Motor control apparatus

Patent metadata

Field	Value
Publication number	US-10122305-B2
Application number	US-201615552631-A
Country	US
Kind code	B2
Filing date	Feb 18, 2016
Priority date	Feb 25, 2015
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

A motor control apparatus which is applied to an actuator provided with a motor and an encoder, and drives the motor is provided. The motor control apparatus comprises: a controller that learns an initial position of a rotor, and also decides an energized phase; and a drive circuit that performs switching operation to energize an energized phase. The controller learns that, in learning the initial position, the initial position of the rotor is a two-phase facing position in which two adjacent salient poles of the rotor face salient poles of two energized phases of a stator, and the initial position of the rotor is a one-phase facing position in which one salient pole of the rotor faces a salient pole of one non-energized phase of the stator.

First claim

What is claimed is:

1. A motor control apparatus which is applied to an actuator provided with
a motor that includes a stator having a plurality of salient poles, wound with three-phase windings, on an inner periphery, and a rotor having a plurality of salient poles on an outer periphery, and
an encoder that outputs, at a predetermined angle interval, an A-phase signal and a B-phase signal that take either Hi or Lo accompanied by rotation of the rotor,
the motor control apparatus driving the motor, the motor control apparatus comprising:
a controller that learns an initial position of the rotor based on the A-phase signal and the B-phase signal acquired from the encoder in a state where two-phases out of three phases have been energized during initial drive after power-on, and also decides an energized phase based on a rotational position of the rotor during normal drive after the initial drive; and
a drive circuit that performs switching operation to energize the energized phase, which is decided by the controller,
wherein:
the controller learns that, in learning the initial position,
the initial position of the rotor is a two-phase facing position in which two adjacent salient poles of the rotor face salient poles of two energized phases of the stator when values of the A-phase signal and the B-phase signal are in a first state of both being Hi or both being Lo,
the initial position of the rotor is a one-phase facing position in which one salient pole of the rotor faces a salient pole of one non-energized phase of the stator when the values of the A-phase signal and the B-phase signal are in a second state of both being Hi or both being Lo;
the encoder is configured to include a rotary magnet having an annular shape and a magnetic sensor of a hall IC; and
a magnetizing pitch of the rotary magnet is set to 7.5° between N-pole and S-pole.

2. The motor control apparatus according to claim 1 , wherein:
in the motor, a ratio of a number of salient poles of the stator and a number of salient poles of the rotor is set to 3:2.

3. The motor control apparatus according to claim 1 , wherein:
the motor is provided by a switched reluctance motor.

4. The motor control apparatus according to claim 1 , wherein:
the actuator is provided by a range switching apparatus of an automatic transmission; and
the motor is used as a drive source that switches a range of the range switching apparatus.

5. The motor control apparatus according to claim 1 , wherein:
after the power-on, the two-phases out of the three phases are energized during the initial drive and the energized two-phases are unchanged during the initial drive.

Assignees

• Denso Corp

Inventors

• Sakaguchi Koji

Classifications

• H02P25/08

  Reluctance motors · CPC title

• H02P1/163

  for starting an individual reluctance motor · CPC title

• H02P25/0925

  wherein the converter comprises only one switch per phase · CPC title

• H02P6/16 Primary

  Circuit arrangements for detecting position · CPC title