JPS63302702A - AC electric car power supply device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a power supply device for an AC electric vehicle, and particularly to a power supply device for an AC electric vehicle.
The present invention relates to a fl power supply device using a (pulse width modulation) converter.

[Conventional technology]

The power supply system for AC electric cars is disclosed in ``Development history of drive system using non-commutator motor in Japanese National Railways'' (June 1986 issue, Science of Electric Cars). In this conventional device, as shown in the above-mentioned known document, a charging resistor is inserted in series in the circuit for a short time in order to suppress the charging current to the filter capacitor. The above document shows an example of a DC overhead wire, but in the case of an AC overhead wire, as in the case of a DC overhead wire, the charging resistor may be placed on the full DC current side or on the AC side. In the case of AC overhead lines, the secondary winding of the transformer is usually divided into two to four parts to reduce harmonic currents.

On the other hand, recently, PWM converters, which are self-exciting converters, have come into use for the purpose of improving the power factor.

If the secondary winding is multi-divided in this way and the PWM converter is connected in parallel when viewed from the DC side, or depending on the size of the control capacity (drive motor capacity x number of units), the charging resistor and its short circuit switch may be required. Since the single capacity of the shorting switch is smaller when the switch is connected to the AC side than when it is connected to the DC full current side, it may be more versatile in terms of device configuration. When the charging resistor and its short-circuit switch are connected to the AC side, the PWM converter supplies power in parallel to the DC side, so it is conceivable to connect them to each secondary circuit.

However, especially for those with a large control capacity, whether the charging resistor and its short-circuit switch are placed on the DC full current side or on the AC side, problems arise in terms of space, weight, and cost in terms of equipment configuration. .

[Problem that the invention seeks to solve]

The above-mentioned conventional technology has a problem in that although the charging resistor and its short-circuit switch are not essential devices in the sense of speed control parts of an electric vehicle, they occupy a large space and weight in terms of device configuration. So 1
SUMMARY OF THE INVENTION An object of the present invention is to provide a power supply device for an AC electric vehicle in which a means for suppressing overcurrent accompanying charging of a filter capacitor at the time of starting can be minimized in device configuration.

[Means for solving problems]

The above object is achieved by configuring the charging resistor charging means so that the filter capacitor can be charged with only one converter circuit.

That is, a transformer (4) whose primary winding is connected to the overhead wire (1) and has a plurality of secondary windings (41, 42);
A plurality of converters (12, 13) each connected to the next winding to convert input AC power into DC power, and an inverter (12, 13) that reversely converts the DC output of the converter into AC output.
15); and a filter capacitor (14) connected to the input end of the inverter, in which the high voltage side circuit output end of any one of the plurality of converters and the filter capacitor One short-circuit switch (7
) and a current limiting resistor (6) in parallel with this is connected in series, and a circuit is opened at startup between the output terminal of the high voltage side circuit of the other converter (13) and the connection point of the filter capacitor. The present invention is characterized in that another short-circuit switch (8) that is closed in synchronization with the first short-circuit switch is connected.

[Effect]

According to the above configuration of the present invention, the parallel circuit of the short circuit switch (7) and the charging resistor (6) is connected to only one converter (12) among the plurality of converters, and during the charging period, the parallel circuit of the short circuit switch (7) and the charging resistor (6) is connected to only one converter (12). The output of (13) is the short circuit switch (
8), therefore, the charging resistor only needs to have a size corresponding to the current capacity of that one converter, and as a result, the power supply device can be made smaller and lighter.

〔Example〕

Next, one embodiment of the present invention will be described based on the drawings.

The figure shows a circuit diagram of a power supply device according to the present invention. In the figure, AC power from an AC overhead wire 1 is input to a converter 4 via a pantograph and an AC circuit breaker 3.

In addition to the primary winding, the transformer 4 has a secondary winding 41, 42, and a tertiary winding 43. This transformer is 2
Since it has two secondary windings, 41 and 42, it is generally called a secondary two-split type.

PWM converters 12 and 13 are connected to each secondary winding 41, 42 of the transformer 4 as a secondary circuit, respectively. These PWM converters 12 and 13
consists of a GTO (gate turn-off thyristor) bridge rectifier circuit, which converts AC power to DC power when the AC electric car is accelerating, and converts DC power back to AC power when decelerating. Perform exchange regeneration.

PWM control using this GTO allows operation at a high power factor close to 1.0 at all times. In addition, PWM by GTO
The details of the control are omitted because they are not directly related to the present invention.

The high voltage side of the output end of the converter 12 is connected to the inverter 15 through a parallel circuit of a short circuit switch and a charging resistor 6 in series.
The low voltage side of the converter 12 is connected to the low voltage side of the inverter 15. On the other hand, the high voltage side output terminal of the converter 13 is connected to the short circuit switch 7 and the output terminal of the charging resistor 6, and the low voltage side thereof is similarly connected to the low voltage side input terminal of the inverter. A filter capacitor 14 for removing ripples in the output voltage of the converter is connected to the high voltage side and the low voltage side of the input terminal of the inverter 15.

The inverter 15 reversely converts the power converted into DC by the converter 12 or 13 into an AC voltage of a predetermined frequency, and is generally a variable voltage variable frequency (VVVF).
) type inverter. The output of inverter 15 is three-phase power.

It is supplied to the AC motor 16.

Next, the operation will be explained.

The operation of the power supply device shown in the figure in the above configuration is as follows. First, after the pantograph 2 rises and contacts the AC overhead wire 1, the AC circuit breaker 3 is turned on. This results in
Tertiary load 11 is driven.

Note that this tertiary load circuit is usually connected to an electric blower for forced air cooling of electrical equipment, an air-conditioning device, and an auxiliary power supply device. Therefore, in order to prevent service to passengers from deteriorating, it is preferable to configure the AC circuit breaker 3 to continue operating without opening in the event of a failure in the secondary circuit.

When the AC circuit breaker 3 is turned on, the short circuit switch 7 and the short circuit switch 8 are open, so that the DC electric power converted by the converter flows into the capacitor 14 via the charging resistor 6. In this case, since the short-circuit switch 8 of the converter 13 is completely open, the charging current flowing into the capacitor 14 is due only to the converter 12. Therefore, the current capacity of the charging resistor 6 is a size corresponding to the current capacity of the converter 12. I'll have to settle for something like that. In this case, the charging time constant of the capacitor 14 is 0.
．． It takes about 5 seconds.

When the capacitor 14 is completely charged by the above operation, the short circuit switch 8 is closed so that the DC power from the converter 13 is supplied to the inverter 15.

In this way, the charging resistance of the capacitor 14 is
Since the charging resistor 6 is provided only on the output side of the converter 1 and contributes to charging the capacitor 14, the charging resistor 6 is provided only on the output side of the converter 1.
There is no need to provide charging resistors corresponding to 2 and 13, and since the charging current is generated only by the converter 12, the charging current in that case only needs to have a current capacity equivalent to one converter. , the device configuration of the power supply device of the AC electric vehicle is simplified and the weight is reduced.

〔Effect of the invention〕

As described above, according to the present invention, the short circuit switch and the charging resistor, which are not essentially required for the speed control of the AC electric vehicle, can be minimized, resulting in the miniaturization of the AC electric vehicle. Weight reduction can be achieved.

[Brief explanation of drawings]

The figure is a main circuit configuration diagram showing an embodiment of the present invention. 4... Transformer, 6... Charging resistor, 7... Short circuit switch, 8... Short circuit switch, 12, 13... Converter, 14... Filter capacitor, 15...
inverter. 16... Drive electric motor.

Claims (1)

[Claims] 1. A transformer having a primary winding connected to an overhead wire and having a plurality of secondary windings, and a plurality of converters each converting input AC power into DC power for each of the secondary windings. , an AC electric vehicle power supply device comprising an inverter that reversely converts DC output of the converter into AC output, and a filter capacitor connected to an input terminal of the inverter, wherein any one of the plurality of converters A circuit consisting of a short-circuit switch that is opened at startup and a current-limiting resistor in parallel is connected in series between the high-voltage side circuit output terminal of the converter and the connection point of the filter capacitor. An AC electric vehicle characterized in that another short-circuit switch is connected between the output end of the high-voltage side circuit and the connection point of the filter capacitor, which is opened at the time of starting and is closed in synchronization with the first short-circuit switch. power supply.