CPC H02P 27/08 (2013.01) [H02M 7/5395 (2013.01); H02P 6/20 (2013.01); H02P 7/06 (2013.01); H02P 2207/05 (2013.01)] | 7 Claims |
1. A motor drive apparatus which drives a motor including a plurality of phase windings arranged in a mutually unconnected state comprising:
a first inverter which controls electrification to one end of each of the phase windings;
a second inverter which controls electrification to the other end of each of the phase windings; and
a controller which, at the time of startup of the motor, rotationally moves a rotor of the motor to an initial position by DC excitation of supplying DC exciting currents from the first and second inverters to the phase windings and, after this rotational movement, PWM-controls switching of the first and second inverters in such a manner that a rotational speed of the rotor becomes the target rotational speed, wherein
the controller carries out the DC excitation by which a zero-axis current in each of the phase windings becomes approximately zero.
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