A Hybrid Renewable DC Microgrid Voltage Control

A DC microgrid is a hybrid renewable system that renewable sources supply the average load demand, while storage and nonrenewable generation maintain the power balance in the presence of the stochastic renewable sources. The control strategy can realize the optimal allocation of power by using DC bus signal and the bus voltage is controlled by PV converter, battery converter and fuel cell converter unaided and time-sharing. It can minimize economic cost of the overall system by giving the low-cost solar energy the first priority. At the same time, the system also has the advantages of high stability, simple control structure and high voltage bus. This paper expatiates on the system's structure and control law by analyzing a distributed hybrid system, describes MPPT control, takes into account the situation that the system operates under a diverse load and takes effective control to limit the influence of the diverse load. Finally, the implemental results are given to verify the correctness of the control method.