OPTIMIZATION BASED TUNING OF STATCOM AND BESS CONTROLLERS

This work investigated how to improve voltage and frequency performance in a power system by properly tuning the control settings of a STATCOM and a Battery Energy Storage System (BESS). The STATCOM is used for voltage support through reactive power control, while the BESS provides frequency support through active power injection using a PI controller. Particle Swarm Optimization (PSO) is applied to automatically search for suitable controller gains that improve dynamic response while respecting practical operating limits such as battery power rating and state-of-charge boundaries. A 10% load increase introduced at 2 seconds is used to evaluate the coordinated control strategy. The optimized controller reduces the maximum frequency deviation from 0.0351 Hz to 0.0186 Hz and improves the lowest frequency point from 49.9649 Hz to 49.9814 Hz. These improvements require increased battery contribution, with peak BESS power rising from 11.20 MW to 14.35 MW and a slightly larger reduction in state of charge. Voltage remains within acceptable limits for both baseline and optimized cases, and the STATCOM operates far below its reactive power capacity for the disturbance considered. The findings show that PSO is an effective tuning tool for coordinated STATCOM–BESS control and highlights the trade-off between improved frequency support and increased battery usage.