Series-connected PV MVDC Converter for Large Scale PV System

This paper presents a novel series-connected PV MVDC converter for large scale PV plant. By analyzing the characteristic of the series-connection PV system, the topology of MVDC converter based on modular structure of input parallel and output series (IPOS) is presented. A novel reconfigurable topology is proposed for the module of the converter. By regulating of switches duty cycle, the module can be reconfigured to realize step-up or step-down mode. With the control strategy and reconfigurable module topology, the series-connected PV MVDC converter achieves wide input voltage range to adapt PV array characteristic and wide output voltage range to adapt to series-connection system requirement with a high efficiency. 5kV/80kW DC-DC module is developed. Series-connected PV converter with modules in IPOS connection is built in simulation environment. The simulation result and experiment result are presented in the paper.