Design and implementation of a high power three-level T-type inverter for a photovoltaic system

Nowadays, the grid-connected photovoltaic systems are an important part of the renewable energy sources, and their performance is getting more and more important. Many reported researches focused on the traditional NPC topology. However, few researches were about the T-type NPC inverter. In this paper, a high power three-phase T-type neutral point clamped grid connected photovoltaic inverter prototype is designed and implemented. The design and implementation procedure of the inverter is discussed in detail. Experimental results showed that the output power of the proposed inverter could reach up to 100kW with unit power factor, while the total harmonic distortion of the grid current was less than 3%. And the total efficiency of the system is measured as 95.6%. The experimental results demonstrated the T-type NPC inverter can operate with a good performance.