Reducing Short Circuit Level in 400kV Iraqi Grid System by Using FACTS Device


Electrical power systems are different in their sizes because of their amount ofgeneration power stations, substations, transmission lines and loads. Therefore, thesefactors may impact on short circuit levels values. Capacity of power stations and dummytransmission lines in Extra high voltage grid (400kV) of the Iraqi Electrical power gridscause high short circuit levels values such that exceed both rating of the peak and breakingcapacity of switchgear equipment's. Reduction of short-circuit levels by using Fast-actingFlexible Alternating Current Transmission Systems (FACTS) types devices in power gridsmaintain the operation of power grids with acceptable value of short circuit levels for theirelectrical equipment's and preventing cascading event outages which may lead toblackouts. This paper mainly studies strategies on how to add Short Circuit Current Limiter(SCCL) device by determining its number, value and location of connection in power gridsby programing with (PSS™E version 30.3 Package Program). IEEE 25-bus system is usedfor testing the adding series SCCL at power transmission lines method procedure. Theresults of adding series SCCL with power transmission lines give significant reducing shortcircuit levels for the stations have highest short circuit levels in order to prevent theblackouts of overall power grid.