JP3089920B2 - Electric car control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electric vehicle, and more particularly to an idling detection device for performing readhesion control.

[0002]

2. Description of the Related Art A conventional idling detection system is disclosed in, for example, Hitachi Review, Vol. 73, No. 3, pp. 21-26, a large-output inverter electric locomotive (March, 1991). The idling is detected when the differential value (acceleration) of the number is equal to or greater than the set value and the difference in the number of rotations between the axes (speed difference) is equal to or greater than the set value.

[0003]

In the conventional idling detection system based on acceleration, the idling detection sensitivity cannot be increased in order to avoid erroneous idling detection at a joint of a rail or a branch portion.
It is necessary to set the idling detection sensitivity to about two to three times the normal maximum acceleration of the electric vehicle. For this reason, there was a problem that it was not possible to detect the idling with a relatively gentle acceleration. In particular, during high-speed running, the acceleration of the electric vehicle is lower than at low speed due to an increase in running resistance and the like, so that the difference between the normal acceleration and the idling detection acceleration is further increased, making it more difficult to detect idling.

[0004] In addition, there is also a problem that the idling detection based on the speed difference between the axes cannot be detected when all the axes are idling at the same time.

It is an object of the present invention to detect idling or prevent idling irrespective of acceleration or speed difference.

[0006]

SUMMARY OF THE INVENTION The speed of an electric vehicle is controlled by ATC.
(Automatic train control device) and the like. Generally, when the electric vehicle is traveling, it travels near the ATC speed limit (about -5 km / h of the speed limit). Therefore, A
When the speed limit is exceeded, it is considered as idling,
The above object can be solved.

[0007]

When the detected speed exceeds the ATC speed limit, idling is detected, and the driving force generated by the motor is reduced, so that the driving force between the wheels and the rails can be reduced and re-adhesion can be achieved.

In the method of reducing the driving force generated by the motor, it has been conventionally performed to reduce the motor current. In the case of an induction motor drive system using an inverter, it is also possible to reduce the motor current and reduce the driving force by reducing the slip frequency.

In the case of an induction motor drive system using an inverter, the upper limit of the control frequency of the inverter is
By limiting to a value corresponding to the ATC speed limit, the AT
The shaft speed does not increase more than the C speed limit, and idling can be prevented.

[0010]

FIG. 1 shows an embodiment of the present invention.

The power collected by the pantograph 1 is converted into three-phase AC by the inverter 2 and the induction motors 4 and 5 are driven. The control device 3 receives the operation command and controls the inverter 2. Specifically, predetermined voltages and currents are supplied to the induction motors 4 and 5 according to a notch command and a speed.
The speed detectors 6 and 7 detect the rotation speed of the induction motors 4 and 5. The speed discriminating unit 8 takes the output of the speed detectors 6 and 7 at a high level and converts it into a vehicle speed. The reason for taking the high rank is to detect a case where there is a plurality of induction motors and only one of the induction motors idles. The comparator 9 compares the output of the speed discriminating unit 8 with the ATC speed limit, and outputs an idling detection signal when the former exceeds the latter. The rotor frequency detector 10 detects the rotor frequency of the induction motor from the outputs of the speed detectors 6 and 7. Unlike the speed discriminating unit 8, in order to make the motor less susceptible to idling, it is general to take a lower position during power running with a plurality of induction motors.

The control device 2 performs control to reduce the driving force of the induction motors 4 and 5 based on the idling detection signal output from the comparator 9 to achieve re-adhesion of idling. Means for reducing the driving force include reducing the currents of the induction motors 4 and 5, reducing the voltage, and reducing the slip frequency. As an example, a time chart when the current is reduced is shown in FIG.

This method has a feature that it can be easily applied without changing the other control functions only by changing the method of detecting the slip. Further, the electric motor is not limited to the induction motor, and can be applied to control devices for various electric motors such as a synchronous motor and a DC motor.

Another embodiment of the present invention is shown in FIG.

1 differs from FIG. 1 only in the parts of the control unit 3, the speed discriminating unit 8, and the comparator 9, and the other units are a pantograph 1, an inverter 2, an induction motor 4, 5, speed detectors 6, 7, and Since the rotor frequency detector 10 is the same, these same parts are omitted in FIG.

FIG. 3 shows details of the inside of the control device 3. Basically, a voltage calculator 34 for calculating the voltage applied to the induction motor, a slip frequency calculator 31 for calculating the slip frequency, and an adder 32 for adding the slip frequency and the rotor frequency to obtain an inverter frequency. , A pulse width modulator 35 for generating an operation signal of the inverter 2 from the applied voltage and the inverter frequency. A feature of the present invention is that a frequency conversion unit 11 that converts the ATC speed limit into a rotor frequency and a limiter 33 that limits the upper limit of the inverter frequency input to the pulse width modulator 35 are provided. Even if the vehicle runs idle and tries to exceed the ATC speed limit, the inverter frequency is limited to a value corresponding to the ATC speed limit. this is,
As the inverter frequency and rotor frequency approach,
The slip frequency decreases (the induction motor current decreases),
This is because the driving force generated by the induction motors 4 and 5 is reduced.

This method also has a feature that if the inverter frequency and the rotor frequency become equal, the driving force becomes zero, so that the ATC speed limit is not exceeded.

Incidentally, the two examples shown above are conventional ones.
It does not hinder the operation of the slip detection system due to the acceleration of each axis or the speed difference between the axes, but rather improves the effect of preventing the slip by using them together.

[0019]

According to the present invention, when the vehicle is running near the ATC speed limit, it is possible to reliably detect idling and achieve re-adhesion, or to prevent idling.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram of the operation in FIG. 1;

FIG. 3 is a block diagram showing another embodiment of the present invention.

[Description of Signs] 3 ... Control device, 8 ... Speed discriminator, 9 ... Comparator, 10 ... Rotor frequency detector, 11 ... Frequency converter, 32 ... Adder, 33 ... Limiter.

Claims (1)

(57) [Claims] An electric motor control device having an electric motor for propelling a vehicle, a means for detecting the number of revolutions of the electric motor, and having a function of adjusting a driving force generated by the electric motor. Comparing the speed detected from the rotation speed of the motor, when the speed exceeds the speed limit,
A control device for an electric vehicle, comprising: means for detecting occurrence of idling and reducing a driving force generated by the electric motor.