Analysis of Zero-Sequence Current Generation Factors of Open-Ended Winding PMSM and Decoupling Controller

Abstract

In recent years, the fields of use of permanent magnet synchronous motors (PMSMs) have expanded, and they are being applied in various fields. As a method for improving the variable speed range under power supply voltage restrictions, an open ended winding permanent magnet synchronous motor (OEW-PMSM) that is driven by two inverters with an open connection instead of the connection of the three phases of the motor is being researched. In this paper, we clarify the factors that cause the generation of the zero-sequence current owing to the PMSM structure and clarify the electrical and magnetic parameters of the PMSM that affect the generation of the zero-sequence current. Furthermore, we propose a feedforward decoupling controller between the dq0 axes that can be easily realized up to a high frequency by using the clarified factors and demonstrate that the proposed method can effectively suppress the zero-sequence current.