Research on an Adaptive Droop Control used in DC Micro-Grid

Compared with AC collection system, DC collection system can reduce line losses and improve the efficiency of new energy. In order to facilitate distributed renewable access to DC-Bus, a variable coefficient droop control strategy is presented in this paper. Compared with conventional droop control strategy, variable coefficient droop control strategy can change the ratio of energy storage unit power on line, reduce the DC bus voltage fluctuations and improve system stability. Variable coefficient droop control strategy also takes state of charge (SOC) into account in droop coefficient optimization process. In this way, the life and economic efficiency of energy storage units can be improved. Finally, the experimental results show the feasibility and effectiveness of the control algorithm.