Contingency Assessment of Medium Voltage Distribution System

A power distribution network is simply an inter-connection of 33/11 kV power transformers, network in-feeds, distribution station buses and the loads. The security of such a system is of great consideration in power utilities. Thus, contingency analysis is often used to determine the security of such system. Several methods used in analyzing power system security include linear programming (LP), least squares (LS), decision trees (DTs), artificial neural network (ANN) etc. These methods were observed from literature to take a long computational period. Therefore, this paper presents a contingency assessment of medium voltage distribution network using Newton–Raphson (NR) technique of NEPLAN software. The approach involves carrying out of power flow analysis of the case study network. This analysis considered four scenarios; base case, case 2, case 3, and case 4 which are respectively defined as system operating under normal condition, abnormal operating condition without contingency, N-1 contingency, and N-2 contingency respectively. The results of the four cases show that contingency has negative effects on power equipment and the customers. The details of these results are presented. This contingency analysis thus provides reliability evaluation of the network while solutions to problems emanating due to contingencies are solved by utility company for revenue improvement