Analytical Method for Optimal Reactive Power Support in Power Network

The excessive reactive power demand/flow over the transmission lines is one of the main reason that adversely impacts the voltage profile and other system parameters. To keep the power system in acceptable working condition, certain methods are being used to compensate for the excessive reactive power demand to subsequently improve the system performance. Placement of capacitors is one such method to provide reactive power support and reduced the level of reactive current in transmission lines. However, placing the suitably sized capacitor at most suitable location is not trivial, hence taken as an objective in this research work. Optimal capacitors have been allocated in the distribution network that minimized the active as well as reactive power losses. There are two cases explained for the capacitor placement. In case 1, the active power losses get reduced with selecting the optimum value of capacitor which is not the same as for the second case. The reduction in reactive power losses are discussed in case 2, in which the value of capacitor injections is decided based on minimized reactive power loss. This research is aimed at developing the analytical expressions and method for optimal capacitor placement that is carried out by using IEEE 37-bus test system. The exhaustive method technique is also implemented for the same problem. The results of exhaustive method are compared with the proposed analytical expression-based method to validate the efficiency of proposed method. The comparative analysis of voltage profile improvement and power loss reduction after each sitting of capacitor are presented. The calculated results clearly show the voltage profile enhancement and power loss reduction with the scheduled installation of capacitors at defined buses.