Sensorless control of a surface mounted permanent magnet motor by signal injection associated with space vector modulation technique

In this paper, an analysis of sensorless vector control of an industrial surface mounted permanent magnet motor PMSM with a small saliency is performed using injection signal method. First the position estimation principle was highlighted and validated through an experimental kit using electromagnetic actuator with variable inductance, where a 1 khz signal was applied. This method was then exploited for sensorless vector speed control of PMSM using space vector modulation signal at 20 kHz sampling frequency over a wide speed range. It was found that the performances produced are satisfactory, however, they depend on an adequate amplitude of the injected signal. Further, the PMSM high frequency modeling with an adequate signal processing of the phase current signal with appropriate filters has led to a comparable performance of those of vector control of PMSM with encoder mounted at its shaft end.