Contingency Analysis of an IEEE 9 Bus System Considering Optimal Location of UPFC by Artificial Bee Colony (ABC) Algorithm

Contingency analysis is essential for protecting the security of the power system. It is the examination of a power system when one or more of its components fails. A power system may experience contingencies as a result of internal component failures or as a result of external causes like equipment overload. Multiple issues, such as voltage instability, overloads, equipment damage, and power supply interruptions, can arise as a result of them. In power systems, a lot of Flexible Alternating Current Transmission System (FACTS) devices are used to minimize these issues. They are also used in the transmission of power to increase transfer capacity and lower transmission line losses. Unified Power Flow Controller (UPFC) is a flexible FACTS device that can minimize active and reactive power loss and improve bus voltage separately or all at once; however, it is crucial to place the UPFC in the most advantageous position in the power system to achieve this functionality. In our work, analysis of contingency has been performed in an IEEE-9 bus system. Outages of generators, transformers, and transmission lines have been observed. Load flow analysis has been done before and after each outage. Based on performance index, the outage of each component has been ranked. The impact of each outage on the transmission lines is measured using another parameter called severity index. The most severe outages violate line MVA and bus voltage limits. Besides, to get the optimal location of the Unified Power Flow Controller (UPFC), Artificial Bee Colony (ABC) Algorithm is proposed considering the most significant outages. The results show that placing UPFC devices in the bus system has reduced active power loss by 13%, and reactive power loss is reduced by 13.47 %. Besides real and reactive power minimization, the voltage profile is also improved after placing UPFC in the bus system.