Facts based fault current limiter utilization in HV grid

Future's load and generation model of Tehran power network depicts fast increase in demand and development of power network. By 2015, Two new generating stations are expected to be installed which result in the increase of short-circuit capacity of a few substations in excess of the interrupting rating of exiting circuit breakers. This paper intends to analyze the consequences of employing thyristor protected series capacitor (TPSC) based short-circuit current limiter (SCCL) in Tehran power grid. Short-circuit, transient stability and transient recovery voltage studies were carried out by using DIgSILENT and EMTP softwares. The results demonstrate that SCCL installation can reduce fault current level in four substations of Tehran power network and improve transient stability margins. On the other hand, rate of rise of recovery voltage across some circuit breakers will exceed the value specified in standard which can be coped with by adding extra capacitor.