therefore, the magnetic flux generated by the alternating current flowing in the alternating current side winding 34 always flows as one upward magnetic flux, for example, in the direct current side winding 30 of the iron core leg 20, and induces a continuous half-wave rectified voltage in the same direction. To do. Then, a rectifying operation for supplying a DC current to a DC external circuit coupled to the DC side winding 30 is performed.

  Further, in the inverter operation, a DC current is passed through the DC side winding 30 of the iron core leg 20 so that a magnetic flux flow in a certain direction, for example, an upward direction is always generated in the iron core leg 20, and the movable support 51 flows through the low voltage AC bus. By rotating in synchronization with the alternating current, the magnetic path in the alternating current side iron core 2 is switched according to the switching period between the superconducting element 53 and the magnetic element 52, and the alternating current is induced in the alternating current side winding 34. . That is, the rotation of the movable support 51 synchronized with the alternating current of the low-voltage AC bus passes through the inner magnetic flux gate portions 6 and 8 and the inner magnetic flux gate portions 5 and 7 in accordance with the ratio of the superconducting element 53 and the magnetic element 52 covering, respectively. Since the amount of magnetic flux and the amount of shielding magnetic flux are controlled so as to gradually increase and decrease, the DC magnetic flux generated in the DC side iron core 3 is gradually and gradually switched between a gradual magnetic flux flow A and a magnetic flux flow B. In 34, a voltage is induced by linking alternating pulse magnetic flux of ± every half cycle. Therefore, if this is combined with an external AC circuit, inverter conversion from DC to AC can be performed.

  FIG. 18 shows still another embodiment. This embodiment is a modification in which the magnetic path switching element 50 of the power conversion device shown in FIG. 12 is changed, and a nonmagnetic movable support body in which at least a pair of superconducting elements 53 and a magnetic element 52 are arranged in the circumferential direction. The magnetic path switching element 50 that switches the magnetic path by swinging the 51 is used. The movable support 51 is oscillated within a certain angle range by a drive source such as an oscillating motor or an oscillating fluid pressure motor, so that a superconducting state and a normal state are kept between the inner magnetic flux gate portion and the outer magnetic flux gate portion. The conduction state is alternately generated at a constant period, and the flow of magnetic flux is controlled. In this case, it is important that the swing speed of the movable support 51 and the frequency of the applied voltage are synchronized, and the magnetic shielding switching is kept in a relationship that coincides with the timing at which the AC side voltage is inverted every time. It is. A direct drive by a swing motor may be used, but a mechanism for converting the rotation of a synchronous motor into a swing, for example, by using a crank and a swing lever to convert a rotary motion into a swing motion like a pendulum, the voltage frequency You may make it obtain the rocking | fluctuation synchronized with. In addition, according to the present embodiment, the support body is configured by a cylindrical body made of FRP similarly to the switching mechanism shown in FIG. 12, but is not particularly limited to this, and in some cases may be a semicircular shape. There may be. Also in this embodiment, when four magnetic connection locations are provided, forward conversion and reverse conversion can be performed by switching input power.

  FIG. 19 shows still another embodiment. This embodiment is a modification in which the magnetic path switching element 50 of the power conversion device shown in FIG. 12 is changed, and a non-magnetic movable support body in which at least a pair of superconducting elements 53 and a magnetic element 52 are arranged vertically. The magnetic path is switched by reciprocating 51. That is, the magnetic path switching element 50 in this power converter is parallel to the core leg 20 of the DC side iron core 3 at a position where the superconducting element 53 and the magnetic element 52 face the inner magnetic flux gate portions 5, 6, 7, 8. A non-magnetic movable support 51 arranged in the axial direction and a drive source for reciprocating the movable support 51, and by reciprocating the movable support 51 by the drive source, the inner magnetic flux gate section 5 6, 7, 8 and the external magnetic flux gate portions 15, 16, 17, 18 alternately generate a superconducting state and a normal conducting state at a constant period to control the flow of magnetic flux. is there. As a drive source of this embodiment, for example, a linear motor composed of an electromagnetic solenoid 61 and a permanent magnet 60 is preferably used. However, in this case as well, a movable support is provided by connecting a low-voltage AC bus to the electromagnetic solenoid 61. The movement speed of the body 51 and the frequency of the applied voltage are synchronized so that the magnetic shield switching is maintained in a relationship that coincides with the timing at which the AC side voltage is inverted every time. Although direct drive by a solenoid may be used, a mechanism that converts the rotation of a synchronous motor into a reciprocating linear motion, such as a cam mechanism using a positive cam or a plate cam, may be used to obtain a displacement synchronized with the voltage frequency. good. Further, according to the present embodiment, the movable support body 51 is constituted by an FRP cylindrical body, similarly to the switching mechanism shown in FIG. 12, and is provided in the heat insulating container 1 so as to surround the DC side iron core 3. However, it is not particularly limited to this, and may be a plate material or a semi-cylindrical shape.

  FIG. 20 shows still another embodiment. The power converter of this embodiment has a simplified iron core structure and a reduced number of magnetic path switching elements. The magnetic path switching element 50 is formed by alternately arranging superconducting elements 53 and magnetic elements 52 on a nonmagnetic movable support made of a rotating disk shown in FIG. 17, and its detailed structure and operation. Description of is omitted.

  In this power converter, paying attention to the fact that the magnetic flux flows in the same direction in the DC side winding portion, the magnetic path entrance side or the exit side is shared and reduced to one location, thereby providing three magnetic connection locations. Furthermore, the number of magnetic connection points for controlling the interruption and passage of magnetic flux is reduced to two. That is, the DC side iron core 3 disposed in the heat insulating container 1 includes the inlet side inner magnetic flux gate portion 74 and the outlet side inner magnetic flux gate portion 76 at both ends of the iron core leg 80, and at the center of the iron core leg 80 at the inlet side. A common inner magnetic flux gate portion 77 serving as both the inner magnetic flux gate portion and the outlet side inner magnetic flux gate portion is provided. The DC side winding 30a, between the common inner magnetic flux gate portion 77 and the inlet-side inner magnetic flux gate portion 74 of the iron core leg 80 and between the common inner magnetic flux gate portion 77 and the outlet-side inner magnetic flux gate portion 76, respectively. 30b is wound and connected to the forward electrode. In addition, the AC side iron core 2 disposed outside the heat insulating container 1 is disposed to face the inlet side inner magnetic flux gate portion 74, the outlet side inner magnetic flux gate portion 76, and the common inner magnetic flux gate portion 77 of the DC side iron core 3. Three outer magnetic flux gate parts, ie, an outlet-side outer magnetic flux gate part 75, an inlet-side outer magnetic flux gate part 73, and a common outer magnetic flux gate part 78, which are magnetically coupled to each other. The AC side winding 34 is wound between the common outer magnetic flux gate portion 78 and the inlet side outer magnetic flux gate portion 73. Further, between the inlet-side inner magnetic flux gate portion 74 and the outlet-side inner magnetic flux gate portion 76 and the heat insulating container 1, a superconducting element 53 and a magnetic body are provided on a disc-like movable support 51 that straddles both the gate portions 74 and 76. A magnetic path switching element 50 on which the element 52 is mounted is disposed. The movable support 51 is supported by a motor shaft 58 of a can synchronous motor 56 supported by a superconducting magnetic bearing 57 embedded in the iron core leg 80. The canned synchronous motor 56 is connected to the AC bus, and alternately switches off and passes the magnetic flux passing through the inlet-side inner magnetic flux gate portion 74 and the outlet-side inner magnetic flux gate portion 76, and passes through the iron core leg 80 to enter the inlet-side outer magnetic flux gate portion 73. And magnetic flux flow A passing between the common outer magnetic flux gate portion 78 and the magnetic flux flow B passing between the common outer magnetic flux gate portion 78 and the outlet-side outer magnetic flux gate portion 75. Are alternately formed in synchronism with the frequency of the AC power flowing through the. By switching the flow of magnetic flux generated by the alternating current flowing in the alternating current side winding 34 by the magnetic path switching element 50, the direct current side windings 30a and 30b generate direct current by magnetic induction, thereby converting power.

  According to the power conversion device configured as described above, for example, the superconducting element 53 is entirely inserted into the outlet-side inner magnetic flux gate portion 76 and the magnetic element 52 is entirely inserted into the inlet-side inner magnetic flux gate portion 74. In the state shown in FIG. 20, when an alternating current flows through the AC side winding 34 and an upward magnetic flux flow is generated, the outlet-side inner magnetic flux gate portion 76 is magnetically shielded by the Meissner effect, and the inlet-side inner magnetic flux gate portion 74 receives the magnetic flux. Since all are passed, a magnetic flux flow A is formed which flows from the inlet-side inner magnetic flux gate portion 74 through the DC-side winding 30a to the iron core leg 79 around which the AC-side winding 34 is wound from the common inner magnetic flux gate portion 77. Next, when the alternating current flowing in the AC side winding 34 is reversed and a downward magnetic flux is generated, the magnetic element 52 covers the outlet side inner magnetic flux gate portion 76 and allows the magnetic flux to pass, while the superconducting element 53 The entrance side inner magnetic flux gate portion 74 is covered and magnetically shielded by the Meissner effect, so that it flows in from the common inner magnetic flux gate portion 77 via the connecting yoke 25 and passes through the direct current side winding 30b to the outlet side inner magnetic flux gate portion 76 from the AC side. A magnetic flux flow B flowing into the winding 34 is formed. A continuous half-wave rectified voltage in the same direction is induced in the two DC side windings 30a and 30b by an AC current flowing alternately in the AC side winding 34. Since the two DC side windings 30a and 30b are forward-polarized, the generated voltage is smoothed by the reactor of the DC side windings 30a and 30b itself, or a smoothing reactor provided as necessary. Thus, the ripple is further removed and the direct current is supplied as a direct current to the external DC circuit.

  FIG. 21 shows still another three-gate type embodiment. The power converter of this embodiment is similar to the power converter shown in FIG. 20, with a simplified iron core structure and a reduced number of magnetic path switching elements. It is different.

  That is, the DC side iron core 3 disposed in the heat insulating container 1 is magnetically connected to the yoke portion 72 having the inlet side inner magnetic flux gate portions 65 and 66 at both ends and the center of the yoke portion 72. An iron core leg having two outlet-side inner magnetic flux gate portions 67 is provided. The DC side winding 30 is wound around the outlet-side inner magnetic flux gate portion 67 serving as an iron core leg. Further, the AC side iron core 2 disposed outside the heat insulating container 1 is disposed opposite to the two inlet side inner magnetic flux gate portions 65 and 66 and one outlet side inner magnetic flux gate portion 67 of the DC side iron core 3. Two inlet-side outer magnetic flux gate portions 69 and 70 and one outlet-side outer magnetic flux gate portion 68 that are magnetically coupled are provided. The AC side windings 32 and 33 are wound around the iron core legs having the two entrance-side outer magnetic flux gates 69 and 70, respectively, and are oppositely coupled so that the outputs are reversed and output. Further, between the inlet-side inner magnetic flux gate portion 65 and the inlet-side inner magnetic flux gate portion 66 and the heat insulating container 1, a superconducting element 53 and a magnetic body are connected to a disk-like movable support 51 straddling both the gate portions 65 and 66. A magnetic path switching element 50 on which the element 52 is mounted is disposed. Then, by the rotation of the can synchronous motor 56 connected to the AC bus, the magnetic flux passing through the two inlet-side inner magnetic flux gate portions 65 and 66 is alternately switched between blocking and passing, and from one inlet-side inner magnetic flux gate portion 65 to the outlet. Two types of magnetic flux flows are alternately formed: a magnetic flux A that passes to the inner magnetic flux gate portion 67 and a magnetic flux B that passes from the other inlet-side inner magnetic flux gate portion 66 to the outlet-side inner magnetic flux gate portion 67. . As a result, for example, by switching the flow of magnetic flux generated by the direct current flowing in the direct current side winding 30 by the magnetic path switching element 50, an alternating voltage is generated in the alternating current side windings 32 and 33 by magnetic induction, thereby generating direct current. Power from AC to AC. In the present embodiment, the DC-side iron core 3 is provided with two inlet-side inner magnetic flux gate portions 65 and 66 and one outlet-side inner magnetic flux gate portion 67, but two outlet-side inner magnetic flux gate portions 67 are provided. Even if one inlet-side inner magnetic flux gate portion and corresponding outer magnetic flux gate portions are provided, the principle is the same except that the direction of the magnetic flux flow is changed.

  According to the power conversion device configured as described above, for example, the superconducting element 53 is entirely inserted into the inlet-side inner magnetic flux gate portion 66 and the magnetic element 52 is entirely inserted into the inlet-side inner magnetic flux gate portion 65. In the state shown in FIG. 21, the synchronous motor 56 rotates in synchronization with the alternating current flowing through the low-voltage alternating current bus in a state where a direct current flows through the direct current side winding 30 and a magnetic flux flow in a certain direction is always generated in the iron core leg 67. Then, the magnetic path is switched in accordance with the switching cycle between the superconducting element 53 and the magnetic element 52, so that a sinusoidal AC half-wave voltage is applied to each of the two AC side windings 32 and 33 of the AC side iron core. Be guided. Since the two AC side windings 32 and 33 are connected so that their outputs are inverted, the outputs are inverted every half cycle and can be taken out as a sinusoidal AC voltage. If this is combined with an external AC circuit, inverter conversion from DC to AC can be performed.

  As shown in FIG. 15, a half-wave rectified voltage with little pulsation fluctuation can be obtained by alternately coupling the DC side windings 30 of the three converters represented by the single phase of FIG. A pair of the superconducting element 53 and the magnetic element 52 of the rotating magnetic path switching element 50 of the three power converters are arranged by being shifted by an electrical angle of 120 °, and this movable support 51 is connected to an external three-phase AC circuit by a synchronous motor. Rotate at a frequency of. On the other hand, if the DC side windings 30 of the three converters are dc-energized from the external dc circuit and the inverter operation is performed in a state in which the switching period of the superconducting element 53 and the magnetic element 52 is synchronized with the external three-phase circuit, The same three-phase AC voltage as that of the external circuit is generated in the AC side winding 34 of the power converter, and the DC system can be coupled to the three-phase AC system. If the AC side windings 34 of the three power converters are coupled to the U, V, and W phases of the three-phase AC, a half-wave rectified voltage shifted by 120 degrees in the electrical angle is applied to the DC side windings of each converter. appear. If the DC side windings 30 of these three converters are combined, a half-wave rectified voltage with little pulsation fluctuation can be obtained. Therefore, the DC side winding 30 can be obtained by directly connecting the three AC / DC power converters by the superconducting cable 40 or by directly connecting the superconducting cable 40 with a smooth winding interposed as necessary. A power storage system for storing electric power in the superconducting cable 40 and the smooth winding provided in the connection portion between itself or the DC side windings 30 can be configured. According to this power storage system, a DC permanent current mode having no electrical resistance loss or AC loss can be formed by the entire superconducting DC circuit configuration, so that all the superconductivity of the magnetic path conversion element 50 is supplied by flowing current once through the DC side winding. If the control magnetic field applied to the element is smaller than the critical magnetic field or zero, the flow of magnetic flux between the AC side iron core and the DC side iron core is interrupted, so it consists of a DC side winding and a superconducting cable connecting them. A direct current flows permanently in the closed circuit, and electric power can be stored as magnetic energy by the sum of the inductances of the superconducting winding and the superconducting cable. In addition, when supplying electric power to an electric power grid | system, the magnetic energy stored in the direct current | flow side coil | winding is converted into alternating current with a power converter device.

  Furthermore, a superconducting DC power transmission system can be constructed using the power converter of the present invention. For example, as shown in FIG. 22, three power converters shown in FIG. 17 are arranged at both ends of the DC superconducting cable 40 as a forward converter and an inverse converter, and three-phase alternating current is once converted to direct current by the forward converter. After the power is converted and transmitted, a direct current power transmission system can be configured to return to three-phase alternating current with an inverse converter. This DC power transmission system is configured by directly connecting the DC side windings 30 made of the superconducting conductors of the forward conversion device and the reverse conversion device with a superconducting cable 40. If the AC side windings 34 of the three forward converters are respectively coupled to the U, V, and W phases of the three-phase AC, the half-wave rectified voltage shifted by 120 degrees in the electrical angle is generated on the DC side windings of the converters. Occurs at 30. If the DC side windings 30 of the three converters are coupled in series, a half-wave rectified voltage with little pulsation fluctuation can be obtained by the reactor of the DC side winding 30 itself of each converter. This half-end rectified voltage is further smoothed by a DC smoothing winding 59 disposed in the middle of the DC power transmission cable 40 as necessary, and is transmitted as a DC current with less ripple and higher quality. In the three power converters on the inverter side, the magnetic path switching element of each power converter is generated at a period in which the magnetic flux generated by the DC current flowing in each DC side winding is shifted by 120 degrees in electrical angle. By controlling the switching of 50, for example, the disk-shaped movable support 51 in which the magnetic plates 52 and the superconducting elements 53 are alternately arranged is synchronized with the frequency of the AC bus by the synchronous motor 56. A three-phase alternating magnetic field having a phase of 120 ° in electrical angle is induced at each AC side winding 34U, 34V, 34W of the power converter at a predetermined frequency, for example, 50 Hz or 60 Hz. Thereby, after returning to a three-phase alternating current, it can supply to a consumer. In addition, since the frequency of the three-phase alternating current at the time of reverse conversion can be set freely, it can be converted into the three-phase alternating current of arbitrary frequency. Therefore, for example, 50 Hz AC power can be DC transmitted from the 60 Hz region to the 50 Hz region or vice versa. Moreover, this DC power transmission system can function as a power storage system (SMES) by controlling the magnetic path switching element to completely block the flow of magnetic flux between the DC side magnetic path and the AC side magnetic path. An energy-saving high-quality new power supply system with a power storage function can be realized.

  Furthermore, FIG. 23 shows another embodiment in which the present invention is applied to a three-phase AC power converter. In the power conversion device of this embodiment, an AC side iron core 2 and an AC side winding 320 corresponding to U, V, and W phases of three-phase AC are arranged in a room temperature space between two heat insulating containers 1 and In the heat insulating container 1, the DC side iron core 3 and the DC side windings 301 and 302 corresponding to the U, V, and W phases are distributed and arranged. That is, the I-shaped DC side iron core 3 shown in FIG. 1 is vertically divided into two, and inner gate magnetic flux portions 211 and 221 are shown at both ends as shown in FIG. 7 (only the upper inner gate magnetic flux portion 211 is shown in FIG. 23). In addition, the iron core leg 201 around which the DC side winding 301 is wound is provided in one heat insulating container 11 and similarly provided with inner gate magnetic flux portions 212 and 222 (only the upper inner gate magnetic flux portion 212 is shown in FIG. 23). The core leg 202 around which the DC side winding 302 is wound is accommodated in the other heat insulating container 12. And between these two heat insulation containers 11 and 12, outer magnetic flux gate portions 311, 321, 312 and 322 that are magnetically coupled (only the upper inner gate magnetic flux portions 321 and 322 are shown in FIG. 23) and the iron core legs 230. The I-shaped AC side iron core 2 having the shape is arranged, and the AC side winding 320 is wound around the iron core leg 230. Although not shown, a connecting yoke (see FIG. 7) is provided outside the heat insulating containers 11 and 12, and magnetically connects at least one end of the core legs 201 and 202 to each other. A control winding (not shown) for generating a DC or AC control magnetic field is wound around the connecting yoke. On the other hand, the end surfaces of the inner magnetic flux gate portions 211, 212, 221, 222 are respectively connected to the end portions of the inner magnetic flux gate portions 211, 212, 221, 222 coupled to both ends of the core legs 201, 202 of the DC side iron core 3. Superconducting elements 41, 42, 43, 44 (only the upper superconducting elements 41, 42 are shown in FIG. 23) made of a Y-based bulk or a Y-based thin film are arranged so as to block the above.

  In the conversion operation in the three-phase AC power converter having this structure, the AC side winding 320 is supplied with current corresponding to each phase of the three-phase AC, and the AC magnetic field Φac is excited in the iron core leg 230. Since it is the same as that of the case of a single phase except for it, the description is abbreviate | omitted. Here, in the case of forward conversion in the case of a three-phase power converter, the common DC side winding 301 has an electrical angle of 120 ° corresponding to each of the three-phase AC U, V, and W phases. The shifted half-wave rectified voltage is continuously induced, and a half-wave rectified voltage with little pulsation fluctuation can be obtained by the reactor of the DC side winding itself. Conversely, if a direct current is passed through the common direct current side winding 301, an alternating current is supplied to the control winding and an alternating control magnetic flux is applied to the superconducting elements 41, 42, 43, 44, each alternating current side In the windings 34U, 34V, and 34W, a three-phase alternating magnetic field having an electrical angle of 120 ° is induced at a control magnetic flux frequency, for example, 50 Hz or 60 Hz.

  FIG. 24 shows another embodiment in which the present invention is applied to a three-phase AC power converter. The power conversion device of this embodiment includes three superconducting windings 30 wound around three DC-phase iron cores 3U, 3V, 3W for three phases in one heat insulating container 1 and these iron core legs. And three AC side iron cores 2U, 2V, 2W and AC side windings 34U, 34V, 34W wound around the respective connecting yokes (iron core legs), respectively, outside the heat insulating container 1. The inner magnetic flux gate portions of the DC side iron cores 3U, 3V, and 3W and the outer magnetic flux gate portions of the AC side iron cores 2U, 2V, and 2W are arranged to face each other. Here, the three DC side iron cores 3U, 3V, 3W and the AC side iron cores 2U, 2V, 2W are arranged so as to be shifted in the circumferential direction at intervals of, for example, about 120 ° so as not to interfere with each other. Superconducting elements 41, 42, 43, 44 (only the upper superconducting elements 41, 42 are shown in FIG. 24) made of Y-based bulk or Y-based thin film covering the end surfaces of the inner magnetic flux gates of the iron cores 3U, 3V, 3W are arranged. Has been. 24, the inner magnetic flux gate portion provided at the lower end of the iron core leg is not shown in FIG. 24, but the inner magnetic flux gate portion and the superconducting element are also provided at the lower end side of the iron core leg as shown in FIG. It goes without saying that and are arranged.

  In the three-phase AC power converter having this structure, for example, a half-wave rectified voltage shifted by 120 ° in electrical angle is continuously induced in the common DC side winding 30 and pulsated by the reactor of the DC side winding itself. A half-wave rectified voltage with little fluctuation can be obtained. Conversely, if a direct current is applied to the common direct current side winding 30, an alternating current is supplied to the control winding and an alternating control magnetic flux is applied to the superconducting elements 41, 42, 43, 44, each alternating current side In the windings 34U, 34V, and 34W, a three-phase alternating magnetic field having an electrical angle of 120 ° is induced at a control magnetic flux frequency, for example, 50 Hz or 60 Hz.

  FIG. 25 shows an embodiment in which the power converter of the present invention is configured as a DC power transformer. This conversion device includes two of the power conversion devices of the above-described embodiments, connects the AC side windings 34 of the power conversion device to each other, and also connects the DC side winding 30 and the AC side winding of the power conversion device. The winding ratio of the wire 34 is varied, and the direct current input to the direct current side winding 30 of one power conversion device is boosted or stepped down from the direct current side winding 30 of the other power conversion device to output a direct current. Is. At this time, as described above, the voltage is finely adjusted by providing a plurality of switching voltage taps and a switch 35 for changing the turns ratio, or by changing the magnetic resistance of the magnetic path to limit the passing magnetic flux amount. By providing the magnetic element insertion / extraction mechanism 26 for voltage adjustment that can be made possible, it is also possible to make the voltage adjustment width of the DC power variable. In the case of the device according to the present embodiment, it is possible to perform power conversion and voltage change with direct current by simply connecting two power conversion devices, convert the current into alternating current, transform it with a transformer, and then again direct current. Therefore, the equipment can be simplified and the loss can be reduced.

  Furthermore, FIG. 26 shows an embodiment of an iron core suitable for using a synchronous motor. In this embodiment, in the case of using a synchronous motor, when the arrangement relationship between the superconducting element 53 and the magnetic element 52 is axisymmetric (interval of 180 °), for example, in the case of 6 pairs as shown, Since the same type of elements are arranged, it is necessary to shift the positions of the external magnetic flux gate portions, for example, the external magnetic flux gate portions 15 and 16, which are the counter electrodes. That is, in the case of an even number pair, the inner and outer magnetic flux gate portions cannot be arranged at an interval of 180 °. Therefore, the position of the inner and outer magnetic flux gate portions is not shifted by 180 °, but is shifted to the front side or the rear side by one element, so that the magnetic element 52 and the superconducting element 53 are simultaneously counter electrodes at the same time. It is necessary to arrange so as to face each part. As a result, the superconducting element 53 and the magnetic element 52 are provided on the counter electrode such that they are always disposed. On the other hand, in the case of an odd pair, for example, in the case where the same type of elements are not arranged on the counter electrode as in the case of the 7 or 5 pairs shown in FIGS. 30 and 31, the present invention is not limited to this. A magnetic flux gate part will be arranged.

  Further, FIG. 27 shows an embodiment in which the magnetic path switching element 50 of the power conversion device of FIG. 17 is changed to one using the Meissner effect of a superconducting element. According to this iron core structure and winding structure, forward conversion and reverse conversion can be easily performed. This power conversion device includes a heat insulating container 1 in which a cooling medium 4 is sealed, a DC side iron core 30 wound around a DC side winding 30 made of a superconducting conductor and disposed in the heat insulating container 1, and a normal conductive conductor. Rare earth superconducting elements 41, 42, 43, which switch the magnetic flux flowing between the AC side iron core disposed outside the heat insulating container 1 and the AC side iron core and the DC side iron core while the AC side winding 34 is wound. And 44 a magnetic path switching element. The rare earth superconducting elements 41, 42, 43, and 44 are controlled by the main magnetic flux generated in the magnetic path by the current passed through the AC side winding 34 or the DC side winding 30 and the control magnetic flux generated by the control winding. It is performed by repeating the transition and return by controlling the generated magnetic field to be greater than or less than the critical magnetic field. In the case of the present embodiment, the control magnetic flux alternately forms two magnetic flux flows A and B by the first control winding 31, the second control winding 46 and the third control winding 47. Thus, an alternating current flowing through one of the alternating current side winding 34 or the direct current side winding 30 or a magnetic flux generated by the direct current causes a direct current or alternating current to be applied to the other of the direct current side winding 30 or the alternating current side winding 34 by magnetic induction. The power is converted by generating a current of The second control winding 46 and the third control winding 47 are reverse-polar coupled. At the time of forward conversion operation, the first to third control coils 31, 46, 47 are DC-excited so that the magnetic field applied to the superconducting element is close to the critical magnetic field. The magnetic path is switched every half wave. Further, during reverse conversion operation, the first and second control magnetic fields 46 and 47 are excited in synchronization with the AC bus while the first control coil 31 is DC-excited so that the magnetic field applied to the superconducting element is close to the critical magnetic field. The magnetic path is switched every half wave.

  Furthermore, FIG. 28 shows an embodiment using a Meissner type magnetic path switching element with a three-gate structure. In the power conversion device of this embodiment, the DC side iron core disposed in the heat insulating container 1 has a yoke part 72 having inlet side inner magnetic flux gate parts 65 and 66 at both ends, and a center of the yoke part 72. An iron core leg that is magnetically connected and includes one outlet-side inner magnetic flux gate portion 67 is provided. The DC side winding 30 and the control winding 31 are wound around the outlet-side inner magnetic flux gate portion 67 serving as an iron core leg. Further, the AC side iron core disposed outside the heat insulating container 1 is arranged to be opposed to the two inlet-side inner magnetic flux gate portions 65 and 66 and one outlet-side inner magnetic flux gate portion 67 of the DC-side iron core. Two inlet-side outer magnetic flux gate portions 69, 70 coupled to each other and one outlet-side outer magnetic flux gate portion 68 are connected via a yoke 71. The AC side windings 32 and 33 are wound around the iron core legs having the two entrance-side outer magnetic flux gates 69 and 70, respectively, and are oppositely coupled so that the outputs are reversed and output. A second control winding 46 is wound around the outlet-side outer magnetic flux gate portion 68, and a third control winding 47 is wound around the outer yoke 23. In addition, rare earth superconducting elements 41 and 43 that cover the end surfaces of the gate portions 65 and 66 are provided between the inlet-side inner magnetic flux gate portion 65 and the inlet-side inner magnetic flux gate portion 66 and the heat insulating container 1. By alternately and periodically repeating the transition and return of the two rare earth superconducting elements 41 and 43, the magnetic flux passing through the two inlet-side inner magnetic flux gate portions 65 and 66 is alternately switched between and blocked. Two types of magnetic flux flows, the magnetic flux A passing from the inner magnetic flux gate portion 65 to the outlet-side inner magnetic flux gate portion 67 and the magnetic flux B passing from the other inlet-side inner magnetic flux gate portion 66 to the outlet-side inner magnetic flux gate portion 67, are alternated. To be formed. As a result, for example, by switching the flow of magnetic flux generated by the direct current flowing in the direct current side winding 30 by the magnetic path switching element 50, an alternating voltage is generated in the alternating current side windings 32 and 33 by magnetic induction, thereby generating direct current. Power from AC to AC. Also in this embodiment, as in the embodiment of FIG. 21, the DC side iron core is provided with two inlet-side inner magnetic flux gate portions 65 and 66 and one outlet-side inner magnetic flux gate portion 67. However, even if two exit-side inner magnetic flux gate portions, one inlet-side inner magnetic flux gate portion and corresponding outer magnetic flux gate portions are provided, they are the same in principle only by changing the direction of the magnetic flux flow.

  According to the power conversion device configured as described above, the first and second control coils 31 and 46 are connected to a direct current so that the magnetic field applied to the superconducting elements 41 and 43 is close to the critical magnetic field during forward conversion operation, for example. Excited. Then, the magnetic path is switched every half-wave by applying an alternating magnetic field by applying alternating current. In reverse conversion operation, the first and second control coils 31 and 46 are in direct current excitation so that the magnetic field applied to the superconducting element is close to the critical magnetic field, and the third control magnetic field 47 is synchronized with the AC bus. Energized to switch the magnetic path every half wave.

  Furthermore, in the power converter device of this invention, it is not specifically limited to the structure of the magnetic path switching element 50, Both Meissner type and replacement | exchange type can implement. Therefore, the magnetic path switching element 50 includes an embodiment in which the Meissner effect of the superconducting element is not used while the superconducting conductor is used as the DC side winding 30 using the heat insulating container 1. For example, the embodiment shown in FIG. 30 does not use the Meissner effect of a superconductor element for a magnetic path switching element, although the DC side winding 30 is formed of a superconductor using the heat insulating container 1. Here, the basic configuration such as the structure and arrangement of the DC side iron core 3 and the DC side winding 30 and the AC side iron core 2 and the AC side winding 34 are the same as those in the above-described embodiment. Omitted. In the power converter of this embodiment, the magnetic body 62 is arranged on the inner peripheral wall surface of the magnetic path switching element 50, that is, the non-magnetic movable support 51, so that the magnetic body It is characterized in that the material that is easy to pass through the magnetic flux by the block 62 and the material that is difficult to pass by the air gap 63 are alternately arranged at a constant period. Of course, superconducting elements that always exhibit the Meissner effect inside the heat insulating container 1 and magnetic blocks are alternately arranged on the inner peripheral wall surface of the non-magnetic movable support 51 to make it difficult for magnetic flux to pass through. The material may be alternately formed with a constant period. The movable support 51 is driven by a motor 64 so as to be synchronized with the alternating current flowing through the low-voltage alternating current bus. The motor 64 is mounted on, for example, a DC side iron core and is provided so as to surround the DC side iron core with the movable support 51. However, it is not necessarily important to surround the motor 64.

  Further, FIG. 31 shows an embodiment in which the DC side iron core and the winding are constituted by a normal temperature environment and a normal conducting winding without using the heat insulating container 1, the superconducting conductor and the superconducting element. Also in the power conversion device in this embodiment, the basic configuration such as the DC side iron core 3, the DC side winding 30, the AC side iron core 2, the AC side winding 34, and the like and the arrangement relationship are the same as those in the above embodiment. Therefore, detailed description thereof is omitted. In the power converter of this embodiment, the magnetic body 62 is arranged on the inner peripheral wall surface of the magnetic path switching element 50, that is, the non-magnetic movable support 51, so that the magnetic body The material which the magnetic flux easily passes through by the block 62 and the material which is difficult to pass by the air gap 63 are alternately arranged at a constant period, and the superconducting conductor is not used as the heat insulating container 1 and the DC side winding 30. Has a special order. Of course, when adopting a diamagnetic block exhibiting diamagnetism at room temperature, the diamagnetic block and the magnetic block are alternately arranged on the inner peripheral wall surface of the non-magnetic movable support 51, A material in which a magnetic flux easily passes and a material difficult to pass through may be alternately formed at a constant period. For example, as shown in FIG. 30, the movable support 51 is driven by a motor 64 so as to be synchronized with the alternating current flowing through the low-voltage alternating current bus.

  The power conversion device of this embodiment loses the effect of using a superconducting conductor as a DC side winding, but still has the advantage of not using a silicon semiconductor, that is, the power conversion capability compared to the allowable current withstand capability of the silicon semiconductor. Since the level must be operated in a small range, or a transformer for converting the AC voltage to a value suitable for the converter and a DC winding reactor winding are required separately, the equipment is large and all costs are high. Can be eliminated. However, as compared with the case of using a superconducting conductor or a superconducting element, temperature control is not required, so that the operation is easy and the structure is simple. Therefore, it is useful for power conversion at a relatively small voltage scale.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, since the number of windings of the DC side windings 301 and 302 with respect to the number of windings of the AC side winding 320 becomes the transformation ratio of the DC half wave voltage with respect to the AC half wave voltage, a transformer function is provided by these winding ratios. According to the turn ratio, it is possible to perform step-up / step-down transformation or equal pressure conversion, and furthermore, by connecting the DC side windings 302 and 301 to an external circuit (not shown), a current flows. However, since the DC side windings 302 and 301 themselves have inductance corresponding to the number of windings, the DC side windings 302 and 301 themselves become smooth windings, and the DC side windings 302 and 301 smooth the half wave. Will be. Moreover, in this embodiment, although the example of the single phase was mainly described, it cannot be overemphasized that it can apply also to three phases. Further, in the present embodiment, an example in which the AC side winding 34 is disposed in the center of the connection yoke 25 is described. However, the connection yoke is a substance that forms a gate shape above the outer yoke. Depending on the case, it may be arranged at a position indicated by a two-dot chain line.

  Furthermore, in the present embodiment, the voltage fine adjustment mechanism 26 is mainly provided in the AC side iron core 2, but is not particularly limited thereto, and may be provided in the DC side iron core 3. In this case, a slit 29 that forms an air gap is provided in the iron core leg 20, and a voltage fine adjustment mechanism 26 that allows the magnetic element 27 to be taken in and out is provided in the slit 29 to adjust the amount of magnetic flux flowing through the iron core leg. Can be further finely adjusted.

  In each of the above-described embodiments in which a superconducting conductor is used for one of the windings, a superconducting conductor that can flow a large current without resistance is used as a DC side winding because the equipment can be made compact. However, in some cases, an AC current may be made to flow using a superconducting conductor as an AC side winding.

  Furthermore, in each of the above-described embodiments using a superconducting element as the magnetic path switching element 50, the heat insulating container 1 is indispensable. However, if the superconducting element or the superconducting bulk is not used as the magnetic path switching element 50, It can implement with the structure which removed the heat insulation container 1 in embodiment. That is, if a magnetic path switching element that combines a material that easily passes magnetic flux (magnetic material) and a material that is difficult to pass magnetic flux (gap or room temperature diamagnetic material) is used, four magnetic connection points that require magnetic flux control can be obtained. In addition to the four-gate type having the three-gate type embodiment having two magnetic connection portions, not only the rotating cylinder and the rotating disk, but also all movable supports that swing or reciprocate linearly are provided. It goes without saying that it can be implemented in an embodiment of the type driven via. Further, since the movable support 51 needs to be disposed in the heat insulating container 1, it is preferable to employ a non-magnetic material such as FRP, but it is preferable to use FRP even when it is disposed outside the heat insulating container, Other nonmagnetic materials can also be used.

BRIEF DESCRIPTION OF THE DRAWINGS It is an apparatus block diagram which has shown both structure of the forward converter and the reverse converter simultaneously about 1st Embodiment of the power converter device of this invention, (a) is front longitudinal cross-sectional view, (b) is plane sectional drawing. It is. It is explanatory drawing of a superconductor, (a) is a block diagram of the Bi type | system | group superconductor which comprises a direct current | flow side winding, (b) is the operation characteristic figure, (c) is the Y type | system | group superconductor which comprises a superconducting element. The configuration diagram, (d) shows the operating characteristic diagram. (A) And (b) is forward conversion operation | movement explanatory drawing of the power converter device shown in FIG. It is a figure explaining a forward conversion operation | movement, (a)-(d) is a waveform diagram, (e) is explanatory drawing which shows the flow of the magnetic flux when a superconducting element is a normal conduction state, (f) is a superconducting state a superconducting element It is explanatory drawing which shows the flow of the magnetic flux at the time. (A) And (b) is reverse conversion operation | movement explanatory drawing of the power converter device shown in FIG. It is a block diagram which shows 2nd Embodiment of the power converter device of this invention, (a) is a front longitudinal cross-sectional view, (b) is a plane sectional view. It is a block diagram which shows 3rd Embodiment of the power converter device of this invention, (a) is a front longitudinal cross-sectional view, (b) is a plane sectional view. (A) And (b) is forward conversion operation explanatory drawing of the power converter device concerning 3rd Embodiment shown in FIG. It is explanatory drawing which shows the superconducting DC power transmission system which is 4th Embodiment using the power converter device of this invention. It is an apparatus block diagram which shows 5th Embodiment of the power converter device of this invention, (a) is a plane sectional view, (b) is a front longitudinal cross-sectional view. It is an apparatus block diagram which shows 6th Embodiment of the power converter device of this invention, (a) is a plane sectional view, (b) is a front longitudinal cross-sectional view. It is an apparatus block diagram which shows 7th Embodiment of the power converter device of this invention, (a) is a plane sectional view, (b) is a front longitudinal cross-sectional view. It is driving | operation operation | movement explanatory drawing of the power converter device shown in FIG. 12, (a)-(h) shows forward conversion operation, (i)-(p) shows reverse conversion operation. It is an apparatus block diagram which shows 8th Embodiment which made the power converter device of this invention corresponding to three phases, (a) is a plane sectional view, (b) is a front longitudinal cross-sectional view. It is an apparatus block diagram which shows 9th Embodiment which comprised the power converter device of this invention as an electric power storage system. It is an apparatus block diagram which shows 10th Embodiment of the power converter device of this invention. It is an apparatus block diagram which shows 11th Embodiment of the power converter device of this invention. It is an apparatus block diagram which shows 12th Embodiment of the power converter device of this invention in a plane cross section. It is an apparatus block diagram which shows 13th Embodiment of the power converter device of this invention in a front longitudinal cross section. It is an apparatus block diagram which shows 14th Embodiment of the power converter device of this invention by a front longitudinal cross-section. It is an apparatus block diagram which shows 15th Embodiment of the power converter device of this invention by a front longitudinal cross-section. It is a block diagram which shows 16th Embodiment which comprised the power converter device of this invention as a DC power transmission system and an electric power storage system. It is a schematic block diagram which shows 17th Embodiment which made the power converter device of this invention corresponding to three phases. It is a schematic block diagram which shows 18th Embodiment which made the power converter device of this invention corresponding to three phases. It is a schematic block diagram which shows 19th Embodiment which comprised the power converter device of this invention as a DC voltage converter device. It is sectional drawing which shows 20th Embodiment which changed arrangement | positioning of the gate part of the iron core at the time of the synchronous motor response | compatibility of the power converter device of this invention. It is an apparatus block diagram which shows 20th Embodiment of the power converter device of this invention by a front longitudinal cross-section. It is an apparatus block diagram which shows 21st Embodiment of the power converter device of this invention by a front longitudinal cross-section. It is an apparatus block diagram which shows 22nd Embodiment of the power converter device of this invention which shows the other modification of a magnetic path switching element in a front longitudinal cross-section. It is a block diagram which shows 23rd Embodiment of the power converter device of this invention, (a) is a front longitudinal cross-sectional view, (b) is a plane sectional view. It is a block diagram which shows 24th Embodiment of the power converter device of this invention, (a) is a front longitudinal cross-sectional view, (b) is a plane sectional view. It is a simplified block diagram of the conventional DC power transmission system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11,12 Thermal insulation container 2 AC side iron core 3 DC side iron core 4 Cooling medium 5, 6, 7, 8 Inner magnetic flux gate part 15, 16, 17, 18 Outer magnetic flux gate part 20 23, 24 Iron core leg 21, 22 Inside Yoke 25 Connecting yoke 26 Voltage fine adjustment mechanism 27 Magnetic element 28 Linear motor 29 Slit 30, 301, 302 DC side winding 31, 46, 47 Control winding 32, 33, 34 AC side winding 41, 42, 43, 44 Superconducting element 50 Magnetic path switching element 51 Movable support 52 Magnetic element 53 Superconducting element 56 Synchronous motor 65 First inlet-side magnetic flux gate part 66 Second inlet-side magnetic flux gate part 67 Common outlet-side magnetic flux gate part 68 Common outlet side outer magnetic flux gate part 69 Iron core leg also serving as first inlet outer magnetic flux gate part 70 Iron core leg serving also as second outer magnetic flux gate part 73 Entrance side Outer magnetic flux gate portion 74 Inlet side inner magnetic flux gate portion 75 Common outlet side outer magnetic flux gate portion 76 Outlet side inner magnetic flux gate portion 77 Entrance / outlet common inner magnetic flux gate portion 78 Entrance / outlet common inner magnetic flux gate portion

Claims (33)

  1.   A DC side core that winds the DC side winding, an AC side core that winds an AC side winding to form a closed magnetic circuit between the DC side core, the DC side core, and the AC side core. The magnetic path connection location is switched by controlling the interruption and passage of the magnetic flux at the magnetic connection location between the magnetic connection locations, and the DC side winding portion of the DC side core flows in the same direction while alternating current. The AC side winding portion of the side iron core includes a magnetic path switching element that periodically and alternately forms two magnetic flux flows whose flow directions are opposite to each other, and the AC side winding or the DC side winding has The power conversion is to convert power by generating a direct current or alternating current by magnetic induction in the other winding by switching the flow of magnetic flux generated by the flowing alternating current or direct current by the magnetic path switching element. apparatus
  2.   The DC side iron core has four inner magnetic flux gate portions, two at each end of the iron core leg, and the AC side iron core is arranged to be opposed to the inner magnetic flux gate portion to be magnetically coupled to each other. An external magnetic flux gate portion, the magnetic flux switching portion is formed by the internal magnetic flux gate portion and the external magnetic flux gate portion, and the magnetic path switching element is provided between the internal magnetic flux gate portion and the external magnetic flux gate portion. The power converter according to claim 1, which is arranged.
  3. The DC side iron core includes an inlet side inner magnetic flux gate portion and an outlet side inner magnetic flux gate portion at both ends of the iron core leg, and also serves as an inlet side inner magnetic flux gate portion and an outlet side inner magnetic flux gate portion at the center of the iron core leg. The iron core leg between the common inner magnetic flux gate portion and the inlet-side inner magnetic flux gate portion and the iron core between the common inner magnetic flux gate portion and the outlet-side inner magnetic flux gate portion. The DC side windings are respectively wound around the legs and are forward-coupled to each other,
    The AC side iron core is an outlet side outer magnetic flux gate portion that is arranged to be opposed to and magnetically coupled to the inlet side inner magnetic flux gate portion, the outlet side inner magnetic flux gate portion, and the common inner magnetic flux gate portion of the DC side iron core. And three outer magnetic flux gate portions, that is, an inlet-side outer magnetic flux gate portion and a common outer magnetic flux gate portion, and between the common outer magnetic flux gate portion and the inlet-side outer magnetic flux gate portion or the outlet-side outer magnetic flux gate portion. Wind the AC side winding around the iron core leg,
    The magnetic path switching element is disposed at the magnetic connection portion configured between the magnetic flux gate portions on the inlet side and on the outlet side, and the magnetic flux switching gate portion on the inlet side through the core leg of the AC core. The magnetic flux passing between the common outer magnetic flux gate portion and the magnetic flux passing between the common outer magnetic flux gate portion and the outlet side outer magnetic flux gate portion are alternately formed. The power converter described.
  4. The DC side iron core includes a yoke portion having an inner magnetic flux gate portion on both ends on the inlet side or the outlet side, and one inner magnetic flux gate portion on the outlet side or the inlet side that is magnetically connected to the center of the yoke portion; An iron core leg that winds the DC side winding;
    The AC side iron core is arranged opposite to the three inner magnetic flux gates of the DC side iron core and magnetically coupled to each other, and two outer flux gates on the inlet side or outlet side and one outer side on the outlet side or inlet side. The magnetic flux gate portion and the outer magnetic flux gate portion on the two inlet sides or the outlet side are each provided with the iron core leg and the two AC side windings connected to each other so that their outputs are reversed.
    The magnetic path switching element is disposed at the magnetic connection portion formed between the outer magnetic flux gate portion at the end of the iron core leg that winds the two AC side windings and the corresponding inner magnetic flux gate portion. do it,
    Two magnetic flux flows are alternately formed such that the magnetic flux passes through one AC side winding and the DC side winding, or the other magnetic flux passes through the AC side winding and the DC side winding. The power conversion device according to claim 1.
  5.   The direct current side iron core is disposed in a heat insulating container in which a cooling medium is enclosed, and the direct current side winding made of a superconducting conductor is wound. The alternating current side iron core is disposed outside the heat insulating container and is formed from a normal conductive conductor. The power converter according to any one of claims 1 to 4, wherein the AC side winding is wound.
  6.   6. The power converter according to claim 5, wherein the DC side winding constitutes a low voltage winding, and the AC side winding constitutes a high voltage winding.
  7.   The magnetic path switching element is arranged by the rare earth superconducting element arranged at the magnetic connection location in the heat insulating container and blocking the passage of the magnetic flux by the Meissner effect, and the current passed through the AC side winding or the DC side winding. And a control winding for generating a control magnetic flux in which the magnetic field generated by adding the main magnetic flux generated in the magnetic path is equal to or higher than the critical magnetic field or less than the critical magnetic field, and the main magnetic flux and the control at the magnetic connection point 6. The power conversion device according to claim 5, wherein a magnetic field based on the magnetic flux is alternately switched over to or below a critical magnetic field to cause a transition in the superconducting element to be switched between a superconducting state and a normal conducting state.
  8.   The magnetic path switching element is configured such that either one of the main magnetic flux or the control magnetic flux is changed to alternating current and the other is made direct current, so that the magnetic field applied to the magnetic connection portion is alternately switched to a critical magnetic field or higher or lower than a critical magnetic field, The power converter according to claim 7, wherein the superconducting element is switched to be switched between a superconducting state and a normal conducting state by causing a transition.
  9.   The magnetic path switching element is configured to increase or decrease a control current flowing to the control winding at a certain period, so that a magnetic field generated by adding the main magnetic flux is alternately switched to a critical magnetic field or more and less than a critical magnetic field, and the superconductivity The power conversion device according to claim 7, wherein the element is switched to be switched between a superconducting state and a normal conducting state by causing a transition.
  10.   8. The power conversion device according to claim 7, wherein the superconducting element is formed by laminating a plurality of rare earth superconducting films formed on an insulating layer.
  11.   10. The power converter according to claim 7, wherein a current that gives a critical magnetic field to the rare earth superconducting element is supplied to the control winding alone.
  12.   10. The power converter according to claim 7, wherein the main magnetic flux is applied to the control winding to pass a current that generates a critical magnetic field to the rare earth superconducting element. 11.
  13.   10. The control winding according to claim 7, wherein all of the rare earth superconducting elements are made less than a critical magnetic field and a control current for maintaining a superconducting state is applied to the control winding, or a magnetic path is cut off as a zero current. The power converter device as described in any one.
  14.   10. The frequency of the alternating current or the fluctuation period of the direct current is variable when the control current flowing through the control winding is alternating current or direct current whose magnitude varies periodically. The power converter described.
  15.   The magnetic path switching element inserts a substance that easily passes magnetic flux and a substance that does not easily pass through into the magnetic connection portion between the DC side iron core and the AC side iron core at a constant cycle, thereby The power conversion device according to any one of claims 1 to 5, wherein the passage and interruption of the magnetic flux flow at the connection location are alternately switched at a constant cycle.
  16.   The power conversion device according to claim 15, wherein the material through which the magnetic flux easily passes is a magnetic material, and the material through which the magnetic flux is difficult to pass is a diamagnetic material.
  17.   The magnetic path switching element is disposed in the heat insulating container, the substance that is difficult to pass the magnetic flux is a superconducting element that interrupts the flow of the magnetic flux by the Meissner effect, and the substance that is easy to pass the magnetic flux is a magnetic element. The power conversion device according to claim 16.
  18.   16. The material difficult to pass the magnetic flux is a gap formed between the magnetic flux gate portions of the DC side iron core and the AC side iron core, and the material easy to pass the magnetic flux is a magnetic body filling the gap. The power converter described.
  19.   The magnetic path switching element is a non-magnetic material that surrounds the DC side iron core and alternately arranges a substance that easily passes the magnetic flux and a substance that hardly passes the magnetic flux in a circumferential direction at a position facing the inner magnetic flux gate portion. And a drive source that rotates the movable support in one direction, and the inner magnetic flux gate portion and the outer magnetic flux gate portion by rotating the movable support with the drive source. The power conversion device according to claim 15, wherein a substance in which magnetic flux easily passes and a substance in which magnetic flux hardly passes are alternately arranged at a constant period to control the flow of magnetic flux.
  20.   The magnetic path switching element is a non-magnetic disk-shaped movable support that is arranged in the circumferential direction so as to alternately pass the substance through which the magnetic flux easily passes and the substance through which the magnetic flux passes at the position facing the inner magnetic flux gate portion. And a drive source that rotates the movable support in one direction, and the magnetic flux passes between the inner magnetic flux gate portion and the outer magnetic flux gate portion by rotating the movable support by the drive source. The power conversion device according to claim 15, wherein a substance that is easy to pass and a substance that is difficult to pass are alternately arranged at a constant period to control the flow of magnetic flux.
  21.   The magnetic path switching element includes a non-magnetic movable support member in which at least a pair of materials through which the magnetic flux easily passes and materials difficult to pass are arranged in the circumferential direction, and a drive source that swings the movable support member at a constant angle. A material that easily passes the magnetic flux and a material that does not easily pass between the inner magnetic flux gate portion and the outer magnetic flux gate portion are alternately generated at a constant period to control the flow of magnetic flux. 15. The power conversion device according to 15.
  22.   The magnetic path switching element is a non-magnetic material in which at least a pair of materials through which the magnetic flux easily passes and materials through which it is difficult to pass are arranged in an axial direction parallel to the iron core leg of the DC side iron core at a position facing the inner magnetic flux gate portion. And a drive source for reciprocating the movable support, and by reciprocating the movable support by the drive source, the movable flux supports the inner magnetic flux gate portion and the outer magnetic flux gate portion. The power conversion device according to claim 15, wherein a material that easily passes magnetic flux and a material that hardly passes magnetic flux are alternately generated at a constant period to control a flow of magnetic flux.
  23.   The power conversion device according to any one of claims 19 and 22, wherein the driving source is a motor that drives the movable support in synchronization with a frequency of an alternating current flowing through a low-voltage alternating current bus.
  24.   The power converter according to claim 23, wherein the motor is a canned synchronous motor in which a permanent magnet rotor is disposed in the heat insulating container and an armature winding is disposed outside the heat insulating container.
  25.   The power converter according to any one of claims 1 to 24, wherein the AC side winding includes a plurality of switching voltage taps.
  26.   An air gap is formed in a part of the magnetic path composed of the AC side iron core so that a magnetic element can be taken in and out, and an amount of magnetic flux flowing through the magnetic path is increased when the magnetic element is inserted. The power converter according to any one of claims 1 to 25, further comprising a magnetic element insertion / extraction mechanism for voltage adjustment that reduces an amount of magnetic flux flowing through the magnetic path when an element is extracted.
  27. 27. The power conversion device according to claim 26, wherein the voltage adjusting magnetic element insertion / extraction mechanism is provided in a portion closer to the connection yoke than the connection yoke or the outer magnetic flux gate portion.
  28.   28. Two power conversion devices according to any one of claims 1 to 27 are provided, the AC side windings of the conversion device are connected to each other, and the DC side winding and the AC of at least one power conversion device are connected. A DC current input to the DC side winding of one converter is output as a DC current stepped up or stepped down from the DC side winding of the other converter with a different winding ratio from the side winding. Is a power converter.
  29.   Three power converters according to any one of claims 1 to 27 are prepared, the DC side windings are connected in series with each other, and the AC side windings are connected to a U phase, a V phase, and a W phase. A power converter that connects any one of the phases to be compatible with three-phase AC.
  30.   Three sets of alternating currents each including three sets of the DC side iron cores around which the common DC side winding is wound in one heat insulating container and each having the AC side windings wound outside the heat insulating container The side iron cores are arranged opposite to each other, and the magnetic path switching element is arranged between each pair of the DC side iron cores and the AC side iron cores so that the current flowing through each AC side winding has a phase of 120 ° in electrical angle. The power conversion device according to any one of claims 5 to 27, which is adapted for three-phase alternating current.
  31.   Three sets of the DC side iron cores around which the common DC side windings are wound in one heat insulating container are arranged with a mechanical angle shifted by 120 ° in the circumferential direction, and each AC side is outside the heat insulating container. The three sets of AC side iron cores around which the windings are wound are arranged so as to face the DC side iron cores, and the magnetic flux of the movable support between each pair of DC side iron cores and AC side iron cores can easily pass therethrough. The magnetic path switching elements in which the positional relationship between the substance and the substance through which magnetic flux does not easily pass are each shifted by 120 ° in electrical angle are arranged, and the alternating current supplied to each AC winding is 120 ° in electrical angle. The power converter according to any one of claims 15 to 27, wherein the power converter is adapted for three-phase alternating current with a phase each.
  32.   A superconducting cable comprising two power converters according to any one of claims 5 to 31, wherein the DC side windings composed of superconducting conductors in the heat insulating container of the converter are drawn into the heat insulating container. A DC power transmission system that connects and circulates a cooling medium in the heat insulating container and the superconducting cable.
  33.   32. Two power conversion devices according to any one of claims 5 to 31, wherein the superconducting windings in the heat insulation container of the conversion device are connected by a superconducting cable drawn into the heat insulation container, and the heat insulation A power storage system in which a cooling medium is circulated in a container and a superconducting cable, and electric power is stored in the superconducting winding itself or a smooth winding provided in a connecting portion between the superconducting windings and the superconducting cable.
JP2006251962A 2006-09-16 2006-09-16 Power converter, dc power transmission system utilizing same, and power storage system Pending JP2008072886A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102087901A (en) * 2010-12-17 2011-06-08 北京云电英纳超导电缆有限公司 Compact iron core structure comprising magnetic bridges
WO2012137245A1 (en) * 2011-04-04 2012-10-11 国立大学法人東北大学 Power conversion device
EP3079254A1 (en) * 2015-04-10 2016-10-12 Hamilton Sundstrand Corporation Dc synchronous machine
EP3082250A1 (en) * 2015-04-14 2016-10-19 Hamilton Sundstrand Corporation Sensorless control of a dc synchronous machine

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102087901A (en) * 2010-12-17 2011-06-08 北京云电英纳超导电缆有限公司 Compact iron core structure comprising magnetic bridges
CN102087901B (en) * 2010-12-17 2013-12-18 北京云电英纳超导电缆有限公司 Compact iron core structure comprising magnetic bridges
WO2012137245A1 (en) * 2011-04-04 2012-10-11 国立大学法人東北大学 Power conversion device
EP3079254A1 (en) * 2015-04-10 2016-10-12 Hamilton Sundstrand Corporation Dc synchronous machine
US10075106B2 (en) 2015-04-10 2018-09-11 Hamilton Sundstrand Corporation DC synchronous machine
EP3082250A1 (en) * 2015-04-14 2016-10-19 Hamilton Sundstrand Corporation Sensorless control of a dc synchronous machine
US10033252B2 (en) 2015-04-14 2018-07-24 Hamilton Sundstrand Corporation Sensorless control of a DC synchronous machine
US10566880B2 (en) 2015-04-14 2020-02-18 Hamilton Sundstrand Corporation Sensorless control of a DC synchronous machine

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