JPS6181102A - Controller for electric railcar - Google Patents

Abstract

PURPOSE:To prevent an inverter and an induction motor from thermally damaging by providing a discriminator for discriminating an improper power drive and an improper recovery. CONSTITUTION:When an input current In arrives at a current Ip corresponding to the level of a reference voltage 22A at recovery instructing time, the output of a comparator 22 changes from '0' to '1'. The output of an AND circuit 23 varies from '0' to '1' by the AND condition of the output signal of the comparator 22 and a regeneration command signal B. If the output of the circuit 23 is '1' even after 0 time, the output of an ON delay circuit 24 becomes 1, a flip-flop circuit 25 is operated to open a breaker 2. Even when an input voltage In arrives at one side IB level corresponding to a reference voltage 27A at power drive instructing time, the delay circuit 24 and a flip-flop 25 operate to open the breaker 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electric vehicle control device that drives a plurality of induction motors using a variable voltage variable frequency inverter.

[Technical background of the invention]

FIG. 1 is a circuit diagram showing a schematic configuration of a conventional electric vehicle control device.

DC power is supplied from the pantograph 1 to the inverter circuit 5 via the circuit breaker 2 and filter reactor 3.

A filter capacitor 4 is connected to the DC input side of the inverter circuit 5. The inverter circuit 5 usually includes a switch cable 6 such as a gate turn-off thyristor having a self-extinguishing ability, and a freewheeling diode 7 connected antiparallel to the switch cable 6.

An induction motor 8 is connected to the AC side output terminal of the inverter circuit 5 and is driven. Further, a rotation speed detection sensor 9 is attached to detect the rotation speed of the induction motor 8, and a detection signal PG1. PG2
etc. are output.

Further, a voltage detector 10 for detecting a DC input voltage is attached to the input side, and an input detection voltage EC is taken out. Similarly, a current detector 11 is attached to the output side, and an output detection current IM is taken out. The inverter circuit 5 is controlled by an inverter gate signal whose firing angle is controlled and which is supplied to the gate of the switch element 6 by the control section 20 .

The power running command P and regenerative brake command B are input to the control unit 20 along with the above-described input detection voltage EC, output detection current (M, and rotation speed detection signals PG1 and PG2).

In this way, induction electric! Power operation and regenerative braking operation of fi8 (electric vehicle) are performed. This classification of operation modes is performed by the control unit 20. The control unit 20 is normally controlled by software using a microcomputer due to the complexity of the control contents.

In this case, the program processing routines are different during power running and during regenerative braking. FIG. 4(a) and FIG. 4(b) are diagrams for explaining the power running control mode and regeneration control mode of the control unit 20, respectively. In the power running control mode, the inverter circuit 5 adds the slip frequency fs given as the power running command P to the frequency signal fr calculated from the detection signals PGI and PG2 output from the rotation detection sensor 9 and outputs the result as the inverter frequency f. 1tll@
do.

In the regenerative mode, control is performed by subtracting the slip frequency fs given as the regenerative brake command B from the frequency signal fr calculated from the rotational speed detection signal PG1°PO2 and outputting the result as an inverter frequency.

[Problems with background technology]

However, in an electric vehicle control device having such a control circuit configuration, if an abnormality occurs in the hardware or software of the microcomputer that constitutes the control section 20,
If operation is performed in power running control mode even though regenerative brake command B has been issued, the driver will recognize the abnormality even if only one unit operates abnormally, especially in multi-unit electric vehicles. That is difficult.

Similarly, when the regenerative brake control mode is operated despite the power running command P, it is similarly difficult for the driver to recognize the abnormality. If incorrect power regeneration occurs due to an abnormality in the control unit 20 as described above, if the operation is continued without being detected, not only will the vehicle performance deteriorate, but the inverter circuit 5 and the induction motor 18 will be thermally destroyed. Situations may also occur where this happens.

In such a conventional control device, protection against abnormal operation of the control unit 20 is not necessarily sufficient.

[Purpose of the invention]

An object of the present invention is to detect abnormal power regeneration caused by abnormal power operation when an abnormality occurs in the control section when driving a plurality of induction motors using a variable voltage variable frequency inverter, and stop the operation of the inverter to generate electricity. The purpose of the present invention is to provide an electric vehicle control device capable of protecting a vehicle system.

(Summary of the Invention) In order to achieve the above object, the present invention provides a variable voltage variable frequency inverter that inputs a DC power source and drives a plurality of induction motors connected to an AC side, and a variable voltage variable frequency inverter that receives a DC power source and drives a plurality of induction motors connected to an AC side. An electric vehicle control device comprising: a control unit for controlling power running and regenerative operation of an induction motor; When the output of the detector has a polarity from the DC power source to the inverter and its magnitude exceeds a predetermined level for a certain period of time or when a power running command is input, the output from the detector has a polarity from the inverter to the DC power source. and a circuit for determining whether power is running incorrectly and outputs an opening command by generating fJ+ when the magnitude thereof exceeds a predetermined level for a certain period of time, and means for stopping the operation of the inverter in response to the opening command. It is characterized by

[Embodiments of the invention]

FIG. 1 is a circuit diagram showing an embodiment of an electric vehicle control device according to the present invention. Note that the same parts as those of the conventional control device shown in FIG. 3 are given the same reference numerals, and the explanation thereof will be omitted.

The device shown in FIG. 1 includes a DC current detector 15 for detecting the input current of DC power supplied to the input side of the inverter circuit 5, and a DC current detector 15 for detecting the input current of DC power supplied to the input side of the inverter circuit 5, and for determining when unauthorized power running or unauthorized regeneration occurs. Unauthorized power running and unauthorized regeneration determination circuit 21
and is provided.

Then, based on the opening command outputted from the discrimination circuit 21, the circuit breaker 2 is opened in order to stop the operation of the inverter circuit 5. Note that the DC current detector 15
is a so-called polarity discrimination detector that can discriminate not only the magnitude of the input current but also the direction of the current. The discrimination circuit 21 receives the detection signal In from the calibrator 15.
A power running command P and a regenerative brake command B are respectively input. The discrimination circuit 21 has a configuration as shown in FIG. 1, and the base i1! A comparator 22 and a reference voltage 27 that compare the magnitude of the voltage 22A and the detection signal ln.
A and detection signal■. The output of the comparator 22 is multiplied by the regenerative brake command B by the AND circuit 23, and the output of the comparator 27 is multiplied by the powering command P by the AND circuit 28, and the output is sent by the OR circuit 29. The signal is input to the on-delay circuit 24 via the signal.

In addition, the regenerative brake command B and the power running command P are connected to the logical sum circuit 3.
0 to the reset terminal of the flip-flop circuit 25.

Further, the output of the on-delay circuit 24 is input to the set terminal of the flip-flop circuit 25. The output of this flip-flop circuit 25 is then output as a command to open the circuit breaker 2.

Note that 228 to 22D and 27B to 270 are resistors, respectively.

Next, the operation of the unauthorized regeneration determination circuit 21 will be explained.

FIGS. 2(a) and 2(b) are characteristic diagrams showing changes over time in input current during power running control and regenerative brake control. The horizontal axis shows time t, and the vertical axis shows input current I.

Note that when the input current is 1°, the DC current detector 15 shown in FIG.
This is the detected current detected from . Input current I. The + side indicates the power running state, and the - side indicates the regenerative braking state. When the input current ■ reaches the current corresponding to the level of the reference voltage 22A during the regeneration command, the output of the comparator 22 changes from O to 1. If an AND condition is established between the output signal of the comparator 22 and the regeneration command signal B, the output of the AND circuit 23 changes from 0 to 1, and is input to the on-delay circuit 24 via the OR circuit 29. Ru. The output of the AND circuit 23 is t. When the signal is still 1 after a certain period of time, the output of the on-delay circuit 24 becomes 1.

As a result, the flip-flop circuit 25 is driven, and the circuit breaker 2 is opened by the open command output from the flip-flop circuit 25, and the operation of the inverter circuit 5 is stopped. Flip-flop 25 has a memory function and stores its output until regeneration command signal B is turned off.

The detection level I is approximately 20% of the maximum level rHP.
Another hour on-day. is selected so that it is about 2 to 3 seconds.

Similarly, when the input current I0 reaches the level I corresponding to the reference voltage 27A during the power running command, the comparator 27, the AND circuit 28, the OR circuit 2
The on-delay circuit 24 and the flip-flop circuit 25 are operated through the circuit 9.

At this time, one side was detected and the bell I8 was also at the maximum level I. 8 of 20
Select around %.

〔Effect of the invention〕

As explained above, in this invention, a discrimination circuit is provided to discriminate between unauthorized power running and unauthorized regeneration, and this is detected and the operation of the inverter circuit is stopped. Therefore, the inverter and induced lightning fJ+ 81 are Accidents such as destruction can be prevented.

In other words, in an electric vehicle control system that drives multiple induction motors, when one train set is composed of 4 to 6 units of inverter systems, only one unit is operating abnormally, that is, it is in regenerative brake control mode even though a power running command is given. If the inverter is operating in the power running control mode despite a regenerative braking command, an abnormality will be detected and the inverter and induction motor will be thermally destroyed. Since this can be prevented and protected beforehand, there is an excellent advantage in that a highly reliable system can be constructed as an electric vehicle.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the electric vehicle control circuit according to the present invention, and FIGS. 2(a) and 2(b) are diagrams for explaining the operation of the discrimination circuit shown in FIG. 1, respectively. A characteristic diagram showing the waveforms of the input current during power running control and the input current during regeneration control, FIG. 3 is a circuit diagram showing an example of a conventional electric vehicle control device, and FIGS. 4(a) and 4(b) ) is a diagram for explaining the operation of the control section in FIG. 3, and is a diagram showing control states in power running mode and regenerative brake mode, respectively. 2...M1gi device, 5...Inverter circuit, 8...
・Induction electric power Akebono, 15... DC current detector for determining input current polarity, 20... Control unit, 21... Incorrect power running, incorrect regeneration discrimination circuit, P... Power running command, B... Regeneration Brake command, I. ···input signal. Applicant's agent Kiyoshi Inomata Figure 2 (2)

Claims (1)

[Claims] It has a variable voltage variable frequency inverter that inputs a DC power source and drives a plurality of induction motors connected to an AC side, and a control section that gives a control command to the inverter to control power running and regenerative operation of the induction motor. An electric vehicle control device comprising: a DC current detector located on the DC side of the inverter and capable of determining the polarity of the input current; and an output of the detector having a polarity such that when a regeneration command is input, the output is directed from the DC power supply to the inverter. It operates when the magnitude exceeds a predetermined level for a certain period of time or more, or when the output of the detector has a polarity from the inverter to the DC power supply when a power running command is input, and the magnitude exceeds a predetermined level for a certain period of time or more. What is claimed is: 1. An electric vehicle control device comprising: a circuit for determining improper power running and improper regeneration for outputting an opening command; and means for stopping operation of the inverter in response to the opening command.