Sensorless Control of IPMSM Drives Using High-Frequency Pulse Voltage Injection with Random Pulse Sequence for Audible Noise Reduction

Saliency tracking based sensorless control schemes of interior permanent magnet synchronous motor (IPMSM) are generally troubled by the audible noise induced by high-frequency (HF) signal injection and the estimation error caused by voltage distortions. Aiming at that, a novel sensorless control strategy of IPMSM drives using HF pulse voltage injection with random pulse sequence (HFPVI-RPS) is proposed. First, the conventional HFPVI method could restrain the impact of voltage distortions, and its mechanism is briefly reviewed. Then, based on that, a novel injected form that injecting HF pulse signals with random pulse sequence into the estimated d-axis is designed to eliminate discrete harmonics in the current power spectra density (PSD) and broaden the current PSD to a wide range. The audible noise can be reduced as much as possible. Furthermore, a signal demodulation scheme matched with the injected form of HFPVI-RPS is proposed for the accurate extraction of rotor position. The PSD analysis of the HFPVI and proposed HFPVI-RPS methods is carried out, and the PSD comparison between reported methods and HFPVI-RPS method is given. Eventually, the effectiveness of the proposed sensorless control strategy is verified on a 750 W IPMSM drive platform.