Optimum Allocation of Reactive Power Sources for Voltage Stability Improvement and Loss Minimization in Power Distribution Systems

Abstract

The real power losses in distribution systems are generally quite appreciable, constituting a major portion of the overall system losses. Low power factors and poor voltage profiles are the main reasons for higher losses and unsatisfactory conditions of power supply to the consumers. Installation of reactive power sources at suitable locations in distribution systems is usually suggested for the dual purpose of achieving improved voltage profiles and reduction in real power losses. Analytical methods are available to find the optimum locations and size of shunt capacitors in primary radial feeders. Most of these methods assume only uniformly loaded radial feeders while very few methods consider feeders with distributed load. However, these methods have limited application and cannot be applied to complex distribution systems, typically urban systems, where the conductor gradation also varies amongst the various feeders. On load transformer tap settings also change the reactive power distribution in the network and hence it is important to account for them while deciding the reactive power compensation requirements in distribution systems. A novel method has been developed for finding the optimum location of feeding point/reactive power compensation point in distribution systems. Results based on the proposed methods and successfully applied to a complex distribution system and an L.T and an H.T radial distribution system are presented. Results on 32-Bus Urban distribution system showed that the system power loss for initial and optimization for case-A and case-B are 23.0, 15.00, and 14.20 MW, respectively.