A comparison of ultracapacitor, BESS and shunt capacitor on oscillation damping of power system with large-scale PV plants

Intermittent and slow generator like PV is augmented with auxiliary device to meet the certain grid code requirements for interconnection. Ultracapacitor, battery energy storage system (BESS) or shunt capacitor at the PV terminal have recently been used as auxiliary devices for large-scale PV generator system to improve the system performance during transients. Although the studies on individual auxiliary devices are well documented, a comparative study of these devices impact on the damping of electromechanical (EM) mode and oscillatory instability problem has not been reported so far. This paper presents the damping performance of large-scale PV with auxiliary devices. The simulation studies have been done on multi-machine infinite bus (MMIB) system and two-area test system. For simulation studies different types of synchronous generators (e.g. hydro, thermal) are also taken into consideration.