Grid-Forming Converter Angular Speed Freezing to Enhance Transient Stability in 100% Grid-Forming and Mixed Power Systems

The transient stability of a power system depends on the relative divergence angular speeds between voltage sources during fault disturbance. A unified speed control strategy is proposed here for grid-forming and synchronous machine sources. Specifically, consisting only converters (GFs), virtual all GFs to be frozen pre-fault value, while with mix machines (SMs), should weighted mean SM rotor speeds. freezing techniques are designed effective short-circuit faults, indifferent phase-jump events. Simulation studies performed 100% GF mixed GF/SM systems both 3-phase events, range settings conditions, demonstrate effectiveness techniques.