Published Paper Details:

Power system stability has become a great concern with the increased power flows across the transmission system. Battery energy storage system (BESS) has widely been used and long been acknowledged that it can significantly contribute in stable power system operation and control. This paper investigates a large-scale power system transient stability improvement by incorporating a large size BESS. Faults have been applied to find the maximum active power transfer limit across the transmission line. The control of BESS is so designed that battery charging/discharging is based on the nominal system frequency as a reference. In addition, faults on the DC side of BESS are also studied to determine their impact on the connected AC system stability. A PI-lead and lead-lag controlled BESS is proposed for multi machine 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 44% increase in power export and the STATCOM fails, incorporating BESS improves the performance and justifies the novelty of this study. Moreover, the proposed leadlag controlled BESS manifests better transient performance than BESS with PI-lead and traditional PI controller, in the event of divergent temporary and permanent faults.