Research On Vector Control System Of PMSM Based On Sliding Mode Controller

In recent years, with the fast development of power electronics technology, microelectronic technology, new motor control theory and the rapid development of rare-earth permanent magnetic materials, the Permanent Magnet Synchronous Motor has developed rapidly.Generally, the traditional two closed loops vector control systems of PMSM come with PI controllers. But PI controller actually is linear controller; meanwhile, vector control system of PMSM is non-linear system. So when come across with high required situation, PI controller makes no way. Sliding mode control is non-linear method, which make system gets better performance if PI controller is instead by SMC.Based on the analysis of MPSM model and the vector control, the simulation of traditional PI control system is done firstly in this paper, analysis of system performance is given in the cases that load changes, and the deficiency of PI is pointed out. Then, considering that the response time is long and ability of anti-disturbance is weak, this paper introduces SMC into vector control system, that is, a scheme of integral SMC is proposed. The results of simulation show that system has a better performance when compared with PI controller.Considering the problem of chattering, this paper figure out two improved schemes based on variable gain which also come with a exponential function instead of the symbol function. The results of simulation demonstrate that the improved schemes make good efforts in reducing chattering and immunity; meanwhile, system has good robustness and responses fast.