Sensorless-MTPA Control of Permanent Magnet Synchronous Motor Based on an Adaptive Sliding Mode Observer

Abstract

Different from the traditional method of the interior permanent magnet synchronous motor (IPMSM), the sensorless maximum torque per ampere (MTPA) control scheme in this paper does not need two observers for rotor position and d-q axis inductances, respectively. It only needs an adaptive sliding mode observer (ASMO) based on the extended flux (EF) to realize double-loop control and MTPA operation simultaneously. The adaptive mechanism of rotor speed is designed to ensure stability of the ASMO. The rotor position and the difference between d-axis and q-axis inductances are obtained from the estimated EF to acquire the MTPA points when the position sensor of the IPMSM is absent. The proposed scheme is realized on a 20kW IPMSM where the sensorless control performance and the MTPA control performance are tested. The effectiveness of the proposed method is verified by the experiment results.