Cost-Volume-Reliability Pareto Optimization of a Photovoltaic Microinverter

A multiobjective Pareto optimization routine is pro-posed to systematically assess the performance factors concerning annual degradation, volume, and cost. As an essential performance criterion of PV microinverters, the reliability is included in the multiobjective optimization, which has not been seen in the previous literature. Thus, a practical trade-off among annual degradation, volume and cost can be made for a two-stage PV microinverter. Firstly, the operation principle of the inverter stage in the boundary conduction mode (BCM) is analyzed for electrical aspect modeling. Then, a system-level electro-thermal model is built for the PV microinverter. After that, critical performance metrics, i.e., reliability, cost, and volume, are modeled before a multiobjective Pareto optimization strategy is proposed and executed. The proposed optimization method leads to a remarkable reliability improvement while maintaining low cost and volume.