LAUSR

This paper investigates the enactment of battery energy storage system (BESS) and static compensator (STATCOM) in enhancing large-scale power system transient voltage and frequency stability, and improving power export capacity within two interconnected power systems. A PI-lead and lead-lag controlled BESS is proposed for multimachine power system to provide simultaneous voltage and frequency regulation within the defined battery state-of-charge ranges and an equivalent Finnish transmission grid is used to evaluate the system performance. According to Australian National Electricity Market grid requirements, the performances of the proposed control schemes are compared with conventional PI controlled BESS and STATCOM under multiple temporary and permanent fault conditions. In addition, two adjacent disturbance events are also applied to evaluate system performance with BESS and STATCOM. Through simulation results, it is shown that when there is a ${\text{44}\%}$ increase in power export and the STATCOM fails, incorporating BESS improves the performance and justifies the novelty of this study. Moreover, the proposed lead-lag controlled BESS manifests better transient performance than BESS with PI-lead and traditional PI controller, in the event of divergent temporary and permanent faults.