JP2000134968A - Sr motor operation control method and apparatus during momentary drop of power supply voltage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operational control characteristic of SR motor during generation of momentary stop of power supply voltage. SOLUTION: A velocity comparing circuit 3 is provided to compare the signal level of preset velocity with the signal level of detected velocity. A means for switching the operation mode to the operating mode when an output signal is positive and to the recovery mode when an output signal is negative, and a voltage comparing circuit 6 for comparing the signal level of preset voltage with the signal level of detected voltage are also provided, and a means for setting the recovery mode when the output signal is negative is additionally provided. As a result, if it is detected that the detected voltage of power supply voltage becomes lower than the preset voltage due to momentary drop of the power supply voltage, the operation mode of SR motor is switched to the recovery mode to assure the control voltage with a rotating inertia of the SR motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of variable speed driving of an SR motor for driving a low voltage battery used in the field of physical distribution and the like.

[0002]

2. Description of the Related Art If the power supply voltage drops due to an instantaneous power failure or the like, a malfunction may occur due to a decrease in the control voltage of the SR motor. And the SR motor was coasted.

[0003]

After the recovery from the power failure, S
If an attempt is made to restart the R motor, the start is performed after a free-run. Therefore, the rotational speed of the SR motor does not match the speed command value, and the start is jerky.
That is, since the start command in the normal operation is soft-started from the zero speed to a set speed, the rotation speed exceeds the command speed until the command speed catches up with the rotation speed of the free running SR motor. ing. For this reason, the control of the SR motor is in the regenerative mode, and the mode is switched to the powering mode when the command speed matches the rotational speed of the SR motor. Therefore, the rotation of the SR motor after the recovery from the power failure does not accelerate at a stretch, but re-accelerates after the rotation speed once decreases, resulting in a jerky movement.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described drawbacks of the prior art, and detects a difference between a signal level of a set speed and a signal level of a detected speed to operate the vehicle. Means for switching the mode and means for setting the operation mode to the regenerative mode when the detected voltage signal level is lower than the set voltage signal level are provided, and the power supply voltage is instantaneously reduced and the detected voltage signal level is set in advance. When the voltage falls below a certain set voltage signal level, an operation control means for switching the operation mode from the power running mode to the regenerative mode without causing the SR motor to free run is provided, and the above-described operation control means is realized. An operation control system was built.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an operation control system in a drive circuit of an SR motor according to the present invention. The speed setting signal 1 and the speed detection signal 2 are input to a speed comparison circuit 3 to compare their respective signal levels, and the voltage detection signal 4 and the voltage setting signal 5 are input to a voltage comparison circuit 6 to compare the respective signal levels. Is done. The output signal of the speed comparison circuit 3 and the output signal of the voltage comparison circuit 6 are configured to be input to the A switch and the B switch of the analog switch circuit 8, respectively. The output signal of the voltage comparison circuit 6 is the first signal. A positive or negative signal is input to the analog switch circuit 8 through the polarity discriminating circuit 7 of the above. When the output signal from the first polarity discriminating circuit 7 is positive, the A switch of the analog switch circuit 8 is turned on. The switch is turned on, and when the value is negative, the B switch is turned on.

The output signals of the A switch and the B switch of the analog switch circuit 8 are input to a gain circuit 9 where they are amplified, input to one terminal of a comparator 10 and input to a second polarity discriminating circuit 11. Further, the comparator 10 receives the output signal from the gain circuit 9 and the detection signal of the current sensor and outputs a PWM signal. The operation mode operation digital circuit 12 inputs the PWM signal and the SR motor rotation position detection sensor signal from the comparator 10 and inputs the plus or minus signal from the second polarity discrimination circuit 11 to calculate the operation mode. .
When the input signal from the second polarity discriminating circuit 11 is positive, the powering mode signal is output, and when the input signal is negative, the regenerative mode signal is output.
It is configured to output as a gate drive signal of the R motor main circuit element.

Next, an operation control method executed by the above-described operation control system will be described. Means are provided for switching the operation mode to the powering mode when the output signal of the speed comparison circuit 3 is positive and to the regenerative mode when the output signal of the speed comparison circuit 3 is negative. There is a means to set
When it is detected that the power supply voltage drops instantaneously and the detected voltage signal level of the power supply voltage has dropped below a preset voltage signal level, the operation mode is changed from the powering mode without causing the SR motor to coast. Switch to regeneration mode. Since the control voltage of the SR motor can be ensured by the rotation inertia, the restart with the recovery of the power supply voltage can be easily performed.

[0008]

As described above, according to the operation control method according to the present invention, even if an instantaneous power failure of the power source occurs, the operation control method is performed.
Since the control power can be secured by setting the R motor in the regenerative mode, the rotation detection and the like are continued, and the continuation of the operation after the power is restored can be smoothly executed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an operation control system according to the present invention.

[Explanation of symbols]

 3 Speed comparison circuit 6 Voltage comparison circuit 8 Analog switch circuit 7, 11 Polarity discrimination circuit 10 Comparator 12 Operation mode operation digital circuit

Claims (2)

[Claims] In the operation control method of an SR motor, when the difference between the signal level of the set speed and the signal level of the detected speed in the speed comparison circuit is plus, the operation mode is set to the powering mode, and when the difference is minus, the operation mode is set to the regeneration mode. Means for switching, and means for setting the operation mode to the regenerative mode when the detected voltage signal level is lower than the set voltage signal level in the voltage comparison circuit. When it is detected that the voltage level has dropped below a preset voltage signal level, the operation mode of the SR motor is switched from the power running mode to the regenerative mode, and the control voltage is secured by the rotation inertia of the SR motor. A method for controlling the operation of an SR motor when the power supply voltage drops instantaneously. 2. A speed comparison circuit for comparing a speed setting signal level with a speed detection signal level, a voltage comparison circuit for comparing a voltage detection signal level with a voltage setting signal level, and an output signal of the voltage comparison circuit. And a first polarity discrimination circuit for outputting a plus or minus signal, and the output signals of the speed comparison circuit and the voltage comparison circuit, respectively, and turning on / off by the output signal from the first polarity discrimination circuit. An analog switch circuit having two analog switches that are controlled to be turned off, a gain circuit that receives and amplifies an output signal from the analog switch circuit, and an output signal of the gain circuit and an output signal of the current detection sensor. A comparator for inputting and outputting a PWM signal, and a second pole for inputting an output signal of the gain circuit and outputting a plus or minus signal A sex discriminating circuit, a PWM signal from the comparator and a signal from a rotational position detection sensor of the SR motor are input, and a plus or minus signal from the second polarity discriminating circuit is input to calculate an operation mode. An operation mode operation digital for outputting a powering mode signal when the input signal from the second polarity discriminating circuit is positive, and a regenerative mode signal when the input signal is negative, as a gate signal for driving the driver main circuit element of the SR motor. 2. The operation control system of an SR motor according to claim 1, wherein the operation control system comprises a circuit.