Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Yasunobu Harada

Kazutaka Takahashi

Tetsuaki Nagano

Kei Terada

In a motor control device according to the invention, upon velocity control of a motor, a superimposed signal generating unitoutputs a superimposed signal idh of a repetitive waveform, such as a triangular wave or a sine wave. A d-axis current command generating unitadds the superimposed signal idh generated by the superimposed signal generating unitto a d-axis current command idc*0 and outputs a d-axis current command idc*. An axial misalignment detecting unit(, and) receives the d-axis current command idc* and a q-axis current command iqc* and outputs an axial misalignment angle estimation value &#x394;&#x3b8;^. An axial misalignment correction unitreceives the axial misalignment angle estimation value &#x394;&#x3b8;^ and an actual detected position &#x3b8;m and outputs a position after correction &#x3b8;m'. Therefore, detection and correction can be performed in real time through calculation at a given timing during a normal operation.

Motor control device

A magnetic-pole detecting system for synchronous AC motors and a magnetic-pole detecting method therefor are provided. The magnetic-pole detecting system for synchronous AC motors includes a position detectorfor detecting the relative position between the moving elementand the stator of an AC motor; a phase-update command unitfor making a plurality of currents with different phases flow in coilsandso that the moving elementmoves to a plurality of stable points; a reversal command unitfor making currents flow in the coilsandso that the moving elementreverses from the previous direction in which the moving elementhas been moved by the phase-update command unit; a current cut-off command unitfor cutting off the currents flowing in the coilsandwhen the position-detectordetects a movement of the moving element; a reversal-determining unitfor determining, based on a position-detecting signal from the position-detector, a direction in which the moving element has moved based on the phase-update command unit, and for determining that the determined direction has reversed between the previous and the present instances; and a stable-point-simulator for simulating a stable point by means of the phase of the currents flowing in the moving elementwhen the reversal-determining unithas detected the reversal.

Growing community of inventors

Tokyo, Japan

Yasunobu Harada