Multi-Objective Minimization of Life-Cycle Environmental Impacts of Three-Phase AC-DC Converter Building Blocks

The goal of net-zero greenhouse gas emissions by 2050 requires a massive expansion of the use of renewable energy sources like photovoltaics and offshore/onshore wind, and the comprehensive electrification of transportation and upscaling of the industry. The energy transition thus implies an unprecedented scaling-up of the installed power electronic conversion capacity. This motivates an in-depth investigation of the environmental impacts (e.g., greenhouse gas emissions, but also damages to human health, ecosystem quality, or resource availability) of power electronic systems, whereby the entire life cycle and in particular the use phase must be considered. Typically, such Life-Cycle Assessments (LCAs) are carried out only for existing products and not during the early design phase. In this paper, we therefore extend a multi-objective Pareto optimization framework for power electronic converter systems, which today typically considers only efficiency and power density as performance indicators, to include environmental compatibility metrics as additional performance dimensions. After describing the models and the data sources used to estimate the environmental footprint of typical power electronic components like transistors, magnetic components, printed circuit boards, etc., we employ these in a multi-objective optimization of an exemplary 10 kW three-phase ac-dc Power Electronic Building Block (PEBB) considering two-level and multilevel flying-capacitor bridge-legs. First results indicate the importance of the mission profile and the available electricity mix during the use phase, which may justify selecting a converter design with an initially larger environmental burden but better efficiency. Finally, the key challenge of LCAs consists in the lack of comprehensive and high-quality environmental impact data of electronic components, which thus should be addressed by the industry, e.g., by providing such information in future smart datasheets.