JP3477068B2 - Electric car power supply - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for an electric vehicle capable of traveling on an AC overhead line and a DC overhead line.

[0002]

2. Description of the Related Art FIG. 6 shows a power supply configuration of a conventional electric vehicle using a converter / inverter. In this system, when traveling on the AC overhead wire 1, power is supplied through the pantograph 2 → high-speed circuit breaker 3 → contact a of the converter 4 → transformer 14, and the contactor 13 is connected from the secondary side of the transformer 14. A single-phase AC power supply is supplied to the converter circuit 19 via the converter circuit 19. The converter circuit 19 is a device for converting the AC voltage Vac into the DC voltage Vd, and the controller 17 controls the DC voltage Vd to be constant. The induction motor 21 is a three-phase inverter circuit 2
0 is supplied with electric power and driven. Where 24
Is a capacitor for smoothing the DC voltage Vd, and 18 is a control device for the inverter.

The charging circuit composed of the charging resistor 12 and the contactors 11 and 13 has a smoothing capacitor 2 when the main circuit is started.
4 suppresses the current flowing through the contactor 13, and the contactor 13
Is opened, the charging current is supplied to the converter circuit 19 via the contactor 11 and the charging resistor 12, and after the charging current becomes zero, the contactor 13 is closed and the contactor 11 is opened to open the converter circuit 19 To start.

When the DC overhead wire 1 is operated, DC power is supplied through the route of pantograph 2-> high-speed circuit breaker 3-> contact b of converter 4-> contactor 5-> contactor 8-> DC reactor 9. In this case, the operations and functions of the contactors 6 and 8 and the charging resistor 7 of the charging circuit are the same as in the case of the AC operation described above.

[0005]

However, in the conventional electric vehicle, the charging circuit is provided for each of the AC and DC power supplies, and the smoothing reactor 9 is required in the case of the DC power supply. Therefore, there have been major problems in promoting weight reduction and cost reduction of the system.

In the case of a DC overhead wire, the voltage is greatly affected by the running of another vehicle and the voltage fluctuation is large. In particular, when the voltage of the overhead wire decreases, it becomes impossible to run at a predetermined speed, and normal operation management cannot be performed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a power supply device for an electric vehicle, which can omit a DC smoothing reactor and can be used as a charging circuit for one AC and DC power supply.

[0008]

In order to solve the above-mentioned problems, a power supply device for an electric vehicle according to claim 1 of the present invention converts DC power into AC power by an inverter in a DC section, and in an AC section. In a power supply device for an electric vehicle that is capable of traveling in a direct current section and an alternating current section by converting alternating current power obtained through a transformer into direct current by a converter and then reconverting it into alternating current by an inverter, the transformer and the converter. An opening / closing means is provided between the switching means and the transformer, and a DC power is supplied between the opening / closing means and the transformer,
In the DC section, the switching means is opened and the DC power is supplied through the winding of the transformer. Thereby, the conventional smoothing reactor for direct current can be omitted.

According to a second aspect of the present invention, there is provided an electric vehicle power source device according to the first aspect, wherein the electric vehicle power source device is inserted between the transformer and the opening / closing means, and the charging circuit and A structure for supplying direct-current power between the switching means and the opening / closing means in the direct-current section, and supplying the direct-current power through the charging circuit and the winding of the transformer. And As a result, one charging circuit can be used for both AC and DC power supplies.

According to a third aspect of the present invention, there is provided an electric vehicle power source device according to the first aspect, wherein the DC output from the converter is supplied to the inverter via a charging circuit and a smoothing capacitor. It is configured to be supplied and converted back to AC power. As a result, one charging circuit can be used for both AC and DC power supplies.

According to a fourth aspect of the present invention, there is provided the electric vehicle power source device according to any one of the first to third aspects, wherein in the direct current section, a switching element that constitutes the converter is provided. The chopper operation is performed by using this. As a result, the DC voltage of the inverter can be controlled to be constant even if the voltage of the DC overhead wire changes.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a power supply device for an electric vehicle showing a first embodiment of the present invention. It should be noted that configurations having the same functions as those of the related art are denoted by the same reference numerals. DC or AC power from the overhead line 1 is transferred from the pantograph 2 to the high-speed circuit breaker 3
After being input to the converter 4, the DC power is converted into AC power by the inverter circuit 20 in the DC section, and the AC power obtained via the transformer 14 is converted into DC by the converter circuit 19 in the AC section, and then the inverter circuit is used. The induction motor 21 is driven by reconverting to AC by 20 so that the DC section and the AC section can travel.

A contactor (switching means) 22 is provided between the transformer 14 and the converter circuit 19, and the transformer 14 is further provided.
A charging circuit including the contactors 11 and 13 and the charging resistor 12 is provided between the contactor 22 and the contactor 22, and DC power is supplied to a connection point A between the charging circuit and the contactor 22. In the DC section, the contactor 22 is released and DC power is supplied through the charging circuit and the secondary winding of the transformer 14.

FIG. 2 shows a power supply configuration when a two-level converter is used for the converter / inverter in this embodiment. However, the switching element is composed of a self-turn-off type element in which a diode is connected in antiparallel.

Next, the power supply of the shift vehicle will be described with reference to FIG. If the voltage supplied from overhead line 1 is DC,
The contactor 22 opens, the contactor 23 closes, and the contact wire 1 → pantograph 2 → high-speed circuit breaker 3 → contact b of the converter 4 → contactor 5
→ Contactor 13 → Transformer 14 → Element QVC is supplied in the route. In this case, by using the secondary winding of the transformer 14 as a substitute for the function of the conventional smoothing reactor 9,
Even if a short circuit failure occurs in the main circuit and an excessive short circuit current flows, it can be suppressed.

When the supply voltage from the overhead line 1 is AC, the contactor 22 is closed and the contactor 23 is opened, and the overhead line 1 →
Power is supplied through the pantograph 2-> high-speed circuit breaker 3-> contact a of the converter 4-> the transformer 14, and single-phase AC power is supplied from the secondary side of the transformer 14 to the converter circuit 19 via the contactor 13. To be done.

FIG. 3 is a block diagram of a power supply device for an electric vehicle showing a second embodiment of the present invention, and FIG. 4 shows an equivalent circuit of its main circuit. The overhead wire voltage is Es, the reactor substituted with the secondary winding of the transformer 14 is L, the element QYC is SW, the anti-parallel diode of the element QVC is D, the smoothing capacitor 24 is C, and the DC voltage of the inverter is replaced with Vd to boost the voltage. It constitutes a chopper circuit.

Therefore, when the element QYC (SW) is turned on / off, the reactor L is turned on when the element QYC is turned on.
When the element QYC is off, the stored energy and the energy from the overhead wire voltage are supplied to the load to raise the voltage. In this case, the relationship between the overhead wire voltage Es and the load voltage Vd can be expressed by the following equation.

Vd = ((ton + toff) / toff) Es However, ton: On time toff: Off time ton + toff: Keep constant.

In FIG. 3, 25 is a DC voltage detector, 3
6 is a voltage control circuit, 27 is an amplifier circuit, 28 is a triangular wave generator, 30 is a gate circuit, 26 and 28 are comparators,
Let Vds be the DC voltage command value and Vd be the voltage value of the main circuit.

Next, the operation of this embodiment will be described. When operating at DC voltage, command value Vds and detection value Vd
Are compared by the comparator 26, and the deviation e is input to the comparator 29 via the amplifier circuit 27. The comparator 29 compares the triangular wave from the triangular wave generator 28 and outputs the voltage command ed to the gate circuit 30. The gate circuit 30 gives a gate signal Gyc to the element QYC to operate the element QYC in a chopper operation.

Therefore, the switching element QYC is turned on.
By controlling the OFF duty, the DC voltage Vd can always be controlled to be constant.

FIG. 5 is a block diagram of a power supply device for an electric vehicle showing a third embodiment of the present invention. It should be noted that the configuration of the same function as the conventional one is shown by the same reference numeral, and only the difference from the first embodiment will be described. Transformer 14 and converter circuit 1
9 is provided between the transformer 14 and the contactor 22, and DC power is supplied to the connection point between the transformer 14 and the contactor 22. In the DC section, the contactor 22 is released and DC power is supplied through the secondary winding of the transformer 14. Further, the DC output from the converter circuit 19 is fed to the charging circuit composed of the contactors 11 and 13 and the charging resistor 12, the smoothing capacitor 2
It is supplied to the inverter circuit 20 (not shown) via 4 and reconverted into AC power.

In the case of a DC overhead wire, the contactor 22 is opened, the contactor 23 is closed, and the contact wire 1 → pantograph 2 → high speed circuit breaker 3 → contact b of the converter 4 → transformer 14 → element QVC → contactor 13 Supplied by route.

In the case of an AC overhead wire, the contactor 22 is closed and the contact 23 is opened, and the overhead wire 1 → pantograph 2 → high-speed circuit breaker 3
-> Contact a of converter 4-> primary winding of transformer 14-> wheel 15
Power is supplied through the route of → Le → Le 16. As a result, a single-phase AC voltage is applied to the converter circuit 19 from the secondary winding of the transformer 14.

[0027]

As described above, according to the power supply device for an electric vehicle according to claim 1 of the present invention, the opening / closing means is provided between the transformer and the converter, and the opening / closing means is provided between the opening / closing means and the transformer. Since DC power is supplied and the opening / closing means is released in the DC section and DC power is supplied through the winding of the transformer, the conventional smoothing reactor for DC can be omitted.

According to a second aspect of the present invention, there is provided a power supply device for an electric vehicle, which includes a charging circuit between the transformer and the opening / closing means.
DC power is supplied between the charging circuit and the opening / closing means, and in the DC section, the opening / closing means is released and DC power is supplied through the charging circuit and the winding of the transformer.
A single charging circuit can be used for both AC and DC power supplies.

According to the third aspect of the present invention, the direct current output from the converter is supplied to the inverter through the charging circuit and the smoothing capacitor to be reconverted into alternating current power. One unit can be used for both AC and DC power supplies.

According to the power supply device for an electric vehicle according to claim 4 of the present invention, the chopper operation is performed in the direct current section by using the switching element forming the converter, so that even when the voltage of the direct current overhead wire changes. The direct-current voltage of the inverter can be constantly controlled.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a power supply device for an electric vehicle according to a first embodiment of the present invention.

FIG. 2 is a power supply configuration diagram when a two-level converter is used for a converter / inverter.

FIG. 3 is a configuration diagram of a power supply device for an electric vehicle showing a second embodiment of the present invention.

FIG. 4 is an equivalent circuit diagram of a main circuit according to a second embodiment.

FIG. 5 is a configuration diagram of a power supply device for an electric vehicle showing a third embodiment of the present invention.

FIG. 6 is a diagram showing a power supply configuration of a conventional electric vehicle.

[Explanation of symbols]

1 ... overhead line, 2 ... pantograph, 3 ... high-speed circuit breaker, 4 ... converter, 5, 6, 7, 11, 13, 22, 23 ... contactor,
9 ... Smoothing reactor, 14 ... Transformer, 15 ... Wheel discharge resistance, 16 ... Rail, 17 ... Converter control device, 18
... Inverter control device, 19 ... Converter circuit, 20
Inverter circuit, 21 induction motor, 24 smoothing capacitor, 25 voltage detector, 36 voltage control circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60L 9/30 B60L 9/16 H02M 3/155 H02M 7/5387

Claims (4)

(57) [Claims] 1. In a DC section, DC power is converted into AC power by an inverter, and in the AC section, AC power obtained through a transformer is converted into DC by a converter, and then converted again into AC by an inverter, so that DC In a power supply device for an electric vehicle capable of traveling in a section and an AC section, an opening / closing means is provided between the transformer and the converter,
It is configured to supply DC power between the switching means and the transformer, and in the DC section, the switching means is released and the DC power is supplied through the winding of the transformer. Power supply device for electric vehicles. 2. A charging circuit is provided between the transformer and the opening / closing means, and DC power is supplied between the charging circuit and the opening / closing means. In the DC section, the opening / closing means is provided. The power supply device for an electric vehicle according to claim 1, wherein the DC power is supplied through the charging circuit and the winding of the transformer while the power supply is released. 3. The power supply device for an electric vehicle according to claim 1, wherein the DC output from the converter is supplied to the inverter through a charging circuit and a smoothing capacitor to be converted into AC power again. 4. The power supply device for an electric vehicle according to claim 1, wherein a chopper operation is performed in the DC section by using a switching element forming the converter.