Sensorless Control of IPMSM Drives Using a Pseudo-Random Phase-Switching Fixed-Frequency Signal Injection Scheme.

The conventional high-frequency (HF) voltage injection method can accurately extract rotor position for interior permanent magnet synchronous motor (IPMSM) drives at low and zero speed ranges. However, the fixed injection frequency will produce a loud audible noise. To solve this problem, a pseudo-random phase-switching fixed-frequency (PRPSFF) signal injection method is proposed in this paper. Ba...