University of Technology, Electrical Engineering Department, Iraq, Baghdad


Electrical power systems are different in their sizes because of their amount of generation power stations, substations, transmission lines and loads. Therefore, these factors may impact on short circuit levels values. Capacity of power stations and dummy transmission lines in Extra high voltage grid (400kV) of the Iraqi Electrical power grids cause high short circuit levels values such that exceed both rating of the peak and breaking capacity of switchgear equipment's. Reduction of short-circuit levels by using Fast-acting Flexible Alternating Current Transmission Systems (FACTS) types devices in power grids maintain the operation of power grids with acceptable value of short circuit levels for their electrical equipment's and preventing cascading event outages which may lead to blackouts. 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 grids by programing with (PSS™E version 30.3 Package Program). IEEE 25-bus system is used for testing the adding series SCCL at power transmission lines method procedure. The results of adding series SCCL with power transmission lines give significant reducing short circuit levels for the stations have highest short circuit levels in order to prevent the blackouts of overall power grid.