Apparatus for estimating rotational position of predetermined magnetic pole of rotary electric machine

Patent metadata

Field	Value
Publication number	US-2016109265-A1
Application number	US-201514887888-A
Country	US
Kind code	A1
Filing date	Oct 20, 2015
Priority date	Oct 21, 2014
Publication date	Apr 21, 2016
Grant date	—

Abstract

In an apparatus for controlling a rotary electric machine, a voltage applier applies a high-frequency voltage to one of the field winding and the armature winding. One of a field winding and an armature winding is defined as an input winding, and the other thereof is defined as an output winding. A current detector detects a high-frequency current flowing through the output winding based on the applied high-frequency voltage. The high-frequency current includes therein information associated with the rotational position of a target magnetic pole of the rotor as a predetermined one of the magnetic poles. An estimator estimates the rotational position of the target magnetic pole of the rotor according to the high-frequency current detected by the current detector.

First claim

What is claimed is:

1 . An apparatus for controlling a rotary electric machine including a rotor with a field winding for generating at least one pair of magnetic poles, and a stator with an armature winding, the field winding and the armature winding being magnetically coupled to each other when energized, the apparatus comprising:
a voltage applier that applies a high-frequency voltage to one of the field winding and the armature winding, one of the field winding and the armature winding being defined as an input winding, and the other thereof being defined as an output winding; a current detector that detects a high-frequency current flowing through the output winding based on the applied high-frequency voltage, the high-frequency current including therein information associated with the rotational position of a target magnetic pole of the rotor as a predetermined one of the magnetic poles; and an estimator that estimates the rotational position of the target magnetic pole of the rotor according to the high-frequency current detected by the current detector.

2 . The apparatus according to claim 1 , wherein the armature winding is defined as the input winding, and the field winding is defined as the output winding.

3 . The apparatus according to claim 2 , wherein:
the apparatus has a target direction of the target magnetic pole, an estimated first direction for the target direction of the target magnetic pole, and an estimated second direction electromagnetically perpendicular to the estimated first direction; the voltage applier applies the high-frequency voltage to the armature winding as a component in the estimated first direction; and the estimator adjusts the estimated first direction for the target direction of the target magnetic pole such that an amplitude of the high-frequency current detected by the current detector is maximized, thus estimating the adjusted estimated first direction as the rotational position of the target magnetic pole.

4 . The apparatus according to claim 2 , wherein:
the apparatus has a target direction of the target magnetic pole, an estimated first direction for the target direction of the target magnetic pole, and an estimated second direction electromagnetically perpendicular to the estimated first direction; the voltage applier applies the high-frequency voltage to the armature winding as a component in the estimated first direction; and the estimator further comprises:
an angular difference calculator that calculates an angular difference between the target direction of the target magnetic pole and the estimated first direction in accordance with an equation that represents the amplitude of the high-frequency current detected by the current detector is maximized upon the angular difference being zero,
the estimator being configured to correct the estimated first direction according to the angular difference, thus estimating the rotational position of the target magnetic pole.

5 . The apparatus according to claim 2 , wherein:
the apparatus has a target direction of the target magnetic pole, an estimated first direction for the target direction of the target magnetic pole, and an estimated second direction electromagnetically perpendicular to the estimated first direction; the voltage applier applies the high-frequency voltage to the armature winding as a component in the estimated first direction; and the estimator adjusts the estimated second direction for the target direction of the target magnetic pole such that an amplitude of the high-frequency current detected by the current detector is minimized, thus estimating the adjusted estimated second direction as the rotational position of the target magnetic pole.

6 . The apparatus according to claim 2 , wherein:
the apparatus has a target direction of the target magnetic pole, an estimated first direction for the target direction of the target magnetic pole, and an estimated second direction electromagnetically perpendicular to the estimated first direction; the voltage applier applies the high-frequency voltage to the armature winding as a component in the estimated first direction; and the estimator further comprises:
an angular difference calculator that calculates an angular difference between the target direction of the target magnetic pole and the estimated first direction in accordance with an equation that represents the amplitude of the high-frequency current detected by the current detector is minimized upon the angular difference being zero,
the estimator being configured to correct the estimated first direction according to the angular difference, thus estimating the rotational position of the target magnetic pole.

7 . The apparatus according to claim 1 , wherein the field winding is defined as the input winding, and the armature winding is defined as the output winding.

8 . The apparatus according to claim 7 , wherein:
the apparatus has a target direction of the target magnetic pole, an estimated first direction for the target direction of the target magnetic pole, and an estimated second direction electromagnetically perpendicular to the estimated first direction; the current detector detects a component of the high-frequency current flowing in the estimated first direction; and the estimator adjusts the estimated first direction for the target direction of the target magnetic pole such that an amplitude of the component of the high-frequency current detected by the current detector is maximized, thus estimating the adjusted estimated first direction as the rotational position of the target magnetic pole.

9 . The apparatus according to claim 7 , wherein:
the apparatus has a target direction of the target magnetic pole, an estimated first direction for the target direction of the target magnetic pole, and an estimated second direction electromagnetically perpendicular to the estimated first direction; the current detector detects a component of the high-frequency current flowing in the estimated second direction; and the estimator adjusts the estimated first direction for the target direction of the target magnetic pole such that an amplitude of the component of the high-frequency current detected by the current detector is minimized, thus estimating the adjusted estimated first direction as the rotational position of the target magnetic pole.

10 . The apparatus according to claim 7 , wherein:
the apparatus has a target direction of the target magnetic pole, an estimated first direction for the target direction of the target magnetic pole, and an estimated second direction electromagnetically perpendicular to the estimated first direction; the current detector detects a first component of the high-frequency current flowing in the estimated first direction, and detects a second component of the high-frequency current flowing in the estimated second direction; and the estimator estimates the rotational position of the target magnetic pole of the rotor according to the first and second components of the high-frequency current detected by the current detector.

11 . The apparatus according to claim 7 , wherein:
the apparatus has a target direction of the target magnetic pole, an estimated first direction for the target direction of the target magnetic pole, and an estimated second direction electromagnetically perpendicular to the estimated first direction, the apparatus further comprising:
a DC power source;
a switch connected between the field winding and the DC power source;
a field voltage determiner that determines a field command voltage for the field winding; and
a field manipulator that:
performs a pulse-width modulation task

Assignees

• Denso Corp

Inventors

• Ishida Jun
• Fujii Kiyoshi

Classifications

• G01D5/208 Primary

  using polyphase currents · CPC title

• H02P6/183

  using an injected high frequency signal · CPC title

• H02P21/24

  Vector control not involving the use of rotor position or rotor speed sensors · CPC title

• G01D5/14 Primary

  influencing the magnitude of a current or voltage · CPC title