Motor control circuit and motor controller

Patent metadata

Field	Value
Publication number	US-10924050-B2
Application number	US-201916576979-A
Country	US
Kind code	B2
Filing date	Sep 20, 2019
Priority date	Sep 27, 2018
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

A motor control circuit includes a control circuit configured to output a pulse width modulation signal for controlling a switching operation of an inverter circuit, the inverter circuit being configured to supply an alternating current power to a motor, and includes a speed-change detecting circuit configured to detect a change in a speed command signal and, output, in response to the change meeting and exceeding a predetermined limit, a signal indicating that the speed command signal has changed to the control circuit to cause the control circuit to change a duty cycle of the pulse width modulation signal, the speed command signal specifying a target value of a rotational speed of the motor.

First claim

What is claimed is:

1. A motor control circuit comprising:
a control circuit configured to output a pulse width modulation signal for controlling a switching operation of an inverter circuit, the inverter circuit being configured to supply an alternating current power to a motor; and
a speed-change detecting circuit configured to:
detect a change in a speed command signal, the change in the speed command signal being a difference between a pre-change speed command signal used before the speed command signal changes and a post-change speed command signal used immediately after the pre-change speed command signal, and
in response to the difference meeting or exceeding a predetermined limit, output a signal indicating that the speed command signal has changed to the control circuit to cause the control circuit to change a duty cycle of the pulse width modulation signal, the speed command signal specifying a target value of a rotational speed of the motor.

2. The motor control circuit according to claim 1 , wherein the speed-change detecting circuit is configured to set a threshold as the limit, the threshold being used to be compared with the difference,
wherein the speed-change detecting circuit is configured not to output the signal upon detecting the difference being smaller than the threshold, based on a comparison between the difference and the threshold, and
wherein the control circuit is configured to maintain the duty cycle of the pulse width modulation signal to be same as a preceding duty cycle when the signal is not outputted.

3. The motor control circuit according to claim 1 , wherein the speed-change detecting circuit is configured to set a threshold as the limit, the threshold being used to be compared with the difference,
wherein the speed-change detecting circuit is configured to output the signal upon detecting the difference being greater than or equal to the threshold, based on a comparison between the difference and the threshold, and
wherein the control circuit is configured to change the duty cycle of the pulse width modulation signal when the signal is outputted.

4. A motor controller comprising:
the motor control circuit according to claim 1 ;
an inverter circuit configured to be controlled by the motor control circuit, the inverter circuit including at least one switching element; and
a drive-signal generating circuit configured to generate a drive signal that causes the switching element to operate, based on a pulse width modulation signal from the motor control circuit.

5. A motor control circuit comprising:
a control circuit configured to output a pulse width modulation signal for controlling a switching operation of an inverter circuit, the inverter circuit being configured to supply an alternating current power to a motor; and
a speed-change detecting circuit configured to:
detect a change in a speed command signal, and
in response to the change meeting or exceeding a predetermined limit, output a signal indicating that the speed command signal has changed to the control circuit to cause the control circuit to change a duty cycle of the pulse width modulation signal, the speed command signal specifying a target value of a rotational speed of the motor

wherein the speed-change detecting circuit is configured to set a threshold as the limit, the threshold being used to be compared with a difference between a pre-change speed command signal used before the speed command signal changes and a post-change speed command signal used immediately after the pre-change speed command signal,
wherein the speed-change detecting circuit is configured not to output the signal upon detecting the difference being smaller than the threshold, based on a comparison between the difference and the threshold, and
wherein the control circuit is configured to maintain the duty cycle of the pulse width modulation signal to be same as a preceding duty cycle when the signal is not outputted.

6. A motor controller comprising:
the motor control circuit according to claim 5 ;
an inverter circuit configured to be controlled by the motor control circuit, the inverter circuit including at least one switching element; and
a drive-signal generating circuit configured to generate a drive signal that causes the switching element to operate, based on a pulse width modulation signal from the motor control circuit.

7. A motor control circuit comprising:
a control circuit configured to output a pulse width modulation signal for controlling a switching operation of an inverter circuit, the inverter circuit being configured to supply an alternating current power to a motor; and
a speed-change detecting circuit configured to:
detect a change in a speed command signal, and
in response to the change meeting or exceeding a predetermined limit, output a signal indicating that the speed command signal has changed to the control circuit to cause the control circuit to change a duty cycle of the pulse width modulation signal, the speed command signal specifying a target value of a rotational speed of the motor,

wherein the speed-change detecting circuit is configured to set a threshold as the limit, the threshold being used to be compared with a difference between a pre-change speed command signal used before the speed command signal changes and a post-change speed command signal used immediately after the pre-change speed command signal,
wherein the speed-change detecting circuit is configured to output the signal upon detecting the difference being greater than or equal to the threshold, based on a comparison between the difference and the threshold, and
wherein the control circuit is configured to change the duty cycle of the pulse width modulation signal when the signal is outputted.

8. A motor controller comprising:
the motor control circuit according to claim 7 ;
an inverter circuit configured to be controlled by the motor control circuit, the inverter circuit including at least one switching element; and
a drive-signal generating circuit configured to generate a drive signal that causes the switching element to operate, based on a pulse width modulation signal from the motor control circuit.

Assignees

• Abe Makio
• Hayashi Shu
• Aoki Masato
• Mitsumi Electric Co Ltd

Inventors

• Abe Makio
• Hayashi Shu
• Aoki Masato

Classifications

• H02P2207/05

  Synchronous machines, e.g. with permanent magnets or DC excitation · CPC title

• H02P27/085 Primary

  wherein the PWM mode is adapted on the running conditions of the motor, e.g. the switching frequency · CPC title

• H02P27/045 Primary

  whereby the speed is regulated by measuring the motor speed and comparing it with a given physical value · CPC title

• G01R31/343

  in operation · CPC title

• H02P6/00 Primary

  Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor (vector control H02P21/00) · CPC title