Research On Open-circuit Fault Diagnosis For Indirect Matrix Converter

The indirect matrix converter(IMC)is derived from the direct matrix converter(DMC),which has attractive merits such as bidirectional power flow,sinusoidal input and output waveform,four-quadrant operation.Moreover,the IMC eliminates bulky dc-link capacitors and has a small volume when compared to the traditional two-stage ac/ac converter.Therefore,the IMC shows promising applications prospects in the industrial fields.In order to enhance the reliability during system operation,the study of fault detection for IMC is of significant importance.However,only a few studies have addressed the problem of open-circuit fault detection for IMC so far,and these studies include only simulated results.Based on the earlier discussion,the open-circuit fault diagnosis for IMC is the focus of this paper.First,the topology and basic operation princple of an IMC are introduced.Following that,the space vector modulation(SVM)strategy is presented,which has been widely used in IMC.Furthermore,the features of the SVM technique are summarized,laying a theoretical foundation for the circuit analysis.Combining with the circuit implementation of an IMC,this paper further study the possible fault types of power device and the available path for the inductive current to flow.Then,this paper presents detailed analytical work in the case that the open-circuit fault occurs in rectifier stage or inverter stage,which reveals the circuit features of an IMC under faulty condition.Based on the circuit analysis,a novel method for locating the faulty switch in both rectifier stage and inverter stage is proposed.To validate the applicability of the proposed method,a simulation model is built by using the Matlab/Simulink software.The simulation results support the theoretical analysis under faulty condition.Furthermore,the obtained results also verify the feasibility of the proposed open-circuit fault diagnosis method.Finally,the experimental prototype of an IMC is built,and the detailed implementation of hardware circuit and control software is introduced.On that basis,experiments are carried out to validate the feasibility and effectiveness of the proposed open-circuit fault detection approach.