ABSTRACT
Power system network is designed to operate in a prescribed voltage and frequency for stability and for better power quality. Unexpected contingencies leads to instability related problems in the system. This research develops a sensitivity index based technique with contingency analysis for Unified Power Flow Controller (UPFC) placement for Nigeria 330kV power transmission system. The research employed Newton Raphson power flow method considering multiple contingency analyses which include double line outages, line and load outages, double load outages and load increments. The identification of the severity of the violated bus voltages was achieved through the use of Active Power Performance Index (APPI) and Reactive Power Performance Index (RPPI). The contingency cases were addressed through the sizing and placement of UPFC on the network and simulated in Matlab R2013a environment. The analyses shows that the predominately violated buses and the sizes of the UPFC placed are Maiduguri bus (-183 MVar), Birni Kebbi bus (99 MVar) Oshogbo bus (-84MVar), Jos bus (-28 MVar), Gombe bus (-13 MVar) and Kano bus (21 MVar). The result shows 1.3% (694.6233MVar) reduction in the total reactive power loss as compared with base case of (703.7499MVar) after the placement of UPFC and a total voltage improvement of 3.11% (31.9298pu) as compared to the base case voltage deviation of (32.9541pu). The developed approach was analyzed on IEEE 30 bus network with a transmission line power loss reduction of (0.00166pu) and a voltage improvement of 0.83% (30.6753pu) as compared to the work of Reddy et al., (2014) with power loss of (0.02116pu) and a voltage of (30.4214pu).