Research On MTPA Control Optimization Strategy Of Permanent Magnet Synchronous Motor For Vehicles

A permanent magnet synchronous motor is widely used in the field of new energy vehicles,because it has the advantages of high starting torque,rather simple structure,and wide speed range.As a key component of the power train,the permanent magnet synchronous motor is particularly critical for the control technology.Consequently,it has important scientific theoretical significance and engineering practical significance to improve the control technology for the motor and improve the control performance of the motor.Since the permanent magnet synchronous motor is a complex nonlinear system with multi-variable and strongly coupled to each other,and the parameter setting of the current loop PI controller of the motor is also complicated.This affects the overall control function of the motor to some extent.In this paper,the Bald Eagle Search(BES)algorithm was introduced into the motor control system,and the PI parameters of the motor current loop were self-tuned by the introduced algorithm.The efficiency of parameter setting was improved by searching the optimal parameters based on the algorithm.In turn,the motor torque and the running stability of the motor was improved,the internal current loss is reduced.The optimization effect was analyzed quantitatively and compared with the control effect of the Particle Swarm Optimization(PSO).The main work of this paper is as follows:Firstly,the mathematical model of permanent magnet synchronous motor was established,and the appropriate vector control strategy was selected according to the optimization goal of this paper.The operation principle of the permanent magnet synchronous motor was analyzed and the mathematical equation of the motor was established.The model was simplified based on the principle of spatial coordinate transformation to facilitate the implementation of vector control strategies.The advantages and disadvantages of various vector controls were analyzed,spatial vector pulse width modulation technology(SVPWM)was used to regulate the speed during motor operation.The Maximum Torque per Ampere Control(MTPA)was selected to optimize the stator current amplitude.The Flux-weakening Control was used to expand the speed regulation area.Secondly,based on the PSO algorithm and the BES algorithm,the motor current loop PI controller was designed,and the performance of the two algorithms were compared and analyzed.Under the same motor parameters,the BES algorithm and PSO algorithm were applied to the current loop PI controller of the motor respectively.Based on the same population size,dimensions,and other initialization parameters,the optimal parameters were sought within the same solution space.The adaptability curve and unit step curve from the two algorithm were compared with each other,and the optimization performance of the vulture algorithm was evaluated.Finally,the simulation model of the permanent magnet synchronous motor was built,the optimized PI controller was embedded,and the power performance and economic efficiency of the motor were analyzed through simulation.Based on the platform of matlab/Simulink,the control simulation model of the motor was built.The PI controller using respectively the BES algorithm and the PSO algorithm were embedded in the model to analyze the speed curve,torque curve,and stator current curve of the motor when it is running.Then,the dynamic performance of the motor under the traditional MTPA control and the optimization of the two algorithms were Comparatively analyzed.Then,the effective current of the motor was obtained by current integration.The reduction rate of energy consumption was calculated using effective current,and the economic efficiency of the motor was evaluated.The simulation shows that the number of optimization iterations of the BES algorithm is significantly less than that of the PSO algorithm,the unit step curve rises faster,and the overshoot is less.Based on the control strategy optimized with the BES algorithm,the performance of the motor has been greatly improved : the torque of the motor is larger,that is,the output power of the motor is larger;The stator armature current of the motor is lower,and the resulting motor power loss is lower.The increase of the motor speed is relatively stable,which reduces the internal consumption of energy.The motor energy consumption was analyzed and compared with the traditional control strategy,the energy consumption from the BES strategy is nearly 61% lower than that from the traditional control strategy,and 22% lower than that from the PSO strategy.The results show that the proposed strategy in this paper can effectively improve the dynamic performance and economic efficiency of the motor.