Multi-Objective Trade-Off Quantification Based Design Optimization for Power Electronic Systems in More-Electric-Aircrafts

In this paper, a comprehensive formulation of reliability models for active and passive power components (i.e., capacitors and power semiconductor devices (MOSFETS)) of a regulated transformer rectifier unit (RTRU) for more electric aircraft application is presented. Additionally, the work focuses on the reliability analysis and evaluation at the system level for a non-modular discrete MOSFET based auxiliary power supply unit for more-electric-aircraft. A rigorous quantitative assessment of reliability, volume and power loss is carried out at the component level as well as system level, verifying how a particular design relates to the specific performance parameters. Keeping this as a motivation, this paper also focuses on studying and analyzing the inter-relation among reliability and other performance metrics such as power density and efficiency taking a 3kW RTRU as an example design. The major metrics under consideration for this study are the failure in time (FIT), mean time to failure (MTTF), power density, efficiency while keeping the eye on most failure prone elements of the power converter - capacitors and active power semiconductors. A comprehensive quantitative evaluation based on thermal management size, system reliability is done on choice of the switching semiconductors where the candidate pool includes Si and SiC MOSFET technologies. From the analysis on three different types of widely used capacitors - film, ceramic, aluminum electrolytic, it is concluded that the optimum choices of capacitors for high voltage DC link and low-voltage output belong to Aluminum and Ceramic types, respectively. Finally, the optimum selection of power stage components is derived from the extensive evaluation of the overall RTRU system in terms of system size and reliability.