Study on Pole Position Detection Technique of PMSM

　　Study on Pole Position Detection Technique of PMSM
　　Permanent Magnet Synchronous Motors (PMSM) have been widely used in high performance speed regulated system for their advantages, such as high power density, high efficiency. In conventional PMSM driving system, to realize high performance control, the position sensors (such as resolvers, optical encoders) are needed to get the pole’s position and velocity. These Ball Neodymium Magnets additional position sensors not only increase the cost of the system but also decrease the system’s reliability. The problems of the position sensors limit the PMSM in some special application.
　　In order to reduce the cost of the PMSM driving system, the paper has proposed two pole position detection techniques, the technique based on two quadrature locked Hall Effect position sensors and the technique based on the sliding mode observer (SMO), for different applications.Firstly, on the basis of analyzing the mathematical model and vector control principle of PMSM, the two position estimation techniques have been researched. Secondly, the position estimation technique based on two quadrature locked Hall Effect position sensors and the possibly estimation error in the technique have been discussed in detail. A compensation method with the consideration of motor acceleration has been proposed to get a high accuracy position. Based on the position estimation technique, the Pseudo-sensorless PMSM controller has been designed. The position estimation technique is http://www.chinamagnets.biz tested on the controller and the experiments results show the correctness of the technique.Finally, the position and velocity estimation techniques based on SMO have been discussed in detail. The impact of the SMO chattering is considered for position and velocity estimation and some feasible measures are proposed to improve it, i.e. the FIR filter method, the saturation function method and the Extended Kalman Filter method. The position and velocity estimation techniques based on SMO are tested on the simulation model for sensorless vector control system of PMSM and the experimental platform based on TMS320LF2407A DSP. The experimental results agree well with the simulation results, and the results have verified the correctness and availableness of the technique.