Concurrent regulation of voltage and frequency of an isolated microgrid considering small hydro plant, DFIG and energy storage systems

With the growing utilization of renewable energy sources, isolated microgrids are becoming highly dynamic and complex particularly when incorporating small hydro power plant. The unpredictable natural of renewable energy poses challenges in maintaining constant frequency and voltage, hence increasing complexity. The presence of randomness inside the system results in fluctuations in both frequency and voltage, so diminishing the efficacy of conventional controllers and potentially resulting in instability. This paper presents a method that integrates a doubly fed induction generator (DFIG), energy storage systems such as batteries, flywheels, and ultracapacitors, together with an appropriate secondary controller. This study utilizes the fractional order proportional integral derivative (FOPID) controller, as well as the PID and PI controllers. The optimization of gains of these controllers is achieved through the utilization of a contemporary Hippopotamus Optimization Algorithm (HOA), which efficiently manages the oscillations of both frequency and voltage. The study also takes practical conditions into account the influence of variables such as random fluctuations in load demand, variations in solar and wind powers. The findings from the simulation analysis indicate that the HOA-optimized FOPID controller exhibits good performance as compared to conventional PID and PI controllers which ensures stable frequency and voltage levels within the isolated microgrid. The suggested technique is additionally verified by using a real-time digital simulator (OPAL-RT) with a hardware-in-the-loop configuration.