Investigation of a Novel Approach for Fault Diagnosis in Power Electronic Converters: The Case of the Subsynchronous Cascade Drive

Condition monitoring of adjustable speed drives (ASDs) gives the ability to prevent catastrophic failures of the electromechanical system. In case of standstills, fast and accurate fault diagnosis is necessary in order to reduce the downtime and consequently the production and revenue losses. For the above mentioned reasons, the investigation of the ASDs behaviour during the presence of faults in the power electronic converter and the development of diagnostic methods is extremely important In the present paper, faults in the rotor side of the power electronic converter of the subsynchronous cascade drive are examined. Furthermore, a novel approach for fault diagnosis is investigated via simulation and experiment The proposed approach is based on monitoring the rotor current space vector angle, in order to extract features which indicate the specific fault modes of operation.