An Approach for Optimal Placement of SVC to Minimize Load Curtailment

Abstract: Modern electric power system is very complex and undergoes unforeseen rapid changes in terms of demand/generation patterns and trading activities that hinder the system security. For example, a steep rise in load or a certain critical line/equipment outage can cause line overload or undesirable voltage profile and such events can push the system towards instability and possibly even a black out. In order to cope with such situations, it is common practice to purchase the rights of asking for a reduction of load from certain customers. However, it is not an ideal situation from reliability perspective, financial as well as having critical load in the power system. Load curtailment is the collection of control strategies employed to reduce the electric power loading in the system and main aim is to push the disturbed system towards a new equilibrium state. Load curtailment may be required even when voltages at some buses are out of their safe operating limits, to prevent a possible voltage collapse. Flexible AC Transmission Systems (FACTS) controllers could be a suitable alternative to provide reactive power support at the load centres locally and hence keep the voltages within their safe operating limits. Due to high costs of FACTS devices, their proper location in the system must be ascertained. To deal with the above problem a new methodology has been proposed, in this thesis, in terms of sensitivity factors for the optimal location of Static Var Compensator (SVC) to minimize the system load curtailment requirements for maintaining the system security. In this work, SVC has been considered for the study to minimize the load curtailment. The effectiveness of the proposed method has been tested on IEEE 14-bus and practical 75-bus Indian systems. Optimal placement have been obtained for the base case loading and to verify its locations, an Optimal Power Flow (OPF) problem has been formulated with an objective to minimize the load curtailment and satisfying all operating constraints along with optimal settings of SVC which is used at suggested places from developed methodology. Moreover, the effects of SVC on load curtailment reduction, which are located at base case loading, have also been investigated for different operating conditions e.g., increased load or having different contractual obligation in the system.