Structure Optimization of DC Distribution Network Considering the Transmission Margin of Converter

The power fluctuation of distributed generation and variable load in DC distribution network is large, so attention should be paid to the system power imbalance caused by it in the operation process. Therefore, when studying the optimal operation of DC distribution network with droop control, the power transmission margin of converter should be considered, so that the DC system has sufficient capacity to adjust the power imbalance and improve the stability of DC voltage. The transmission margin is related to its adaptive droop coefficient. In this paper, the adaptive droop coefficient of converter with droop control is taken as one of the optimization objectives of DC distribution network structure. It is regarded as one of the three indexes of optimization objective function with network loss and node voltage offset. The fuzzy membership function combined with spatial Euclidean distance is used to comprehensively deal with it, and Newton Raphson method is used to calculate load flow with the accurate loss model of converter. Finally, binary particle swarm optimization (BPSO) algorithm is used to get the optimal structure of DC distribution network. The correctness and effectiveness of the algorithm are verified in the modified ieee33 bus DC distribution network.