Performance Analysis of UPFC and SVC- TCSC Combination in Transmission Network

Voltage stability is the most challenging part of recent deregulated power transmission systems and Flexible AC transmission system (FACTS)devices support to sustain and advance voltage stability. But, choosing the suitable FACTS device and its optimal placement in the network is a matter of concern under practical constraints. In the context of the voltage profile (VP)improvement, active and reactive power losses reduction, cost of device, and Comparative environmental pollution Reduction Index (CEPRI), the combination of SVC and thyristor controlled series compensator (TCSC)and the unified power flow controller (UPFC)are compared to determine the most preferable FACTS device and its optimal placement in the system for optimum outcome. The standard IEEE 30-bus test system with haphazardly increased load is used for this purpose. A new online voltage stability index (NVSI), comparative Environmental Pollution Reduction Index (CEPRI)are the novel inclusion. The multiple objective functions (MOFs)are normalized and converted by proposed weighted combined objective function (COF)to define the apt device and its optimal location for placement of FACTS device. The results show that in presence of system's physical constraints, the combination of SVC and TCSC is the most suitable device.