Grid Connected DG Systems Based on Z-Source NPC Inverters

Z-source neutral-point-clamped (NPC) inverters have been recently presented as a buck-boost three-level inverter. In this paper five new grid-connected distributed generation (DG) systems are proposed using z-source NPC inverters. With the proposed systems, output power of two separate DG systems such as photovoltaic (PV) arrays and fuel cell (FC) stacks are extracted and delivered to the grid. Since NPC inverter consumes same power from both DC inputs, different control systems are used for each of five proposed topologies. The performance of the proposed topologies is verified by simulation results.

Keywords:

Multilevel inverters , grid-connected distribution generation , fuel cells , photovoltaic cells , power conversion