Railway vehicle drive system and method

Abstract

To provide a hybrid drive type railroad vehicle driving device that enables a power storage device for intermediate-voltage large-capacity use, to more safely distributing electric power also for low-voltage small-capacity use.SOLUTION: A railroad vehicle driving device comprises: an engine; an induction rotary machine engaged with the engine; a first power converter which, on one side, supplies / receives electric power to / from the induction rotary machine, meanwhile, which is, on the other side, interconnected with a main circuit DC part; a smoothing capacitor connected to a DC side of the first power converter; a second power converter which use the smoothing capacitor as a DC voltage source to drive or regenerate a driving rotary machine with AC; the driving rotary machine which the second power converter is interconnected with, and supplies / receives AC electric power to / from; a third power converter which is, on one side, interconnected with the main circuit DC part, meanwhile, which, on the other side, supplies / receives the AC electric power; a transformer which the third power converter supplies / receives the AC electric power and inputs / outputs the AC electric power to a primary side; a fourth power converter which, on one side, supplies / receives the AC electric power to / from a secondary side of the transformer, meanwhile, which, on the other side, supplying / receiving DC electric power; and a power storage device, which is connected to, and supplies / receives electric power to / from a DC side of the fourth power, wherein the smoothing capacitor is charged from the power storage device through the fourth power converter, the transformer and the third power converter.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a railway vehicle drive system and method. [Background technology]

[0002] Patent Document 1 discloses a hybrid railway vehicle that can start the engine using the output of a secondary battery. Do In railway vehicles, an induction motor shaft-coupled to the engine and a medium-voltage, large-capacity storage device that can also drive the vehicle are connected to the DC section of the main circuit. The induction motor can be used as either a generator or a motor depending on the situation. When functioning as an induction motor to start the engine, it is driven by the energy from the storage device, and when functioning as an induction generator, it is rotated by the engine to generate electricity and output power.

[0003] The engine generator can provide not only the driving power for the hybrid railway vehicle but also the power to charge the battery. In a hybrid railway vehicle with this configuration, the induction generator directly connected to the engine can also be used as an induction motor for starting the engine. In this case, the excitation current required for the induction motor is supplied from the battery connected to the main circuit.

[0004] Patent Document 2 describes a non-hybrid, engine-generated electric railway vehicle that is equipped with only a low-voltage (e.g., 110V) small-capacity power storage device, rather than a large-capacity one for driving the vehicle. When the engine starts, even a small-capacity power storage device is used to drive an induction generator directly connected to the engine as an induction motor using the discharge power from the device. Such low-voltage, small-capacity power storage devices are primarily used for on-board devices, and are wired at low voltage to areas close to where people can come into contact. This low-voltage wiring is provided with insulation measures for the main circuit DC section to prevent electric shock accidents and damage to control equipment. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-49811 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-11828 Summary of the Invention [Problem to be solved by the invention]

[0006] The non-hybrid engine-generator electric railway car of Patent Document 2 is equipped with only one low-voltage, small-capacity system as an electricity storage device, rather than a medium-voltage, large-capacity system. Therefore, there was no need to freely interchange power between the medium-voltage system and the low-voltage system in order to distribute power to the low-voltage on-board equipment. More specifically, the low-voltage, small-capacity system is sufficient for starting the engine, and the car does not have the function of converting medium-voltage regenerative power to low voltage and charging a small-capacity storage battery.

[0007] On the other hand, the hybrid Do The medium-voltage, large-capacity storage devices used in railway vehicles are connected to the main circuit DC section, and their voltage to ground can sometimes reach the high voltage of overhead lines. Therefore, stepping down this voltage and distributing it to low-voltage onboard equipment has been restricted from a safety standpoint. More specifically, the onboard equipment includes control computers and, in recent years, passenger service outlets, and if high voltage of overhead lines leaks into these vulnerable systems, the damage that can occur is not small.

[0008] Therefore, hybrid Do The storage device used in the drive system is a medium-voltage, large-capacity device, and a low-voltage, small-capacity device, and these two independent systems must be isolated from each other, which is wasteful. Do In the drive system, a medium-voltage, large-capacity storage device is provided as the main power source. In this case, it is desirable from the viewpoint of equipment efficiency to step down the medium voltage and distribute it to the low-voltage on-board device so that the large can serve the small. The present invention has been made in view of the above-mentioned problems, and its object is to provide a hybrid system that can more safely distribute power from a medium-voltage, large-capacity storage device to a low-voltage, small-capacity device. Do To provide a drive system for a railway vehicle. [Means for solving the problem]

[0009] The present invention, which solves the above problems, is a hybrid Do a first power converter capable of converting between AC and DC, which supplies and receives AC power to the induction rotating machine on the one hand and is connected to a main circuit DC section on the other hand; a smoothing capacitor connected to the DC side of the first power converter; a second power converter capable of converting between AC and DC, which uses the smoothing capacitor as a DC voltage source to drive or regenerate the driving rotating machine with AC; and a driving rotating machine which is connected to the system by receiving and sending AC power from the second power converter on the other hand. The system is equipped with a third power converter capable of bidirectional AC / DC conversion, connected to the main circuit DC section via DC and supplying and receiving AC power at the other end; a transformer through which the third power converter supplies and receives AC power and inputs and outputs it to the primary side; a fourth power converter capable of bidirectional AC / DC conversion, supplying and receiving AC power to the secondary side of the transformer on one side and supplying and receiving DC power on the other side; and a power storage device connected to the DC side of the fourth power converter and supplying and receiving DC power, and the smoothing capacitor is charged from the power storage device via the fourth power converter, the transformer, and the third power converter. [Effects of the Invention]

[0010] According to the present invention, a hybrid system is provided that enables a medium-voltage, large-capacity storage device to distribute electricity more safely to a low-voltage, small-capacity device. Do It is possible to provide a drive system for a railway vehicle. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a block circuit diagram showing a schematic configuration of a railway vehicle drive device (hereinafter also referred to as "the device") according to an embodiment of the present invention. [Figure 2] 2 is a timing chart showing changes in voltage and current at each part when the device shown in FIG. 1 is started up. [Figure 3] FIG. 2 is a circuit diagram showing in detail the connection configuration of the power converter and the transformer. [Figure 4]This is a timing chart of the voltage waveforms at each part when the primary side V1 and secondary side K·V2 of the transformer shown in Figure 3 are switched with a phase difference of α=0. [Figure 5] 5 is a timing chart of the voltage waveforms at each part when switching is performed with a phase difference α>0 in comparison with FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described in brief first, followed by detailed explanation. FIG. 1 is a block circuit diagram showing the schematic configuration of the present device 19. As shown in FIG. 1, a hybrid Do This drive-type device 19 includes a medium-voltage (e.g., 1500 V) power storage device 6 with a capacity sufficient to drive a railway vehicle (not shown) (hereinafter also referred to as a "vehicle"). This power storage device 6 discharges the power stored therein and supplies it to the main circuit DC section. The main circuit DC section referred to here is a high-voltage charging section that is likely to be connected closest to the overhead line, and can be thought of as a DC section that can be measured by the PT1 power sensor 13.

[0013] Depending on the vehicle's operating mode, the power generated by induction generator (induction rotating machine) 2 driven by engine 1 is charged to power storage device 6 via the main DC circuit section. Alternatively, depending on the operating state, regenerated power is charged to power storage device 6 via the main DC circuit section. In this way, a transformer 10 is interposed in the path along which power storage device 6 is charged and discharged. The primary and secondary coils of this transformer 10 have the necessary dielectric strength voltage. The "induction generator 2" and "induction motor 2" correspond to the "induction rotating machine" as defined in the present invention.

[0014] Furthermore, the power required to drive the induction motor (induction rotating machine) 2 that starts the engine 1 is far less than the power required to drive the vehicle. Therefore, a small capacity battery is sufficient for starting the engine 1, and even a small, low-voltage, small-capacity storage battery such as that used for on-board equipment (not shown) will suffice. Therefore, a large-capacity storage battery 6 will more than suffice for this purpose.

[0015] However, from the viewpoint of equipment efficiency, where "big can do small" is preferred over "two large and small," if the large-capacity power storage device 6 is also used for starting the engine 1, for which a small capacity is sufficient, then a small-capacity storage battery will be unnecessary, and the equipment efficiency of the railway vehicle drive device will be improved. The withstand voltage performance of this power storage device 6 may be equivalent to a medium-voltage DC 1500V output, for example, and may be lower than the voltage of the main circuit DC part, which corresponds to a high-voltage DC 3000V as an example of the overhead line voltage, or it may be equally high.

[0016] 1, the power storage device 6 is connected to the main circuit DC section to enable bidirectional power transfer while maintaining insulation. There is a voltage difference of approximately 1500 V between the main circuit DC section, which is measured as a high voltage of 3000 V DC by the PT1 power sensor 13, and the power storage device 6, which is measured as a medium voltage of 1500 V DC by the PT2 power sensor 15. This voltage difference allows power to be transferred while maintaining insulation due to the withstand voltage between the primary and secondary coils of the transformer 10.

[0017] Furthermore, in a certain operation mode, if the power stored in the power storage device 6 is suddenly supplied to the main circuit DC section, an overcurrent will flow, which may destroy the circuit elements including the switching elements 17 to 24 (FIG. 3). Therefore, the controller 16 controls the power converters 8, 9 and other components so that the current flows gradually, thereby preventing the destruction of the circuit elements.

[0018] The above has provided an overview of the device 19, which in one operating mode charges a medium-voltage, large-capacity storage battery 6 isolated from the main circuit DC section with the power generated by an induction machine 2 driven by an engine 1 while driving a vehicle, and in another operating mode drives the vehicle with the power of the storage battery 6 and is also capable of starting the engine 1.

[0019] Although there will be some overlap, this device 19 will be described in more detail below. As shown in Fig. 1, this device 19 is composed of an engine 1, an induction generator 2 driven by the engine 1, a converter (first power converter) 3 that converts AC power output from the induction generator 2 into DC power, a smoothing capacitor 5 that smooths the DC power output from the converter 3 and connects it to a DC section of the main circuit, an inverter device (second power converter) 4 that converts the smoothing capacitor 5 into AC power as a DC voltage source, and an electric motor (driving rotating machine) 11 that is driven by the inverter device 4.

[0020] This device 19 further includes a smoothing capacitor 14 connected in parallel to the large-capacity storage device 6 via a contactor 7, a PT2 voltage sensor 15 that measures the voltage of the smoothing capacitor 14, a power converter (fourth power converter) 9 that converts the DC power of the smoothing capacitor 14 into AC, a transformer 10 that transforms the AC output voltage of the power converter 9, a power converter (third power converter) 8 that converts the AC power of the transformer 10 into DC, a contactor 12 that supplies the power converted by the power converter 8 to the smoothing capacitor 5, a PT1 voltage sensor 13 that measures the voltage of the smoothing capacitor 5, and a control unit 16 that inputs information from each sensor and controls the power converter 8 and the power converter 9.

[0021] The power storage device 6 can store not only the power generated by the induction generator 2 but also the power regenerated by the electric motor 11 when the vehicle decelerates. When the vehicle accelerates, the power storage device 6 can discharge the power stored therein to supply power to drive the electric motor 11. The "electric motor 11" corresponds to the "driving rotating machine" as defined in the present invention, and functions as a generator when regenerating power.

[0022] Next, the state transitions at the start of a vehicle to which the device 19 is applied will be illustrated, and the procedure of the railway vehicle driving method according to the embodiment of the present invention will be described with reference to Fig. 2. As an example of the state transitions, from a state in which both the engine 1 and the vehicle are stopped, the induction motor 2 is driven, which starts the engine 1 shaft-coupled thereto, which drives the induction generator 2, which generates AC power that is rectified to DC by the converter 3, which uses the DC power to generate three-phase AC, which drives the electric motor 11, which rotates and drives wheels (not shown), causing the vehicle to move forward.

[0023] Figure 2 is a timing chart showing the changes in voltage and current at each component during startup of device 19 shown in Figure 1. In Figure 2, the horizontal axis represents common time, and the vertical axis represents, from top to bottom, the transient phenomena of six components: battery current Ib, voltage FC2 of smoothing capacitor 14, voltage FC1 of smoothing capacitor 5, excitation current Ig of induction generator 2, torque current It of induction generator 2, and startup status of inverter device 4. The following describes the states at timings (1) to (5) in Figure 2.

[0024] (1) Charge FC1 at the same time as FC2. That is, when charging smoothing capacitor 14, control unit 16 controls power converters 9 and 8 to simultaneously charge smoothing capacitor 5.

[0025] (2) Converter operation starts and excitation current is applied (Converter operation started → Excitation current applied). That is, control unit 16 makes the voltage of smoothing capacitor 5 equal to or greater than a voltage (A [V]) sufficient to excite induction generator 2. That is, control unit 16 stores energy in smoothing capacitor 5 via converter 3. This energy is more than enough power to generate the excitation current Ig and torque current It required for induction generator 2 to generate electricity. At timing (2) when this state is reached, converter 3 converts the voltage of smoothing capacitor 5 to AC and starts flowing excitation current Ig to induction generator 2.

[0026] (3) Converter constant voltage operation started. That is, control unit 16 starts constant voltage control by increasing the torque current It of induction generator 2 using converter 3. In this way, induction generator 2 starts generating power. Thereafter, the voltage of smoothing capacitor 5 increases to and is maintained at a predetermined voltage (B [V]) by the power generated by induction generator 2.

[0027] (4) FC1 charging is completed. That is, when the voltage of smoothing capacitor 5 rises to a predetermined voltage (B [V]), control unit 16 performs constant voltage control on converter 3 and controls torque current It of induction generator 2 to be constant. As a result, the voltage of smoothing capacitor 5 is maintained at B [V].

[0028] (5) Inverter 4 starts to start up.

[0029] Here, the power storage device 6 is not a small, low-voltage, small-capacity storage battery for supplying power to on-board control equipment, but is configured as a group of medium-voltage, large-capacity storage batteries that can also store medium-level power generated during regeneration.

[0030] By setting the turns ratio N (N = [number of turns on the primary side (main circuit side)] / [number of turns on the secondary side (storage battery side)]) of the transformer 10 to 1 or more, it is possible to charge the smoothing capacitor 5 to a voltage higher than the storage battery voltage. Furthermore, it is also possible to charge the smoothing capacitor 5 to a voltage higher than the withstand voltage of the storage device 6.

[0031] 3 is a circuit diagram showing in detail the connection configuration of power converters 8 and 9 and transformer 10. Power converter 8 is a full-bridge circuit composed of switching elements 17 to 20, and power converter 9 is a full-bridge circuit composed of switching elements 21 to 24. Coil 26 performs a smoothing function in cooperation with smoothing capacitor 14 (FIG. 1).

[0032] By controlling the on / off of switching elements 21 to 24, the voltage V1=V1u-V1V applied to the primary side of transformer 10 and the voltage V2=V2u-V2V applied to the secondary side are controlled, and their respective voltages and phases are controlled. Here, the turns ratio of transformer 10 is N:1=1:K.

[0033] FIG. 4 is a timing chart of the voltage waveforms of each part when the primary side V1 and secondary side K·V2 of transformer 10 shown in FIG. 3 are switched with a phase difference of α=0. In FIG. 4, the phase difference between the phases is 180°. When there is no potential difference between K·V1, which is the primary voltage V1 converted to the secondary side, and the secondary voltage V2, and when the phase difference α=0, the power converted between the primary and secondary sides becomes 0, and no charging or discharging of the energy storage device 6 occurs. Note that the graph at the bottom of FIG. 4 shows a small amplitude for ease of explanation, even though K·V1-V2=0.

[0034] Figure 5 is a timing chart of the voltage waveforms of each part when switching is performed with a phase difference α>0, as compared to Figure 4. That is, as shown in Figure 5, the primary side V1 and secondary side K·V2 of transformer 10 are switched with a phase difference α>0. At this time, the power converted from the primary side to the secondary side becomes positive, and power storage device 6 is charged.

[0035] On the other hand, if the phase difference α<0, the power converted from the primary side to the secondary side becomes negative, and the storage device 6 is discharged. In this way, the direction and amount of current are controlled by changing the positive and negative of the phase difference α, and switching or adjusting the phase lead and lag, and the charge and discharge of the storage device 6 are controlled in a hybrid manner. Do This is convenient for the drive control system.

[0036] The transfer of energy that occurs when a railway vehicle is accelerated or decelerated will now be described. First, during acceleration, the traction AC motor 11 receives power generated by the induction generator 2 or power discharged from the power storage device 6 to generate power torque and increase its rotational speed. At this time, the control unit 16 electric power Converters 9 and 8 are controlled to move the power discharged from power storage device 6 in the discharging direction, thereby supplying it to driving AC motor 11. That is, the vehicle can be powered by at least either the generated power or the discharged power, depending on the driving conditions.

[0037] When the vehicle is in a driving state other than acceleration, control unit 16 controls power converters 8 and 9 to transfer surplus power generated by induction generator 2 or regenerated power generated by drive AC motor 11 during deceleration in the charging direction and store it in power storage device 6. In this way, control unit 16 charges large-capacity storage battery 6 with the power generated by induction generator 2 or drive AC motor 11 via power converter 8, transformer 10, and power converter 9. That is, control unit 16 may charge the battery with at least one of the generated power and the regenerated power depending on the driving state of the vehicle, or may stop the engine or select not to charge the battery.

[0038] Conversely, the control unit 16 discharges the large-capacity storage battery 6 according to the driving conditions of the vehicle, and supplies driving power to the induction generator 2 and the driving AC motor 11 via the power converter 9, the transformer 10, and the power converter 8. According to this device 19, the control unit 16 controls the phase difference α, so that power can be efficiently exchanged between the main circuit DC section and the storage device 6. As a result, a vehicle to which this device 19 is applied can be used as a hybrid vehicle. Do This allows the advantages of the drive system to be better utilized.

[0039] The railway vehicle drive device (the device) according to the embodiment of the present invention can be summarized as follows. [1] The device 19 shown in Figure 1 includes an engine 1, an induction rotating machine 2, a driving rotating machine 11, first to fourth power converters 3 to 9 capable of bidirectional AC / DC conversion, a smoothing capacitor 5, a transformer 10, and a medium-voltage (e.g., 1500V) large-capacity storage device 6.

[0040] The induction rotating machine 2 and the drive rotating machine 11 can selectively operate as an induction generator or an induction motor depending on the operating conditions. The induction rotating machine 2 is also axially coupled to the engine 1, and can mutually utilize driving force and electric power depending on whether the engine is started or is an engine generator.

[0041] The first power converter 3 (converter) supplies AC power to the induction rotating machine 2 on one hand, and is connected to the main circuit DC section via DC on the other hand, allowing for bidirectional AC / DC conversion. A smoothing capacitor 5 is connected to the DC side of the first power converter 3 and is connected to the main circuit DC section via DC. The driving rotating machine 11 is connected to the system by receiving AC power from a second power converter (inverter) 4. This second power converter 4 is capable of bidirectional AC / DC conversion, and uses the smoothing capacitor 5 as a DC voltage source to drive or regenerate AC power for the driving rotating machine 11. Note that if the main circuit DC section is connected via DC, a DC voltage close to the overhead line voltage is shared, allowing for mutual interchange of power.

[0042] The third power converter 8 is capable of bidirectional AC / DC conversion, and is connected to the main circuit DC section as DC on one side, and supplies and receives AC power on the other side. The transformer 10 receives and outputs AC power from the primary side, with the third power converter 8 receiving and sending AC power. The fourth power converter 9 is capable of bidirectional AC / DC conversion, and receives and sends AC power to the secondary side of the transformer 10 on one side, and receives and sends DC power on the other side. The power storage device 6 is connected to the DC side of the fourth power converter 9 and receives and sends DC power. This device 19 charges the smoothing capacitor 5 from the power storage device 6 via the fourth power converter 9, the transformer 10, and the third power converter 8.

[0043] The device 19 described above in [1] is a hybrid DoA medium-voltage, large-capacity power storage device 6 for driving is insulated from the high-voltage main circuit DC portion via a transformer 10. Therefore, the power storage device 6 connected to the secondary side of the transformer 10 is insulated from the main circuit DC portion and the high-voltage portion (e.g., 3000 V) of the overhead line connected to the primary side of the transformer 10.

[0044] As a result, the medium-voltage, large-capacity storage battery 6 of this device 19 can be prevented from being directly connected to the most dangerous high voltage of the overhead line. Therefore, this device 19 makes it possible to distribute electricity more safely from the medium-voltage, large-capacity storage battery 6 to low-voltage, small-capacity applications. Note that the distribution lines from the medium-voltage storage battery 6 to the low-voltage on-board equipment, etc. are not shown in the figure.

[0045] Furthermore, from the viewpoint of safety, the power storage device 6 of the present device 19 is not directly connected to the overhead line, so there is no possibility of a fire caused by an abnormally large current flowing in from the overhead line. The larger the capacity of the power storage device 6, the greater the damage caused by a fire in the unlikely event of one occurring, so the present device 19 is also technically significant in that it can easily prevent such a fire.

[0046] [2] In the above [1], a control unit 16 is further provided that can control the amount and direction of power transfer between the primary side and secondary side of the transformer 10 by controlling the phase difference α between the voltage of the third power converter 8 and the voltage of the fourth power converter 9. This control unit 16 can also charge the power storage device 6 with regenerative power during braking.

[0047] According to the present device 19, power can be efficiently interchanged between the main circuit DC section and the electricity storage device 6. This power interchange not only allows surplus power and regenerated power of the power generation output of the induction generator 2 using the driving force of the engine 1 to be charged to the electricity storage device 6, but also allows the control unit 16 to freely charge the smoothing capacitors 5, 14 as needed by controlling the phase difference α.

[0048] [3] In the above [2], the control unit 16 sets the phase difference α at the start of control to 0. If the phase difference α is 0, the amount of power transfer between the primary and secondary sides of the transformer 10 is maintained at 0, so the device 19 alleviates the inrush current at startup and gradually starts it up, realizing a stable start of control.

[0049] [4] In the above [2], the control unit 16 performs different control when the engine 1 is not operating and when it is operating. When the engine 1 is not operating and external power such as from overhead lines cannot be obtained, the control unit 16 controls the fourth power converter 9, which receives power from the power storage device 6, to perform constant voltage control. This allows the device 19 to output power at a constant voltage, and simulates a state in which external power such as from overhead lines can be obtained, thereby driving the railway vehicle stably. As a result, the device 19 operates in a hybrid manner. Do By taking advantage of the advantages of the drive system, more stable driving can be achieved.

[0050] Furthermore, when external power such as from overhead lines cannot be obtained and the engine 1 is operating instead, the control unit 16 controls the first power converter 3 to maintain constant voltage control, maintaining a supply of voltage close to the rated voltage of the overhead lines. This allows the railway vehicle to receive only the power required for traveling. If there is surplus power, the control unit 16 inputs it at a low voltage to the fourth power converter 9, which then performs constant current control to supply an appropriate charging current to the battery 6. This allows the device 19 to travel long distances on non-electrified sections using only the battery 6, further reducing fuel consumption.

[0051] [5] In the above [1], the dielectric strength voltage of the smoothing capacitor 5 is set higher than that of the storage battery 6. The smoothing capacitor 5 is connected to the main circuit DC section and can withstand the maximum voltage equivalent to the overhead line voltage. As long as the medium-voltage storage battery 6 has the capacity to drive the vehicle, its voltage may be less than half that of the overhead line or the main circuit DC section, and the voltage deficiency can be easily adjusted by the voltage ratio determined by the winding ratio between the primary and secondary sides of the transformer 10.

[0052] [6] In the above [2], in Fig. 1, the control unit 16 adjusts the phase difference between the third power converter 8 and the fourth power converter 9 under the condition that the frequencies of the two are the same. This makes it possible to equalize the switching frequencies of the switching elements 17 to 24 provided in each of the two converters. As a result, it is possible to equalize the life spans of all the switching elements 17 to 24.

[0053] [7] Hybrid according to an embodiment of the present invention Do The railway vehicle drive method (this method) of this system has the following operations. However, the operation procedure may be changed as appropriate depending on the vehicle's operating conditions. First, the induction rotating machine 2, which is shaft-coupled to the stopped engine 1, may start by being driven as an induction motor.

[0054] In addition, induction rotating machine 2, shaft-coupled to engine 1 while it is running, may also generate AC power as an induction generator. A first power converter 3 capable of AC / DC bidirectional conversion supplies AC power to induction rotating machine 2 on one side and is connected to the main circuit DC section on the other side. A smoothing capacitor 5 is connected to the DC side of first power converter 3 and the main circuit DC section. A second power converter 4, also capable of AC / DC bidirectional conversion, drives or regenerates AC power to driving rotating machine 11 using smoothing capacitor 5 as a DC voltage source.

[0055] A third power converter 8 capable of bidirectional AC / DC conversion is connected to the main circuit DC section via DC power on one side, and supplies and receives AC power to the primary side of a transformer 10 on the other side. A fourth power converter 9 capable of bidirectional AC / DC conversion supplies and receives AC power to the secondary side of the transformer 10 on one side, and supplies and receives DC power on the other side.

[0056] Furthermore, the power storage device 6 is connected to the DC side of the fourth power converter 9 to exchange DC power. The smoothing capacitor 5 is charged from the power storage device 6 via the fourth power converter 9, the transformer 10, and the third power converter 8. According to this method, it is possible to more safely distribute power from the medium-voltage, large-capacity power storage device 6 to a low-voltage, small-capacity power storage device. Furthermore, power can be efficiently shared between the main circuit DC section and the power storage device 6. [Explanation of symbols]

[0057] 1...engine, 2...induction generator, 3...converter (first power converter), 4...inverter (second power converter), 5...smoothing capacitor, 6...(large-capacity) power storage device, 7, 12...contactor, 8, 9...third and fourth power converters, 10...transformer, 11...electric motor (driving rotating machine), 13, 15...PT1 and PT2 voltage sensors, 14...smoothing capacitor, 16...controller, 17-24...switching elements, Ib...battery current, voltage, α...phase difference, 19...railway vehicle drive device (this device)

Claims

1. An engine; an induction rotating machine engaged with the engine; a first power converter capable of bidirectional AC / DC conversion, which supplies AC power to the induction rotating machine on the one hand and connects DC power to a main circuit DC section on the other hand; a smoothing capacitor connected to a DC side of the first power converter; a second power converter capable of bidirectional AC / DC conversion that uses the smoothing capacitor as a DC voltage source to drive or regenerate a driving rotary machine with AC; a driving rotating machine connected to the grid by the second power converter receiving and sending AC power; a third power converter that is connected to the main circuit DC section via a DC power supply and is capable of bidirectional AC / DC conversion, supplying and receiving AC power via the third power converter; a transformer through which the third power converter receives and outputs AC power to and from a primary side; a fourth power converter capable of bidirectional AC / DC conversion, which supplies and receives AC power to and from the secondary side of the transformer on one side and supplies and receives DC power on the other side; a power storage device connected to a DC side of the fourth power converter to supply and receive DC power; A control unit; Equipped with The control unit When the engine is not operating, the fourth power converter performs constant voltage control; When the engine is operating, the first power converter is controlled to a constant voltage, and the fourth power converter is controlled to a constant current. Railway vehicle drive unit.

2. Charging the smoothing capacitor from the power storage device via the fourth power converter, the transformer, and the third power converter. The railway vehicle drive device according to claim 1 .

3. The control unit controls the amount and direction of power transfer between the primary side and secondary side of the transformer by controlling the phase difference between the voltage of the third power converter and the voltage of the fourth power converter, The power storage device is also capable of storing regenerative power during braking. The railway vehicle drive device according to claim 2.

4. The control unit has a phase difference of 0 at the start of control.

4. The railway vehicle drive device according to claim 3.

5. The dielectric strength voltage of the smoothing capacitor is set higher than that of the power storage device. The railway vehicle drive device according to claim 1 .

6. The control unit adjusts a phase difference between the third power converter and the fourth power converter under the condition that the frequencies of the third power converter and the fourth power converter are made identical.

4. The railway vehicle drive device according to claim 3.

7. An engine in a stopped state is started by driving an induction rotating machine engaged with the engine as an induction motor, an induction rotating machine engaged with the engine while it is running serves as an induction generator to generate AC power; a first power converter capable of converting between AC and DC in both directions, which supplies AC power to and receives AC power from the induction rotating machine on one side and is connected to a main circuit DC section on the other side; a smoothing capacitor is connected to the DC side of the first power converter and to a DC part of the main circuit; a second power converter capable of converting between AC and DC in both directions drives or regenerates AC to a driving rotating machine using the smoothing capacitor as a DC voltage source; a third power converter capable of bidirectional AC / DC conversion, which is connected to the main circuit DC section as a DC power source on one side, and supplies AC power to and receives AC power from a primary side of a transformer on the other side; a fourth power converter capable of bidirectional AC / DC conversion, which supplies AC power to and receives AC power from the secondary side of the transformer on one side and supplies DC power to and receives DC power from the other side; a power storage device connected to a DC side of the fourth power converter to exchange DC power; The control unit When the engine is not operating, the fourth power converter performs constant voltage control; When the engine is operating, the first power converter is controlled to a constant voltage, and the fourth power converter is controlled to a constant current. Driving method for railway vehicles.

8. Charging the smoothing capacitor from the power storage device via the fourth power converter, the transformer, and the third power converter.

8. A method for driving a railway vehicle according to claim 7.

9. The control unit controls the amount and direction of power transfer between the primary side and secondary side of the transformer by controlling the phase difference between the voltage of the third power converter and the voltage of the fourth power converter, The power storage device can also store regenerated power during braking.

9. A method for driving a railway vehicle according to claim 8.

10. The control unit sets the phase difference to 0 at the start of control.

10. A method for driving a railway vehicle according to claim 9.

11. The dielectric strength voltage of the smoothing capacitor is set higher than that of the power storage device.

8. A method for driving a railway vehicle according to claim 7.

12. The control unit adjusts a phase difference between the third power converter and the fourth power converter under the condition that the frequencies of the third power converter and the fourth power converter are made identical.

10. A method for driving a railway vehicle according to claim 9.

13. An engine; an induction rotating machine engaged with the engine; a first power converter capable of bidirectional AC / DC conversion, which supplies AC power to the induction rotating machine on the one hand and connects DC power to a main circuit DC section on the other hand; a smoothing capacitor connected to a DC side of the first power converter; a second power converter capable of bidirectional AC / DC conversion that uses the smoothing capacitor as a DC voltage source to drive or regenerate a driving rotary machine with AC; a driving rotating machine connected to the grid by the second power converter receiving and sending AC power; a third power converter that is connected to the main circuit DC section via a DC power supply and is capable of bidirectional AC / DC conversion, supplying and receiving AC power via the third power converter; a transformer through which the third power converter receives and outputs AC power to and from a primary side; a fourth power converter capable of bidirectional AC / DC conversion, which supplies and receives AC power to and from the secondary side of the transformer on one side and supplies and receives DC power on the other side; a power storage device connected to a DC side of the fourth power converter to supply and receive DC power; Equipped with the power storage device can be charged from the driving rotating machine via the second power converter, the third power converter, the transformer, and the fourth power converter; Railway vehicle drive unit.

14. An engine; an induction rotating machine engaged with the engine; a first power converter capable of bidirectional AC / DC conversion, which supplies AC power to the induction rotating machine on the one hand and connects DC power to a main circuit DC section on the other hand; a smoothing capacitor connected to a DC side of the first power converter; a second power converter capable of bidirectional AC / DC conversion that uses the smoothing capacitor as a DC voltage source to drive or regenerate a driving rotary machine with AC; a driving rotating machine connected to the grid by the second power converter receiving and sending AC power; a third power converter that is connected to the main circuit DC section via a DC power supply and is capable of bidirectional AC / DC conversion, supplying and receiving AC power via the third power converter; a transformer through which the third power converter receives and outputs AC power to and from a primary side; a fourth power converter capable of bidirectional AC / DC conversion, which supplies and receives AC power to and from the secondary side of the transformer on one side and supplies and receives DC power on the other side; a power storage device connected to a DC side of the fourth power converter to supply and receive DC power; A control unit; Equipped with The turns ratio of the transformer N = [Number of turns on the primary side] / [Number of turns on the secondary side] satisfies one or more conditions, the control unit controls the third power converter and the fourth power converter and supplies power from the power storage device to the driving rotating machine via the transformer. Railway vehicle drive unit.

Images