Single-Phase String Solar qZS-based Inverter: Example of Multi-Objective Optimization Design

Abstract

This article describes an example of a solar inverter design based on the quasi-Z-source network taking into account multi-objective optimization. An overview of the solar inverter market is provided. Based on this overview, the specification of the most important parameters of commercial solutions is derived. The target efficiency profile and operation range are selected as the main criteria for the design of a competitive solution. The theoretical losses model is designed for preliminary estimation of efficiency profile at any operation point. Optimal switching frequency range is defined. Active and passive components are selected according to the defined efficiency profile and the switching frequency range. The experimental setup including a pre-industrial prototype is built and tested. Experimental results demonstrate the performance of the solar inverter with different photovoltaic string profiles. Finally, the results and feasibility in the commercial application are discussed, and conclusions are drawn.