Enhancement of critical loading for electric power distribution systems

Abstract

In this thesis it has been tried to explore the possibilities of enhancement of critical loading of radial electrical power distribution networks. It has been found that the critical loading can be enhanced by optimal conductor size selection, optimal capacitor placement, and network reconfiguration. To apply these corrective steps on the distribution networks an efficient load-flow solution method is required so that the actual condition related to node voltage and its angle, branch current, real power loss, reactive power loss, branch losses etc. of the network can be studied and analyzed. A new efficient method is proposed for load-flow solution of radial distribution networks. Simple transcendental equations are used to relate the sending-end voltage, receiving-end voltage and voltage drops in each branch of the distribution system. The effect of charging capacitance of the line has been incorporated in load-flow solution. A computer algorithm is developed in such a way that there is no need to adopt any sequential node numbering scheme for the solution of the networks. The angle of the receiving-end voltage is also computed along with the magnitude of the voltage. It is an iterative method. The flat voltage (1p.u.) start from substation to every end-node is considered. The voltage magnitude and angle are updated after each successive iteration and the voltage drops are then computed by using the new obtained values of voltage magnitude and angle. The comparison of speed and memory requirement by the proposed method with the other methods has been verified to show its efficiency. To investigate the present state of loading and loadability limit, a line loadability index is derived. The change in resistance with the change in operating temperature of the branch conductors is incorporated in the computation of voltage stability index and line loadability index.