Research On Fault-Tolerant Control System For Excitation Fault Of Doubly Salient Electromagnetic Generator

Doubly Salient Electro-magnetic Genreator(DSEG)is a new type of brushless DC generator with high reliability.There are no windings or permanent magnets on the rotor and it can adjust the output voltage by adjusting excitation current.It has the characteristics of simple structure,low manufacturing cost,and is suitable for high temperature and high speed conditions.It has a good application prospect.At present,there are some research results on the fault-tolerance of the main power converter and the motor structure of DSEG,but the fault-tolerant control of the excitation fault has not been studied yet.Once the excitation fault occurs and the excitation current disappears,the whole power generation system can not output electric energy to the load.Therefore,it is important to study the fault-tolerant control of the DSEG.Firstly,this paper introduces the development history of Doubly Salient Electro-magnetic Motor(DSEM),the research status of fault-tolerant control and the research status of fault-tolerant control of generator for excitation fault,and analyses the mathematical model and working principle of three-phase DSEG.Secondly,loss-of-excitation fault and fault-tolerant generation principle of DSEG is analyzed on this basis and three kinds of power converter topologies and their control strategies are proposed to realize fault-tolerant operation after excitation fault.The circuit modes of each stage under fault-tolerant control are studied and the winding current and output power of generator under fault-tolerant operation are derived mathematically.Finally,the simulation model of fault-tolerant generation system of DSEG Based on four-leg converter is built in MATLAB.The simulation results verify the validity of theoretical analysis and control strategy.The hardware platform based on DSP28335 and CPLD is built,and the corresponding control program is written for experimental verification.The experimental results show that the proposed system can realize fault-tolerant operation under loss-of-excitation fault.