Effective utilization of large-capacity battery systems for transient stability improvement in multi-machine power system

This paper investigates use of BESS (battery energy storage system) for transient stability improvement, and proposes a novel control scheme for the BESS using wide-area information. The control scheme adopts two stability indices, the energy function and rotor speed of the critical machine, to make it applicable to multi-machine power systems. Besides, it can control active and reactive power injection of the BESS coordinately to make the best use of its converter capacity for the stability enhancement. Digital simulations are conducted on the modified IEEE RTS-24 system with multiple BESSs. The results show that active and reactive power control by the BESSs is effective for the transient stability improvement. It is also made clear that distributed installation of BESSs is preferable in terms of voltage behavior during the transient period since absorption of the reactive power by a large-capacity BESS furthers the voltage drop during the grounding faults.