Modelling of an Electric Power Grid for New Power Plant Evacuation

Abstract

Injection of a new power system component into an existing power grid often cause change in the behaviour of the power grid to which it is injected. Therefore, forecasting possible unsafe condition(s) of the power grid using an efficient power study tool is essential; and, provision of necessary mitigation actions to ensure a reliable grid is important. This paper, therefore, presents evacuation study of a 400 MW power plant connecting to the 15 GW planned transmission network of the Transmission Company of Nigeria (TCN). The NEPLAN power system analytical software was used in the modelling and simulation of the electric power grid. In the research, load flow, short circuit, transient stability, and contingency analyses were performed on the case study. From the short circuit study, it is observed that if TCN network expansion program is fully implemented, the short circuit level will go beyond the existing switchgear ratings in major substations of the network. However, with the introduction of substation splitting at Omotoso and ongoing Ogijo substations, the short circuit level will be reduced by 15%; leading to improvement in the overall system stability. Keywords—Load flow, short circuit study, transient stability study, and contingency analysis