JPS6212304A - Controller of electric railcar - Google Patents

Abstract

PURPOSE:To suppress the variation of an armature current when a main motor makes transition from series to parallel connections by altering the proportional constant for proportionally controlling a field in response to the operating conditions such as empty, full-state or power redrive of an electric railcar. CONSTITUTION:Main circuit current controllers 6A, 6B control a main circuit current in response to the outputs of an operating mode instructing unit 11, a load responding unit 12 and armature current detectors 10A, 10B. A field current controller 30 controls a field current to a value proportional to an armature current. When the controller 30 inputs a signal representing that an electric railcar is empty or full from the unit 12, the controller 30 increases the proportional constant thereof larger than a reference value when the railcar is full under the condition that a main motor is in a series control state, and decreases the constant smaller than the reference value when the railcar is empty and power redriving state.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the control of an electric vehicle using a plurality of DC motors, and in particular, to controlling the field strength in proportion to the armature current,
The present invention also relates to a control device for an electric vehicle that includes serial-parallel switching control for speed control.

[Background of the invention]

For electric cars that are equipped with multiple DC motors for running drive and that perform DC power supply, for example, Japanese Patent Laid-Open No. 54-1
As shown in Japanese Patent No. 02714, a so-called series-parallel control system has been widely used, and such a conventional example will be explained with reference to FIGS. 2 to 4.

First, Figure 2 shows the main circuit. In the figure, 1 is a pantograph for collecting current from the overhead wire, 2 is a field current breaker,
3 is a field current control device, 4A and 4B are main motor field magnets, 5
is the main circuit current breaker, 6A, 6B is the main circuit current control device such as camshaft type, 7A, 7B is the main motor armature, 8A, 8
B and 8C are series-parallel switching switches for the main circuit, 9 is a field current detection device, and 10A and IOB are armature current detection devices.

FIG. 3 shows a control circuit, in which numeral 11 indicates a command device for instructing the operation mode, and numeral 12 indicates a variable load device for adjusting the torque depending on the load. Other equipment that is the same as in FIG. 2 is indicated by the same reference numerals.

1. FIG. 4 is a notch curve showing the state in which the main motor is controlled in FIGS. 2 and 3, and the operation will be explained below using this curve.

That is, when starting an electric car, by issuing a start command from the driver's cab 11, the field circuit breaker 2, the main circuit circuit breaker 5, and the main circuit series/parallel switch 8A are turned on, and the S
The electric car will start when there is only one notch.

The armature circuit at this time is main motor armature 7A.

7B is in series, and all starting resistances are inserted.

Thereafter, the main circuit current control devices 6A, 6B sequentially short-circuit the starting resistors connected in series to the armatures 7A, 7B of the main motor, thereby controlling the voltage applied to the armatures. Here, when the starting resistor is short-circuited, the current limit value is advanced so that the main circuit current value becomes constant in order to keep the starting acceleration force of the electric vehicle constant.

This main circuit current value (current limit value) changes as shown in FIG. In addition, ``■'' in FIG. 4 shows an empty car state, and ``■'' shows a full car state.

On the other hand, at this time, the field current is controlled by the field current control device 3 so that a current proportional to the armature current flows. The reason why this field current is controlled to a value proportional to the armature current is to make the characteristics of the main motor to be those of a series motor, and this type of control is generally called proportional control. If all starting resistors are short-circuited in series connection, the final stage in series S
It will be in the IO notch state.

In order to further increase the speed, series-to-parallel switching switches 8B and 8C are closed, and switch 8A is opened.

As a result, the main motor armatures 7A and 7B are connected in parallel to the overhead wire, resulting in a parallel P1 notch state.

The above is a very general control method for an electric vehicle control device using a shunt-wound motor (or compound-wound motor).

Let us now consider the state when switching from series to parallel. As mentioned above, the starting current (current limit value) changes depending on the amount of load due to the action of the load adjusting device t12.

Now, in FIG. 4, ■ indicates the state of acceleration when the vehicle is empty, and the armature current (■1) increases significantly at the time of transition from the series control stage to the parallel control stage.

4 shows the acceleration state when the vehicle is full, and in this case, the drop in armature current is noticeable when changing from series to parallel.

Further, O in FIG. 3 shows the state when repowering is performed at high speed, and in this case, the change in armature current at the time of transition from series to parallel is even larger than when the vehicle is idle.

In other words, with the conventional control method, there is no problem when the vehicle is fully occupied, but when the vehicle is empty or full, and when repowering at high speed, the armature current changes when switching from series to parallel, regardless of the amount of load. This has the disadvantage that the change in speed is significant, resulting in an unfavorable driving condition in terms of riding comfort.

[Purpose of the invention]

An object of the present invention is to provide a control device for an electric vehicle that can sufficiently suppress changes in armature current when the main motor is connected in series and parallel, and provide good riding comfort, while eliminating the drawbacks of the prior art described above. It is on offer.

[Summary of the invention]

In order to achieve this object, the present invention provides a proportional constant for proportional control of the field, which is performed in response to the armature current of the traction motor, under various operating conditions such as empty, full, and re-powering operation of the electric vehicle. It is characterized by the fact that it changes depending on the situation.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A control device for an electric vehicle according to the present invention will be explained in detail below using illustrated embodiments.

FIG. 1 shows a control circuit according to an embodiment of the present invention. In the figure, numeral 30 is a field current control device, and the other parts are the same as the conventional example shown in FIG.

The main circuit is also the same as the conventional example shown in FIG.

The field current control device 30, as in the conventional example shown in FIG. field current! , and the armature current 1. In this embodiment, the field current control device 30 operates so that the field current Tr is supplied with a predetermined proportional relationship to the main circuit current control device 6A,
It takes in commands from 6B that the main motor is in the series control stage and that it has started powering again, and also takes in commands from the load adjustment device 12 that indicate when the electric car is empty and when it is full, and these Based on the directive, the above-mentioned armature current when the electric car is full, provided that the traction motor is in series control state! , and field current! .

The proportionality constant is made larger than the reference value, and when the electric car is empty or when it is re-powered, the proportionality constant is made smaller than the reference value, and the field current ! .

It is configured to perform control operations. That is, the characteristics of this field current control device 30 change as shown in the upper right corner of FIG.

Next, the operation of this embodiment will be explained.

First, FIG. 5 shows a state where the electric car is fully loaded. At this time, as mentioned above, the proportionality constant of the field current control device 30 is set to a large value, so that the main motor is controlled in series. When in step, the armature current is 1. In contrast, the field current (2) is increased, resulting in stronger field control.

As a result, as shown in Figure 5 (■), the characteristics S10 and Pl near the full current limit value are close to each other, and the armature current when switching from series to parallel! It is possible to suppress the drop in , sufficiently small, and to migrate with almost no change in .

Next, Fig. 6 shows the characteristics when the electric car is idle or moves from high speed to power running again. In this case, as mentioned above, the proportionality constant is set small, so field weakening control is performed, and Fig. 6 The characteristics S10 and PI become close to each other in the region near and below the empty vehicle current limit shown in , and even at this time, a large change in transition from series to parallel is suppressed, and the armature current ■.

Migration can be carried out without a significant increase in

Furthermore, the characteristics when re-entering the power line at high speed are shown in Figure 6.
The armature current due to crossover is 1. changes are sufficiently suppressed.

Therefore, according to this embodiment, by setting the magnitude of the proportionality constant of the field current control device 30 to appropriate values when the vehicle is full, when the vehicle is empty, and when re-powering, it is possible to adapt to the operating conditions of the electric vehicle. It can always provide a good ride comfort.

In the above embodiment, a shunt-wound motor is used as the main motor, but it goes without saying that a compound-wound motor may also be used.

〔Effect of the invention〕

As explained above, according to the Zero invention, it is possible to significantly suppress the change in armature current when switching from series to parallel, thereby eliminating the drawbacks of the conventional technology and improving the ride comfort of electric cars. can be improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the electric car control device according to the present invention, Fig. 2 is a connection diagram showing an example of the main circuit configuration of the electric car, and Fig. 3 is a block diagram showing a conventional example of the control device. 4, 5, and 6 are characteristic curve diagrams for explaining the operation. 4^, 4B... Main motor field, 6A, 6B... Main circuit current control device, 7A, 7B... Main motor armature, 9... Field current detection device, IOA, IOB ...
Armature current detection device, 12... Load adjustment device, 30...
・Field current control device. ! z′ dimension

Claims (1)

[Claims] 1. A plurality of DC motors for running are provided with a method of controlling the field strength in proportion to the armature current, and speed control is reduced by switching between series and parallel of these plurality of DC motors. In a control device for an electric vehicle, the control means for controlling the field strength in proportion to the armature current is provided with means for changing a proportionality constant for the control. 1. A control device for an electric vehicle, characterized in that it is configured to perform field control based on predetermined proportionality constants that vary depending on operating conditions of the electric vehicle. 2. A control device for an electric vehicle according to claim 1, wherein the operating condition of the electric vehicle is at least one of empty vehicle operation, full vehicle operation, and repowering operation.