JPS6212301A - Controller for dc electric railcar - Google Patents

Abstract

PURPOSE:To simplify and to eliminate contacts of a main circuit by performing the charging of a filter capacitor and the interrupting function of the main circuit of a DC electric railcar by a common GTO thyristor. CONSTITUTION:After a pantograph 4 is raised and a line breaker 5 is closed, a charge controller 9 generates a GTO ON gate command SON. A gate driving circuit 10 generates ON and OFF gate pulses to repeat a GTO thyristor ON and OFF in response to the signal SON. Thus, a filter capacitor 8 is charged. When the capacitor 8 is sufficiently charged, an inverter 1 operates. When a malfunction detector 11 detects the overcurrent or its cause of a main circuit, it generates an OFF gate command SOFF to turn OFF a GTO thyristor 61.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a control device for a DC electric vehicle, and particularly to an improvement of a control device suitable for making the main circuit contactless.

[Background of the invention]

chopper, DC TA machine, inverter and induction motor,
In DC electric vehicles that combine a power converter and main motor, an inverted filter is installed between the DC power receiving end and the power converter via a current breaker, high-speed circuit breaker, or charging resistor. We are prepared.

For example, in 1% Publication No. 57-145501, there is a flow interrupter (
unit switch 2), high speed circuit breaker (3) and current limiting resistor (4)
) and a parallel body of a charging resistor (6) and a switch (5) are inserted in front of the filter reactor 7 and the filter capacitor 8, and when the current interrupter is turned on, the filter capacitor 8 is It is disclosed that when an overcurrent occurs, a high-speed circuit breaker is opened, and then a current interrupter is opened.

Further, Japanese Patent Application Laid-Open No. 55-100001'' also discloses a similar type of charging resistor.

By the way, in these conventional configurations, 1 mechanical opening/closing liquid point is 3
Various types are also required, and there is a strong demand for contactless technology. For example, Japanese Unexamined Patent Publication No. 19301/1983 proposes replacing the shorting switch in parallel with the charging resistor with a thyristor.

However, contactless technology is still not enough.

[Purpose of the invention]

The purpose of the present invention is to simplify the circuit before the filter in a DC electric vehicle equipped with an inverted filter before the power converter (chopper or inverter) that supplies power to the main motor (DC machine or induction machine). It is to aim for.

[Summary of the invention]

The features of the present invention include a semiconductor circuit breaker inserted between a current breaker and an inverted filter, and equipped with a GTO thyristor, an anti-parallel diode, and a parallel nonlinear resistor; The present invention is characterized in that a gate control device is provided which controls the GTO thyristor on and off and thereafter turns it on continuously, detects an overcurrent in the main circuit, and provides an extinguishing signal to the GTO.

That is, when an overcurrent in the main circuit due to failure of commutation of a power converter or the like or its cause is detected, an off-gate signal is given to the GTO, causing it to function as a high-speed circuit breaker. At this time, the main circuit current cut off by the GTO applies a large voltage in the forward direction of the GTO due to the effect of inductance. Therefore, in addition to the normal snubber circuit, a nonlinear resistor is connected in parallel with the GTO to protect the AK voltage from exceeding a predetermined value.

Since the normal resistance value of this nonlinear resistor is sufficiently large, when the current interrupter is turned on, the parallel GTO is controlled on and off to adjust the resistance value and charge the filter capacitor appropriately. After charging is completed, GTO remains conductive.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a DC electric train control device to which the present invention is applied to a DC electric train equipped with an inverter 1 and an induction motor 2.

Current is collected from the DC overhead contact line 3 by a pantograph 4, and a semiconductor circuit breaker 6 is connected through a current breaker 5. A filter reactor 7 and a filter capacitor 8, which constitute an inverted filter, are connected between the semiconductor circuit breaker 6 and the inverter 1.

The semiconductor circuit breaker 6 is mainly composed of a GTO 61, and includes a well-known snubber diode 62 and a capacitor 6.
3 and a resistor 64.

In addition, a diode 65 is connected in antiparallel to the GTO 61.
・Connected to allow regenerative current to flow.

A nonlinear resistor 66 is connected in parallel to the GTO 61 . This nonlinear resistor 66 functions as an arc extinguishing device when the main circuit current is interrupted by the GTO 66, and an example of its voltage-current characteristics is shown in FIG. That is, G
When the voltage YAK between AK of TO reaches a predetermined value, the resistance value becomes extremely low and the voltage is clamped.

Now, after the bank has risen and a current breaker closing command is given and the current breaker 5 is closed, the charging control circuit 9 generates a GTO on-gate command So as illustrated in FIG. Upon receiving this signal, the gate drive circuit 10 generates an on-gate pulse and an off-gate pulse that cause the GTO 61 to repeatedly turn on and off in response to this signal SON.

Therefore, during the time to-t shown in FIG.
By chopping the GTO in parallel with the filter capacitor 8, the desired current can flow through the filter capacitor 8. Although the conduction rate is shown as being constant in FIG. 3, the conduction rate may be gradually increased, and can be set in any manner by simple modification of the charging control circuit 9.

Now, when the filter capacitor 8 is sufficiently charged, or at a suitable time, the inverter 1 is allowed to operate.

Here, the control device for the inverter 1 will not be mentioned because it is not directly related to the present invention.

Next, we will discuss the interrupting operation in the event that an overcurrent or fault occurs in the main circuit.

When the abnormality detection circuit 11 detects an overcurrent in the main circuit or its cause (commutation failure, etc.), it generates an off-gate command 5OFF to turn off the GTO 61. The gate drive circuit 10 receiving this gives an off-gate pulse to the GTO 61. The situation at this time is shown in FIG.

GTO62 electrical work was rapidly increasing. ? 0 is
It will try to be cut off in a very short time. Along with this, due to the energy stored in the inductance of the circuit, the G
A very high surge voltage is about to be applied between AK of TO61. Here, the nonlinear resistance 66 is, for example, 250
It exerts a clamping effect of about 0V, and the voltage V of GTO61
A Kij: , it will not rise further,
GTO will never be destroyed. Therefore, nonlinear resistance 6
A current 6 flows sharply, and the energy corresponding to Ii''R is converted into thermal energy and dissipated.Then, the current interrupter 5 is opened to complete the main circuit interruption.

〔Effect of the invention〕

As described above, according to the present invention, a common GTO can perform the functions of charging the filter capacitor of a DC electric vehicle and interrupting the main circuit, contributing to the simplification and non-contact of the main circuit.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a control device for a DC electric vehicle showing an embodiment of the present invention, Fig. 2 is a voltage-current characteristic diagram of a nonlinear resistor, and Fig. 3 is a diagram showing an example of an output signal of a charging control circuit. , FIG. 4 is a voltage and current change diagram illustrating the main circuit breaking operation.

Claims (1)

[Claims] 1. In a device that connects a DC overhead line through a current breaker to an inverted L-type filter and supplies the capacitor voltage of this filter to the main motor through a power converter, the GTO is inserted between the current breaker and the filter. A semiconductor circuit breaker equipped with a thyristor, an anti-parallel diode, and a parallel non-linear resistance, and the GTO thyristor is controlled on and off at the initial stage of turning on the current breaker, and then turned on continuously and detects overcurrent in the main circuit. and a gate control device for giving an arc extinguishing signal to the GTO.