RELIABILITY EVALUATION OF POWER ELECTRONIC CIRCUITS

Abstract

With the development in the field of electronics, the complexity and power handling capability of electronic circuits have increased many fold. Failures, specially drift failures, in power electronic circuits, is a major problem. This necessitates the reliability analysis of the circuit .during design process, prior to fabrication. An effort has been made to evaluate the, component failure rate of power electronic circuits with database structures of failure rate.data. Part stress analysis method is most suited and has been used for failure rate evaluation. The electrical and thermal stress for each component is obtained from circuit analysis. Models for Silicon controlled rectifier, diac and triac have been developed and incorporated in the circuit analysis program for d.c. and transient analysis. The models of these devices for transient analysis simulate off-state, on-state, turn-on period and turn-off period. This furnishes the data of current and voltage transients ,and rate of chane of voltage and current, which is very important from relia-bility view-point but not used in part stress analysis. The dBASE III PLUS package for reliability evaluation stores the component failure rates in a database structure. Two examples are reported.