Voltage and frequency control of an islanded microgrid through robust control method and fuzzy droop technique

In this paper, voltage and frequency control of an islanded ac microgrid is presented against load perturbation and emergency condition such as DG unit disconnection. The voltage controller is robust LMI-based mixed H2/H
_∞
static state feedback controller with regional pole placement constraints. The frequency controller is droop method which its coefficient is tuned by fuzzy logic system. Both of these controllers structure are decentralized and all of the measurements for controllers are local. The mathematical modeling is also done for DG units instead of the whole microgrid. The effectiveness of the controller is evaluated through some scenarios which is simulated by MATLAB SimPower system toolbox. The results of fuzzy based frequency control are compared with conventional droop method.