Optimal sizing based on environmental and economic life-cycle criteria applied to a static DC circuit breaker

The sustainable design of power electronic systems requires an integrated approach that simultaneously considers environmental and economic dimensions. This paper proposes an eco-design methodology to support decision-making for the sustainable sizing of power electronic systems, targeting a service lifetime consistent with the functional unit requirements. The proposed approach combines Life Cycle Assessment (LCA) and Total Cost of Ownership (TCO), and integrates a reliability model based on Monte Carlo simulations. Using a DC circuit breaker as a case study, the results show that the use phase is the dominant contributor, accounting for 63.5% of the overall environmental impact due to conduction losses in the SiC MOSFETs. From a manufacturing perspective, the discrete SiC MOSFETs and the heatsink concentrate most of the environmental impacts. In this example, a configuration of four parallel SiC MOSFETs provides the most balanced trade-off between environmental and economic performance. These findings suggest that eco-design efforts should be primarily directed toward the SiC MOSFETs and the heatsink. The proposed framework serves as a decision-support tool for an eco-sizing approach that considers both environmental impacts and economic costs within the context of a constant-lifetime design applied to power electronic systems.