Research On Model Predictive Current Control And Harmonic Suppression Of Open-end Winding Permanent Magnet Synchronous Motor

Permanent Magnet Synchronous Motor(PMSM)has been widely used in new energy vehicles,military,industrial and other related fields due to its high power density,flexible control and reliable and stable operation.Open-end Winding Permanent Magnet Synchronous Motor(OW-PMSM)means that the neutral point of the three-phase star connection winding in the traditional PMSM is opened.And the inverter is connected to both ends of the open-end winding respectively for power supply.The topology of OW-PMSM can be divided into common DC bus topology,isolated dual power supply topology and hybrid power supply topology.Compared with the traditional PMSM system,OW-PMSM system can effectively improve the utilization rate of DC bus with higher power demand.And the OW-PMSM can achieve multi-level output effect and have higher fault tolerance.In this paper,the OW-PMSM with common DC bus system is taken as the research object,and its basic theoretical analysis,mathematical model derivation,control strategy design and simulation experiment verification are analyzed and studied.Firstly,this paper takes OW-PMSM topology with common DC bus as the research object,and conducts theoretical analysis and derivation of its mathematical model under three different coordinate systems.According to the needs of subsequent studies,this paper combined with the topological structure and mathematical model of OW-PMSM to establish the simulation model of OW-PMSM in Matlab,and established the OW-PMSM control system based on vector control to carry out relevant verification experiments.Secondly,according to the characteristics of OW-PMSM,the Model Predictive Current Control strategy and its optimization strategy are designed in this paper.In order to solve the delay hysteresis of Model Predictive Current Control,a one-beat delay compensation strategy is designed.To solve the problem of voltage vector acting on the whole time period,two predictive current control strategies based on vector acting time are designed in this paper.Based on the idea of voltage vector distribution of action time,an expected voltage vector Model Predictive Current Control strategy combining basic vector and action time is designed.By establishing OW-PMSM control system under different strategies in Matlab,the steady and dynamic performance of the system under different working conditions were analyzed to verify the good performance of the control strategy.Then,according to the characteristics of OW-PMSM with common DC bus,this paper designs two Model Predictive Current Control strategies with zero-sequence current suppression.Based on the topological analysis of OW-PMSM,the zero-sequence loop model of the system and the key variables affecting the generation of zero-sequence current are derived.According to the characteristics of different influence variables and the common-mode voltage generated by different voltage vectors,two kinds of zero-sequence current suppression strategies based on Model Predictive Current Control are designed: zero common-mode vector suppression strategy and expected common-mode vector suppression strategy.Finally,the OW-PMSM control system with zero-sequence current suppression is established in this paper,and relevant dynamic and steady-state verification experiments are carried out to verify the control strategy designed in this paper.