The Research of the Photovoltaic DC Grid-Connected Converter Applied in Flexible DC Grid

With the rapid development of flexible HVDC technology in China, the demand for the DC grid of new energy generation projects growth. This paper studies the topology of the DC grid photovoltaic converter, a topological scheme is proposed and detailed analysis of the topology of the work mode is presented. For the device extension problem of equipment used in high-voltage direct current power level, a connecting scheme based on modular IPOS program and a control strategy of uniform duty cycle are given. In this paper, the equivalent controlled source method for small-signal dynamic modeling is established, and the stability of the control scheme is analyzed using Bode diagram. Finally, a 10kW prototype platform topology programs is built and control strategies experimentally is verified. This paper has important reference value for the HVDC grid-connected research of new energy power generation and the research of small power scale AC-DC hybrid microgrid network.