Frequency Regulation Control Strategy for Microgrid in Islanded Mode

Abstract

In view of the microgrid consisting of inverters controlled by droop method, a frequency regulation strategy for the microgrid in the islanded mode is studied. Through the modeling and analysis of the microgrid system, as well as the equivalent and simplification of transfer functions, a parameter correction formula for the frequency regulation controller has been derived. When the system condition changes result in distribution ratio altering, output impedance changing and the varying of access number of inverters connected to the microgrid, the controller is able to adjust parameters online for quick restoring the system frequency to stability. Experimental results show that, the system frequency can quick recover to the given value and keep steadily due to the parameter auto-adjustment algorithm.