Fault diagnoses for the Dc filters of power electronic converters

DC filters are responsible for more than half of the failures in electric power converters. One approach to improving the reliability, performance and maintainability is to include failure diagnosis logic within the power converter. DC bus capacitor failures may be classified as gradual faults caused by capacitor aging and sudden faults which may take the form of breakdown faults resulting from a blown capacitor fuse, and open circuit O-C faults. This paper presents new methods to detect and isolate failures in the DC filters of power converters caused by capacitor aging and O-C faults.