Study On The Predictive Current Control Of Permanent Magnet Synchronous Motor

With the widespread application of permanent magnet synchronous motor(PMSM)in aerospace,electric vehicles,servo drives and other fields,the demands on the control performance of PMSM drive systems are becoming higher and higher.In the PMSM drive system,the current link can determine the electromagnetic torque output of the motor and directly affect the control performance of the system,so it is of great significance to study the current control strategy.In recent years,a variety of control strategies have been applied to current control,among which predictive current control has become a much more popular strategy for research and application.This thesis takes the interior permanent magnet synchronous motor(IPMSM)as the research object,and focuses on the application of finite control set model predictive control(FCSMPC)and deadbeat predictive control(DBPC)in the current control of its drive system.First,the mathematical model of PMSM in three common coordinates is derived based on the coordinate transform theory.Also,the PMSM vector control system and space vector pulse width modulation technology are introduced.In the simulation experiment,the voltage feedforward decoupling is added to improve the control performance of traditional vector control.When deal with the problem that the unfixed frequency of the inverter switching in the traditional finite control set model predictive current control(FCSMPCC),the improved algorithm is proposed,and it solve the problem by combining space vector pulse width modulation(SVPWM)technology;The sampling and calculation delay of the digital controller are analyzed,and a two-step prediction method is adopted to deal with it.Simulation results show that the improved algorithm has made the inverter operat at the fixed switching frequency and achieved a good control performance.Aiming at the problem that the current control performance of the traditional deadbeat predictive current control(DBPCC)is affected by the PMSM parameter change,it is found that the motor inductance parameter disturbance has the greatest impact based on the simulation analysis results.An improved algorithm is also proposed to overcome the problem by adopting a new current deadbeat constraint condition,and the improved algorithm will reduce the influence of the inductance parameter in the DBPCC.Simulation results show that the improved DBPCC algorithm has been significantly less sensitive to the inductance parameter and its current control performance has great improved.Finally,an IPMSM drive control system was built with the existing platform in the laboratory and experiments of control performance of the improved DBPCC algorithm was performed with this experimental system.The first experiment is the current given response experiment and it proves that the improved DBPCC algorithm has parameter robustness.Based on the previous experiment,the double closed-loop speed regulation experiment of the IPMSM drive control system is performed and the results show that the improved DBPCC algorithm not only has improved the system's parameter robustness,but also has got a good current control performance.