Research On Control Strategy For Starter/Generator System Of Switched Reluctance Motor

Integrated starter/generator system(ISG)both has the starting and generating function,and it is efficient and economic.Switched reluctance motor(SRM)has high reliability,low loss,simple constructions.It is easy to change between starting and generating,which is very suitable to be used in the starter/generators.While it is a problem to optimize the control parameters and to depress the torque ripple,which has become the hot researches of switched reluctance starter/generator(SRS/G).The construction and working principle of SRS/G is analyzed.Then with the study of the basic equations and the linear model,the change rules of inductance,flux linkage and torque are researched.The control principle and features of angle position control and chopped current control of starting control and generating control is analyzed.To solve the problem of optimizing of turn-on and turn-off angle,the method for maximizing the generated power is researched.The influence of turn-on and turn-off angles to average torque is analyzed by simulations.The average torque of generating is derived with the starting average torque equation.Then the method of optimizing turn-on and turn-off angles is obtained by the analyzation of the position relationship of current and inductance and the use ratio of the generating sections.The constructing process of the generating model of SRM is elaborated.And the steady-state performance and dynamic performance of SRM generating system are researched by simulations.To solve the problem of large torque ripple of SRM while starting operation,the instant torque control strategy is proposed.The loop of torque is imported to complete the closed-loop control of torque.When two phases or one phase switches on,the expected torque is distributed to switching phase by the sine torque distribution function.The switch states are control by hysteresis comparison control with two threshold values to control the total torque.The model of instant torque control and chopped current control are analyzed.And the torque performance of them is compared by simulations,which verified the effectiveness of instant torque control for the depression of the torque ripple.Finally,the starting and generating experiments are conducted on the system experiment platform and proves the correctness of theoretical analysis and realize the function of starting and generating of experimental system.