JPS63262002A - Detection of wheel slip of electric vehicle - Google Patents

Abstract

PURPOSE:To effectively detect a small wheel slip by detecting the slip by the fact that a state in which the currents of armature circuits are balanced so that the currents of field circuits are not balanced is continued for a predetermined time. CONSTITUTION:When any wheel slips, the output of a motor for driving a slipped wheel is reduced. However, if the wheel slip is relatively small, the readhesion of the slipped wheel is unstable so that a small slip still continues. The fact that the currents of armature circuits 2A, 2B are balanced is detected by an armature circuit current balance detecting means 9 and the fact that the currents of field circuits 3A, 3B are unbalanced is detected by a field circuit current unbalance detecting means 10. When both the outputs are simultaneously continued for a predetermined time, the output of motor group belonging to the motor for driving the slipped wheel is temporarily suppressed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention connects a motor group each consisting of a plurality of series-wound motors in parallel to a DC power supply, and connects each motor group to a field circuit. The present invention relates to a method for detecting wheel slippage of an electric vehicle in which the electric motor group is operated at constant current by controlling the current in a field circuit using an added variable power DC power supply.

[Conventional technology]

In general, in an electric vehicle in which the field current of a plurality of series-wound motors connected to a series power supply is controlled to perform constant current control of the motors, if any of the wheels slips, especially the When electric motors are connected in series, the counter electromotive force of the electric motor driving the wheel in which the wheel has spun increases as its rotational speed increases, and the torque of each of the other electric motors connected in series decreases. This works in the direction of readhesion of the wheel, but once a wheel has started spinning, it continues to spin with very little torque, so in practice it is difficult to readjust it.As a result, the wheel that has spun is driven. In some cases, the rotation of the electric motor may increase to a dangerous speed, leading to damage to the electric motor, so it is necessary to take measures to allow the spinning wheels to re-stick as quickly as possible.

Conventionally, as a means of measuring re-adhesion of this kind of wheel idling, the general method is to provide a idling detection means such as a idling relay on each of the electric motors, and when any wheel idling occurs, the idling of the electric motor driving the wheel is activated. The idling relay is operated to shunt the armature current of the motor through a resistor so that the torque of the motor becomes less than the adhesion torque to measure re-adhesion.

On the other hand, a motor group consisting of a plurality of series-wound motors is connected in parallel to a DC power source, and the current in the field circuit of each motor group is continuously controlled to perform constant current operation of each motor group. In an electric vehicle that is equipped with an electric vehicle, when any wheel slips, the electric current in the field circuit is reduced to suppress the back electromotive force and torque of the electric motor that drives the wheel that is slipping, thereby re-adhering the wheel that is slipping. At the same time, the variable power DC power source is controlled so that the armature currents of each motor group are mutually balanced at a predetermined value.

[Problem that the invention seeks to solve]

However, in the above-mentioned method of measuring the readhesion of idling wheels of an electric vehicle, if the idling that has occurred in any of the wheels is slight, the field circuit of the motor group to which the motor driving the idling wheel belongs The variable power DC power supply is controlled to reduce the current in accordance with the increase in rotation of the motor, so that the spinning wheels are re-adhered and the armature current of the motor group reaches a predetermined value. As the current in the field circuit of the motor group decreases, the counter electromotive force of motors other than the motor driving the idling wheels also decreases, so that the output of the motors during idling does not decline, which prevents the idling wheels from re-sticking. In a stable state, the slight wheel spinning may continue for a long time.

In the above-mentioned state, it is functionally impossible to detect slippage using a conventional slipping detection method such as providing a slipping relay for each motor in the motor group, and therefore it is impossible to make the slipping wheels re-adhesion. Therefore, there is a problem in that it is extremely disadvantageous in terms of the use of the output of the motor.

In the present invention, a motor group consisting of a plurality of series-wound motors is connected in parallel to a DC power source, and the current of the field circuit of each motor group is controlled to perform constant current control of each motor group. In this electric vehicle, the above-mentioned problems associated with a wheel slip detection method in which each electric motor of the motor group is provided with a wheel slip detection means are solved, and even the slightest wheel slip of the vehicle is ensured by a simple means. It is an object of the present invention to provide a method for detecting wheel slipping of an electric vehicle, which can detect wheel slippage of the electric vehicle and cause re-adhesion to occur, thereby ensuring perfect utilization of the output of the electric motor.

[Means for solving problems]

In order to achieve the above object, in the present invention, motor groups each consisting of a plurality of series-wound motors are connected in parallel to a DC IT source, and a variable In an electric vehicle in which the current in a field circuit is controlled by a DC power source to perform constant current operation of the motor group, there is provided a means for detecting a current in the electric machine circuit for each of the motor groups, and a field for each of the motor groups. The outputs of the means for detecting a magnetic current and the means for detecting a current in the armature circuit are input, and the outputs of the means for detecting balance between the outputs and the means for detecting a current in the field circuit are respectively inputted. means for detecting unbalance between the input and outputs; and means for detecting the current in the armature circuit; wheel slip detection means to which the outputs of the means for detecting unbalance between the respective outputs are input together; When the output and the output of the means for detecting the unbalance between the outputs of the means for detecting the current of the field circuit are simultaneously and continuously input for a predetermined period of time, the wheel slip detecting means detects the wheel slip. It is intended to be detected.

[Effect]

By configuring the method for detecting wheel slipping of an electric vehicle according to the present invention as described above, the motor group to which the motor driving the wheel in which the wheel slipping belongs belongs and the motor group connected in parallel to the motor group. detects that a state in which the current in the armature circuit is balanced and the current in the field circuit is not balanced continues for a predetermined period of time, and detects the minute slip occurring in the wheels of the electric vehicle. It can be detected reliably.

〔Example〕

Next, the present invention will be described in detail based on embodiments shown in the drawings.

In an electric vehicle in which wheel slip is detected by the slip detection method according to the present invention, as illustrated in FIG.
, 3B are connected in series and each field circuit 3A
, 3B, variable power DC power sources 4A and 4B are added, and the series circuit of the field circuit 3A and the variable power DC amount tA4A and the series circuit of the field circuit 3B and the variable power DC power source 4B are reactors 5A, 3B, respectively. Two series motor groups are connected in parallel to the DC power source 1, so as to be shunted by 5B. In this type of electric vehicle, variable power DC amounts a4A and 4B are controlled by a variable power DC power supply control circuit 8 as illustrated in FIG.
The currents in the armature circuits 2A and 2B are controlled by non-impactly dividing the currents through the reactors 5A and 5B, respectively, so that the motor group can perform a predetermined constant current operation.

In that case, the series circuit of each of the motor groups includes armature circuit current detectors 6A and 6B for detecting the current in the armature circuits 2A and 2B, and a field circuit for detecting the current in the field circuit, as illustrated in FIG. Circuit current detectors 7A and 7B are provided, including armature circuit current detectors 6A and 6B and field circuit current detector 7.
A, 7B are directly input to the control circuit 8, and the outputs of the armature circuit current detectors 6A, 6B are input to the armature circuit current balance detection means 9, and the field circuit current detector 7.
The outputs of A and 7B are inputted to the field circuit current unbalance detection means 10, the outputs of the balance detection means 9 and the outputs of the unbalance detection means 10 are inputted to the slip detection means 11, and The output of the control circuit 8 is inputted to the control circuit 8.

In an electric vehicle in which wheel slip is detected by the wheel slip detection method of the present invention configured as described above, the armature circuit current and field circuit current of both of the motor groups are as normal. While driving in a mutually balanced state, one of the wheels may spin and the electric motor driving that wheel, for example, among the electric motors represented by two armature circuits in Fig. 1. If the rotational speed of any of the motors increases, the reverse starting power of the motor increases and the armature current decreases, so the armature circuit current detectors 6A and 6
The output from B is different, and upon detecting the difference, the control circuit 8 controls the variable power DC power supply 4A, diverts the current of the field circuit 3A to the reactor 5, and weakens the magnetomotive force of the field circuit 3A. It is possible to reduce the output of the electric motor that drives the wheel that has caused the wheel to prevent the wheel from spinning again.

However, if the wheel slipping is relatively small, when reducing the current of the field circuit 3A to reduce the output of the electric motor that drives the wheel that has caused the wheel slipping, other motors in the motor group to which the motor belongs may be used. Since the output of the motor is also reduced at the same time,
Even if the armature circuit current of the motor group reaches a predetermined value and balance is restored with the armature circuit current of the motor group represented by armature circuit 2B, the readhesion of the idling wheel is unstable and there is still slight idling. Since this continues, it is difficult to achieve an equilibrium between the current in the field circuit 3A and the current in the field circuit 3B. In that case, the armature circuit current detectors 6A and 6B confirm that the currents in the T4 armature circuits 2A and 2B are balanced with each other.
The armature circuit current balance detection means 9 detects that the currents in the field circuits 3A and 3B are in a mutually unbalanced state through the field circuit current imbalance detection means 10, and the detection means 9.10 Both outputs are manually inputted to the wheel slip detection means 11, and when both manual inputs continue simultaneously for a predetermined period of time, the wheel slip detection means outputs an output, and for example controls the variable power DC power supply 4A to detect the wheel that has caused the wheel slip. The re-adhesion of the spinning wheels can be measured by temporarily suppressing the output of the motor group to which the driving motor belongs.

〔Effect of the invention〕

As explained above, the present invention connects motor groups each consisting of a plurality of series-wound motors in parallel to a DC power supply, and generates a field by a variable power DC power supply added to the field circuit of each motor group. An electric vehicle configured to control current in a magnetic circuit to perform constant current operation of the motor group, comprising means for detecting current in an armature circuit for each motor group; the means for detecting the current in the armature circuit; and the means for detecting the current in the armature circuit; means for detecting unbalance between the outputs, and means for detecting the current in the armature circuit; a wheel slip detection means to which the output of the means for detecting a mutual complaint 6j is input together; The wheel slip detecting means detects the wheel slip when the output of the means for detecting the current of the field circuit and the output of the means for detecting the imbalance between the respective outputs are simultaneously and continuously input for a predetermined period of time. By doing so, it is possible to detect minute wheel slips that are likely to occur and continue in the electric vehicle, and to take necessary measures to re-adhesion, thereby making it possible to fully utilize the output of the electric motor group. effective.

[Brief explanation of drawings]

FIG. 1 shows a circuit diagram illustrating a method for detecting wheel slippage of an electric vehicle according to the present invention. 1...DC power supply, 2A, 2B...armature circuit, 3A
. 3B... Field circuit, 4A, 4B... Variable power DC power supply, 6A, 6B... Armature circuit current detection means, 7A,
7B... Field circuit current detection means, 8... Variable power DC power supply control means, 9... Balance detection means, 10... Unbalance detection means, 11... Idle rotation detection means. Fj1 diagram

Claims (1)

[Claims] 1) Motor groups each consisting of a plurality of series-wound motors are connected in parallel to a DC power supply, and the current in the field circuit is controlled by a variable power DC power supply added to the field circuit of each motor group. In the electric vehicle, the electric motor group is operated at a constant current. The output of each of the means for detecting current is inputted, and the output of the means for detecting the balance between the outputs and the means for detecting the current of the field circuit is inputted, and the unbalance between the outputs is detected. and means for detecting imbalance between the outputs of the means for detecting the balance between the outputs of the means for detecting the current in the armature circuit and the outputs of the means for detecting the current in the field circuit. wheel slip detection means to which the output is input together, and means for detecting the output of the means for detecting balance between the outputs of each of the means for detecting the current of the armature circuit and the current of the field circuit. An electric vehicle characterized in that the wheel slip detecting means detects the wheel slip by simultaneously inputting the output of the means for detecting unbalance between the outputs thereof continuously for a predetermined period of time. wheel slip detection method.