Solid State Condenser (SSC) - A New FACTS Device for Grid Inertia Support

Synchronous generators are increasingly replaced by inverter-based resources (IBRs). Grid stability and control for these inertia-less resources are subject to intensive investigation worldwide. Grid forming inverters and synchronous condensers are well-known methods to ensure power grid stability by providing adequate frequency and voltage support. This paper presents a single stage solid state synchronous condenser (SSC), which utilizes a super-capacitor energy storage (SCES) at the DC link of a grid forming inverter to provide pulsating active power required for inertia support. Moreover, with volt-var control the SSC supplies reactive power to the grid. The proposed control plus SCES solution is verified by simulation results with real time frequency data and hardware results connected to a three-phase 208V grid emulator.