Patent ID: 8917041
Filing Date: 2014-12-23
Classification: H02P

Abstract:
1. A phase-shift detection device for detecting a phase shift caused by misalignment in rotational position detection of a motor that comprises: a rotor and multi-phase drive coils; and magnetic pole position sensors, corresponding in number to the multi-phase drive coils, configured to detect positions of rotating magnetic poles of the rotor, the phase-shift detection device comprising: a measurement signal generator configured to output a sinusoidal measurement signal induced in one of the multi-phase drive coils during rotation of the rotor in a non-driving state; a level difference calculator configured to receive a pulse-shaped position detection signal formed based on a sensor signal from one of the magnetic pole position sensors and calculate a level difference between a level of the sinusoidal measurement signal measured at a rising timing of the pulse-shaped position detection signal and a level of the sinusoidal measurement signal measured at a falling timing thereof; and a phase-shift calculator configured to calculate a degree of the phase shift, based on the level difference from the level difference calculator.