Design and Implementation of a High-Efficiency Seven-Level Inverter for Solar Power Generation Systems

This paper presents a novel solar power generation system that integrates a DC/DC power converter with a new seven-level inverter, offering enhanced efficiency and simplified design. The DC/DC power converter combines a boost converter and a transformer to produce two independent voltage sources. These are processed by a capacitor selection circuit and a full-bridge power converter in cascade to generate a seven-level AC voltage. The proposed inverter topology uses only six power electronic switches, with only one switch operating at high frequency at any given time, thereby minimizing switching losses and improving overall power conversion efficiency. The reduced switching harmonics also decrease filter inductor requirements, contributing to a compact and cost-effective design. A prototype system was developed and tested, demonstrating its ability to deliver sinusoidal output current synchronized with utility voltage, confirming its suitability for residential solar power applications. This system represents a significant advancement in the field of solar energy conversion, addressing key challenges of efficiency, cost, and reliability.