JP2015061392A - Voltage converter, electric motor vehicle, voltage conversion method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voltage converter, electric motor vehicle, voltage conversion method, and program, capable of switching between use of a fuel cell in a non-electrification section and use of an AC power supply from a wiring in an AC electrification section and converting a DC voltage output from the fuel cell with one converter and an AC voltage output from a transformer on AC power supply side into a DC voltage.SOLUTION: The voltage converter includes a switch and a voltage conversion control section. The switch switches a connection so that either one of an AC voltage and a DC voltage is input into a converter. The voltage conversion control section executes control for switching the switch, changes control for the converter by whether an AC voltage is input or a DC voltage is input into the converter, and causes the converter to output a DC voltage.

Description

  Embodiments described herein relate generally to a voltage conversion device, an electric vehicle, a voltage conversion method, and a program.

  Research on the application of fuel cells to railway vehicles is being conducted by various companies and institutions. As one of the technologies for applying a fuel cell to a railway vehicle, a hybrid railway vehicle having a fuel cell as one of power sources has been devised (see, for example, Patent Document 1 and Non-Patent Documents 1 to 4).

JP 2008-131835 A

Ryosuke Furuta, 1 other person, “Development of Fuel Cell Hybrid Vehicle in JR East”, Railway Vehicle and Technology, Rail and Tech Publishing, 2007, No. 129, p. 2-9 Takamitsu Yamamoto, “Development of Fuel Cell Railway Vehicles at Railway Technical Research Institute”, Railway Vehicles and Technology, Rail and Tech Publishing, 2007, No. 129, p. 10-13 Yasuhiro Yasu, two others, “Railway Research Institute Kuya R291 Series”, Railway Fan, Koyusha, 2006, January 2007, p. 60-63 “Fuel Cell Hybrid Railway Vehicle”, Railway Fan, Koyusha, 2006, January 2007, p. 66

  By the way, as for the electrification situation of the railway vehicle, there is a tendency that the area where the operation frequency of the railway vehicle is high is DC electrification, the area where the railway vehicle is low is non-electrified, and the area between them is AC electrification. Therefore, there are more cases where the AC electrification section is adjacent to the non-electrification section than the DC electrification section. Therefore, as a railway vehicle to which a fuel cell is applied, there has been a demand for a technique capable of switching between a case where a fuel cell is used in a non-electrified section and a case where an AC power source from an overhead line is used in an AC electrified section. In addition, there is a need for a technique that can convert a DC voltage output from a fuel cell and an AC voltage output from a transformer on the AC power source into a DC voltage by a single converter.

  The problem to be solved by the present invention is that it is possible to switch between using a fuel cell in a non-electrified section and using an AC power source from an overhead line in an AC electrified section. Is to provide a voltage converter, an electric vehicle, a voltage conversion method, and a program capable of converting the DC voltage output by the converter and the AC voltage output by the transformer on the AC power supply side into a DC voltage.

  The voltage conversion device of the present invention includes a switch and a voltage conversion control unit. The switch is switched so that either an AC voltage or a DC voltage is input to the converter. The voltage conversion control unit performs control to switch the switch, changes the control for the converter between when the AC voltage is input to the converter and when the DC voltage is input, and causes the converter to output the DC voltage.

It is a figure which shows the example of the electric vehicle 1 provided with the voltage converter 10 by 1st embodiment. It is a figure which shows the example of the processing flow of the electric vehicle 1 provided with the voltage converter 10 by 1st embodiment. It is a figure which shows the example of the control signal which controls the converter 103, when AC voltage 1500V is applied to the converter 103 with which the voltage converter 10 is provided. It is a figure which shows the example of the control signal which controls the converter 103, when DC voltage 500V is applied to the converter 103 with which the voltage converter 10 is provided. It is a figure which shows the example of the electric vehicle 1 provided with the voltage converter 10 by 2nd embodiment.

  Hereinafter, a voltage conversion device, an electric vehicle, a voltage conversion method, and a program according to embodiments will be described with reference to the drawings.

<First embodiment>
FIG. 1 is a diagram illustrating an example of an electric vehicle 1 including a voltage conversion device 10 according to the first embodiment.
As shown in FIG. 1, the electric vehicle 1 according to the first embodiment includes a voltage conversion device 10, a pantograph 20, a vacuum circuit breaker 30, a transformer 40, a fuel cell 50, and a static auxiliary power supply for an auxiliary circuit. Device 60, filter capacitor 70, battery 80, brake chopper 90, inverter 100, induction motor 110, inductor 120 (120a, 120b), and inductor 130 (130a, 130b) are provided.

The voltage conversion apparatus 10 according to the first embodiment is a functional unit that inputs an AC voltage or a DC voltage and creates a DC voltage. The voltage conversion device 10 includes a switch 101, a voltage conversion control unit 102, and a converter 103.
The switch 101 is a functional unit that switches the connection so that either an AC voltage or a DC voltage is input to the converter 103. The switch 101 includes a switch 101a and a switch 101b. Each of the switch 101a and the switch 101b switches between two connection destinations.
The voltage conversion control unit 102 is a functional unit that performs control to switch the switch 101. The voltage conversion control unit 102 is a control unit that changes the control of the converter 103 depending on whether an AC voltage is input to the converter 103 or a DC voltage, and causes the converter 103 to output the DC voltage.
The converter 103 is a functional unit that outputs a DC voltage based on control by the voltage conversion control unit 102. Converter 103 includes switching elements Q1 to Q4. The switching elements Q1 to Q4 are, for example, IGBTs (Insulated Gate Bipolar, Transistor).

The pantograph 20 is a functional unit that is attached on the roof of the electric vehicle 1 and collects electrical energy from an overhead line.
The vacuum circuit breaker 30 is a functional unit that cuts off when an accident current, in particular, a short-circuit accident current occurs, and protects the load side device. The vacuum circuit breaker 30 is also referred to as VCB (Vacuum Circuit Breaker).

The transformer 40 is a functional unit that converts a transformer primary voltage into a transformer secondary voltage based on the relationship between the transformer primary side and the transformer secondary side. The transformer 40 includes a transformer primary side 40a and a transformer secondary side 40b.
The fuel cell 50 is a functional unit that generates electrical energy by chemically reacting the positive electrode agent and the negative electrode agent. The fuel cell 50 can generate electric energy by continuing to replenish both the positive electrode agent and the negative electrode agent.
For example, the fuel cell 50 chemically generates oxygen as a positive electrode agent and hydrogen as a negative electrode agent, and generates electric energy by utilizing a reaction opposite to the electrolysis of water. Most of the waste discharged when the fuel cell 50 generates electric energy is water, which is an environmentally friendly energy source.

The auxiliary auxiliary power supply 60 for auxiliary circuits is a functional unit that converts a DC voltage into an AC voltage in place of the failed inverter 100 or other device when the inverter 100 or other device fails. The static auxiliary power supply device 60 for auxiliary circuits has a function of replacing a device with a high failure rate, and the devices with a low failure rate are made common to reduce the size.
With this auxiliary auxiliary static power supply device 60 for the auxiliary circuit, for example, even if the inverter 100 fails, it is not necessary to reduce the load such as an air conditioner or a reduction operation, and it is possible to improve the service.

The filter capacitor 70 is a functional unit that smoothes the DC voltage output from the converter 103.
The battery 80 is a functional unit that compensates for power that is insufficient from the power supplied from the overhead line or the power supplied from the fuel cell 50 via the pantograph 20.

The brake chopper 90 is a functional unit that controls the current flowing through the resistor R1 that functions as a brake resistor. The bipolar transistor Q5, which is a power transistor, operates as a chopper element, and the diode D1 operates as a freewheeling diode.
The diode D1 circulates the current flowing through the resistor R1, which is a brake resistor, at the timing when the bipolar transistor Q5 is turned off. Bipolar transistor Q5 and diode D1 also control the rate of current flowing through resistor R1. Thereby, the extra electric power which cannot be regenerated can be consumed appropriately.

The inverter 100 is a functional unit that converts the DC voltage input from the converter 103 into an AC voltage necessary for the operation of the induction motor 110.
The induction motor 110 is a functional unit that drives the wheels of the electric vehicle 1.
The inductor 120 is a functional unit that determines the voltage output by the voltage conversion device 10 by boosting the output voltage of the fuel cell 50.
The inductor 130 is a functional unit that stabilizes the output current of the battery 80 at the output voltage.

FIG. 2 is a diagram illustrating an example of a processing flow of the electric vehicle 1 including the voltage conversion device 10 according to the first embodiment.
Next, the processing flow of the electric vehicle 1 including the voltage conversion device 10 according to the first embodiment will be described by taking as an example a case where the traveling section of the electric vehicle 1 changes from an AC electrified section to a non-electrified section.

  For example, when an AC voltage of 20000 volts is applied to the overhead line and the pantograph 20 included in the electric vehicle 1 is in contact with the overhead line, an AC voltage of 20000 volts is applied to the transformer primary side 40a of the transformer 40 included in the electric vehicle 1. The voltage conversion control unit 102 included in the voltage conversion device 10 determines whether or not a predetermined voltage is applied to the transformer primary side 40a (step S1).

At this time, the voltage conversion control unit 102 detects the voltage applied to the transformer primary side 40a, and when the detected voltage exceeds a predetermined threshold, the predetermined voltage is applied to the transformer primary side 40a. (Step S1, YES). Then, the voltage conversion control unit 102 performs control so that the switch 101 (101a, 101b) is connected to the transformer secondary side 40b (step S2).
The transformer 40 converts an AC voltage of 20000 volts into, for example, an AC voltage of 1500 volts based on the relationship such as the coil turn ratio between the transformer primary side 40a and the transformer secondary side 40b (step S3).
When switch 101 is connected to transformer secondary side 40b, an AC voltage of 1500 volts on transformer secondary side 40b is applied to converter 103 (step S4).

FIG. 3 is a diagram illustrating an example of a control signal for controlling the converter 103 when the switch 101 is connected to the transformer secondary side 40b.
The voltage conversion control unit 102 controls the switch 101 to be connected to the transformer secondary side 40b. Voltage conversion control section 102 controls the gate voltage of IBGT (Insulated Gate Bipolar Transistor), which is switching elements Q1-4 provided in converter 103, using the control signal shown in FIG.
In this case, the voltage conversion control unit 102 performs control to make the gate voltages of all the switching elements Q1 to Q4 zero (step S5).

In the half-wave section where the terminal voltage on the switch secondary side 40b of the transformer secondary side 40b is higher than the terminal voltage of the switch 101b on the transformer secondary side 40b, the switch 101a, the switching element Q1, the filter capacitor 70 (and the filter capacitor 70 are connected in parallel). Current), the switching element Q4, and the switch 101b in this order.
Further, in the half-wave section where the terminal voltage on the switch 101a side of the transformer secondary side 40b is lower than the terminal voltage of the switch 101b on the transformer secondary side 40b, the switch 101b, the switching element Q2, the filter capacitor 70 (and the filter capacitor 70) Other loads connected in parallel), the current flows in the order of the switching element Q3 and the switch 101a.
By alternately repeating these half-wave sections, converter 103 converts AC voltage 1500 volts into DC voltage 1500 volts, for example, based on the operation of the single-phase rectifier bridge of the CR parallel load (step S6).

In the process of step S1, when the voltage conversion control unit 102 determines that the voltage applied to the transformer primary side 40a does not exceed a predetermined threshold value (NO in step S1). The voltage conversion control unit 102 controls the switch 101 to be connected to the fuel cell 50 (step S7).
When the switch 101 is connected to the fuel cell 50, a DC voltage of 500 volts, for example, the voltage of the fuel cell 50 is applied to the converter 103 (step S8).

FIG. 4 is a diagram illustrating an example of a control signal for controlling the converter 103 when the switch 101 is connected to the fuel cell 50.
When the voltage conversion control unit 102 controls the switch 101 to be connected to the fuel cell 50, the voltage conversion control unit 102 controls the gate voltage of the IBGT, which is the switching elements Q1 to 4 included in the converter 103, using the control signal shown in FIG. .
In this case, the voltage conversion control unit 102 controls the gate voltage timing, cycle, duty ratio, and the like so that the gate voltages of the switching elements Q1 and Q2 become zero and are turned on alternately according to the amount of current flowing through Q3 and Q4. (Step S9).

In a section in which the gate voltage is applied and the switching element Q3 is turned on, the diode of the switching element Q1 is turned off. A current flows in the order of the switch 101a, the switching element Q3, and the fuel cell 50. Further, in a section in which the gate voltage is applied and the switching element Q3 is turned off, the diode of the switching element Q1 is turned on. Then, the current flows in the order of the switch 101a, the diode of the switching element Q1, the filter capacitor 70 (and other loads connected in parallel to the filter capacitor 70), and the fuel cell 50.
Similarly, in a section in which the gate voltage is applied and the switching element Q4 is turned on, the diode of the switching element Q2 is turned off. A current flows in the order of the switch 101b, the switching element Q4, and the fuel cell 50. Further, in a section in which the gate voltage is applied and the switching element Q4 is turned off, the diode of the switching element Q2 is turned on. A current flows in the order of the switch 101b, the diode of the switching element Q2, the filter capacitor 70 (and other loads connected in parallel to the filter capacitor 70), and the fuel cell 50.
By repeating these sections, the converter 103 converts the DC voltage of 500 volts into, for example, the DC voltage of 1500 volts based on the operation of the DC boost chopper of the CR parallel load (step S10).

Converter 103 outputs to inverter 100 DC voltage 1500 volts converted in step S6 or step S10.
When the inverter 100 receives a DC voltage of 1500 volts from the converter 103 (step S11), the inverter 100 converts the DC voltage of 1500 volts into, for example, the induction motor 110 (110a, 110b, 110c, 110d) is converted into a three-phase AC voltage 0 to 1500 volts for driving (step S12).
The inverter 100 may be any inverter that can convert a DC voltage into an AC voltage that can be driven by the induction motor 110. The inverter 100 is, for example, a VVVF (Variable Voltage Variable Frequency) inverter.

Inverter 100 outputs converted AC voltage 0 to 1500 volts to induction motor 110. When the induction motor 110 receives an AC voltage of 0 to 1500 volts, the induction motor 110 drives the wheels according to the input AC voltage (step S13).
Note that the battery 80 may be used in parallel for the voltage source of either the overhead line or the fuel cell 50. Further, the brake chopper 90 may consume energy that cannot be regenerated during regenerative braking. Further, when the inverter 100 or other device fails, the auxiliary auxiliary static power supply device 60 for the auxiliary circuit may convert the DC voltage into an AC voltage in place of the failed inverter 100 or other device.

As described above, the electric vehicle 1 includes the voltage conversion device 10. The voltage conversion device 10 includes a switch 101 and a voltage conversion control unit 102. The connection of the switch 101 is switched so that either an AC voltage or a DC voltage is input to the converter 103. The voltage conversion control unit 102 performs control to switch the switch 101, changes the control for the converter 103 between when an AC voltage is input to the converter 103 and when a DC voltage is input, and outputs the DC voltage to the converter 103. Let Moreover, the voltage conversion control part 102 is controlled so that the gate voltage which turns off the switching elements Q1-4 which comprise the converter 103 is applied when an AC voltage is detected, thereby making the converter 103 a single-phase rectifier bridge. Make it work. The voltage conversion control unit 102 controls the converter 103 to be a single-phase rectifier bridge by controlling the switching elements Q1 to Q4 constituting the converter 103 to be turned off when an AC voltage is detected. To act as. Further, the voltage conversion control unit 102 controls the converter 103 to be DC by controlling the switching elements Q3 and Q4 constituting the converter 103 to be turned on and off when the AC voltage is not detected. Operate as a boost chopper.
By doing so, it is possible to switch between the case where the fuel cell 50 is used in the non-electrified section and the case where the AC power supply from the overhead line is used in the AC electrified section. The direct current voltage and the alternating current voltage output from the transformer 40 on the alternating current power source side can be converted into direct current voltage.

<Second Embodiment>
FIG. 5 is a diagram illustrating an example of the electric vehicle 1 including the voltage conversion device 10 according to the second embodiment.
As shown in FIG. 5, the electric vehicle 1 according to the second embodiment further includes switches 140, 150, 160 a, and 160 b with respect to the electric vehicle 1 according to the first embodiment.
By doing so, the electric vehicle 1 according to the first embodiment is an AC dual mode train with the fuel cell 50, whereas the electric vehicle 1 according to the second embodiment is AC / DC connected with the fuel cell 50. A dual-mode train is realized.
In addition, the voltage converter 10 by 2nd embodiment is the structure similar to the voltage converter 10 by 1st embodiment.

The electric vehicle 1 according to the second embodiment controls the switch 140 and the switch 150 so that the AC power source from the overhead line is used in the AC electrification section and the DC power source from the overhead line is used in the DC electrification section. Switch.
Specifically, when the electric vehicle 1 is traveling in the AC electrification section, for example, the voltage conversion control unit 102 controls the switches 140 and 150 to be connected to the “A” side shown in FIG. At this time, the electric vehicle 1 according to the second embodiment is the same as the case where the electric vehicle 1 according to the first embodiment detects an AC voltage of 20000 volts, and a description thereof will be omitted.

Further, when the electric vehicle 1 is traveling in the DC electrification section, for example, the voltage conversion control unit 102 controls the switches 140 and 150 to be connected to the “B” side shown in FIG.
When the switches 140 and 150 are connected to the “B” side, for example, a DC voltage of 1500 volts is applied to the inverter 100 from the overhead wire. The processing performed by the electric vehicle 1 thereafter is the same as S11 to S13 in the processing flow of the electric vehicle 1 according to the first embodiment shown in FIG.
The switches 160a and 160b are switches for connecting the battery 80 to the input of the inverter 100 as necessary.

As described above, the electric vehicle 1 includes the voltage conversion device 10, the switch 140, and the switch 150. The voltage conversion device 10 includes a switch 101 and a voltage conversion control unit 102. The connection of the switch 101 is switched so that either an AC voltage or a DC voltage is input to the converter 103. The voltage conversion control unit 102 performs control to switch the switch 101, changes the control for the converter 103 between when an AC voltage is input to the converter 103 and when a DC voltage is input, and outputs the DC voltage to the converter 103. Let Moreover, the voltage conversion control part 102 is controlled so that the gate voltage which turns off the switching elements Q1-4 which comprise the converter 103 is applied when an AC voltage is detected, thereby making the converter 103 a single-phase rectifier bridge. Make it work. The voltage conversion control unit 102 controls the converter 103 to be a single-phase rectifier bridge by controlling the switching elements Q1 to Q4 constituting the converter 103 to be turned off when an AC voltage is detected. To act as. Further, the voltage conversion control unit 102 controls the converter 103 to be DC by controlling the switching elements Q3 and Q4 constituting the converter 103 to be turned on and off when the AC voltage is not detected. Operate as a boost chopper.
By doing so, it is possible to switch between the case where the fuel cell 50 is used in the non-electrified section and the case where the AC power supply from the overhead line is used in the AC electrified section. The direct current voltage and the alternating current voltage output from the transformer 40 on the alternating current power source side can be converted into direct current voltage. Moreover, the electric vehicle which can respond also to a direct current electrification area is realizable.

  According to the voltage conversion device 10 of the embodiment described above, it is possible to switch between the case where the fuel cell 50 is used in the non-electrified section and the case where the AC power from the overhead line is used in the AC electrified section. In 103, the DC voltage output from the fuel cell 50 and the AC voltage output from the AC power supply-side transformer 40 can be converted into a DC voltage.

  In addition, although embodiment was described, the above-mentioned voltage converter 10 may have a computer system inside. The process described above is stored in a computer-readable recording medium in the form of a program, and the above process is performed by the computer reading and executing this program. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. Various omissions, replacements, and changes can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 10 ... Voltage converter 20 ... Pantograph 30 ... Vacuum circuit breaker 40 ... Transformer 40a ... Transformer primary side 40b ... Transformer secondary side 50 ... Fuel cell 60 ... Auxiliary Static auxiliary power supply for circuit 70 ... Filter capacitor 80 ... Battery 90 ... Brake chopper 100 ... Inverter 101, 101a, 101b, 140, 150, 160a, 160b ... Switch 102 ... Voltage conversion control unit 103 ... converters 110, 110a, 110b, 110c, 110d ... induction motor D1 ... diodes 120a, 120b, 130, 130a, 130b ... inductors Q1, Q2, Q3, Q4 ...・ IGBT (Insulated Gate Bipolar Transistor)
Q5 ... Bipolar transistor R1 ... Resistor

Claims (9)

A switch for switching the connection so that either one of the AC voltage and the DC voltage is input to the converter;
A voltage conversion control unit that performs control to switch the switch, changes control for the converter between when an AC voltage is input to the converter and when a DC voltage is input, and causes the converter to output a DC voltage; A voltage conversion device comprising: The voltage conversion controller is
The switch is connected so that the AC voltage is input to the converter when the AC voltage is detected, and the switch is connected so that the DC voltage is input to the converter when the AC voltage is not detected. The voltage converter according to claim 1, wherein the voltage converter is connected. The voltage conversion controller is
By controlling so that the voltage that turns off the switching element that constitutes the converter when the AC voltage is detected is applied to the gate, it operates as a single-phase rectifier bridge,
2. The operation as a DC boosting chopper by controlling the switching element that constitutes the converter to be turned on and off so as to be applied to the gate when the AC voltage is not detected. The voltage converter according to claim 2. The voltage conversion controller is
The voltage converter according to any one of claims 1 to 3, wherein the control for the converter is changed based on a timing at which the switch is switched. The AC voltage is
It is the voltage of the transformer secondary power supply that outputs a lower voltage than the power supply of the transformer primary connected to the AC power supply,
The voltage conversion device according to any one of claims 1 to 4, wherein the DC voltage is a voltage output from a fuel cell. In the AC electrification section, it is connected to the transformer side, and in the DC electrification section, it has two switches connected to the output of the converter,
The voltage converter according to any one of claims 1 to 5, wherein: An electric vehicle comprising the voltage conversion device according to any one of claims 1 to 6. Control to switch,
The connection is switched so that either AC voltage or DC voltage is input to the converter.
A voltage conversion method, wherein the control for the converter is changed depending on whether an AC voltage is input to the converter or a DC voltage is input to the converter, and the DC voltage is output to the converter. The voltage converter computer,
Switch means for switching the connection so that either one of the AC voltage and the DC voltage is input to the converter;
Voltage conversion control means for performing control to switch the switch means, changing control for the converter between when an AC voltage is input to the converter and when a DC voltage is input, and outputting the DC voltage to the converter A program to make it work.

Images