A Control Strategy of Microgrid Inverter Based on Feeder Power-flow Optimization

For the operation of autonomous microgrids, it is a major task to share the load demand economically. This paper proposes an economic operation method of microgrid for feeder power-flow optimization, taking into consideration the generation costs of the micro-sources and power loss in the transmission line. A detailed analysis of the cost-based nonlinear droop control scheme of micro-source inverter is performed, which reduces the generation costs of the micro-sources. And on this basis, Feeder Flow Control (FFC) strategy which combined with nonlinear droop control is proposed to reduce the transmission loss in the microgrid at the same time. Through the configuration of weighting factors which is set in this paper, the feeder loss and generation costs of micro-sources can be reduced simultaneously, thus realizing the optimal feeder power flow in the microgrid. The power sharing arrived in the steady state will meet the intended objectives, as demonstrated in the simulation.