JP5363781B2 - Superconducting coil power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easy and inexpensive method for steeply changing a current to be supplied to a superconducting coil. <P>SOLUTION: In the superconducting coil power supply system, a high-voltage short-time rated power supply 6 is connected to a low-voltage continuous rated power supply 1 in series thereto, a predetermined voltage is applied to the system from the high-voltage short-time rated power supply 6, a current of a switch 3 is set to zero, after that, the switch 3 is opened, and thereby the current to be supplied to the superconducting coil 5 is steeply changed by using the low-voltage continuous rated power supply 1 and the high-voltage short-time rated power supply 6. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to a large-capacity DC power supply system that generates a high magnetic field by supplying a large current to a superconducting coil, and normally supplies a steady current to the superconducting coil to generate a high voltage during a required period. Thus, the present invention relates to a power supply system that makes it possible to sharply change the energization current of the superconducting coil.

In a fusion experimental device, a magnetic field generating coil that generates a strong magnetic field by controlling the magnetic field to confine plasma is required, and in the large experimental device, a superconducting coil is used as the magnetic field generating coil. ing.

Excitation of the superconducting coil requires a large current, and during the period of exciting the plasma or moving the position of the plasma, a high voltage is applied to the superconducting coil so that the energizing current is steep. It is necessary to change to.

  As a power supply system for energizing the magnetic field generating coil, for example, the one shown in FIG. 12 is known. In the conventional example shown in FIG. 12, a load coil 11 and a resistor 12 are both provided with a high voltage small current power source 13 and a low voltage large current power source 14 which are thyristor power sources, and open / close switches 15 to 17. In the power supply system for the fusion device, during the high voltage generation period, the open / close switches 15 and 17 are turned on and the open / close switch 16 is turned off, and the high voltage / low current power supply 13 is connected to the load coil 11. 13 power is supplied to the load coil 11.

  When the low voltage high current power source 14 is connected to the load coil 11, the output voltage of the high voltage small current power source 13 is throttled, the open / close switch 16 is turned on, and the current of the load coil 11 is transferred to the open / close switch 16. Next, by utilizing the low-voltage high-current power supply 14 and turning off the open / close switch 17, the current of the load coil 11 is commutated to the low-voltage high-current power supply 14.

According to the above configuration, the high voltage small current power source 13 is connected to the load coil 11 during the high voltage generation period, power is supplied from the high voltage small current power source 13 to the load coil 11, and the low voltage is generated during other periods. Since the large current power source 14 is connected to the load coil 11 and power can be supplied from the low voltage large current power source 14 to the load coil 11, the capacity of both power sources 13 and 14 can be reduced (Patent Document). 1).
JP-A-3-2593

  However, in the power supply system for the nuclear fusion device, it is possible to switch the current path in the energized state by using the circuit breaker or the input device having the current interruption capability as the on / off switches 16 and 17. Such a circuit breaker or charging device is generally large and expensive, and a plurality of circuit breakers are required. Therefore, there is a problem that the power supply system as a whole is increased in size and the equipment cost is increased.

  If a high voltage power supply can be connected in series with a low voltage large current power supply during a high voltage generation period, that is, a period requiring a high voltage and operated simultaneously, the voltage applied to the load coil 11 can be Since the current power supply and the high voltage power supply can be shared, the output voltage of the high voltage power supply can be reduced, and the high voltage power supply can be reduced in size and cost.

  However, in the conventional example, since both the power sources 13 and 14 cannot be operated simultaneously, the equipment capacity of the high voltage small current power source 13 becomes large, and it is difficult to reduce the size and cost.

  Therefore, the present invention has been made to solve such a problem, and is required to continuously energize a large current with a simple circuit configuration and using small and inexpensive components. An object is to provide a power supply system capable of generating a high voltage during a period.

The invention according to claim 1 is a first power supply having a low voltage continuous rating and a second power supply having a high voltage short-time rating connected in series, and a continuous rated diode is connected to the continuous rated switch in the positive direction. In a large-capacity DC power supply system that is connected in series and connected in parallel with the output of the second power supply, the first power supply and the first power supply are switched from the state in which the superconducting coil is energized only by the first power supply. When shifting to a state in which current is passed by the second power source, the second power source outputs a positive voltage, and the current path flowing through the switch is controlled to be switched to the second power source. And when the current flowing through the switch becomes a predetermined value or less, the switch is opened, and the superconducting coil is energized with a first power source and a second power source. When switching to a state where only the first power source is energized, the switch The second power supply outputs a positive voltage so that the current flowing through the second power supply does not flow to the switch when it is poled, and after closing the switch, the second power supply is negative A voltage is output and control is performed to switch the path of the current flowing through the second power source to the switch.

  According to the first aspect of the present invention, when a steady current is applied to the superconducting coil, the superconducting coil is energized via the switch only by the first power source, and the current of the superconducting coil is sharply increased. When changing the voltage, the first power supply and the second power supply output voltage, and the output voltage of both power supplies is added so that a high voltage can be applied to the superconducting coil. It is possible to provide an inexpensive power supply system.

According to the first aspect of the present invention, when the current path is switched while the superconducting coil is energized, the switch is opened or closed after the output voltage of the second power source is controlled. Therefore , no current flows through the switch at the time of opening and closing, so there is no need to use a large and expensive switch with current interrupting capability, and there is no need for a plurality of switches. Therefore, it is possible and cost reduction in size of equipment.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a circuit diagram showing an entire power supply system A for a magnetic field generating coil according to the present invention. In FIG. 1, reference numeral 1 denotes a DC power supply (hereinafter referred to as a steady power supply) which is a low voltage continuous rating, and reference numeral 2 denotes a diode having an anode connected to the positive electrode side of the steady power supply 1.

  Reference numeral 3 denotes a small and inexpensive switch having no current interruption capability, and is connected to the cathode of the diode 2 in series with the diode. Reference numeral 4 denotes a DC current transformer connected in series to the switch 3, and detects a current flowing through the switch.

In the present embodiment, the switch 3 is a device having no interruption capability. However, the switch 3 is not limited to this embodiment, and if it is not particularly required to be configured in a small size and at a low cost, the breaker having a current interruption capability is used. It can also be configured with a vessel.

In addition to the above, it is also possible to use a semiconductor switch element such as a thyristor or IGBT for the switch 3, and in that case, the diode 2 may be omitted.

  Reference numeral 5 denotes a superconducting coil connected in series to a series circuit composed of the steady power source 1, the diode 2, the switch 3, and the DC current transformer 4. For example, the method according to the present invention is a power system for a fusion apparatus. In this case, a magnetic field generating coil for generating a magnetic field in the fusion reactor is applicable.

  Reference numeral 6 denotes a DC power source (hereinafter referred to as a pulse power source) composed of a high-voltage short-time rated thyristor converter that applies a high voltage to the superconducting coil, and a pulse is interposed between the steady power source 1 and the superconducting coil 5. A negative circuit side of the power supply 6 is connected in series with the positive electrode side of the steady power supply 1, and a positive electrode side of the pulse power supply 6 is connected in series with the superconducting coil 5. Are connected in parallel.

  Further, the pulse power supply 6 includes a control unit (not shown) that controls the pulse power supply 6 and the switch 3 in response to a command from a control computer (not shown).

  According to the method of the present invention, it is possible to operate by connecting the pulse power source 6 in series to the stationary power source 1 with the simple component configuration as described above, and a high voltage is applied to the superconducting coil 5 at a desired timing. Therefore, one application example is the use of the power supply system for the fusion apparatus.

  In a fusion device, it is necessary to pass a large current through the magnetic field generating coil in order to create a magnetic field for confining the plasma, and when the plasma is excited or controlled, the magnetic field generating coil is short. Since it is necessary to apply a high voltage for a long time, the present invention is a method suitable for use in a power supply system used for the application (for plasma control).

  Below, the case where the serial connection method of the pulse power supply which concerns on this invention is utilized for a nuclear fusion apparatus is demonstrated. The technical scope of the present invention is not limited to use in a power supply system for a fusion device, but can be used in any application having the purpose of abruptly changing the current applied to a superconducting coil. Of course it is.

  2-10 is explanatory drawing which shows the transition of the driving | running operation | movement of the power supply connected in series to which this invention is applied in time series. Moreover, in FIGS. 2-9, the direction of the arrow which does not comprise the closed loop has shown the direction of the positive direction of a voltage or an electric current. The arrows constituting the closed loop indicate the current flow.

FIG. 2 shows the state of the entire power supply system A during normal plasma control, that is, during steady operation, the switch 3 is in a closed state, and the pulse power supply 6 is in a state where the firing angle is larger than 90 °. Waiting in (gate shift state).

At this time, the diode 2 from a steady power supply 1, the magnetic field generating coil (superconducting coil) 5 via the switch 3, the current Isw flows in the direction of the arrow shown in FIG. 2, the superconducting coil 5 is fusion furnace A magnetic field is generated (steady operation state).

Next, when it is necessary to apply a high voltage to the superconducting coil 5 to change the energized current sharply (pulse operation), a control computer (not shown) outputs a pulse operation command and performs control. In response to this, the unit (not shown) controls the output voltage Vpls of the pulse power supply 6 to a predetermined positive voltage (for example, 5 [V]) (see FIG. 3).

As a result, the current Isw flowing through the switch 3 is attenuated and the output current Ipls of the pulse power supply 6 is increased. Finally, the current Isw flowing through the switch 3 becomes zero as shown in FIG. Thus, the current Icon of the steady power supply 1 and the current Ipls of the pulse power supply 6 have the same current value, and become the current Ic flowing through the superconducting coil 5.

  When the output voltage Vpls of the pulse power supply 6 becomes 5 [V], the diode 2 is connected to the switch 3, so that the current flowing through the switch 3 does not flow in the reverse direction. A state of zero current can be maintained.

  The control unit (not shown) detects the current of the switch 3 with a DC current transformer 4 connected in series with the switch 3, so that when the current becomes zero, the controller 3 The electrode is opened as shown in FIG.

The steady power supply 1 and the pulse power supply 6 receive voltage command values from the control computer (not shown), respectively, the power supplies 1 and 6 change the output voltage, and the output voltages of the power supplies 1 and 6 are changed. The added voltage is applied to the superconducting coil 5 to change the current sharply (pulse operation state).

  Next, when transitioning to the steady operation state, in the pulse operation state shown in FIG. 5, when the control computer outputs a steady operation command, the control unit (not shown) receives this, and the pulse power source 6 Is controlled to a predetermined positive voltage (for example, 5 [V]) (see FIG. 6).

On the other hand, the steady power supply 1 outputs an output voltage according to a voltage command value from the control computer.

  When the output voltage Vpls of the pulse power supply 6 reaches a predetermined voltage (for example, 5 [V]), the control unit (not shown) closes the switch 3 as shown in FIG.

  When closing the switch 3, no current flows through the switch 3 because the diode 2 is connected to the switch 3.

  Thereafter, the control unit (not shown) causes the pulse power supply 6 to output a negative voltage, the current Isw flowing through the switch 3 increases, and the output current Ipls of the pulse power supply 6 decreases (see FIG. 8). Then, the output current Ipls of the pulse power supply 6 becomes zero, and this completes the transition from the pulse operation state (FIG. 5) to the steady operation state (see FIG. 9).

  FIG. 10 is a timing chart showing a current waveform or a voltage waveform in each component of the entire power supply system A during the state transition between the above-described steady operation state and pulse operation state.

  FIG. 10A shows the waveform of the output voltage Vcon in the steady power supply 1, and FIG. 10B shows the waveform of the output current Icon in the steady power supply 1.

  FIG. 10C shows the waveform of the output voltage Vpls in the pulse power source 6, and FIG. 10D shows the waveform of the output current Ipls in the pulse power source 6.

  FIG. 10 (e) shows the open / close state of the switch 3, and FIG. 10 (f) shows the waveform of the current Isw flowing through the switch 3. FIG.

Figure 10 (g), the shows the waveform of the voltage Vc at the superconducting coil 5, FIG. (H) show waveforms of the current Ic flowing through the superconducting coil 5.

  Hereinafter, the voltage or current waveform of each component of the entire power supply system A and the state of change in the switching state of the switch 3 during the state transition described above will be described with reference to FIG.

The output current Icon of the steady power supply 1 and the current Ic flowing through the superconducting coil 5 are the same.

In a steady operation state (period (1)), the steady power supply 1 applies an output voltage to the superconducting coil 5 in accordance with a voltage command value from the control computer, while the pulse power supply 6 has an ignition angle. Is greater than 90 ° (gate shift state), and the switch 3 is in a closed state. Here, when a pulse operation command is input from the control computer to the control unit (not shown), the pulse power supply 6 changes its output voltage Vpls to a predetermined positive voltage (main) as shown in FIG. In the embodiment, the voltage is raised to 5 [V]) (period (2)).

As a result, the output current Ipls of the pulse power supply 6 increases to the current value of the superconducting coil 5. At this time, the current Isw flowing through the switch 3 decreases and eventually becomes zero (period (2)). By detecting the current Isw in the DC current transformer 4, wherein the control unit (not shown), open pole causing the switch 3 at the time the current Isw becomes zero (FIG. 10 (e) see. Period (3), (4)).

Thereafter, according to the voltage command value from the control computer (not shown), the output voltage Vcom of the steady power supply 1 increases as shown in FIG. 10 (a) and the output voltage Vpls of the pulse power supply 6 increases as shown in FIG. 10 (c). . As a result, the voltage Vc applied to the superconducting coil 5 also increases rapidly (period (5)) as shown in FIG. As a result, the current Ic flowing through the superconducting coil 5 can be changed sharply as shown in FIG. 5H, and can be effectively used for plasma control in the fusion apparatus.

  When transitioning from the pulse operation state to the steady operation state, when a steady operation command is input from the control computer (not shown) to the control unit (not shown), the pulse power supply 6 sets its output voltage Vpls to a predetermined value. To a positive voltage (5 [V] in this embodiment) (period (6)). On the other hand, the steady power supply 1 outputs a voltage according to a voltage command value from the control computer (period (6)).

  When the output voltage Vpls reaches a predetermined value (5 [V]), the control unit (not shown) closes the switch 3 (period (7)). Thereafter, when the pulse power supply 6 is controlled to the gate shift state to output a negative voltage, the current Isw flowing through the switch 3 increases and the output current Ipls of the pulse power supply 6 decreases (period (8)).

  As a result, the output current Ipls of the pulse power supply 6 becomes zero, and the transition to the steady operation state is completed (period (9)). At this time, the pulse power supply 6 stands by in the gate shift state as shown in FIG.

Although the above description has shown a case where the current Ic of the superconducting coil 5 is sharply increased, when the current Ic of the superconducting coil 5 is sharply decreased, the state is similarly changed to the pulse operation state (FIG. 10). This period (5)) is made possible by the steady power supply 1 and the pulse power supply 6 outputting a negative voltage in the operation state.

  From the above description, according to the present invention, when a steady current is passed through the superconducting coil 5, the superconducting coil 5 is energized via the switch 3 with only the steady power supply 1. In order to change the current sharply, the steady power supply 1 and the pulse power supply 6 output voltages, and the output voltages of both power supplies 1 and 6 are added together so that a high voltage can be applied to the superconducting coil 5. An increase in equipment capacity can be prevented, and an inexpensive power supply system can be provided.

In addition, according to the present invention, a power supply system that can be operated by connecting a pulse power supply 6 in series to a stationary power supply 1 with a simple component configuration and that can change the current supplied to the superconducting coil 5 sharply is provided. Has the effect of becoming possible.

  In addition, according to the present invention, since the switch 3 can be opened with zero current, it is possible to reliably prevent an arc from being generated at the time of opening, and to prevent contact loss of the switch 3. As a result, the life of the switch 3 can be extended.

  Furthermore, according to the present invention, since the switch 3 can be opened and closed with zero current, it is possible to use a small and inexpensive disconnector having no current interruption capability as the switch. Thus, it is possible to reliably suppress an increase in size and cost of the power supply system.

  According to the above embodiment, the pulse power supply 6 outputs a positive voltage to reduce the current flowing through the switch 3 before opening the switch 3, but the diode 2 is connected to the switch 3. Since it is connected in series, the current flowing through the switch 3 does not flow in the reverse direction, and the switching of the current path to the pulse power source 6 is completed automatically when the current becomes zero. There is no need to adjust the timing for opening the switch 3 severely.

  Further, according to the above embodiment, since the diode 2 is connected in series to the switch 3, the pulse power supply 6 outputs an excessive current via the switch 3 when the switch 3 is closed. There is nothing.

  Moreover, in the said Example, although the switch 3 used the disconnector without current interruption capability, and demonstrated the small and cheap structure which connects and operates a power supply in series, this invention is small and cheap. When it is not necessary to constitute, it is natural that it may be constituted by a circuit breaker having a current interruption capability or a switch instead of the disconnector.

In addition to the above, it is needless to say that the switch 3 can be configured by using a semiconductor switch element such as a thyristor or IGBT, and the diode 2 can be omitted when the switch 3 is configured by a thyristor.

Further, in this embodiment, the entire power supply system A is configured as shown in FIG. 1, but as shown in FIG. 11, the cathode of the diode 2 is connected to the negative side of the steady power supply 1, and the anode of the diode 2 and the switch 3 and a series circuit connected to a DC current transformer 4 and the positive electrode side to the negative pole of the constant power supply 1 pulse power supply 6, connected in parallel with the pulsed power supply 6 connected to the negative side of the pulse power supply 6 to the superconductive coil 5 Even if configured, the same effect as the power supply system A shown in FIG. 1 can be obtained.

  Moreover, in the above-described embodiment, the case where the control of the pulse power source 6 is voltage control (closed loop control) so as to output a predetermined positive voltage when the switch 3 is opened or closed has been described. The present invention is also established as firing angle control (open loop control), and the control of the pulse power supply 6 is also established when the current flowing through the switch 3 is controlled to zero.

  It is possible to provide a power supply system capable of continuously allowing a constant current to flow through the superconducting coil and abruptly changing the current passing through the superconducting coil as necessary.

It is a circuit diagram of the power supply system of this invention. In the circuit diagram, it is an explanatory diagram when the pulse power supply is in a gate shift state. It is explanatory drawing which shows the state in which the said pulse power supply is outputting predetermined positive voltage (5 [V]). It is explanatory drawing which shows the state from which the electric current which flows into a switch with the said voltage became zero. It is an explanatory view showing a state where the switch was open pole. To close pole the switch is an explanatory view showing a state in which the pulse power supply is outputting a predetermined positive voltage (5 [V]). It said switch is an explanatory view showing a state where the closing pole. It is explanatory drawing which shows the state which the said pulse power supply shifted the gate. It is explanatory drawing which shows the state from which the output current of the said pulse power supply became zero. In the said circuit diagram, it is explanatory drawing which shows the waveform of the output voltage and output current of each component. It is a circuit diagram of the power supply system which concerns on the other Example of this invention. This is a power supply circuit for a conventional fusion device.

Explanation of symbols

1 Low voltage continuous rated power supply (steady power supply)
2 Diode 3 Switch 4 DC current transformer 5 Superconducting coil 6 High voltage short-time rated power supply (pulse power supply)
A Power supply system as a whole

Claims (1)

A first low-voltage continuous power supply and a high-voltage short-time second power supply are connected in series, and a continuous-rated diode is connected in series to a continuous-rated switch in the positive direction. In a large-capacity DC power supply system configured to be connected in parallel with the output of the second power supply, current is supplied from the first power supply and the second power supply to the superconducting coil from the state where only the first power supply is supplied. When transitioning to a state, the second power supply outputs a positive voltage, and the current flowing through the switch is controlled to be switched to the second power supply, and the current flowing through the switch The switch is opened when the current falls below a predetermined value, and the superconducting coil is energized with only the first power source from the state where the first power source and the second power source are energized. When shifting to the state, when the switch is closed, the second power The second power supply outputs a positive voltage so that the current flowing through the switch does not flow to the switch, and after closing the switch, the second power supply outputs a negative voltage, A superconducting coil power supply system that controls to switch a path of a current flowing through a second power supply to the switch.

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