A droop control method of microsources based on divided self-adjusting slope coefficient

Microgrid, as a new effective way for large scale new energy and renewable energy power generation systems connected to the grid, injects new vigor into the power system. Focusing on the characteristics of P-f (active power versus frequency) droop and Q-V (reactive power versus voltage) droop, on the basis of analyzing the variable slope coefficient of droop characteristic, a droop control method of microsources based on divided self-adjusting slope coefficient is proposed in this paper. By calculating the quantity of the load fluctuation, this control method dynamically adjusts the active and reactive power maximums of inverters in the range of the inverter ratings to change the slope coefficients of droop curves. The aim of this method is to decrease the deviation of the frequency and voltage magnitude of the microgrid bus effectively. The simulation result verifies the correctness and feasibility of this control method.