Switching Frequency Signal-Injection Sensorless Control Robust to Non-Ideal Characteristics of Inverter System for Dual Three-Phase PMSM

In this paper, the switching frequency signal-injection sensorless control (SISC) is mainly described. It has been known that the switching frequency SISC is vulnerable to inverter nonlinearity effects. In dual three-phase permanent magnet synchronous motor (DPMSM), it is able to implement SISC independently in the two individual three-phase windings. Based on the concept, two kinds of asymmetric SISC are suggested, which have immunity against the non-ideal characteristics of the inverter system. Afterward, it has been found by experimental tests that the switching frequency SISC with 180 degrees carrier-shifted PWM reduces harmonics of angle error significantly in DPMSM.