Research On High Bandwidth Current Loop Control Technology Of Wound Rotor Synchronous Machine Based On SiC Controller

Wound Rotor Synchronous Machine(WRSM)is widely used in the aero power-supply system.It is able to integrate start and generation and has advantages of high reliability.However,the armature winding of the WRSM has low-inductance characteristics resulting in large current harmonics during control.The current tracking effect is poor because of low current loop bandwidth and the control accuracy is reduced.The increased torque ripple reduces the starting performance of the WRSM.Therefore,this thesis researches the design method of high current loop WRSM controller based on SiC MOSFET.This thesis first analyzes the mathematical model and control principle of the WRSM,illustrates the FOC control algorithm of the WRSM,and analyzes the current loop of the WRSM control system.The definition of the bandwidth and its influencing factors are analyzed,and the relationship between the current loop bandwidth and the speed and stability of the current loop is analyzed.The methods of expending the bandwidth of current loop are carried out.Finally,simulation results show the validity of the described method of expending current loop bandwidth.Secondly,this thesis analyzes the design method of high-performance current loop controller of WRSM based on SiC MOSFET.From one hand,the designing principle of the stacked busbars are illustrated,and a 3D model of WRSM controller based on SiC MOSFET is designed in Solidworks.The parasitic inductance of the stacked busbar is extracted by Ansys Q3D Extractor.From the another hand,a high current-loop bandwidth control algorithm based on FPGA is designed,and the functions of each module in the control algorithm based on FPGA are simulated by Modelsim.The efficiency of FPGA are compared with DSP,which shows the superiority of the FPGA-based control algorithm.Finally,a high-performance WRSM control platform based on SiC MOSFETs is designed.The current loop bandwidth under different switching frequencies and control strategies is tested and the methods of expending bandwidth are verified.And the current harmonic suppression effects under several switching frequencies and control strategies is tested on the platform,which verifies the feasibility and superiority of the WRSM controller based on SiC MOSFET and FPGA in terms of current loop bandwidth and harmonic suppression.