Utilizing diverse mix of energy storage for LFC performance enhancement of a microgrid: A novel MPC approach

Integration of highly fluctuating renewable energy source (RES)-based distributed generation units (DGUs) and a low inertia of an islanded microgrid (MG), resulting from absence of direct coupling between the various DGUs and the MG, can stimulate severe frequency deviation problems. In such a scenario implementation of the energy storage units (ESUs) becomes imperative. Consequently, this paper examines the impact of diverse mix of two widely employed ESUs namely electric vehicle (EV) battery and superconducting magnetic energy storage (SMES) on the dynamic responses of an islanded MG. A novel discrete-time Laguerre functions-based intelligent model predictive control (LiMPC) approach is administered as a secondary controller. Realization of the Laguerre functions-based MPC approach, as compared to the classical MPC approach, reduces the number of parameters to be optimized and simultaneously downsizes the computational time of the control vector trajectory. Simulation results clearly validate the potency of the energy storage-based LiMPC approach, when both the ESUs are engaged, in improving the dynamic responses of the MG and simultaneously satisfying the load frequency control (LFC) requirements. A maximum percentage improvement of 41.91% in peak overshoot and 51.98% in peak undershoot of the dynamic responses, and 94.93% in the performance index value is observed. Furthermore, the superiority of the suggested control approach over a few widely used control approaches is shown. Finally, the robustness to parametric modifications of the proposed LiMPC approach is verified.