Performance Investigation and Observer-based Condition Monitoring Scheme for a PMSG-based Grid-Connected Wind Power System under Switch Open Fault

To analyze responses under open fault conditions in switching devices, a performance investigation and condition monitoring scheme are presented through an integrated simulation study of a permanent magnet synchronous generator (PMSG) based variablespeed grid-connected wind power system. Among various faults in power electronics components, the open fault in switching devices may arise due to the destruction of switches by an accidental over current or the forced disconnection for protection. When the switch open fault occurs in the generator-side converter, the grid-side inverter as well as the generator-side converter does not operate normally, resulting in an increase of the current harmonics and a reduction in generated output and efficiency. As an effective way of the condition monitoring for the generation system by online basis without requiring any diagnostic apparatus, the estimation schemes for the generated voltage, flux linkage, and stator resistance are proposed in this paper and the validity of the proposed scheme is proved through comparative simulations.