Research On Finite Control Set Model Predictive Control Method Of Permanent Magnet Synchronous Motor

The Permanent Magnet Synchronous Motor(PMSM)is widely used in industry and daily life because of its own high power factor,good security and low power consumption advantages,corresponding control strategy are becoming matured.The basic idea of the Field Oriented Control(FOC)or vector control method is to transform the stator three phase currents into two equivalent orthogonal currents which are decoupled from each other.One of these currents produces the magnetic field and the other is the torque producing current.The stator currents are controlled in phase and amplitude such that the magnetic field remains essentially constant at its maximum permissible value,and only the torque producing current is changed to control the output torque.With the modern PMSM speed control system on the simplicity and rapidity are increasingly high,the traditional control strategy in many occasions has been difficult to meet higher control needs than before.Based on the structure principle of PMSM,combined with the mathematical model of PMSM,this paper presents a detailed description of Finite Control Set Model Predictive Control(FCS-MPC)applied to PMSM.The design of the predictive current controller is started from the concept and operation principle of FCS-MPC.The most extensively used high performance control strategies for electrical drives as FOC are compared to a new FCS-MPC method.Both strategies are implemented on the same experimental bench and similar tests are performed,achieving the fairest possible comparison at steady state.The torque ripple of FCS-MPC is high in steady state.According to the influence of the active vector and zero vector on the torque,this paper reduces the torque ripple by changing the time of the active vector and adding the zero vector during a sample period.The existing literature have proposed some methods to reduce torque and flux ripple by optimizing the duty ratio of the active vector.However,these methods are usually complicated and parameter dependent.In order to eliminate these shortcomings,a new method of setting the constant value of some parameters is proposed to obtain the duty ratio of the active vector,and the simulation experiment is designed before and after adding the active vector duty ratio.Simulation and physical experiment results verify the effectiveness of the proposed method.FCS-MPC can achieve results similar to FOC,possibly even improving performance in transient conditions.In the sampling period embedded in the zero vector,and calculate the active vector of the optimal duty ratio can significantly reduce the FCS-MPC torque ripple.