Study on fault diagnosis system design for power supplies based on built-in test theory

Power supplies are one important type of electric products. They are widely used in both military and commercial applications. Power supply faults will directly result in system failures. For some critical systems, power supply faults can even cause a catastrophe, leading to great economic loss, casualties, and deterioration of the company's reputation. In this paper, an approach of fault diagnosis was provided for power supply systems. Subsequently, a BIT-based implementation of the design for a switching mode power supply (SMPS) product was presented. Techniques from engineering disciplines including fault tree analysis, system level failure evolution modeling, sensor-based condition monitoring, and built-in test design were applied. After the failure diagnosis system is utilized by the customers in nuclear industry, failures of power supplies at the system level can be quickly and automatically isolated to Line Replaceable Units (LRU) in situ, which improved availability of the power supply system and reduced maintenance and support cost.