Research On Sensorless PMSM Parameters Identification

The Permanent Magnet Synchronous Motor (PMSM) is an ideal candidate for high performance industrial drive field because it has simple-structure, small-size, high-energy efficiency, reliable operation and high power density. Obtaining the rotor position and speed information exactly is the basis of permanent synchronous motor control. In the legacy PMSM drive systems, speed control is achieved by obtaining the rotor position or speed information through shaft sensors such as optical encoders. The popularization and application of PMSM are restrained because of the unreasonable price, volume as well as weight of such sensors, besides, they are hard to maintain.Speed-position sensorless control of motor drive systems, which overcomes above shortcomings ,is becoming a hot subject.Sliding mode is an efficient tool to control complex high-order dynamic plants under uncertainty conditions because of its order reduction property, low sensitivity to disturbances and parameters variations. We apply it to estimate the parameters of PMSM.Two kinds of mode reference observers based on double manifolds sliding mode will be presented to estimate the rotor position and speed without sensor. Both of the two strategies will select PMSM itself as the reference mode and its current mode in dq frame and ?? frame as the adjustable mode respectively. Each strategy will combine MRS (Mode Reference System) with variable structure control to formulate two slide mode surfaces according to two mode output errors.The effectiveness of the algorithm and the advantages and disadvantages of two different algorithms are examined using the MATLAB/Simulink.