JP2007202250A - Electric vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the erroneous operation of a signal apparatus by detecting the lowering of a capacity of a filter capacitor. <P>SOLUTION: In a power converter for an electric vehicle control device having an LC filter circuit, the lowering of the capacity of the filter capacitor 9 and the change of a voltage of the filter capacitor 9 at the initial charging of the filter capacitor 9 can be detected by a voltage detection means of the filter capacitor 9 composed of a filter capacitor voltage detector 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an electric vehicle control device including a power converter having an LC filter.

In the electric power converter for an electric vehicle control device, an LC filter is provided at the input part thereof to suppress the outflow of harmonics to the train line and prevent malfunction of the signal device.

Among the constituent devices of the filter device, the filter capacitor is a very important confirmation item because if the capacity is reduced, the filter function is lowered, and in the worst case, the signal device may malfunction.

In recent power converters, electrolytic capacitors are often used to reduce the size and weight, and the need for protection against capacity reduction due to secular change or the like has increased.

When there are many electric vehicle control devices, it is not easy to periodically check the capacity of the filter capacitor. So far, a method for detecting deterioration based on the magnitude of the ripple voltage of the filter capacitor has been proposed, but in the case of electric vehicle control devices, the fluctuation range of the train line voltage is large, the carrier frequency also changes, the ripple It is necessary to detect the voltage, and the discrete detection system using the microcomputer has a problem in detecting the accurate ripple voltage. (For example, see Patent Document 1.)
JP-A-11-160377

The problem to be solved is to detect a decrease in the capacity of the filter capacitor of the power converter for an electric vehicle control device having the LC filter.

In the power converter for an electric vehicle control device having the LC filter circuit, the present invention reduces the capacity of the filter capacitor (9) by changing the voltage of the filter capacitor (9) when the filter capacitor (9) is initially charged. It is easy to detect.

The present invention makes it possible to reliably detect the filter capacitor capacity of a power converter for an electric vehicle control device having an LC filter at each initial charge, and a signal due to a change in filter characteristics due to a decrease in the filter capacitor capacity. A function to avoid the influence on the equipment can be added to the electric vehicle control device, which leads to an improvement in safety.

If the charging capacitor is charged at a rate equal to or greater than the specified ratio of the voltage across the filter capacitor to the voltage on the train line after a certain period of time since the charging contactor is charged, it is determined that the capacity has decreased. Since the determination can be made simply by detecting the train line voltage and the filter capacitor voltage, it can be realized more easily than a method such as ripple detection.

FIG. 1 is a connection diagram of one embodiment of the apparatus of the present invention. In the illustrated connection diagram, the filter capacitor 9 is initially charged by the following operation.
Train line 1 is under pressure. Moreover, the current collector 2 is in contact with the train line, and the high-speed circuit breaker 3 is also closed. The main circuit breaker 6 is in an open state, and the charging resistor 5 connecting contactor 4 is also in an open state. 7 is a detector of the train line voltage, 8 is a filter reactor that forms a filter circuit together with the filter capacitor, 10 is a detector of the filter capacitor voltage, 11 is a power converter part of the electric vehicle control device, and 12 is Main motor.

      When the power running command is received, the charging resistor connecting contactor 4 is first closed. As a result, the charging capacitor 5 passes through the charging resistor 5 and the filter reactor 8, and the charging of the filter capacitor 9 starts. It changes like the curve shown in.

      Depending on the allowable capacity reduction range of the filter circuit, a determination threshold is determined based on the value of the filter capacitor voltage Vc after the measurement time tm for determination after the charging resistor connection contactor is turned on, and the capacity decrease is determined. . For example, NG is a capacity drop. GO is within the allowable capacity range.

The voltage change of the filter capacitor is VL for the train line voltage and the voltage for the filter capacitor.
If the Vc filter capacitor capacity is C and the charging resistor resistance value is R, it can be roughly calculated by the following equation.
Vc = VL (1−ε (-(t / R * C)))

Since the train line voltage VL changes, the filter capacitor voltage with respect to the train line voltage VL
The ratio of Vc is used as the discriminant value by giving the lower limit value of the capacitor capacity allowed in the above equation. Consider margins such as detector errors.

      If a capacity drop is detected, there is a risk of traffic signal malfunction, etc., so as to protect the electric vehicle control device, if it is prohibited to start or if a set value with a margin larger than the allowable value is secured, the maintenance information For example, it is possible to select only notification of a decrease in capacity.

      It can be used as a means for easily detecting a decrease in the capacity of the filter capacitor of the electric vehicle control device, and is effective in improving safety, such as preventing malfunction of signal equipment.

It is a connection diagram of one Example of this invention. Example 1 It is explanatory drawing which showed the change at the time of the initial charge of a filter capacitor voltage with the capacity | capacitance of a filter capacitor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Train line 2 Current collector 3 High-speed circuit breaker 4 Charging contactor 5 Charging resistor 6 Main circuit breaker 7 Train line voltage detector 8 Filter reactor 9 Filter capacitor 10 Filter capacitor voltage detector 11 Electric vehicle controller power converter 12 Main motor

Claims (1)

In a power converter for an electric vehicle control device having an LC filter circuit, the capacity of the filter capacitor (9) is reduced, and the voltage change of the filter capacitor (9) is detected when the filter capacitor (9) is initially charged. An electric vehicle control device characterized in that it can be detected by voltage detection means of the filter capacitor (9) comprising (10).

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