2021 Volume 10 Issue 6 Pages 624-631
Recently, high-efficiency permanent magnet synchronous motors (PMSMs) have been used in various fields as the performances of permanent magnets have improved rapidly. PMSM position sensorless control based on high-frequency (HF) voltage injection is investigated herein, where the HF voltage is injected into the fundamental voltage. The HF current response, which includes information on the rotor position, is used for position estimation. There are two problems with this approach: the control becomes unstable as the speed increases and estimated position errors occur under load condition. The study considers the impact of speed and load on position estimation. Based on the consideration, a speed independent detection of HF current amplitude and estimated position error compensations under load condition are proposed. Further, an estimated position error compensation method is proposed by considering the impact of speed and load. Finally, experiments are conducted with an interior PMSM to demonstrate the validity of the proposed methods.
