Research On Torque Ripple Suppression Methods Of Dsem Based On DITC

There are no additional structures such as windings and permanent magnets on the rotor of the doubly salient electro-magnetic machine,it has competitive advantages such as simple and reliable structure,flexible control methods,strong fault tolerance and high power density compared with other types of motors,there is no doubt that it more suitable for high-speed,high temperature,humidity,strong vibration and other harsh working environments with these advantages.But it suffers the serious torque ripple problem during electric operation due to the inherent doubly salient cogging structure of the stator and rotor as well as the special commutation methods,in order to overcome this defect and expand its application field,methods of the torque ripple suppression of the doubly salient electro-magnetic machine are studied in this paper.Firstly,the structure and mathematical model of the research object of which the 12/8-pole external rotor doubly salient electro-magnetic machine are briefly introduced and deduced;the finite element calculation model of the prototype is built by the finite element software ANSYS/Maxwell,and the electromagnetic characteristics of the static field and transient field are solved and analyzed;the electric operation principle of the double salient electro-magnetic machine is briefly introduced according to the mathematical model of the prototype and combined with the results of finite element analysis and calculation.Secondly,introduced several basic commutation control methods of doubly salient electro-magnetic machine and in order to verify the electric performance of the prototype,the co-simulation model of the prototype is built in the environment of ANSYS/Maxwell,ANSYS/Simplorer,MATLAB/Simulink based on the traditional double closed-loop control algorithm of speed and current.The reasons for the torque ripple of the doubly salient electromagnetic machine under those commutation control methods are briefly analyzed according to the results of co-simulation.And then,a direct instantaneous torque control algorithm with adjustable excitation current is proposed to solve the shortcomings of the existing direct instantaneous torque control algorithm,the intrinsic mathematical relationship between varying excitation current and torque is derived ideally,and the possibility of controlling the torque by the excitation current is analyzed by finite element calculation,the logic conditions for controlling the torque by using the excitation current are analyzed and designed,the torque fluctuations of the proposed direct instantaneous torque control algorithm and the existing direct instantaneous torque control algorithm are compared when the load changes and the speed changes through co-simulation,to solve the problem of the fixed commutation angle of the proposed control algorithm cannot adapt to the commutation process under various working conditions of the motor,a real-time optimization of the commutation angle control algorithm is designed and verified by co-simulation.Finally,the hardware circuit and control algorithm of the doubly salient electro-magnetic machine control system are designed according to the parameters of the experimental motor prototype,and parts of the control algorithms proposed in this paper are verified experimentally through the prototype experimental platform.