In the context of voltage regulation using a STATCOM (Static Synchronous Compensator), the Horse Herd Optimization algorithm is utilized to tune the parameters of a proportional-integral (PI) controller. The STATCOM is a power electronics-based device used for reactive power compensation and voltage control in electrical power systems. The PI controller adjusts the output of the STATCOM to maintain the desired voltage level at a specified point in the system. The Horse Herd Optimization algorithm, inspired by the behavior of horse herds, is employed to optimize the parameters of the PI controller, such as proportional gain and integral time constant, to enhance the performance of voltage regulation. By integrating the Horse Herd Optimization algorithm with the PI controller for the STATCOM in MATLAB or other simulation environments, engineers can design robust and efficient voltage regulation systems capable of maintaining grid stability and reliability under varying operating conditions.