A Novel Demodulation Method Based High-Frequency Signal Injection for Sensorless SPMSM Control Considering Cross-Saturation Effect

Abstract

This paper presents a novel demodulation method based high-frequency (HF) square-wave voltage injection scheme for surface-mounted permanent magnet synchronous motors (SPMSMs) sensorless control. The cross-saturation effect is compensated in this paper. In traditional HF square-wave voltage injection sensorless control schemes, the digital filters used to extract HF induced current envelope deteriorate the dynamic performance. The proposed demodulation method can eliminate low-pass filters (LPFs) by discretizing the current in the measured frame. The cross-saturation effect should be considered when the HF square-wave voltage injection scheme is applied in SPMSMs. A straightforward compensation strategy is introduced in this paper. The proposed sensorless control scheme was verified on a sensorless SPMSM drive, and the experimental results confirm the expected performance.