Placing IPFC at multiple generator connected grid for reducing short circuit current

The Interline power flow controller (IPFC) is one of the latest generation Flexible AC transmission system (FACTS) controller and its major application is to control power flows of multiple transmission lines. In addition to its primary function of controlling power flow, IPFC can be utilized for reducing fault current. The electrical equipment (Busbar, circuit breaker (CB), Current transformer) in a switchyard is designed for standard fault currents at different voltage levels. But day by day with increasing power demand, large powered generator units are also increased to fulfill the power demand. Consequently more generator units are installed at the available generation sources and connected to the grid. Subsequently this increases the fault levels to a new value beyond the designed value and damages the equipment. This requires replacement of existing equipment to meet the new fault level requirement. This leads to economical impact on utilities. One solution would be to reduce the new fault current to the previous rated value at which existing equipment has been designed. In this aspect the IPFC will be employed to reduce the new fault current. The aim of this paper is to demonstrate how effectively IPFC will ride through the fault during the new loading conditions and reduce the fault to the previous designed threshold value. Case study is simulated without and with IPFC models in MATALB/SIMULINK for system with large generator units (seven in number each of 660MW generators) connected to a 400kV switchyard. A 3 phase fault created on 400kV outgoing line feeder, line fault currents are captured for both the models and results are analyzed. The effectiveness of the IPFC at the grid in restricting the fault current is examined.