JPS60207403A - Controller for electric railcar - Google Patents

Abstract

PURPOSE:To normally perform a redriving operation after a filter capacitor overvoltage operation by not allowing a reclosure of main circuit if the prescribed time is not elapsed after the filter capacitor is operated at the overvoltage. CONSTITUTION:When the voltage of a filter capacitor 7 is an overvoltage, an overvoltage suppression thyristor 6 is triggered by a trigger circuit 22, an overvoltage relay 23 is operated to open a unit switch 2 and a high speed breaker 4. When an operation command is released and a flip-flop 21 is reset, the relay 23 does not become OFF until charge stored in a capacitor 31 is discharged. The time that the relay 23 becomes OFF is set to a time that a current flowed to the thyristor 6 becomes a holding current or less of the thyristor 6. Thus, the redriving operation of an induction motor can be normally performed after the capacitor is operated at an overvoltage.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to an improvement of an electric vehicle control device that drives a plurality of induction motors with a variable voltage, variable frequency inverter.
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[Technical background of the invention and its problems]

FIG. 1 shows a schematic configuration of an example of a conventional electric vehicle control device of this kind. , 3 is a noise reactor, 4 is a high-speed breaker having a coil 4C and a contact 4a, 5 is an overvoltage suppression resistor, 6 is an overvoltage suppression thyristor, 7 is a filter capacitor, 8 is a DC voltage detector, 9 is an inverter circuit, 1
0 is an induction motor. The inverter circuit 9 is composed of semiconductor elements having a self-extinguishing ability, such as a turn-off thyristor 9-1 and a free-wheeling diode 9-2.

1(b) and (C) show a main circuit breaker closing circuit and a filter capacitor overvoltage detection circuit, 20 is a level comparison circuit, 21 is a flip-flop, 22 is a trigger circuit for the overvoltage suppression thyristor 6, and a coil 23C. Contact 23bl
, 23b2, and 24 is an overvoltage relay drive circuit.

As a result, the voltage of the filter capacitor 7 increases, and the level comparison circuit 20 detects that it has exceeded a predetermined value, and operates the flip 70□ knob 21. This flip-flop 21 operates when a motion command is input, and is reset when a drive command is released.

When the flip 70 knob 21 operates, the overvoltage suppressing thyristor 6 is introduced by the trigger circuit 22 of the overvoltage suppressing thyristor 6 to short-circuit the filter capacitor 7 via the overvoltage suppressing resistor 5.

At the same time, the overvoltage relay coil 23C is excited by the overvoltage relay drive circuit 24, and the unit switch 2. Turn off the solenoid valve of the high-speed breaker 4, and turn off the unit switch 2.
High-speed breaker 4 is opened.

When the operation command is released, the flip-flop 21 is reset, and the overvoltage relay 23 is turned off (the operation command can be re-entered).Here, in the main circuit of FIG. , the waveform of the current flowing through the overvoltage suppression thyristor 6 is shown in FIG. 2(b).11
is the current flowing from the DC input side, and time T is the unit switch release time of 2 (approximately 100 m5>. 12 is
With the discharge current of the filter capacitor 7, the discharge time T2 is:
It is about several tens of milliseconds. i3 indicates the induction motor current,
This is due to residual magnetism in the induction motor 10, and time
Flow only to be self-excited. This time T3 is generally several seconds, which is quite short. Therefore, after the overvoltage operation, the overvoltage suppressing thyristor 6 is still in the state when the operation command is released, the restart command is immediately issued, and the main circuit is shut off. [Purpose] The present invention has been made to solve the above-mentioned problems,
An object of the present invention is to provide an electric vehicle control device that can normally perform a restart operation after a filter capacitor overvoltage operation.

[Summary of the invention]

In order to achieve the above object, the present invention provides that the filter capacitor 2. An off-delay circuit is provided so that the main circuit will not be turned on again until a predetermined period of time has elapsed.

(Embodiments of the Invention) The present invention will be described below with reference to embodiments shown in FIG. The difference from the above-mentioned Fig. 1 is that an off-delay circuit consisting of a resistor 30 and a capacitor 31 is added in parallel to the overvoltage relay 23, and other points are the same as Fig. 1, so the same parts are given the same reference numerals and their explanation will be omitted here.

The operation of the electric vehicle control device configured as described above will be explained below. When the voltage of filter capacitor 7 is overvoltage,
The overvoltage suppression thyristor 6 is triggered by the trigger circuit 22, and the overvoltage relay 23 is operated, and the unit switch 2. High speed breaker 4 is opened. Therefore, when the operation command is canceled, the flip-flop 21 is reset to
However, the overvoltage relay 23 does not turn off until the mold cylinder stored in the capacitor 31 is discharged. The time during which the overvoltage relay 23 is turned off is determined by the capacitance of the capacitor 31 (therefore, the capacitance of the capacitor 31 is
, it is necessary to determine the overvoltage relay 23 not to be turned off until the electric current W&ia flowing through the overvoltage suppression thyristor 6 in FIG. 1 becomes equal to or less than the holding current of the overvoltage suppression thyristor 6. In this manner, the induction motor can be restarted normally after the overvoltage operation of the filter capacitor.

(Effects of the Invention) According to the present invention described above, when a predetermined period of time elapses when the filter capacitor on the DC input side of the variable frequency inverter operates due to overvoltage, the filter capacitor on the DC input side of the inverter Since an off-delay circuit is added so as not to accept the reinjection of the filter Igi device, it is possible to provide an electric vehicle control device that can normally perform the restart operation after the overvoltage operation of the filter capacitor.

[Brief explanation of drawings]

Figures 1 (a>, (b)', and (c) are main circuit diagrams, main circuit breaker closing circuit diagrams, overvoltage detection and detection circuit diagrams, and Figure 2 ( a) and (b) are diagrams showing the current path and current waveform flowing through the thyristor when the overvoltage suppression thyristor is triggered in Figure 1, and Figure 3 (a>, <b).
) and (c) are a main circuit diagram, a main circuit breaker closing circuit diagram, and an overvoltage detection circuit diagram, respectively, showing an example of an electric vehicle control device according to the present invention. 2... Unit switch, 4... High speed breaker, 5
-・Overvoltage suppression resistor, 6...Overvoltage suppression thyristor,
7... Filter capacitor, 8-... DC voltage detector, 9-... Inverter circuit, 10... Induction motor, 2
0...Reher comparison circuit, 21...Noritubu flop, 23-...Overvoltage relay, 24--Relay live circuit, 30...Resistor, 31-...Condenry-0 applicant's agent Patent Attorney Takehiko Suzue Figure 1 (a) Figure 2 (a)

Claims (1)

[Claims] (1) A filter and a breaker consisting of a filter reactor and a filter capacitor are installed on the DC input side of the variable voltage and variable frequency inverter, and a plurality of inductors are installed on the AC output side of the variable voltage and variable frequency inverter. An electric vehicle capable of driving an electric motor, wherein an overvoltage detection circuit detects that the filter capacitor voltage has become an overvoltage, and triggers an overvoltage suppression thyristor to short-circuit the filter capacitor via a resistor. An electric vehicle control device characterized in that an off-delay circuit is provided in the overvoltage detection circuit so that the circuit breaker does not accept re-opening until a predetermined period of time has elapsed when the filter capacitor is in overvoltage operation. (2) An electric vehicle control device characterized in that the predetermined time set forth in claim (1) is the time until the current flowing through the thyristor becomes equal to or less than the holding current when the overvoltage suppressing thyristor is triggered.