Prognostics and Health Management for Power Electronics and Electrical Power Systems

The present paper studies the dependency of grid reliability on asset hazard rates, repair rates and redundancy. It reviews and evaluates present prognostics & health management methods against operational experience. It also reflects on the anticipated wide-scale introduction of high power electronics beyond HVDC systems. Central to the discussion on maintenance are hazard rates, associated bathtub curves and maintenance concepts. The effect of preventive maintenance, repair strategies and redundancy configurations are weighed. Hazard rate estimation is key in the analysis and common assessment methods are discussed against the background of operational experience with historic data, testing, technical expertise and data driven models. Finally, a discussion follows the aspects that determine the mix and why distribution and transmission grids may lead to different choices.