Research On Speed Control System For High-speed Doubly Salient Electro-magnetic Motor Based On SiC MOSFET

With the improvement of technology,the demamd for high-speed AC motor is more and more urgent.High-speed AC motor has the advantages with small volume,light weight and high power density because of its high speed which is benefical for the installation.Meanwhile,the direct connection with the high-speed load removes the high-weight mechanical drive structure,which improves the space utilization further.The stator and rotor of doubly salient elector-magnetic motor(DSEM)are salient.The stator is equipped with armature winding and excitation winding and the rotor has no winding.Its structure is reliable and safe when DSEM works in high speed.The paper studies the speed control system for high-speed DSEM,which includes the three-phase inverter based on SiC MOSFET and digital controller based on DSP and FPGA.What’s more,power busbar is used for connection in the inverter,which decreases the voltage spike caused by the stray inductor when DSEM works in high speed.Firstly,the paper introduces the researches of SiC’s characteristics and application and DSEM’s structure and speed control system.Then establish the mathmatical model based on the structure and characteristic curve of DSEM and introduce three operating modes for motor control.Besides,analyse the infulences on the stray inductance of power busbar by Ansoft Q3 D and design the laminated busbar.By the double pulse test for SiC,the stray inductance of busbar is calculated,which verifys the rationality of design.Compare and analyse different control strategies for DSEM including three-phase three-state(TPTS),three-phase three-state advanced angle(TPTSAA),three-phase six-state(TPSS)and three-phase nine-state(TPNS).At the same time,compare and analyse fixed PI and fuzzy self-adapted PI control method.The result shows that the latter is more suitable for the strong nonlinear high-speed motor speed control system,which can improve the dynamic and steady performance.Lastly,built the experimental platform and design the hard circuit and software.The simulation and experimental waveforms verify the correctness of theoretical analysis further.