Frequency regulation of a weakly connected microgrid using the fuzzy-PID controller

Abstract Microgrid system stability is a major source of concern due to the rapid increase in load demand and a high level of renewable energy penetration. During the grid- connected mode, the microgrid power quality is mainly affected by the level of connection strength with the host grid. Thus, this paper aims to investigate the impact of the implemented control strategy in the microgrid, on frequency response when its level of connection strength is weak, that is, the frequency and voltage are not dominantly controlled by the grid. A control scheme based on a fuzzy logic-based self-tuning PID controller (fuzzy-PID) is used to maintain the frequency within the acceptable range. Simulations illustrate that the frequency dynamic response of the microgrid guarantees a good performance using the fuzzy-PID controller despite a large drop in grid inertia and the presence of disturbances whereas the classical PID controller cannot maintain the frequency within the acceptable range.