A Phase Current Reconstruction Method With Sampling Error Compensation for Open-End-Winding Permanent Magnet Synchronous Motor Drive System

A simple phase current reconstruction method with sampling error compensation for open-end-winding permanent magnet synchronous motor (OEW-PMSM) is proposed. Compared with the conventional OEW-PMSM drive system with three current sensors, the number of current sensors is reduced. In the conventional current reconstruction technologies, the reconstructed phase currents use the asymmetric modulation or asymmetric sampling points typically. The sampled current used to reconstruct the phase currents are instantaneous values and sampled at different points can not calculate the actual average current accurately. The error between the reconstructed phase current and real average phase current are introduced. In this article, the characteristic of the phase current is analyzed and a simple phase reconstruction strategy using two sensors is proposed for OEW-PMSM drive. The complex process of shifting phase in modulation is avoided. To obtain the accurate average current, a compensation method by calculating the change rates is proposed. Simulation and experimental results are shown to verify the effectiveness of the proposed method.