Real-Time Multiple Open-Switch Fault Diagnosis in Three-phase AC/DC PWM Converter for PMSG Based Grid-Connected Wind Power Generation System

Abstract

This paper proposes a new multiple open-switch fault diagnosis method and faulty switch localization algorithm in three-phase AC/DC PWM converter for permanent magnet synchronous generator (PMSG) based grid-connected wind power generation system. In the proposed scheme, the open-switch fault is detected by using normalized three-phase RMS currents and faulty switch location is identified by using normalized three-phase RMS currents as well as average phase currents. Various kinds of fault may occur in AC/DC PWM converter, which decreases the generator output power and degrades the stability in wind power generation system. In this paper, multiple as well as single open-switch fault conditions are investigated. The proposed fault detection and faulty switch localization algorithms do not require additional sensors or hardware since they use only the information on measured phase currents. In addition, they are quite simple, cost-effective and easy to use. To verify that the proposed methods are effective to detect faults and to identify the faulty switches position, the simulation results under twenty-one cases of open-switch faults are presented on different operating conditions.