Control device of AC motor

Patent metadata

Field	Value
Publication number	US-9419554-B2
Application number	US-201414458503-A
Country	US
Kind code	B2
Filing date	Aug 13, 2014
Priority date	Aug 20, 2013
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A control device of a three-phase AC motor includes: an inverter for driving the motor; a current sensor for sensing a sensor phase current of the motor; and a controller for controlling the motor. The controller includes: a current estimation device for estimating d-axis and q-axis current estimated values based on the sensor phase current and an electric angle of the motor; and a zero-crossing interpolation device for interpolating the d-axis and q-axis current estimated values by fixing the d-axis and q-axis current estimated values when the sensor phase current is in a zero cross range, which includes a zero point, so that the sensor phase current crosses the zero point, and for outputting interpolated d-axis and q-axis current estimated values as fixed d-axis and q-axis values, which are used for a feedback control relating to current flowing through the motor.

First claim

What is claimed is:

1. A control device of a three phase AC motor comprising:
an inverter for driving the AC motor;
a current sensor for sensing a current flowing in a sensor phase among three phases of the AC motor as a sensor phase current; and
a controller for switching on and off a plurality of switching elements, which provide the inverter, in order to control a current flowing through the AC motor,
wherein the controller includes:
a current estimation device for estim…

Assignees

• Denso Corp

Inventors

• Omata Ryuji
• Oowada Takahumi

Classifications

• H02P21/14 Primary

  Electricity · mapped topic