Analysis and diagnosis method of open-circuit faults in matrix converter

Reliable diagnosis and location of matrix converter failure switch is the basis for efficient implementation of fault isolation and fault-tolerant technology. Based on the simulation platform of MC-PMSM system, an analytical work concerning the affected interval of open-circuit switches in MC and faulty behaviors of MC-PMSM system was presented. A new method for detecting and identifying open-circuit switch was proposed. The algorithm based on modulated error current was implemented in two stages: In the first stage, the faulty phase was diagnosed by measuring the differential values between motor currents and MC output currents, which reduced the range of possible faulty switches from nine to three. In the second stage, the MC switch modulated signals were combined to locate faulty switch. The validity and reliability of the proposed method were verified by the simulation results, which demonstrates that the strategy can avoid misdiagnosis under the unstable situations.