JP2018078763A - Power conversion device, power conversion method, power conversion program, and electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion device operable to charge a storage battery without marring a performance of driving a main electric motor in a DC electrified section.SOLUTION: The power conversion device comprises: an inverter and a converter which are connected to a power source line; a transformer; a switch circuit for supplying a DC voltage to the power source line in a first mode, and supplying an AC voltage to the transformer in a second mode; a first switch circuit electrically connected between the converter and a storage battery; and a second switch circuit electrically connected between the secondary side of the transformer and the converter. In the first mode, the converter lowers the DC voltage supplied to the power source line to produce a lowered voltage, and supplies the lowered voltage to the storage battery through the first switch circuit, to charge the storage battery. In the second mode, the converter converts an AC voltage supplied from the transformer through the second switch circuit into a DC link voltage, and supplies the DC link voltage to the power source line.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power conversion device used in an electric vehicle such as a railway vehicle. Moreover, this invention relates to the power conversion method and power conversion program which are used in such a power converter device. Furthermore, this invention relates to the electric vehicle carrying such a power converter device.

  2. Description of the Related Art In recent years, railway vehicles have been developed that travel while being supplied with a DC voltage or an AC voltage from an overhead line in an electrified section and capable of traveling in a non-electrified section. Among such railway vehicles, there are those that travel using electric power supplied from a fuel cell or a storage battery in a non-electrified section. Although the storage battery is charged even in the electrification section, it is required to allow the storage battery to be charged in both the direct current electrification section and the alternating current electrification section.

  As a related technique, Patent Document 1 discloses a voltage converter for a hybrid railway vehicle using a fuel cell as one of power sources. This voltage converter can switch between a case where a fuel cell is used in a non-electrified section and a case where an AC power source or a DC power source is used from an overhead line in an electrified section. In addition, storage batteries are used to make up for the lack of power.

  Non-Patent Document 1 discloses a storage battery-driven train that can travel even in a non-electrified section. This storage battery-driven train travels by a DC voltage supplied from an overhead line in the electrified section and charges the main circuit storage battery. For this purpose, the power converter is composed of a DC / DC converter that steps down a DC voltage supplied from an overhead wire, and a VVVF (variable voltage variable frequency) inverter that drives a main motor.

Japanese Patent Laying-Open No. 2015-61392 (paragraphs 0029-0031, FIG. 5)

Kazunori Hasebe, two others, “JR East EV-E301 series battery-powered train”, Vehicle Technology No. 248, Japan Railway Vehicle Industry Association, September 2014, p. 28-44

  Referring to FIG. 5 of Patent Document 1, in a DC electrification section, a DC voltage (for example, 1500 V) supplied from an overhead line via a pantograph 20 is supplied via a switch 140 to an inverter 100 that drives an induction motor 110. Is done. On the other hand, in the non-electrified section, the DC voltage (for example, 500 V) supplied from the fuel cell 50 is boosted to, for example, 1500 V by the converter 103 and is supplied to the inverter 100.

  Further, the railway vehicle is provided with a battery (storage battery) 80 as a functional unit that compensates for the insufficient power. Generally, the charging voltage of a storage battery for a railway vehicle is lower than the DC voltage supplied from the overhead line, for example, about 600V to 1000V, and there is a large voltage difference between the two. However, since Patent Document 1 does not disclose a circuit configuration for controlling charging / discharging between different DC voltages, the storage battery could not be charged using a DC voltage supplied from an overhead line in a DC electrification section. . If a DC / DC converter is added to step down the DC voltage of the overhead line, the circuit scale and the number of parts increase, and the weight of the railway vehicle also increases.

  Further, in FIG. 9 of Non-Patent Document 1, the VVVF inverter and the battery system group (main circuit storage battery) are connected in parallel to each other. Therefore, the DC / DC converter to the VVVF inverter is supplied with the same DC 630V as that supplied to the main circuit storage battery, so that a general train induction motor cannot be adopted as the main motor. In addition, since the DC voltage supplied to the VVVF inverter is low, the driving capability for the main motor is reduced, and traveling performance such as acceleration of the vehicle is limited.

  Therefore, in view of the above points, the first object of the present invention is to drive the main motor in the DC electrification section, the AC electrification section, and the non-electrification section without increasing the circuit scale and the number of parts so much. An object of the present invention is to provide a power conversion device capable of charging a storage battery without impairing the driving capability for a main motor in a DC electrification section. The second object of the present invention is to provide a power conversion method and a power conversion program used in such a power conversion device.

  A third object of the present invention is to provide a power converter capable of charging a storage battery even in an AC electrification section, in addition to the first object of the present invention. According to a fourth object of the present invention, in addition to the third object of the present invention, it is possible to drive a main motor using electric power supplied from a fuel cell, and to charge a storage battery. It is to provide a power conversion device.

  The fifth object of the present invention is that the vehicle can travel in a DC electrified section, an AC electrified section, and a non-electrified section without significantly increasing the weight of the vehicle. An object of the present invention is to provide an electric vehicle capable of charging a storage battery without damage.

  In order to solve at least a part of the above problems, a power converter according to a first aspect of the present invention includes an inverter that generates a drive voltage for a main motor based on a DC voltage supplied from a power supply line, an inverter, A converter connected in parallel to the power supply line, a transformer that transforms the AC voltage supplied to the primary side and outputs it from the secondary side, and a DC voltage supplied to the input terminal in the first mode In the second mode, the switching circuit that supplies the AC voltage supplied to the input terminal to the primary side of the transformer is electrically connected between the converter and the storage battery. The first switch circuit, which is turned on and turned off in the second mode, is electrically connected between the secondary side of the transformer and the converter, and enters the first mode. And a second switch circuit that is turned off in the second mode and the converter generates a step-down voltage by stepping down the DC voltage supplied to the power supply line in the first mode, Supplying the storage battery via the first switch circuit to charge the storage battery, and in the second mode, converting the AC voltage supplied from the secondary side of the transformer via the second switch circuit into a DC link voltage And supply it to the power line.

  A power conversion method according to a second aspect of the present invention includes an inverter that generates a drive voltage for a main motor based on a DC voltage supplied from a power line, and a converter that is connected to the power line in parallel with the inverter. A power conversion method used in a power converter including a transformer that transforms an alternating voltage supplied to a primary side and outputs from a secondary side, and in a first mode, between a converter and a storage battery The step of controlling the first switch circuit electrically connected to the on state and the second switch circuit electrically connected between the secondary side of the transformer and the converter to the off state (a) And (b) controlling the switching circuit to supply the DC voltage supplied to the input terminal to the power supply line in the first mode, and in the first mode. A step (c) of controlling the converter so as to step down the DC voltage supplied to the power supply line to generate a step-down voltage and supply the storage battery via the first switch circuit to charge the storage battery; In the second mode, the step (d) of controlling the first switch circuit to the OFF state and the second switch circuit to the ON state, and the AC voltage supplied to the input terminal in the second mode are Step (e) for controlling the switching circuit to supply to the primary side of the transformer, and in the second mode, the AC voltage supplied from the secondary side of the transformer via the second switch circuit is converted to the DC link voltage. And (f) controlling the converter so as to convert it into a power supply line.

  Furthermore, the power conversion program according to the third aspect of the present invention includes an inverter that generates a driving voltage for the main motor based on a DC voltage supplied from the power line, and a converter that is connected to the power line in parallel with the inverter. A power conversion program used in a power conversion device including a transformer that transforms an alternating voltage supplied to a primary side and outputs from a secondary side, and in a first mode, between a converter and a storage battery Procedure for controlling the first switch circuit electrically connected to the on state and controlling the second switch circuit electrically connected between the secondary side of the transformer and the converter to the off state (a ), A procedure (b) for controlling the switching circuit to supply a DC voltage supplied to the input terminal to the power supply line in the first mode, and a first mode. A step (c) for controlling the converter so as to step down the DC voltage supplied to the power supply line to generate a stepped down voltage and supply the storage battery via the first switch circuit to charge the storage battery; In the second mode, the step (d) of controlling the first switch circuit to the OFF state and the second switch circuit to the ON state, and the AC voltage supplied to the input terminal in the second mode (E) for controlling the switching circuit so as to supply the primary side of the transformer to the primary side of the transformer, and in the second mode, the alternating current voltage supplied from the secondary side of the transformer via the second switch circuit is the direct current link The CPU is caused to execute a procedure (f) for controlling the converter so as to convert it into a voltage and supply it to the power supply line.

  According to the first to third aspects of the present invention, in the first mode, the DC voltage supplied to the input terminal is supplied to the inverter, and the converter generates a step-down voltage by stepping down the DC voltage. Then, the storage battery is charged by supplying the storage battery via the first switch circuit. The electric power charged in the storage battery can be used to drive the main motor in the non-electrified section. Further, in the second mode, the AC voltage supplied to the input terminal is supplied to the transformer, and the converter converts the AC voltage supplied via the transformer and the second switch circuit into a DC link voltage and converts it into an inverter. To supply.

  Accordingly, the main motor is driven in the DC electrified section, the AC electrified section, and the non-electrified section without increasing the circuit scale and the number of parts so much, and the storage battery can be installed without impairing the driving ability for the main motor in the DC electrified section. A power conversion device that can be charged can be provided. Moreover, the power conversion method and power conversion program which are used in such a power converter device can be provided.

  Here, the power conversion device further includes a third switch circuit that is electrically connected between the power supply line and the storage battery and is turned off in the first mode and turned on in the second mode, The converter may charge the storage battery by supplying a DC link voltage to the storage battery via the third switch circuit in the second mode. Thereby, the storage battery can be charged even in the AC electrification section.

  Further, the power converter is electrically connected between the fuel cell and the converter, and further includes a fourth switch circuit that is turned off in the first and second modes and turned on in the third mode. In the third mode, the first and second switch circuits are turned off, and the converter boosts the DC voltage supplied from the fuel cell through the fourth switch circuit to generate a boosted voltage. However, it may be supplied to the power supply line. As a result, the main motor can be driven using the electric power supplied from the fuel cell.

  Further, in the third mode, the third switch circuit may be turned on so that the converter supplies the boosted voltage to the storage battery via the third switch circuit to charge the storage battery. Thereby, it becomes possible to charge a storage battery using the electric power supplied from a fuel cell.

  An electric vehicle according to a fourth aspect of the present invention includes the power conversion device according to any one of the aspects of the present invention. According to the fourth aspect of the present invention, the vehicle can travel in a DC electrified section, an AC electrified section, and a non-electrified section without significantly increasing the weight of the vehicle, and travel such as acceleration of the vehicle in the DC electrified section. An electric vehicle capable of charging a storage battery without impairing performance can be provided.

It is a circuit diagram showing an example of composition of an electric vehicle provided with a power converter concerning one embodiment of the present invention. It is a figure which shows the example of the waveform of the control signal supplied to the converter of the electric vehicle shown in FIG. It is a figure for demonstrating the operation | movement in the 2nd mode of the electric vehicle shown in FIG. It is a figure which shows the example of the waveform of the control signal supplied to the converter of the electric vehicle shown in FIG. It is a figure for demonstrating the operation | movement in the 3rd mode of the electric vehicle shown in FIG. It is a figure which shows the example of the waveform of the control signal supplied to the converter of the electric vehicle shown in FIG. It is a flowchart which shows the power conversion method which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same referential mark is attached | subjected to the same component and the overlapping description is abbreviate | omitted.
<Electric vehicle>
FIG. 1 is a circuit diagram illustrating a configuration example of an electric vehicle including a power conversion device according to an embodiment of the present invention. The electric vehicle 100 travels while being supplied with a DC voltage or an AC voltage from an overhead line in the electrified section, and can travel in a non-electrified section (under the overhead line). FIG. 1 shows a connection state when a DC voltage is supplied to electric vehicle 100 from an overhead line.

  As shown in FIG. 1, an electric vehicle 100 includes a pantograph 10, a vacuum circuit breaker 11, a DC high speed circuit breaker 12, start switch circuits 13 and 14, a ground switch circuit 15, a storage battery 20, In addition to the main motor 30 and the auxiliary circuit power supply device (auxiliary device) 40, a power conversion device including an inverter 50 and the like is provided. The electric vehicle 100 also includes a resistor R1, inductors L1 and L2, and capacitors C1 and C2, and further includes fuel cells FC1 and FC2, inductors L3 and L4, and capacitors C3 and C4. good.

  The pantograph 10 is attached on the roof of the electric vehicle 100 and is supplied with power from an overhead line. The vacuum circuit breaker 11 and the DC high-speed circuit breaker 12 protect the internal circuit of the electric vehicle 100 by interrupting the circuit when a short circuit accident current or the like flows. Further, when the ground switch circuit 15 is turned on, the ground potential (0 V) is applied to the ground line GL through the wheel that contacts the rail.

  When the pantograph 10 contacts the overhead line and starts collecting power, the start switch circuit 13 is turned on, the start switch circuit 14 is turned off, and the start switch circuit 13 and the resistor R1 are switched from the pantograph 10. Power is supplied to the power conversion device via the. Thereafter, the start switch circuit 14 is turned on, and power is supplied from the pantograph 10 to the power conversion device via the start switch circuit 14.

  The inductor L1 and the capacitor C1 constitute a low-pass filter, and smooth the voltage supplied from the pantograph 10 to the power supply line PL. The inductor L2 and the capacitor C2 constitute a low-pass filter, and smooth the voltage supplied to the storage battery 20.

  As the storage battery 20, for example, a rechargeable lithium ion secondary battery or the like is used. The storage battery 20 is charged mainly in the electrified section, and supplies power to the power conversion device in the non-electrified section. The charging voltage of the storage battery 20 is, for example, 600V to 1000V.

  The main motor 30 is constituted by, for example, an induction motor (IM), and is supplied with a three-phase AC voltage (U phase, V phase, W phase) during power running to drive the wheel, and at the time of regeneration, the brake force is applied to the wheel. To generate AC electromotive force.

  The auxiliary circuit power supply device 40 includes, for example, an inverter, and converts the DC voltage supplied from the power supply line PL into an AC voltage, thereby supplying the AC voltage to in-vehicle equipment such as an air conditioner other than for traveling.

  The fuel cells FC1 and FC2 generate electric energy by utilizing a reaction opposite to the electrolysis of water, for example, by chemically reacting oxygen as a positive electrode agent and hydrogen as a negative electrode agent. When the fuel cells FC1 and FC2 are mounted on the electric vehicle 100 for traveling in the non-electrified section, the fuel consumed in the fuel cells FC1 and FC2 can be saved by utilizing the storage battery 20. .

<Power conversion device>
The power converter according to this embodiment includes an inverter 50, a converter 60, a transformer 70, a switching circuit 80, a first switch circuit 81, a second switch circuit 82, a control unit 90, and a storage unit. 91, and may further include a third switch circuit 83 and a fourth switch circuit 84.

  Inverter 50 generates a drive voltage for main motor 30 based on a DC voltage supplied from power supply line PL. Converter 60 is connected to power supply line PL in parallel with inverter 50. The transformer 70 transforms the AC voltage supplied to the primary side and outputs it from the secondary side.

  The switching circuit 80 and the first switch circuit 81 to the fourth switch circuit 84 include, for example, a switch configured by a relay circuit or an electronic switch, and follow the control signals T0 to T4 supplied from the control unit 90, respectively. Operate.

  The control unit 90 may be configured with an analog circuit or a digital circuit. Or the control part 90 may be comprised with a central processing unit (CPU) and the software (power conversion program) for making a CPU perform various procedures. The software is stored in a recording medium of the storage unit 91. As a recording medium, a built-in hard disk, an external hard disk, a flexible disk, MO, MT, RAM, CD-ROM, DVD-ROM, or various memories can be used.

  The electric vehicle 100 travels by being supplied with a DC voltage from the overhead line in the first mode, and travels by being supplied with an AC voltage from the overhead line in the second mode. In addition, the electric vehicle 100 can also travel by being supplied with a DC voltage from the fuel cells FC1 and FC2 or the storage battery 20 in the third mode.

  Control unit 90 may set the power conversion device to any one of the first mode to the third mode in accordance with the operation of the operator. Alternatively, the control unit 90 sets the power converter to the first mode when the DC voltage supplied to the input terminal 80a of the switching circuit 80 is larger than the first threshold, and inputs the input terminal 80a of the switching circuit 80. When the AC voltage supplied to is greater than the second threshold, the power converter may be set to the second mode. In other cases, the control unit 90 may set the power conversion device to the third mode.

  The switching circuit 80 supplies the DC voltage supplied to the input terminal 80a to the power supply line PL in the first mode, and supplies the AC voltage supplied to the input terminal 80a to the primary side of the transformer 70 in the second mode. To supply.

  The first switch circuit 81 is electrically connected between the converter 60 and the storage battery 20, and is turned on in the first mode, and is turned off in the second mode and the third mode. In the example shown in FIG. 1, the converter 60 has a plurality of nodes N1 and N2 as input / output nodes, and the first switch circuit 81 is connected between the node N1 and the storage battery 20 via the inductor L2. And a switch connected between the node N2 and the storage battery 20 via an inductor L2.

  The second switch circuit 82 is electrically connected between the secondary side of the transformer 70 and the converter 60 and is turned off in the first mode and the third mode, and is turned on in the second mode. Become. In the example shown in FIG. 1, the second switch circuit 82 includes two switches respectively connected between the two terminals on the secondary side of the transformer 70 and the nodes N <b> 1 and N <b> 2 of the converter 60.

  The third switch circuit 83 is electrically connected between the power supply line PL and the storage battery 20, and is turned off in the first mode, and turned on in the second mode and the third mode. In the example illustrated in FIG. 1, the third switch circuit 83 includes a switch connected between the power supply line PL and the storage battery 20 via the inductor L2.

  The fourth switch circuit 84 is electrically connected between the fuel cells FC1 and FC2 and the converter 60, and is turned off in the first and second modes and turned on in the third mode. In the example shown in FIG. 1, the fourth switch circuit 84 includes a switch connected via an inductor L3 between the fuel cell FC1 and the node N1 of the converter 60, a node N2 of the fuel cell FC2 and the converter 60, and And a switch connected via an inductor L4.

  The inductor L3 and the capacitor C3 form a low-pass filter, and smooth the voltage across the fuel cell FC1 even if the voltage at the node N1 changes when the fourth switch circuit 84 is in the ON state. Turn into. The inductor L4 and the capacitor C4 constitute a low-pass filter, and even if the voltage at the node N2 changes when the fourth switch circuit 84 is on, the voltage across the fuel cell FC2 Is smoothed.

<Inverter>
Inverter 50 includes, for example, switching elements Q51 to Q56 and diodes D51 to D56 connected in parallel to switching elements Q51 to Q56 to supply a three-phase AC voltage to main motor 30, respectively. In the example shown in FIG. 1, each of switching elements Q51 to Q56 is an IGBT (insulated gate bipolar transistor).

  Switching elements Q51 to Q53 have a collector connected to power supply line PL, an emitter connected to each of three terminals of main motor 30, and a gate supplied with each control signal. Diodes D51 to D53 have a cathode connected to power supply line PL and an anode connected to each of the three terminals of main motor 30.

  Switching elements Q54 to Q56 each have a collector connected to each of three terminals of main motor 30, an emitter connected to ground line GL, and a gate to which each control signal is supplied. Diodes D54 to D56 each have a cathode connected to each of the three terminals of main motor 30 and an anode connected to ground line GL.

Switching elements Q51 to Q56 perform a switching operation in accordance with a control signal supplied from control unit 90 to the gate. Thereby, for example, the inverter 50 converts the DC voltage 1500V supplied from the overhead wire to the power supply line PL into a three-phase AC voltage 1500V _0-P , and generates a drive voltage for the main motor 30.

  The inverter 50 converts the DC voltage supplied to the power supply line PL into a three-phase AC voltage during power running and supplies it to the main motor 30 and also converts the AC electromotive force generated in the main motor 30 into DC voltage during regeneration. To supply the power line PL. This DC voltage is used for charging the storage battery 20 or is supplied to another electric vehicle via an overhead line. The inverter 50 may be any inverter that can generate the drive voltage of the main motor 30 based on the DC voltage, and may be a VVVF (variable voltage variable frequency) inverter.

<Converter>
Converter 60 includes, for example, switching elements Q61 to Q64 and diodes D61 to D64 connected in parallel to switching elements Q61 to Q64, respectively. In the example shown in FIG. 1, each of switching elements Q61 to Q64 is an IGBT (insulated gate bipolar transistor).

  Switching elements Q61 and Q62 have a collector connected to power supply line PL, an emitter connected to each of nodes N1 and N2, and a gate to which each control signal is supplied. Diodes D61 and D62 have a cathode connected to power supply line PL and an anode connected to nodes N1 and N2, respectively.

  The switching elements Q63 and Q64 have collectors connected to the nodes N1 and N2, respectively, emitters connected to the ground line GL, and gates to which the respective control signals are supplied. Diodes D63 and D64 have a cathode connected to nodes N1 and N2, respectively, and an anode connected to ground line GL.

<First mode>
In the first mode, electric vehicle 100 travels using a DC voltage supplied from an overhead line. For this purpose, the switching circuit 80 supplies a DC voltage supplied from the overhead wire to the input terminal 80a to the power supply line PL. As a result, a DC voltage is supplied to the inverter 50, and the electric vehicle 100 travels as the inverter 50 generates a drive voltage for the main motor 30 under the control of the control unit 90. In addition, the first switch circuit 81 is turned on, and the second switch circuit 82, the third switch circuit 83, and the fourth switch circuit 84 are turned off.

  Switching elements Q61 and Q62 of converter 60 perform a switching operation in accordance with a control signal supplied from control unit 90 to the gate. Thereby, the converter 60 steps down a DC voltage (for example, 1500 V) supplied from the overhead line to the power supply line PL to generate a stepped-down voltage (for example, 600 V to 1000 V), and stores the storage battery via the first switch circuit 81. 20 to charge the storage battery 20.

  2 is a diagram showing an example of a waveform of a control signal supplied to the converter of the electric vehicle shown in FIG. The control unit 90 alternately activates the control signals G1 and G2 supplied to the gates of the switching elements Q61 and Q62 to the high level, and sets the control signals G3 and G4 supplied to the gates of the switching elements Q63 and Q64 to the low level, respectively. Keep on level. Thereby, switching elements Q61 and Q62 are alternately turned on, and switching elements Q63 and Q64 remain off.

  Thereby, converter 60 operates as a step-down chopper that steps down the DC voltage supplied to power supply line PL and outputs the stepped-down voltage from nodes N1 and N2. The value of the step-down voltage can be controlled to a desired value by the duty of the control signal supplied to the gates of the switching elements Q61 and Q62.

  The step-down voltage is supplied to the storage battery 20 via the first switch circuit 81 and the inductor L2, and the storage battery 20 is charged. Thereby, in the DC electrification section, the storage battery 20 can be charged without impairing the driving capability for the main motor 30. When the storage battery 20 is sufficiently charged, the control unit 90 deactivates the control signals G1 to G4 to a low level, or controls the first switch circuit 81 to an off state.

<Second mode>
FIG. 3 is a diagram for explaining the operation in the second mode of the electric vehicle shown in FIG. In the second mode, electric vehicle 100 travels using an AC voltage supplied from an overhead line. For this purpose, the switching circuit 80 supplies the AC voltage supplied from the overhead wire to the input terminal 80 a to the primary side of the transformer 70. In addition, the first switch circuit 81 and the fourth switch circuit 84 are turned off, and the second switch circuit 82 and the third switch circuit 83 are turned on. The DC high speed circuit breaker 12, the start switch circuits 13 and 14, and the ground switch circuit 15 are turned off.

  The transformer 70 transforms an AC voltage (for example, 20 kV) supplied from the overhead line to the primary side, and outputs an AC voltage (for example, 800 V) from the secondary side. The AC voltage on the secondary side is supplied to the nodes N1 and N2 of the converter 60 via the equivalent reactance of the transformer 70 and the second switch circuit 82.

  Switching elements Q61 to Q64 of converter 60 perform a switching operation in accordance with a control signal supplied from control unit 90 to the gate. Thereby, converter 60 converts the AC voltage supplied from the secondary side of transformer 70 through second switch circuit 82 into a DC link voltage (for example, 600 V to 1000 V) and supplies it to power supply line PL. Note that the DC link voltage refers to a pulsating DC voltage generated between both ends of the capacitor C1. By increasing the capacitance of the capacitor C1, the pulsation amplitude of the DC link voltage can be reduced.

  FIG. 4 is a diagram showing an example of a waveform of a control signal supplied to the converter of the electric vehicle shown in FIG. The control unit 90 alternately activates the control signals G1 and G3 supplied to the gates of the switching elements Q61 and Q63, respectively, to the high level, and controls the control signals G2 and G4 supplied to the gates of the switching elements Q62 and Q64, respectively. Are alternately activated to a high level. Thereby, switching elements Q61 and Q63 are alternately turned on, and switching elements Q62 and Q64 are alternately turned on.

  Here, an example of a method for generating the control signals G1 to G4 will be described. In the upper part of FIG. 4, the waveforms of triangular wave carriers VC1 and VC2 having opposite phases and the waveform of a unit sine wave (modulated wave) VM synchronized with the AC voltage supplied from the overhead wire are shown. In the example shown in FIG. 4, the amplitudes of the triangular wave carriers VC1 and VC2 are normalized to “1”.

  The control unit 90 activates the control signal G1 to a high level and deactivates the control signal G3 to a low level during a period in which the modulation wave VM is larger than the triangular wave carrier VC1. In addition, the control unit 90 deactivates the control signal G1 to a low level and activates the control signal G3 to a high level during a period in which the modulated wave VM is smaller than the triangular wave carrier VC1.

  Furthermore, the control unit 90 activates the control signal G2 to a high level and deactivates the control signal G4 to a low level during a period in which the modulated wave VM is smaller than the triangular wave carrier VC2. In addition, the control unit 90 deactivates the control signal G2 to a low level and activates the control signal G4 to a high level during a period in which the modulated wave VM is larger than the triangular wave carrier VC2.

  As a result, when the DC link voltage generated across the capacitor C1 is Vd, the line voltage (voltage command value) Vc, which is the difference between the potential of the node N1 and the potential of the node N2, is In the positive half cycle, it alternately becomes “0” and Vd, and in the negative half cycle of the modulated wave VM, it becomes “0” and -Vd alternately.

  Thereby, converter 60 operates as a PWM (pulse width modulation) converter (rectifier) that converts the AC voltage supplied to nodes N1 and N2 into a DC link voltage and supplies it to power supply line PL. The value of the DC link voltage can be controlled to a desired value by the cycle or duty of the control signal supplied to the gates of the switching elements Q61 to Q64. The DC link voltage is supplied to the power supply line PL. Thereby, the DC link voltage is supplied to the inverter 50, and the electric vehicle 100 travels as the inverter 50 generates the drive voltage of the main motor 30 under the control of the control unit 90.

  Further, in the second mode, converter 60 supplies DC link voltage to storage battery 20 via third switch circuit 83 to charge storage battery 20. Thereby, the storage battery 20 can be charged even in the AC electrification section. During regeneration, the storage battery 20 may be charged using a DC voltage supplied from the inverter 50 to the power supply line PL.

  When the storage battery 20 is sufficiently charged, the control unit 90 may control the third switch circuit 83 to be in an off state. At the time of regeneration, after charging of the storage battery 20 is completed, the converter 60 may convert the DC voltage supplied from the inverter 50 to the power supply line PL into an AC voltage and supply it to the overhead line.

  In FIG. 3, a DC / DC converter may be provided before the inverter 50. In that case, the DC / DC converter can supply a high voltage (for example, 1500 V) to the inverter 50 by boosting the DC link voltage (for example, 600 V to 1000 V).

<Third mode>
FIG. 5 is a diagram for explaining an operation in the third mode of the electric vehicle shown in FIG. 1. In the third mode, the electric vehicle 100 travels using electric power supplied from the fuel cells FC1 and FC2 or the storage battery 20. Therefore, the first switch circuit 81 and the second switch circuit 82 are turned off, and the third switch circuit 83 and the fourth switch circuit 84 are turned on. The vacuum circuit breaker 11, the DC high speed circuit breaker 12, and the start switch circuits 13 and 14 may be turned off, and the ground switch circuit 15 may be turned off.

  The DC voltage output from the fuel cells FC1 and FC2 is supplied to the nodes N1 and N2 via the inductors L3 and L4, respectively. Switching elements Q63 and Q64 of converter 60 perform a switching operation in accordance with a control signal supplied from control unit 90 to the gate. Thereby, the converter 60 boosts a DC voltage (for example, 300V to 400V) supplied from the fuel cells FC1 and FC2 via the fourth switch circuit 84 to generate a boosted voltage (for example, 600V to 1000V). , Supplied to the power line PL.

  FIG. 6 is a diagram illustrating an example of a waveform of a control signal supplied to the converter of the electric vehicle illustrated in FIG. The control unit 90 maintains the control signals G1 and G2 supplied to the gates of the switching elements Q61 and Q62 at a low level, and alternately sets the control signals G3 and G4 supplied to the gates of the switching elements Q63 and Q64 to a high level. Activate. Thereby, switching elements Q61 and Q62 remain off, and switching elements Q63 and Q64 are alternately turned on.

  During the period in which the control signal G3 is activated to a high level, the switching element Q63 is turned on. Thereby, a current flows from the fuel cell FC1 to the ground line GL via the inductor L3, the fourth switch circuit 84, and the switching element Q63. At that time, electric energy is converted into magnetic energy and stored in the inductor L3 by the current flowing through the inductor L3. On the other hand, the diode D61 is turned off.

  On the other hand, switching element Q63 is turned off during a period in which control signal G3 is inactivated to a low level. At that time, the magnetic energy stored in the inductor L3 is released as electric energy, and a current flows from the fuel cell FC1 to the power supply line PL via the inductor L3, the fourth switch circuit 84, and the diode D61. .

  Similarly, switching element Q64 is turned on during a period in which control signal G4 is activated to a high level. Thereby, a current flows from the fuel cell FC2 to the ground line GL via the inductor L4, the fourth switch circuit 84, and the switching element Q64. At that time, electric energy is converted into magnetic energy and accumulated in the inductor L4 by the current flowing through the inductor L4. On the other hand, the diode D62 is turned off.

  On the other hand, switching element Q64 is turned off during a period in which control signal G4 is deactivated to a low level. At that time, the magnetic energy stored in the inductor L4 is released as electric energy, and a current flows from the fuel cell FC2 to the power supply line PL via the inductor L4, the fourth switch circuit 84, and the diode D62. .

  Thereby, converter 60 operates as a boosting chopper that boosts the DC voltage supplied to nodes N1 and N2 and supplies the boosted voltage to power supply line PL. The value of the boosted voltage can be controlled to a desired value by the duty of the control signal supplied to the gates of the switching elements Q63 and Q64. The boosted voltage is supplied to the power supply line PL. Thus, the boosted voltage is supplied to the inverter 50, and the main motor 30 can be driven using the power supplied from the fuel cells FC1 and FC2. Under the control of the control unit 90, the electric vehicle 100 travels when the inverter 50 generates the drive voltage of the main motor 30.

  In the third mode, converter 60 supplies boosted voltage to storage battery 20 via third switch circuit 83 to charge storage battery 20. Thereby, the storage battery 20 can be charged using the electric power supplied from the fuel cells FC1 and FC2. During regeneration, the storage battery 20 may be charged using a DC voltage supplied from the inverter 50 to the power supply line PL.

  When the storage battery 20 is sufficiently charged, the control unit 90 deactivates the control signals G1 to G4 to a low level, or controls the fourth switch circuit 84 to be in an off state, so that the electric vehicle 100 You may make it drive | work using the electric power supplied from 20. FIG.

  In FIG. 5, a DC / DC converter may be provided before the inverter 50. In that case, the DC / DC converter can supply a high voltage (eg, 1500 V) to the inverter 50 by boosting the boosted voltage (eg, 600 V to 1000 V).

  As described above, the control unit 90 controls the switching circuit 80 and the first switch circuit 81 to the fourth switch circuit 84, and causes the converter 60 to operate as a step-down chopper, a PWM converter, or a step-up chopper. A plurality of control signals are generated and supplied to the converter 60.

<Power conversion method>
Next, a power conversion method according to an embodiment of the present invention will be described with reference to FIG. 1, FIG. 3, FIG. 5, and FIG. FIG. 7 is a flowchart illustrating a power conversion method according to an embodiment of the present invention.

  In this power conversion method, as shown in FIG. 1, an inverter 50 that generates a drive voltage for the main motor 30 based on a DC voltage supplied from the power supply line PL, and the power supply line PL connected in parallel to the inverter 50. It is used in a power converter including a converter 60 and a transformer 70 that transforms an alternating voltage supplied to the primary side and outputs it from the secondary side.

  In step S1 illustrated in FIG. 7, the control unit 90 sets the power conversion device to any one of the first mode to the third mode. The electric vehicle 100 travels using the DC voltage supplied from the overhead line in the first mode, travels using the AC voltage supplied from the overhead line in the second mode, and operates in the third mode as the fuel. The vehicle travels using electric power supplied from the batteries FC1 and FC2 or the storage battery 20.

  Steps S2 to S4 shown in FIG. 7 represent the operation of the power conversion device in the first mode (see FIG. 1). First, in step S <b> 2, the control unit 90 electrically connects the second switch circuit 82 electrically connected between the secondary side of the transformer 70 and the converter 60, between the power supply line PL and the storage battery 20. The third switch circuit 83 connected and the fourth switch circuit 84 electrically connected between the fuel cells FC1 and FC2 and the converter 60 are controlled to be in an OFF state. In addition, the control unit 90 controls the first switch circuit 81 that is electrically connected between the converter 60 and the storage battery 20 to be in an ON state.

  In step S3, the control unit 90 controls the switching circuit 80 so that the DC voltage supplied to the input terminal 80a is supplied to the power supply line PL. As a result, a DC voltage is supplied to the inverter 50, and the electric vehicle 100 travels as the inverter 50 generates a drive voltage for the main motor 30 under the control of the control unit 90.

  In step S4, the control unit 90 reduces the direct current voltage supplied to the power supply line PL to generate a step-down voltage, and supplies the storage battery 20 via the first switch circuit 81 to charge the storage battery 20. The converter 60 is controlled. Thereby, in the DC electrification section, the storage battery 20 can be charged without impairing the driving capability for the main motor 30.

  Steps S5 to S7 shown in FIG. 7 represent the operation of the power conversion device in the second mode (see FIG. 3). First, in step S5, the control unit 90 controls the first switch circuit 81 and the fourth switch circuit 84 to the off state, and controls the third switch circuit 83 to the on state, and then the second switch circuit. 82 is controlled to be in an ON state.

  In step S6, the control unit 90 controls the switching circuit 80 so as to supply the AC voltage supplied to the input terminal 80a to the primary side of the transformer 70.

  In step S7, the control unit 90 controls the converter 60 so that the AC voltage supplied from the secondary side of the transformer 70 via the second switch circuit 82 is converted into a DC link voltage and supplied to the power supply line PL. To do. Thereby, the DC link voltage is supplied to the inverter 50, and the electric vehicle 100 travels as the inverter 50 generates the drive voltage of the main motor 30 under the control of the control unit 90. In addition, converter 60 supplies DC link voltage to storage battery 20 via third switch circuit 83 to charge storage battery 20.

  Steps S8 to S10 shown in FIG. 7 represent the operation of the power conversion device in the third mode (see FIG. 5). First, in step S8, the control unit 90 controls the first switch circuit 81 and the second switch circuit 82 to an off state, and controls the third switch circuit 83 and the fourth switch circuit 84 to an on state. To do.

  In step S9, the control unit 90 causes the converter 60 to boost the DC voltage supplied from the fuel cells FC1 and FC2 via the fourth switch circuit 84 to generate a boosted voltage and supply the boosted voltage to the power line PL. Control. Thereby, the boosted voltage is supplied to the inverter 50, and the electric vehicle 100 travels as the inverter 50 generates the drive voltage of the main motor 30 under the control of the control unit 90. The converter 60 supplies the boosted voltage to the storage battery 20 via the third switch circuit 83 to charge the storage battery 20.

  When the storage battery 20 is sufficiently charged, it is determined in step S10 whether or not only the storage battery 20 is used. When it is determined that only the storage battery 20 is used, in step S11, the control unit 90 deactivates the control signals G1 to G4 of the converter 60 to a low level, or turns off the fourth switch circuit 84. Control. Thereby, the electric vehicle 100 travels using electric power supplied only from the storage battery 20.

  According to the present embodiment, in the first mode, the DC voltage supplied to the input terminal 80a is supplied to the inverter 50, and the converter 60 steps down the DC voltage to generate a step-down voltage. Is supplied to the storage battery 20 via the switch circuit 81 and the storage battery 20 is charged. The electric power charged in the storage battery 20 can be used for driving the main motor 30 in the non-electrified section. In the second mode, the AC voltage supplied to the input terminal 80a is supplied to the transformer 70, and the converter 60 converts the AC voltage supplied via the transformer 70 and the second switch circuit 82 to the DC link voltage. And converted to the inverter 50.

  Therefore, the main motor 30 is driven in the DC electrification section, the AC electrification section, and the non-electrification section without increasing the circuit scale and the number of parts, and the driving capability for the main motor 30 is not impaired in the DC electrification section. The power converter device which can charge the storage battery 20 can be provided. Moreover, the power conversion method and power conversion program which are used in such a power converter device can be provided.

  Furthermore, according to the present embodiment, the vehicle can travel in a DC electrified section, an AC electrified section, and a non-electrified section without significantly increasing the weight of the vehicle. Electric vehicle 100 that can charge storage battery 20 without damage can be provided.

  The present invention is not limited to the embodiments described above, and many modifications can be made within the technical idea of the present invention by those having ordinary knowledge in the technical field.

  The present invention can be used in a power conversion device used in an electric vehicle such as a railway vehicle or an electric vehicle equipped with such a power conversion device.

  DESCRIPTION OF SYMBOLS 10 ... Pantograph, 11 ... Vacuum circuit breaker, 12 ... DC high speed circuit breaker, 13, 14 ... Switch circuit for starting, 15 ... Switch circuit for grounding, 20 ... Storage battery, 30 ... Main motor, 40 ... Power supply device for auxiliary circuit , 50 ... Inverter, 60 ... Converter, 70 ... Transformer, 80 ... Switching circuit, 80a ... Input terminal, 81 ... First switch circuit, 82 ... Second switch circuit, 83 ... Third switch circuit, 84 ... First 4 switch circuit, 90 ... control unit, 91 ... storage unit, 100 ... electric vehicle, FC1, FC2 ... fuel cell, R1 ... resistor, L1-L4 ... inductor, C1-C4 ... capacitor, Q51-Q64 ... switching element, D51-D64 ... Diode

Claims (10)

An inverter that generates a driving voltage for the main motor based on a DC voltage supplied from a power line;
A converter connected to the power line in parallel with the inverter;
A transformer that transforms an AC voltage supplied to the primary side and outputs it from the secondary side;
A switching circuit for supplying a DC voltage supplied to the input terminal to the power supply line in the first mode, and supplying an AC voltage supplied to the input terminal to the primary side of the transformer in the second mode; ,
A first switch circuit that is electrically connected between the converter and the storage battery and is turned on in the first mode and turned off in the second mode;
A second switch circuit that is electrically connected between the secondary side of the transformer and the converter, and is turned off in the first mode and turned on in the second mode;
And the converter generates a step-down voltage by stepping down a DC voltage supplied to the power line in the first mode, and supplies the stepped-down voltage to the storage battery via the first switch circuit. In the second mode, the AC voltage supplied from the secondary side of the transformer through the second switch circuit is converted into a DC link voltage and supplied to the power line. apparatus. A third switch circuit that is electrically connected between the power line and the storage battery and is turned off in the first mode and turned on in the second mode;
The power converter according to claim 1 with which said converter supplies a direct-current link voltage to said storage battery via said 3rd switch circuit, and charges said storage battery in said 2nd mode. A fourth switch circuit electrically connected between the fuel cell and the converter, wherein the fourth switch circuit is turned off in the first and second modes and turned on in the third mode;
In the third mode, the first and second switch circuits are turned off, and the converter boosts the DC voltage supplied from the fuel cell via the fourth switch circuit. The power converter according to claim 1, wherein a voltage is generated and supplied to the power supply line.   In the third mode, the third switch circuit is turned on, and the converter supplies the boosted voltage to the storage battery via the third switch circuit to charge the storage battery. 3. The power conversion device according to 3.   In the first mode, the converter operates as a step-down chopper that steps down a DC voltage supplied to the power supply line and outputs a stepped-down voltage from a plurality of nodes. In the second mode, the converter operates the plurality of nodes. Operates as a PWM converter that converts the AC voltage supplied to the DC link voltage and supplies it to the power supply line. In the third mode, the DC voltage supplied to the plurality of nodes is boosted to increase the boosted voltage. The power converter device of Claim 3 or 4 which operate | moves as a pressure | voltage rise chopper supplied to the said power supply line.   The switching circuit and the first to fourth switch circuits are controlled, and a plurality of control signals are generated and supplied to the converter so as to operate the converter as a step-down chopper, a PWM converter, or a step-up chopper. The power converter according to any one of claims 3 to 5, further comprising a control unit.   The controller sets the power converter to the first mode when the DC voltage supplied to the input terminal is greater than a first threshold, and the AC voltage supplied to the input terminal is The power conversion device according to claim 6, wherein the power conversion device is set to the second mode when greater than a threshold value of 2.   An electric vehicle provided with the power converter device of any one of Claims 1-7. An inverter that generates a driving voltage for the main motor based on a DC voltage supplied from a power line, a converter connected to the power line in parallel with the inverter, and an AC voltage supplied to the primary side are transformed. A power conversion method used in a power conversion device including a transformer that outputs from a secondary side,
In the first mode, the first switch circuit electrically connected between the converter and the storage battery is controlled to be turned on, and is electrically connected between the secondary side of the transformer and the converter. Controlling the switched second switch circuit to an off state;
(B) controlling the switching circuit to supply a DC voltage supplied to the input terminal to the power supply line in the first mode;
In the first mode, the converter is configured to step down a DC voltage supplied to the power supply line to generate a step-down voltage, and supply the storage battery via the first switch circuit to charge the storage battery. Step (c) for controlling
In the second mode, the step (d) of controlling the first switch circuit to an OFF state and controlling the second switch circuit to an ON state;
(E) controlling the switching circuit to supply an alternating voltage supplied to the input terminal to the primary side of the transformer in the second mode;
In the second mode, the converter is controlled to convert an AC voltage supplied from the secondary side of the transformer via the second switch circuit into a DC link voltage and supply it to the power line. (F) and
A power conversion method comprising: An inverter that generates a driving voltage for the main motor based on a DC voltage supplied from a power line, a converter connected to the power line in parallel with the inverter, and an AC voltage supplied to the primary side are transformed. A power conversion program used in a power conversion device including a transformer that outputs from a secondary side,
In the first mode, the first switch circuit electrically connected between the converter and the storage battery is controlled to be turned on, and is electrically connected between the secondary side of the transformer and the converter. A step (a) for controlling the second switch circuit that has been switched to an OFF state;
In the first mode, a procedure (b) for controlling the switching circuit so as to supply the DC voltage supplied to the input terminal to the power supply line;
In the first mode, the converter is configured to step down a DC voltage supplied to the power supply line to generate a step-down voltage, and supply the storage battery via the first switch circuit to charge the storage battery. A procedure (c) for controlling
In the second mode, the step (d) of controlling the first switch circuit to an off state and controlling the second switch circuit to an on state;
A step (e) of controlling the switching circuit so as to supply an alternating voltage supplied to the input terminal to the primary side of the transformer in the second mode;
In the second mode, a procedure for controlling the converter to convert an AC voltage supplied from the secondary side of the transformer via the second switch circuit into a DC link voltage and supply it to the power line. (F) and
The power conversion program which makes CPU execute.

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