Sensor less speed control of PMSM using Space Vector Pulse Width Modulation based on MRAS method

Permanent Magnet Synchronous Motor (PMSM) is now available as better alternate to induction motor for variable speed drives applications in industries. This is due to their small size, high potency, low weight, high ratio of torque to current, high power factor, maintenance free and ease to operational control. The study in this paper describes the structure and modeling of PMSM along with implementation of Model Reference Adaptive System (MRAS) technique with Space Vector Pulse Width Modulation (SVPWM) and voltage space vector process for speed estimation in sensor less speed control. Sensor less speed control of PMSM is achieved by using estimated speed deviation as feedback signal for the PI controller. Simulation studies reveal that the proposed MRAS technique can effectively estimate the speed of rotor with high exactness and torque response is significantly quick. It demonstrates that the entire control system is easy, effective, and feasible.

I. Introduction

There has been tremendous demand for variable speed drives in low and high power applications like aircraft, electrical vehicles, submarines, nuclear power stations, medical, industrial servo drives and in many automotives. This has resulted in variety of products offering many advanced features. In these products, the control strategy plays an important in meeting the requirements of these applications. But, high cost, temperature sensitivity and strict requirement are the major barriers in the practical implementation of these drive system [1]. To overcome these problems, sensor less speed control of PMSM can be useful, because position sensing element might be large, less robust, may get failed in harsh atmospheric conditions [2].