Design of a PV-Micro Inverter with Universal Three-Phase and Single-Phase Output Configurations

Inhalt:
The impact of photovoltaic (PV) systems is essential for the upcoming energy transition towards renewable sources. Cost reduction in recent decades due to system improvements in terms of high density and high efficiency PV-inverters using new wide-bandgap (WBG) devices have made PV a cost effective source of electrical energy. In recent years, PV-micro inverters became an object of interest due to scalability effects and simplified connection technology. This paper presents a PVmicro inverter with an universal output leading to optional use in single-phase or three-phase applications. An overview of different output configurations and modulation schemes will be provided in this paper, investigating corresponding common mode (cm)-voltages and ripple current distribution. Based on that, an analytical LCL-filter design is presented. Advantageous configurations regarding their cm-voltages and power losses were identified. A hardware prototype was built for verification and performance analysis.