AUTOMATIC DROOP CONTROL METHOD FOR MICROGRIP INVERTERS BASES ON SMALL-SIGNAL STABILITY ANALYSIS

摘要

Disclosed is a microgrid inverter sagging automatic control method based on small-signal stability analysis. According to the control method, on the basis that the slope of a P-f sagging curve and the slope of the Q-V sagging curve are actively regulated, small-signal stability analysis is introduced, the feasibility of the slopes after the active regulation is verified, and no-deviating regulation of voltages and frequencies is implemented on the premise that the stability of a system is ensured. According to the present invention, for distributed generation under sagging control in an islanding state, the requirement of load changes is met by automatically regulating the slopes of the sagging curves and changing a reference active power value corresponding to a rated frequency in the sagging curves and a reference reactive power value corresponding to a rated voltage, and no-deviating frequency regulation and voltage regulation are implemented; the range of the slopes of the sagging curves allowed for stable operation of the system is obtained through the small-signal stability analysis, and when the sagging slopes are automatically regulated, the range needs to be met, and instability of the system caused by an operation of purely implementing the no-deviating frequency regulation and voltage regulation is avoided.