Motor drive controller

Patent metadata

Field	Value
Publication number	US-2016285403-A1
Application number	US-201615075328-A
Country	US
Kind code	A1
Filing date	Mar 21, 2016
Priority date	Mar 26, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

A motor drive controller includes: a phase current detection circuit including: an RC network circuit in which a resistor and a capacitor are connected in series, the RC network circuit being configured to be connected in parallel with one or more coils of each phase of a motor; and a filter circuit that smooths a signal based on a voltage signal across the capacitor, wherein the phase current detection circuit generates a DC voltage signal that corresponds to a change in a value of a phase current flowing in the coils; a motor driver that drives the motor by applying a voltage to each phase of the motor; and a controller that receives the DC voltage signal from the phase current detection circuit and controls the motor driver based on the DC voltage signal.

First claim

What is claimed is:

1 . A motor drive controller comprising:
a phase current detection circuit including:
an RC network circuit in which a resistor and a capacitor are connected in series, the RC network circuit being configured to be connected in parallel with one or more coils of each phase of a motor; and
a filter circuit that smooths a signal based on a voltage signal across the capacitor,
wherein the phase current detection circuit generates a DC voltage signal that corresponds to a change in a value of a phase current flowing in the coils;
a motor driver that drives the motor by applying a voltage to each phase of the motor; and a controller that receives the DC voltage signal from the phase current detection circuit and controls the motor driver based on the DC voltage signal.

2 . The motor drive controller according to claim 1 ,
wherein the phase current detection circuit further includes an attenuator that outputs a voltage signal, which is obtained by attenuating the voltage signal across the capacitor, to the filter circuit.

3 . The motor drive controller according to claim 1 ,
wherein the motor is a three-phase brushless motor having Y-connected wirings, and wherein the RC network circuit is connected in parallel with arbitrary two of the three phases of the motor.

4 . The motor drive controller according to claim 1 ,
wherein the motor is a three-phase brushless motor having Y-connected wirings, and wherein the RC network circuit is connected in parallel between a midpoint of the Y-connected wirings and one of the three phases of the motor.

5 . The motor drive controller according to claim 1 ,
wherein the DC voltage signal sets a time constant of the RC network circuit so as to correspond to the change in a value of the phase current flowing in the coils.

6 . The motor drive controller according to claim 1 ,
wherein a time constant of the RC network circuit is set based on a value which is obtained by dividing an inductance value of the one or more coils of each phase of the motor by a DC resistance component.

7 . The motor drive controller according to claim 1 ,
wherein the controller operates to perform a overcurrent protection based on the DC voltage signal generated by the phase current detection circuit.

Assignees

• Minebea Co Ltd

Inventors

• Masuda Shigemi
• Koshiba Toshikazu

Classifications

• H02P29/032

  Preventing damage to the motor, e.g. setting individual current limits for different drive conditions · CPC title

• H02P29/027 Primary

  the fault being an over-current · CPC title

• H02P6/28

  Arrangements for controlling current (H02P6/10 takes precedence) · CPC title