| For the features of high efficiency, high power per volume, high reliability and easy maintenance, permanent magnet synchronous motor(PMSM) has been widely used in some industrial applications, such as industrial robots, numerical control machine and aircrafts. In some occasions with high performance requirements, fast torque response is often needed to ensure the dynamics of the whole system. As a result, the performance of current controller, which is in the inner loop, is the key of the servo system. It's quite necessary to investigate the current control strategy.Due to its high performance, predictive control has attracted extensive attention recently, which has been widely used in industrial process control. However, the research on its applications to PMSM drives are still limited and this paper will focus on predictive current control for PMSM. Firstly, the servo system and the development of PMSM were introduced. The mathematical model of PMSM was established in different frames and its nonlinearities were also analyzed. A nonlinear model was constructed based on the simulation and test of PMSM parameters. Secondly, the principle of vector control was discussed and the PI controllers were designed. Then, the thesis researches the model predictive control and deadbeat predictive control in current loop and proposed new algorithm to improve the performance. Model predictive control abandons SVPWM and achieves fast current response but has larger current ripple. Deadbeat predictive control applies the deadbeat ideology into predictive control. This paper analyzed the stability to find it has higher control performance with easier control algorithm and implementation.At last, a series of simulation and experiment have been conducted on MATLAB/Simulink and TMS320F28335 digital control platform respectively to compare the control performance of each algorithm. The results prove the feasibility and validity of algorithm which is in accordance with the theory analysis. |
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