JP2020010524A - Rotary machine drive system and vehicle - Google Patents

Abstract

To reduce the size of a coil switching device without generating current concentration, spark, arc, or the like at a specific place of a switching contact.SOLUTION: A rotary machine drive system includes: a rotary machine having a plurality of coils; an inverter device including an inverter circuit for converting direct current power from a direct current power source into alternating current power and a control device for controlling power conversion by the inverter circuit to perform variable speed operation by the inverter circuit; and a coil switching device for switching connection of the plurality of coils by a command from the control device. The control device commands the coil switching device to perform connection switching of the coils when the rotation of the rotary machine transits between a low-speed rotation area and a high-speed rotation area due to acceleration/deceleration. In the coil switching device, the switching contact for switching connection of the plurality of coils comprises a multi-surface contact having a spring characteristic.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotating machine drive system using a winding switching device and a vehicle.

  The efficiency of a rotating machine driven at variable speed by an inverter device is generally represented by an efficiency curve obtained by changing the rotation speed under a constant load condition, and the efficiency reaches a peak in a part of the required rotation range. Become. In order to achieve energy saving of the equipment, it is important to improve the efficiency curve over a wide rotation range and reduce the power loss of the rotating machine.

  It is known that the efficiency of a rotating machine is reduced in a low-speed rotation range, but by increasing the inductance of the rotating machine at the design stage, the current value itself can be reduced and harmonic components can be reduced. This makes it possible to improve the efficiency in the low-speed rotation range, but has the problem that the efficiency in the high-speed rotation range decreases.

  To solve such a problem, there is a technique for switching the connection of the stator winding between a low-speed rotation region and a high-speed rotation region as disclosed in Patent Document 1. When the connection is switched while the rotating machine is being driven, an arc is generated at the switching contact, and the contact life is reduced. Patent Literature 1 discloses a technique in which a compression coil (spring) and an electrode are used to avoid a contact arc.

JP-A-2017-070112

  2. Description of the Related Art High output densities are required for rotating machines mounted on automobiles, railway vehicles, and the like, and the demand is met by generating a high torque by flowing a large current. When the winding switching is applied to such an application, it is necessary to maintain the pressing force of the switching contact by a spring mechanism or the like in order to always supply a large current, and there has been a problem in the prior art that the switching device becomes large.

  Also, it is necessary to make the contact surface of the switching contact large in order to flow a large current.However, it is difficult to equalize the surface pressure with the spring mechanism, so current concentration, sparks, arcs, etc. occur in specific places, and the contact life is shortened. There was a problem that led to a decrease.

  As one means for solving these problems, a method is disclosed in which the switching contact is configured by a semiconductor switching element. However, in this method, the switching element is always energized when the rotating machine is driven, so that conduction loss occurs. That is, since a new power loss occurs at the switching contact portion, it cannot be said that it is advantageous from the viewpoint of improving the energy efficiency of the entire rotating machine drive system.

  An object of the present invention is to reduce the size of a winding switching device in a rotating machine drive system without causing current concentration, spark, arc, or the like at a specific portion of a switching contact.

  In order to achieve the above object, in the present invention, a rotating machine drive system includes a rotating machine having a plurality of windings, an inverter circuit that converts DC power from a DC power supply into AC power, and power conversion by the inverter circuit. An inverter for controlling the rotating machine at a variable speed; and a winding switching device for switching connection of the plurality of windings according to a command from the control device. The control device, when the rotation of the rotating machine transitions between a low-speed rotation region and a high-speed rotation region due to acceleration and deceleration, instructs the winding switching device to switch the connection of the winding, the winding switching device The switching contact for switching the connection of the plurality of windings is constituted by a multifaceted contact having a spring characteristic.

  According to the present invention, it is possible to reduce the size of the winding switching device without causing current concentration, sparks, arcs, or the like at specific locations of the switching contacts.

FIG. 1 is a block diagram illustrating an entire configuration of a rotating machine drive system according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram of a winding switching device according to the first embodiment of the present invention. The figure showing the efficiency curve of the conventional rotary machine operated by variable speed by the inverter device. FIG. 4 is a current waveform diagram of a conventional rotating machine driven by an inverter device. Explanatory drawing showing the structure of the conventional switching contact. FIG. 2 is a perspective view illustrating a configuration of a switching contact according to the first embodiment of the present invention. FIG. 2 is a side view illustrating a configuration of a switching contact according to the first embodiment of the present invention. FIG. 4 is an explanatory diagram of a connection switching method using a switching contact according to the first embodiment of the present invention. FIG. 7 is a block diagram illustrating an entire configuration of a rotating machine drive system according to a second embodiment of the present invention. FIG. 9 is a configuration diagram of a rotating machine drive system used for a railway vehicle according to a third embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same symbols. Their names and functions are the same, and duplicate descriptions are avoided. In the following description, the connection switching between the 1Y connection and the 2Y connection is intended. However, the effect of the present invention is not limited to this. The present invention is also applicable to a configuration in which the number of parallel connections is switched or a configuration in which Y connection and Δ connection are switched. Further, the rotating machine may be an induction machine, a permanent magnet synchronous machine, a wound synchronous machine, or a synchronous reluctance rotating machine. Further, the winding method of the stator may be concentrated winding or distributed winding. Further, the number of phases of the stator winding is not limited to the configuration of the embodiment. Further, although the semiconductor switching element of the inverter device is intended for an IGBT (Insulated Gate Bipolar Transistor), the effect of the present invention is not limited to this, and a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) may be used. Power semiconductor element. Further, as a control method of the rotating machine, a vector control without using a speed detector or a voltage detector is targeted, but the present invention is also applicable to a control method using a speed detector or a voltage detector.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing an entire configuration of a rotating machine drive system according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram of the winding switching device according to the first embodiment of the present invention. FIG. 3 is a diagram illustrating an efficiency curve of a conventional rotating machine that is operated at a variable speed by an inverter device. FIG. 4 is a current waveform diagram of a conventional rotating machine driven by an inverter device. FIG. 5 is an explanatory diagram illustrating a configuration of a conventional switching contact. FIG. 6 is a perspective view illustrating the configuration of the switching contact according to the first embodiment of the present invention. FIG. 7 is a side view showing the configuration of the switching contact according to the first embodiment of the present invention. FIG. 8 is an explanatory diagram of a connection switching method using the switching contacts according to the first embodiment of the present invention.

  The overall configuration of the rotating machine drive system 1S of the present embodiment will be described with reference to FIG. In FIG. 1, an inverter device 101 converts DC power output from a DC power supply 102 into AC power, and outputs the AC power to a rotating machine 103 and an inverter circuit 104 connected to the inverter circuit 104. Inverter control (power conversion control) for the inverter circuit 104 is performed using the phase current detection circuit 106 for detecting current and the applied voltage command pulse signal 108A based on the phase current information 106A detected by the phase current detection circuit 106. And a control device 105 for operating the rotating machine 103 at a variable speed.

  The phase current detection circuit 106 includes a Hall CT (Current Transformer) and the like, and detects three-phase current waveforms Iu, Iv, and Iw of U-phase, V-phase, and W-phase. However, it is not always necessary to detect all three phases of current by the phase current detection circuit 106, and any two phases are detected, and the other one phase is obtained by calculation assuming that the three-phase current is in a balanced state. A configuration may be used. Inverter circuit 104 includes an inverter main circuit 141 including a plurality of semiconductor switching elements such as IGBTs Q1 to Q6 and diodes (return diodes) D1 to D6, and an inverter based on an applied voltage command pulse signal 108A from inverter control unit 108. The main circuit 141 includes a gate driver 142 that generates a gate signal to the IGBTs Q1 to Q6.

  The rotating machine 103 is constituted by, for example, an induction machine having a plurality of windings, and the starting and ending ends of some of the windings are drawn out so that the connections of the windings can be switched, and stored in the winding switching device 120. I have. The winding switching device 120 has a circuit configuration capable of switching the connection of the windings of the rotating machine 103. When the rotation of the rotating machine 103 transitions between the low-speed rotation range and the high-speed rotation range, the winding switching command unit The winding connection is switched based on a signal output from 110.

  The control device 105 includes an inverter control unit 108 that generates an applied voltage command pulse signal 108A using the phase current information 106A detected by the phase current detection circuit 106, and a winding that supplies a connection switching signal to the winding switching device 120. It is composed of a switching command unit 110.

  The rotating machine drive system 1S is configured to include at least the inverter device 101, the rotating machine 103, and the winding switching device 120.

  Next, the configuration of the switching device will be described with reference to FIG. 2, and the problems and solutions of the related art, and the downsizing of the winding switching device, which is the object of the present invention, can be realized with reference to FIGS. 3 to 8. The principle will be described.

  FIG. 2A shows the U-phase winding 150u of the stator of the rotating machine 103, in which the starting ends (terminals) U1 and U2 and the ending ends (terminals) U3 and U4 of the two U-phase windings 150u1 and 150u2 are pulled out and connected in series. FIG. 3 is a diagram schematically showing a configuration for switching between parallels. The description of the V phase and the W phase is omitted because it is the same. The start end U1 and start end U2, and the end U3 and end U4 of the U-phase winding 150u in FIG. 2A are connected in parallel by short-circuit lines 130u2, respectively. A configuration in which the points 151 are connected in a Y-shape is called a 2Y connection. On the other hand, the terminal U3 of the U-phase winding 150u1 and the starting end U2 of the U-phase winding 150u2 in FIG. 2A are connected in series by a short-circuit line 130u1, and the V-phase and W-phase are connected in series in the same manner. A configuration in which the neutral points 151 are connected in a Y-shape is called 1Y connection. Hereinafter, the short-circuit line 130u1 and the short-circuit line 130u2 are collectively referred to as the short-circuit line 130.

  Here, the short-circuit line 130 may be formed of a flexible cable or a bus bar made of a metal plate, but as will be described later, the starting ends U1, U2, the ending U3, It is desirable that the contact portion with U4 be made of a rigid metal body. As shown in FIG. 2A, the combined inductance of the parallel connection (2Y connection when viewed in three phases) is L / 2, whereas the combined inductance of series connection (1Y connection when viewed in three phases) is 2L. And the inductance is quadrupled. Therefore, the harmonic components of the current supplied from the inverter device 101 to the rotating machine 103 are greatly reduced by the series connection.

  In the conventional rotating machine, since the inductance is designed to be small in order to enlarge the rotation range, the harmonic component of the current becomes large, and as shown by the curve (a) -1 in FIG. 2 (b) and FIG. In particular, there is a problem that the efficiency η is reduced in a low-speed rotation range of the rotation speed N. One of the factors is that a conventional rotary machine is designed to have a small inductance in order to expand a rotation range. In a conventional rotating machine having a small inductance, a substantially sinusoidal current waveform supplied to the rotating machine is obtained as shown in a graph (b) -1 of FIG. On the other hand, a harmonic component corresponding to the switching frequency of the inverter device is superimposed. For this reason, harmonic components of iron loss generated in the core of the rotating machine, AC copper loss generated by the skin effect and proximity effect of the stator winding, and the like become large, and as a result, the efficiency of the rotating machine is reduced.

  On the other hand, it is known that by increasing the inductance of the rotating machine at the design stage, the current value itself can be reduced and the harmonic component can be reduced, as shown by the graph (b) -2 in FIG. . As a result, as shown by the curve (a) -2 in FIG. 3, it is possible to improve the efficiency in the low-speed rotation range, but on the other hand, the efficiency in the high-speed rotation range is reduced, and up to the high-speed rotation range. There is a problem that the rotor cannot be driven and loses synchronism.

  With respect to such a problem, the winding switching device 120 is used to connect in series in a low-speed rotation region (1Y connection when viewed in three phases) and in parallel connection (2Y connection in three phases). As a result, it is possible to improve the efficiency curve over a wide rotation range while enabling driving in a required wide rotation range, and to reduce the power loss of the rotating machine 103. In the low-speed rotation range, the rotating machine 103 has a high inductance due to the series connection, so that the current value supplied from the inverter device 101 itself can be reduced, and the power loss of the inverter device 101 can be greatly reduced. . However, in the related art, it is necessary to maintain the pressing force of the switching contact by a spring mechanism or the like in order to flow a large current, and there is a problem that the winding switching device 120 becomes large. In addition, there is a problem that current concentration, sparks, arcs, and the like are generated in a specific portion of the switching contact, and the contact life is reduced. This problem will be described in detail below with reference to FIG.

  FIG. 5 is an explanatory diagram illustrating a configuration of a conventional switching contact. The starting end U1 of the U-phase winding 150u of the stator shown in FIG. 2 is connected to the switching contact 1201 via the terminal connecting portion 1206. With this configuration, the switching contact 1201 and the start end U1 shown in FIG. 2 are integrated, and therefore, the entire configuration is defined as the start end U1 in FIG. The conduction surface 1201a of the switching contact 1201 is connected to a terminal of another winding by a short-circuit line 130. Since contact resistance is generated at the contact surface between the conduction surface 1201a and the short-circuit line 130, heat generation due to the contact resistance poses a problem when a large current continues to flow. Therefore, it is desirable to reduce the contact resistance as much as possible. In order to realize this, the spring 1202 generates a force for pressing the conductive surface 1201a against the short-circuit line 130. The reason that it is better to provide the contact portion of the short-circuit line 130 with rigidity in the above description is to secure this pressing force. The switching contact 1201 has a convex portion in a direction opposite to the surface of the conduction surface 1201a, and is stored in a housing 1204 having a concave portion so as to sandwich the spring 1202. A movable margin 1203 is provided between the switching contact 1201 and the housing 1204 so as to correspond to the expansion and contraction operation of the spring 1202. The conventional switching contact has the above configuration, but this configuration has the following problems.

(Problem 1) Since the switching contact 1201, the housing 1204, and the spring 1202 are required for each terminal, the number of parts and the assembly cost are increased.
(Problem 2) Further, the size of the winding switching device 120 increases.
(Problem 3) It is necessary to increase the contact area in order to allow a large current to flow, but since the spring 1202 only contacts the outer peripheral portion of the switching contact 1201, it is possible to equalize the surface pressure over the entire conductive surface 1201a. Have difficulty. For this reason, current concentration, sparks, arcs, and the like are generated at a specific portion of the conduction surface 1201a, and the life of the switching contact 1201 is shortened.
(Problem 4) The problem (3) is more likely to occur due to the magnitude of the clearance tolerance in the fitting portion between the convex portion of the switching contact 1201 and the concave portion of the housing 1204. Specifically, if the clearance is large, the posture of the switching contact 1201 cannot be maintained, and it becomes more difficult to equalize the surface pressure over the entire conductive surface 1201a. On the other hand, if the clearance is small, rubbing or galling is likely to occur at the fitting portion due to the repeated expansion and contraction of the spring 1202, and it becomes impossible to secure the surface pressure of the conduction surface 1201a. For this reason, it is necessary to manage the clearance tolerance with high accuracy, which causes an increase in processing cost.
(Problem 5) Since the terminal connecting portion 1206 moves in accordance with the expansion and contraction operation of the spring 1202, there is a risk that the fixing screw of the terminal connecting portion 1206 may be loosened during long-term use, which may cause a decrease in reliability.

  These problems can be solved by adopting the configuration of the switching contact as shown in FIGS. The specific solution and the principle by which the size of the winding switching device which is the object of the present invention can be realized will be described in detail below.

  FIG. 6 is a perspective view illustrating the configuration of the switching contact according to the first embodiment of the present invention. FIG. 7 is a side view showing the configuration of the switching contact according to the first embodiment of the present invention. In the following, as shown in FIGS. 6 and 7, the X-axis and the Y-axis of a positive XYZ coordinate system in which the width direction of the switching contact 201 is defined as the X axis and the longitudinal direction is defined as the Y axis to define the positive and negative directions. The configuration of the switching contact according to the first embodiment of the present invention will be described using the Z axis. FIG. 7 shows one side surface of the switching contact according to the first embodiment of the present invention as viewed in the positive direction of the Y axis shown in FIG. The shape and direction of the switching contact 201 are not limited by the width direction, the longitudinal direction, and the XYZ coordinate system.

  The starting end U1 (see FIG. 2) of the U-phase winding 150u of the stator is connected to the housing 204 via the terminal connection part 206. It is assumed that the housing 204 is formed of a conductive material (for example, metal or the like), but is not limited thereto. Storage grooves 207 for storing the switching contacts 201 are provided at both ends in the X-axis direction of the housing 204. As will be described later, the clearance of the width W (see FIG. 7) of the storage groove 207 in the X-axis direction is larger than the width of the switching contact 201 as long as the width in the X-axis direction in which the switching contact 201 can be stored can be secured. May be.

  The switching contact 201 has a polyhedral contact 205 in a convex shape in the positive direction of the Z-axis with respect to the housing 204, and has a plurality of rows of polyhedral contacts 205. 2) is connected to the terminal of another winding. Polyhedral contacts are also called current collectors. The polyhedral contact 205 is formed in a convex shape as shown in FIGS. 6 and 7, so that each row has a spring characteristic in the Z-axis direction. For this reason, the spring 1202 required in the prior art becomes unnecessary, and the number of parts and the assembly cost can be reduced (the above (Problem 1) is solved).

  In FIG. 7, the conductive surface 205 a of the multi-surface contact 205 has a height protruding from the upper surface 204 S in the positive direction of the Z-axis of the housing 204, but is not limited thereto. Any height may be used as long as contact can be secured.

  Further, since the spring 1202 is eliminated, the movable margin 1203 becomes unnecessary, and the configuration is simplified, so that the winding switching device 120 can be reduced in size (the above (Problem 2) is solved).

  Further, by dividing the conductive surface 205a into a plurality of rows, the contact area of each conductive surface 205a is reduced, so that the contact surface pressure can be made uniform. In addition, by increasing the number of conductive surfaces 205a, it is possible to secure a contact area necessary for flowing a large current. As a result, current concentration, sparks, arcs, and the like do not occur at specific locations on the conduction surface 205a, and the life of the switching contact 201 can be extended (the above (Problem 3) is solved).

  In a state in which the conductive surface 205a of the switching contact 201 is pressed against the contact portion of the short-circuit line 130, the other conductive surface 205b of the switching contact 201 has a housing 204. Therefore, since the contact surface pressure between the conductive surface 205b and the housing 204 is uniformly and sufficiently ensured, the contact resistance between the conductive surface 205b and the housing 204 can be extremely reduced. The reason that the clearance of the storage groove 207 may be large in the above description is that the surface pressure of the conductive surface 205b and the housing 204 can always be secured according to the above-described configuration principle. As a result, it is not necessary to control the clearance of the storage groove 207 of the housing 204 with high accuracy, and the processing cost can be reduced (the above (Problem 4) is solved).

  Further, the terminal connection portion 206 is provided on the housing 204, and the housing 204 is fixed without such a movement unlike the conventional switching contact 1201 that moves with the expansion and contraction of the spring 1202. Therefore, there is no risk of loosening of the fixing screw of the terminal connection portion 206 during long-term use, and the reliability can be improved (the above (Problem 5) can be solved).

  When the current is small, the conductive surfaces 205a do not necessarily have to be in a plurality of rows, but may be in a single row. In addition, the conductive surface 205a may be configured such that at least one of the plurality of rows has a wide width as shown in FIG. 6, or may have substantially the same width. Further, the switching contact 201 and the housing 204 may be configured to be electrically conductive, and may be fixed by welding, bonding, or the like, or may be integrally formed, in addition to the method of fixing by the storage groove 207. You may.

  The problems and solutions of the related art and the principle of achieving the miniaturization of the winding switching device according to the present invention have been described above. In FIGS. 6 and 7, the description has been made with respect to the start end U1, but the same configuration is applied to the start end U2 and the end ends U3, U4.

  FIG. 8 shows a circuit configuration when the configurations of FIGS. 6 and 7 are employed for the start ends U1, U2 and the end ends U3, U4, respectively. FIG. 8A shows a parallel connection (2Y connection when viewed in three phases), and FIG. 8B shows a series connection (1Y connection when viewed in three phases). In FIG. 8, the multi-face contact 205 is in contact with the short-circuit line 130. In order to switch between contact with the short-circuit line 130u1 and contact with the short-circuit line 130u2, the multifaceted contact 205 slides on the surface of the short-circuit line storage section 140 in the X-axis direction. The short-circuit line 130 is formed of a conductor, and the short-circuit line storage section 140 may be made of any material as long as insulation of the plurality of short-circuit lines 130 can be ensured. The short-circuit line 130 and the short-circuit line storage section 140 may be integrally formed using a printed circuit board. The start ends U1, U2 and the end ends U3, U4 may be held in any manner as long as insulation can be ensured from each other. However, in order to reduce the size of the winding switching device 120, at least two of the terminals are made of an insulator. It is desirable that they are mechanically connected and fixed to each other, but are not limited to mechanical fixing. Switching between the parallel connection and the series connection in FIG. 8 may be performed by moving the start ends U1, U2 and the end points U3, U4 while fixing the short-circuit line storage section 140, or on the contrary, by changing the start ends U1, U2 and the end points U3, U4. The short-circuit line storage section 140 may be moved while being fixed. In order to avoid loosening of the fixing screw of the terminal connection part 206, it is desirable to move the short-circuit wire storage part 140.

  FIG. 9 is a block diagram illustrating an entire configuration of a rotating machine drive system 2S according to a second embodiment of the present invention. The difference from FIG. 1 is that the control device 105b includes an abnormality alert output unit 109 in addition to the inverter control unit 108 and the winding switching command unit 110. The abnormality alert output unit 109 is a detection circuit that monitors the drive current of the rotating machine 3 based on the phase current information 106A detected by the phase current detection circuit 106 and outputs an abnormality alert for the switching contact 201 and the multi-face contact 205. is there. Specifically, the contact resistance of the switching contact 201 changes when at least one surface of the multi-surface contact 205 is damaged or broken, or when the contact area is not sufficiently ensured due to a malfunction of the switching operation or the like. , The current waveforms Iu, Iv, Iw of the motor behave differently from those in the normal state. The abnormality alert output unit 109 outputs an abnormality alert based on the current change information.

  In the prior art, it was difficult to keep the contact surface pressure of the switching contact constant from the viewpoint of the configuration principle. For this reason, it is difficult to maintain a constant contact resistance, and it has not been possible to clearly distinguish between a normal state and an abnormal state. On the other hand, in the present invention, since the contact surface pressure of each of the multifaceted contacts 205 can be kept constant, the contact resistance in a normal state can be quantified using the size of the contact area. As a result, when at least one of the multifaceted contacts 205 is damaged or damaged, or when the contact area is not sufficiently ensured due to a malfunction of the switching operation or the like, a clear difference in the contact resistance as compared with the normal state is obtained. Therefore, an abnormality can be detected based on the current change information.

  After the abnormality is detected, the rotating machine 103 can be driven using at least one of the multifaceted contacts 205 that has not been damaged or damaged. It is desirable that a vehicle such as a railway, a car, and a construction machine be capable of self-propelled even in the event of a failure, and the configuration of the present invention can satisfy this requirement.

  A third embodiment of the present invention will be described with reference to FIG. FIG. 10 is a configuration diagram of a rotating machine drive system used for a railway vehicle 500 according to the third embodiment of the present invention.

  The driving device of the railway vehicle 500 drives the rotating machine 103 by supplying power from the overhead line 2 via the current collector 5 and supplying AC power to the rotating machine 103 via the power converter 1. The rotating machine 103 is connected to the axle 4 of the railway vehicle 500, and the running of the railway vehicle is controlled by the rotating machine 103. The electric ground is connected via the rail 3. Here, the voltage of the overhead wire 2 may be either DC or AC.

  According to this embodiment, by mounting the rotating machine drive system of the first or second embodiment on a railway vehicle system, it becomes possible to operate the rotating machine drive system of a railway vehicle with high efficiency. Similar effects can be obtained in vehicles such as automobiles and construction machines.

  A rotating machine drive system 1S or 2S provided in a vehicle such as a railway, an automobile, or a construction machine has a configuration of 1C1M driven by combining one inverter device 101 and one rotating machine 103. Alternatively, a rotating machine drive system 1S or 2S provided in a vehicle such as a railroad, an automobile, or a construction machine is configured as 1CnM (n = 2, 3, 4,...) Driven by combining one inverter device 101 and at least two rotating machines 103. ..). The rotating machine drive system 1S or 2S included in a vehicle such as a railway, an automobile, or a construction machine is configured by a combination of at least two or more groups of the inverter devices 101 and the rotating machine 103.

  The present invention is not limited to the above-described embodiments, and other forms that can be considered within the technical idea of the present invention are also included in the scope of the present invention unless departing from the spirit of the present invention. . For example, the configurations and processes exemplified in the above-described embodiments may be integrated or separated as appropriate according to the implementation form and the processing efficiency. In addition, for example, the above-described embodiments and modified examples may be partially or entirely combined without departing from the scope of the present invention.

1S, 2S: rotating machine drive system 1: power converter 2: overhead wire 3: rail 4: axle 101: inverter 102: DC power supply 103: rotating machine 104: inverter circuits 105 and 105b: controller 106: phase current detection circuit 108: Inverter control unit 109: Abnormal alert output unit 110: Winding switching command unit 120: Winding switching devices 130, 130u1, 130u2: Short circuit line 140: Short circuit storage unit 141: Inverter main circuit 142: Gate driver 201: Switching contact 204: Housing 205: Multifaceted contacts 205a, 205b: Conductive surface 206: Terminal connection part 207: Storage groove

Claims (9)

A rotating machine having a plurality of windings,
An inverter device for converting DC power from a DC power supply to AC power and a control device for controlling power conversion by the inverter circuit, an inverter device for operating the rotating machine at a variable speed,
A winding switching device that switches connection of the plurality of windings according to a command from the control device,
With
The control device includes:
When the rotation of the rotating machine transitions between a low-speed rotation region and a high-speed rotation region due to acceleration / deceleration, instructs the winding switching device to switch connection of the winding,
The winding switching device,
A rotating machine drive system, wherein the switching contact for switching the connection of the plurality of windings is constituted by a polyhedral contact having spring characteristics. The switching contact is configured by a housing that stores the multi-face contact and the multi-face contact,
The rotating machine drive system according to claim 1, wherein the housing has a connection portion for connecting a start end or an end of the winding. The winding switching device,
It is configured with a plurality of the switching contacts for connecting to a starting end or an end of a plurality of windings of a plurality of phases of the rotating machine,
The rotating machine drive system according to claim 2, wherein at least two of the housings adjacent to the plurality of switching contacts are connected and fixed by an insulator.   4. The rotating machine drive system according to claim 3, wherein the drive current of the rotating machine is supplied to at least one surface of the multi-face contactor. 5. A detection circuit that monitors a drive current of the rotating machine,
The detection circuit,
The rotating machine according to claim 4, wherein an abnormality alert for the multi-face contact is output based on current change information generated when at least one face of the multi-face contact is damaged or broken. Drive system.   The rotating machine drive system according to any one of claims 1 to 5, wherein the rotating machine drive system has a 1C1M configuration driven by combining one of the inverter devices and one of the rotating machines.   6. A configuration of 1 CnM (n = 2, 3, 4,...) Driven by combining one inverter device and at least two rotating machines. The rotating machine drive system according to the paragraph.   The rotating machine drive system according to claim 6 or 7, wherein the rotating machine drive system is configured by a combination of at least two or more groups of the inverter devices and the rotating machine.   A vehicle comprising the rotating machine drive system according to claim 1.

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