Fault diagnostics in power electronics-based brake-by-wire systems

Abstract

A d.c.—motor—based brake—by—wire system is studied for the purpose of fault diagnostics of the power electronic switches. The voltage and current generated in the switching circuit under normal and six faulted conditions are observed. A hierarchical fuzzy diagnostic system has been developed to detect certain types of fault condition in any specific solid state power switch at the moment immediately after the occurrence of the fault. The hierarchical fuzzy diagnostic system has been tested and validated using data from both a simulation and a laboratory set—up with a 1 / 3 hp d.c. motor and a d.c.—to—d.c. converter. The system performance has been compared with two different fuzzy diagnostic systems and the results are presented. The hierarchical fuzzy diagnostic system trained on the simulated model has the capability of detecting certain types of fault condition occurring in a brake—by—wire actuator system set—up in a laboratory in less than 0.0009 s and pinpointing the specific types of fault within less than 0.013 s.