Super-twisting Sliding Mode Observer based Sensorless Control for TPFSI-Fed IPMSM Drives

The sliding mode observer (SMO) is widely used in sensorless control for IPMSM drives in medium- and high- speed region. However, the low pass filter (LPF) in conventional SMO to reduce the chattering effect led to a degradation in position estimation accuracy. This paper presents a super-twisting SMO (STSMO) based sensorless control strategy for three-phase four-switch inverter (TPFSI) fed PMSM drives. Firstly, the SVPWM for TPFSI considering capacitor voltage offset (CVO) and current compensation based CVO suppression scheme are illustrated in detail. Secondly, The parameter design of STSMO for extended back electromotive force (EEMF) and PLL-based sensorless observer are presented. The chattering effect of EEMF is reduced due to the continuous output of STSMO. Finally, the simulation results verify the proposed method.