Research On Torque Performance Optimization Strategy Of Electrically Excited Doubly Salient Moto

Doubly salient electro-magnetic machine has many advantages,such as simple structure,low cost,high reliability,and strong high-speed operation ability.It has potential advantages in aerospace,industrial drive and other fields.However,the special stator rotor structure makes the motor exhibit significant nonlinear and strong coupling characteristics.And there are problems such as slow response speed,small output torque,and large torque ripple when running at high speed,which hinder the development of doubly salient motor.In view of this,taking optimizing the output torque performance of the DSEM drive system as the research goal,this paper conducts a detailed analysis of motor control strategies,studies improvement methods,so that the torque performance of the drive system is effectively improved.Firstly,the common angle control strategies for doubly salient electrical machines are discussed,including the angle control strategies of three state,six state,and nine state.Considering that the first two angle control strategies are special situations of nine state angle control strategies,this paper analyzes the working modes and operating principles of the nine state angle control strategy in detail.Moreover,the working principles of two motor drive control methods,square wave control and multiple sinusoidal superposition control,are analyzed,and a Maxwell+Simpler field circuit joint simulation model is established to provide a foundation for the subsequent research of torque optimization strategy.Secondly,to reduce the difficulty of selecting the advanced angle and increase the output torque of the motor,this paper studies a self-optimizing control method of advanced.Under square wave control,the influence of the selection of advanced angle on the output torque of the motor is discussed.It is found that a large or small advanced angle will reduce the torque output ability of the motor,and there is an optimal value for the advanced angle in the global range.Furthermore,the relationship among the motor output torque,the surrounding area of armature current,and the advanced angle is established.On this basis,the advanced angle is perturbed by a fixed step size,and the relative magnitude of the motor output torque under different advanced angles is compared to find the corresponding advanced angle when the motor output torque is maximum.The simulation results show that the method can effectively simplify the selection of advanced angle and improve the output torque of the motor.Thirdly,to solve the problem of large three-time ripple in output torque under multiple sinusoidal superposition control,this paper studies a torque ripple suppression method based on excitation current injection.The time-domain torque and torque ripple model of the motor are derived by Fourier series,which can quantitatively analyze the output torque and the generation mechanism of the three-time ripple of the motor drive system.With this for basis,the amplitude and phase of the excitation current injection are derived,and a specific implementation scheme is designed to reduce the torque ripple effectively.The simulation results show that the excitation current injection method effectively.Finally,based on the 12/8 DSEM experimental platform,the feasibility and effectiveness of the self-optimizing control method of advanced angle and the torque ripple suppression method based on excitation current injection in this paper are verified respectively.