Control Strategy Of Switched Reluctance Motor Based On Maximum Average Torque Optimization

Switched Reluctance Motor(SRM)stator and rotor are made of high permeability silicon steel sheet impact laminated,and there is no permanent magnet embedded in the rotor,the stator salient pole is wrapped with insulated metal wire,so its speed range can be Reaching more than 100000r/min,it supports the lack of phase operation,has a large power density and other advantages,and has a wide range of prospects in the motor drag industry.However,with the increase of the speed,the higher the requirements for the motor control theory,the current common control method at high speed is to adjust the switching angle,and then adjust the size of the phase current to achieve effective control of SRM at high speed.However,because the internal magnetic circuit of SRM is highly saturated and nonlinear,and there are many controllable parameters,it is impossible to analyze the explicit expression,so it is more difficult to adjust the switching angle at the same time.This paper proposes a control strategy for switched reluctance motors based on maximum average torque optimization.By reasonably selecting the best turn-off angle position,the motor can be operated at maximum average torque at high speed.This article first analyzes the SRM operation mechanism and commonly used mathematical models,and concludes that the current common control method of the motor at high speed is Angle Position Control(APC).Because the internal magnetization curve of SRM is a nonlinear function,it is difficult to derive The mathematical expression of the switching angle under the maximum average torque output is obtained through multiple simulation experiments to obtain the relationship between the off angle and the torque output,thereby obtaining a fixed off angle APC control scheme,that is,the off angle is fixed At the same time as the optimal position,the opening angle position is changed by PI,and the optimal off angle value is the off angle position of the maximum average torque output obtained through multiple experiments on the actual experimental platform.This control scheme reduces the difficulty of controlling the switch angle parameters,and also improves the torque output capability of the motor.Then when the proposed fixed off angle APC control method can not meet the situation where the speed and load change are large,so further optimization,a SRM high-speed APC control method based on maximum average torque optimization is proposed,and the maximum average torque output is selected as the optimization target,Off-line optimization of the off-angle parameters at different peak currents and speeds,and for the problem that traditional genetic algorithms are prone to fall into local optimal solutions,adaptive crossover and mutation operators are used to compare the genetic algorithm with offline simulation The cut-off angle curves under different peak currents and speeds are combined.The Matlab / Simulink simulation software was used to build an SRM control system optimized based on maximum average torque.The cut-off angle curve optimized by genetic algorithm was applied to the system and compared with the fixed cut-off angle APC control method.The results proved that The optimization results based on genetic algorithm can improve the torque output of the motor and improve the adaptability of the motor in the occasion of large changes in load and speed.Finally,the software and hardware design of the SRM control system based on maximum average torque optimization with DSP as the core is introduced,and the experimental motor test platform is built.A physical test experiment was carried out on the experimental test platform to further verify the effectiveness and feasibility of optimizing the SRM control system based on maximum average torque.