Design for reliability in renewable energy systems

Power electronics are widely used in renewable energy systems to achieve lower cost of energy, higher efficiency and high power density. At the same time, the high reliability of the power electronics products is demanded, in order to reduce the failure rates and ensure cost-effective operation of the renewable energy systems. This paper thus describes the basic concepts used in reliability engineering, and presents the status and future trends of Design for Reliability (DfR) in power electronics, which is currently undergoing a paradigm shift to a physics-of-failure approach. Two case studies of a 2 MW wind turbine system and a 6 kW photovoltaic system are presented to demonstrate the use of the DfR approach as a design tool to predict lifetime of components (e.g., power devices) as well as the overall systems (e.g., power converters) based on the required operating conditions (i.e., mission profile).