A New PV Converter for Grid Connection through a High-Leg Delta Transformer Using Cooperative Control of Boost Converters and Inverters
山口, 大輝 ,
Yamaguchi, Daiki ,
藤田, 英明Fujita, Hideaki
661 , 2016-09 , 電気学会 , Institute of Electrical Engineering in Japan
This paper proposes a new high-efficiency PV converter for grid connection through a high-leg delta transformer, which is composed of a symmetrically-connected boost converter and three half-bridge inverters. One of the three half-bridge inverters is connected to the boost converter, and the others are directly connected to the PV terminals. This circuit configuration enables to reduce the power losses in both boost converter and inverter. This paper also proposes a new cooperative control method between the symmetrically-connected boost converter and inverter. The control method can reduce the average switching frequency to 75% of that in a conventional one, resulting in a great reduction in switching power loss. Experimental results show that the proposed circuit improves its European efficiency from 91.6% to 94.5%.