Three-Phase Inverter Topologies for Grid-Connected Photovoltaic Systems

In this paper, the energy conversion efficiency (ECE) and cost characteristics of three-phase photovoltaic (PV) inverters (3P-PVIs) are studied comprehensively based on the operating principles of topologies and with respect to various performance indicators such as semiconductor device count and utilization factors, semiconductor efficiency (SE), dc-bus capacitor and filter inductor voltage/current ripple factors. The evaluation of topologies are based on datasheet parameters and analytical results are provided for 50 kW, 100 kW, and 200 kW power ratings. Such an evaluation of topologies is beneficial to engineers to wisely choose the appropriate topology for both transformerless and transformer based PV systems and to design the inverter accordingly.