ABSTRACT
Design and implementation of a low cost control scheme of sensor less Permanent Magnet Synchronous Motor (PMSM) for efficiency improvement of pump and compressor is presented in this paper. The main problems of sensor less control of PMSM are starting jerk and loss of synchronism during acceleration. Due to absence of rotor position sensor, controller has to start the motor from an arbitrary initial rotor position and mismatch between actual position and assumed position is the principle reason behind starting problem. It is described in this work how a simple modification in motor turn-off process can solve the aforesaid problem. On other hand, loss of synchronism problem occurs mainly due to improper selection of rate of change of stator voltage and frequency. The previously described simple procedure is used to determine the optimal rate of change of stator voltage and frequency. Experimental results are presented to demonstrate effectiveness of the proposed control scheme.
