Research On Control Strategy Of Aviation Fault-tolerant Generation System Based On Three-phase Four-Leg Convertor

With the rapid development of more-electric and all-electric aircraft,the aviation power system has become more and more important.The requirements of it also have been increased highly in terms of power level,power quality and reliability.The glaring need for aviation power system is developing a strong fault tolerant generation system.Fault tolerant permanent magnet motor(FTPMM)has the charactistics of high power density and high reliability,it can constitute high quality generation system with a suitable convertor which gives it great value in the area of avation generator.Firstly,the paper introduced the feature and math model of the six-phase ten-pole FTPMM which used as the generator.Then the three-phase four-leg topology is proposed to as the main circuit topology of the fault tolerant generation system.According to the math model,relationship between output voltage and phase current can be deduced,and then the id analysis flux-weakening control method is proposed by considering the limit circle of voltage and power conservation to realize the constant voltage generation control in a wide speed range.Secondly,the control strategy of fault tolerant generation system is proposed on the basic of keep the magnet motive force constant.Combining the three-phase four-leg topology with 3D Space Vector Pulse Width Modulation to keep the output charactisitic unchanged when a open-circuit or short-circuit fault occur.Also the torque ripple will keep small at the same time.Use the FTPMM as a dual-winding motor and controled by two three-phase four-leg convertor,so the reliabilitycan be improved.When one redundancy is invalid,keep it out of the system and the rest redundancy produces full power.Finally,the simulation model of the generation system is set up in MATLAB to verify the control strategy.The normal situation,open-circuit and short-circuit faults have been simulated and analyzed.The hardware platform is established based on FTPMM and three-phase four-leg convertor,it use the DSP TMS320F28335 as the control core.The control software is given by C language,including control algorithm procedures,3DSVPWM procedures,fault detection procedures and so on.Based on the hardware and software,the normal experiments and fault experiments have been done,which verify the feasibility and effectiveness of the generation system.