Influence of Inductive Fault Current Limiter on Generator Synchronization

Controllable inductive fault current limiters can not only protect against short-circuit faults, but can also enable "gentle" synchronization of turbine generators in isolated power systems and help to maintain synchronization during fault events. These effects are proven by simulations of systems containing two 36 MW, 13.8 kV turbine generators operating in an isolated power system. The use of controllable inductive fault current limiters increases the transient stability, yields smaller oscillations in active power (2.8 versus 6.8 MW) and reactive power (1.6 versus 5.2 MVAr) during a faulty synchronization process (with 5 degrees initial phase difference). Also, during a three-phase-to-ground fault, the current limiter reduces peak currents by 61.2% (from 12.9 to 5.0 kA(arms)), and helps to maintain generator synchronization during and following serious short-circuit faults.