FACTS, Synchronous Condensers, and Grid-Forming BESS for High-PV Stability

The increasing substitution of conventional synchronous generation by photovoltaic resources has introduced significant challenges to voltage stability, reactive power management, and dynamic system performance. This paper compares a STATCOM, an SVC, a synchronous condenser (SC), and a BESS with a grid-forming inverter (BESS-GFM) in the IEEE 9-bus system using DIgSILENT PowerFactory 2023 SP 5. PV generation is ramped up while synchronous output is reduced to effectively emulate the global movement to greater renewable energy generation as part of decarbonization strategies. Performance is assessed using AC load flows, quasi-dynamic time-series load flows, PV curves, and three-phase short-circuit calculations, concentrating on voltage compliance, additional active power headroom, reactive power capability, and LVRT/HVRT tendency. However, existing work is technology-specific or uses inconsistent assumptions and metrics, which prevent a like-for-like comparison of STATCOM, SVC, SC, and BESS-GFM as PV displaces synchronous generation. This paper addresses that gap by applying a single, consistent study framework across all four technologies. The results indicate that the best performing options provide broadly comparable voltage support at the PCC (Point of Common Coupling), the STATCOM and BESS-GFM maintain voltage close to the setpoint through fast, continuous converter-based reactive control, while the synchronous condenser achieves similar regulation with the added benefit of increasing system strength and fault level through synchronous contribution. Overall, the findings support coordinated deployment of continuous VAR control and strength enhancing support to maintain voltage resilience in high-PV networks.