A new method for the detection and location of faults in matrix converters

This paper presents a new method to diagnose open-circuit faults in matrix converters. The proposed method consists in the measurement and estimation, simultaneously, of the three output phase voltages of the matrix converter. Afterwards, three error voltage signals are generated, which will be subsequently modulated using the control signals of each bidirectional switch of the converter. The nine modulated error voltages thus obtained are then monitored continuously and averaged over a certain period of time. When the converter is in healthy conditions, the values obtained for these signals are small. If an open-circuit fault arises in one or more switches, the modulated signals assigned to the faulty switches increase beyond a certain threshold value, hence giving the indication of the faulty condition. The obtained results shown in the paper demonstrate the effectiveness and applicability of the proposed diagnostic approach for the detection of open-circuits faults in matrix converters whether it feeds an induction motor or a passive load. The main advantages of this new diagnostic approach are its fast fault detection capability and easiness of implementation, associated to the possibility of diagnosing the presence of more than one faulty switch at the same time.