Load Frequency Control of an Autonomous Microgrid Using Robust Fuzzy PI Controller

Abstract

This paper proposes a robust load frequency control (LFC) strategy using a fuzzy logic-based PI controller for an autonomous hybrid microgrid with high renewable penetration. Such a high amount of renewable energy sources (RES) penetration replaces the contribution of diesel engine generators (DEGs), which intern reduces the system inertia as a result, microgrid (MG) experiences a frequency instability problem. Furthermore, the intermittent nature of the RES, load shedding and load restoring causes large frequency deviations which may weaken the MG and could lead to complete blackout. To solve the aforementioned problem, this work proposes an optimal coordinated control strategy between DEGs and SMES system for MG frequency control. Where this coordinated control strategy is based on the PI controller, which is optimally tuned by using a fuzzy logic approach. This proposed control strategy is tested on the BELLA-COOLA MG (in Canada), which was modelled in MATLAB/ Simulink. Finally, the simulation outcomes confirm the robustness and effectiveness of the proposed approach against all possible critical operational scenarios over various controllers in literature.