Improved Frequency Response of Parallel Virtual Synchronous Generators Using Grey Wolf Optimization

Abstract

This paper optimizes the frequency response of parallel operation of a grid connected Virtual Synchronous Generators (VSG) using a Gray-Wolf Optimization (GWO). The frequency response is achieved when the VSG is synchronized with the grid. The load demand is covered by using only VSGs (Eliminating the existence of conventional generators). The control scheme includes the active power loop aided with the proportional-integral-derivative (PID) controller with optimized parameters, proportional gain Kp, integral gain Ki, and the derivative gain kd. The PID controller gains are optimized using Grey Wolf Optimization. The control scheme resulted in increasing the stability of the power system. The simulation results show the effectiveness of using GWO to reduce the overshoot and steady state deviation of the frequency through the provided damping torque that enhances the VSG inertia. The overshot in the grid frequency due to synchronization is reduced from 8% to 0% with GWO. Therefore, the effect is a more stable system with less overshoot in the frequency (nearly zero). Moreover, the settling time of optimized response has no changed compared with the original frequency response. The system rated is supposed to be 4 kVA for better indication which simulated using MATLAB/Simulink.