Improving Synthetic Inertial Response of Supercapacitor Using Supplementary Control Signal

Power systems with high penetration of inverter-based renewable generation units result in reduced inertia. In such power systems, the frequency events due to plant outage or large sudden increase/decrease in load power cause an increased rate of change of frequency (RoCoF) and larger frequency deviations. The higher RoCoF and larger frequency nadir can cause frequency instability which leads to blackout. Energy storage units may be deployed in such systems to support the frequency response. In this paper, Supercapacitor (SC) energy storage is used to provide the inertial response in power system with high penetration of intermittent renewable energy sources. Derivative control is employed for inertia emulation of SC. An additional control input signal based on the frequency deviation is added to improve the inertial response. The robustness of the proposed control is tested with different penetration levels of renewable generation. A comparison between the derivative control and the proposed control is presented to show the effectiveness of the proposed scheme.