Practical application of PHM/prognostics to COTS power converters

An easily-adopted method of adding prognostics/health management (PHM) to electronic systems is described. As an example, a PWM-type switching power supply was chosen for analysis in this paper, due to the ubiquitous nature of these power converters in Mil/Aero systems, and the criticality of their reliable performance. Switch mode power supplies (SMPS) provide significant advantages to users in terms of conversion efficiency, weight, and size. According to Industry Analysts, over $7.7 Billion of SMPS power systems were produced worldwide in 2002. However, SMPS's have unique reliability issues when used within a system due to size constraints, heat dissipation and varying load conditions. The internal components of a SMPS, including the power switch (MOSFET or IGBT), catch diode, capacitors, and magnetics are under repetitive stress conditions that contribute to elevated failure rates. Often the SMPS is considered the most vulnerable and weakest part of a system. Having an early warning of an impending failure (through PHM) would be very useful information and critical to mission success.