Improvement of Power Quality through SMES Control in a Standalone Hybrid Microgrid System

An electrochemical hybrid power system composed of superconducting magnetic energy storage (SMES), fuel cells, and electrolyzers is presented in this paper. A novel control algorithm is developed for such a system to maintain a constant DC link voltage by managing converters connected to the fuel cell (FC) and electrolyzer. This algorithm also serves as the Maximum Power Point Tracker (MPPT) for photovoltaics, eliminating the need for a separate MPPT circuit. Due to the slow dynamics of the FC and electrolyzer, proper management allows for instantaneous charging and discharging of the SMES, as well as steady-state power supply and consumption by the FC/electrolyzer. A straightforward DC voltage controller is presented, requiring only a few measurements. This controller employs pulse width modulation to maintain voltages at a predefined reference value at the point of common coupling. Comprehensive MATLAB/SIMULINK simulations demonstrate the excellent performance of these controllers in both transient and steady-state scenarios.