Design of Smart Energy Converter with Distribution and Storage Integrated for LVDC Distribution Grid

Abstract

With the rapid development of low-voltage DC distribution grids, especially the full DC power supply grid, various DC loads and distributed energy sources are directly connected to the DC grid, resulting in the voltage stability, power coordination and distribution of the DC grid. Therefore, the voltage stability, power coordination and distribution of the DC grid and the load switching shock the DC grid. Those problems have become increasingly prominent. At the same time, problems such as a large voltage drop at the end and DC grid failure have affected the stable operation of the load in the LVDC(Low Voltage DC Grid). Therefore, this paper proposes a Smart Energy Converter with Distribution and Storage Integrated(SECDSI), it controls the power electronic converter, energy storage equipment and LVDC grid as a whole. The basic topology and intelligent control strategy of the SECDSI will be introduced in this paper. The designed SECDSI can smooth the DC bus fluctuation, maintain the stable operation of the DC grid, reduce the instantaneous current spike of DC load switching, supplement the voltage drop at the end of the grid, and provide the terminal load with seamless switching of uninterrupted power when the DC grid faults. This paper firstly analyzes status and the problems of the LVDC distribution grid. Secondly, design a SECDSI to sole these problems. Then analyze the working principle and control method of the SECDSI. Finally, the function of the SECDSI is verified by the experimental prototype test. The test result shows that SECDSI can effectively suppress voltage fluctuations and provide uninterrupted power to the load when LVDC grid fault.