Research On Fault Analysis And Fault-tolerant Control Of Four-phase Wound-field Doubly Salient Motor

Fault-tolerant driving system has been the research focus of scholars both at home and abroad.Comparing to a three-phase machine,four-phase Wound-field Double Salient Machine(WFDSM)enjoys higher fault tolerant ability.This thesis mainly researches on operation characteristics and fault-tolerant strategies under single phase open circuit condition and single phase short circuit condition.The validity of the fault-tolerance control strategies is fully proved by results of both simulations and experiments.First of all,the structure and working principles of four-phase WFDSM are introduced in this thesis as well as the mechanism and properties of electromagnetic torques production.Then the operation characteristics of four-phase WFDSM under two typical faults,including the single phase open circuit fault and single phase short circuit fault,are compared to normal condition with the help of Finite Element Analysis.To improve the electromagnetic performance with two faulty modes,remedial strategies are proposed for the WFDSM machine by researching the contributions of each armature winding to electromagnetic torques,which are proved by results of simulations.An experimental platform based on NI LabView and FPGA board is established to verify the proposed fault tolerant control strategies.Designing processes of hardware and software parts are introduced as well.In order to validate the effect of the proposed strategies by experiments,tests have been performed when WFDSM works in different modes including normal,single phase open or short circuit fault and fault tolerant conditions.Results show that the proposed strategies can effectively reduce the influence of faults on the electromagnetic performance of the motor which has been theoretically demonstrated by simulations.