Research On Vector Control Technology Of The Four-phase Transverse Flux PM Machine

Compared with the traditional AC motor,the transverse flux PM machine(TFPMM)has the advantages of high torque density,high power density and design flexibility as well as modular structure.Because of the great prospect in low speed and high torque electric-driven applications,TFPMM has been the research focus of scholars both at home and abroad.Therefore,taking a novel Flux-Concentrating TFPMM designed by our research group as the object,the vector control technology has been studied in this paper.First of all,the structure and operating principle of the four-phase TFPMM are given in this paper.Then the variation of d-axis and q-axis inductances are analysed by 3D finite element method and the fitting formula of self-inductances and mutual-inductances are proposed.On this basis,the mathematical model for the TFPMM in the abcd reference frame is developed and its accuracy is validated.A new voltage space vector pulse width modulation(SVPWM)method for Four-phase H-bridge based on the characteristics of TFPMM is proposed and the simulation model of vector control system is built with Matlab.The validity of the control strategy for TFPMM is proved by the simulation results under different load conditions.Moreover,the operation characteristics of TFPMM under single phase open circuit condition and single phase short circuit condition are analysed and the results show the novel TFPMM enjoys fault tolerant ability.The hardware and software of the control system are designed and the designing processes of hardware circuit and software module are given as well.The test rig is constructed and tests have been performed when TFPMM works in different modes including normal,single phase open or short circuit fault.The experimental results is in consistent with theoretical analyse.