A Modified Modulation Scheme for Capacitor Voltage Control of Renewable Energy-Fed Grid-Connected Z-Source Inverters

An important issue in grid connection applications is boosting the limited output voltage of the renewable energy sources. Two-stage converters are most commonly employed for successful grid connection and optimum power transfer. Single-stage converters can be used as alternative solution, since they are more reliable, compact, and efficient. Grid-connected Z-Source Inverter (ZSI) can be employed effectively as a single-stage power conversion process. For renewable energy sources, a splitting-based modulation scheme (SBMS) is proposed for capacitor voltage control to enhance the inverter response and reduce the voltage stress on the semiconductor devices. Simulation results substantiate the proposed concept. Moreover practical results of the inverter in island mode of operation are introduced.