Open-Circuit Fault Analysis and Diagnosis for Indirect Matrix Converter

Due to the absence of bulky dc-link capacitors, the matrix converter (MC) is a prospective candidate to replace the conventional two-stage ac-ac converter, especially in some applications which require high reliability. In order to enhance the reliability during system operation, this paper investigates an open-circuit fault detection technology for indirect MC. First, combining with the characteristics of the space vector modulation technique, this paper presents analysis work during the appearance of an open-circuit fault. Then, a novel fault diagnosis approach is proposed based on the circuit analysis. The proposed method establishes a unique corresponding relationship between switches and modulation sectors, and the faulty switch can be discriminated exactly by measuring the three-phase output voltages and the dc-link voltage. This method, which can locate the failure that occurs in rectifier stage or inverter stage correctly, offers favorable antidisturbance ability. The experiments are carried out to verify the feasibility and validity of the proposed fault detection method.