Reliability Assessment of Natural Gas Transmission Systems and their Impact on the Operational Performance of Electric Power Systems

During the recent years, a significant number of modern thermal power plants use natural gas as fuel in order to achieve reduction of their environmental impact from greenhouse gas emissions and increase their efficiency. The new plants are connected to the existing natural gas transmission network leading to a high interdependence between it and the respective electric power system. Therefore, the failure events occurring in the natural gas network can cause interruption of gas supply to one or more power generating units connected to it. This means that there will be a significant impact on the secure and the reliable operation of the power system. For this reason, an additional reliability analysis is required in order to examine the impact of the natural gas network on the operation of the respective power system. The purpose of this paper is to describe an efficient methodology that is based on the Monte - Carlo sequential simulation approach in order to realistically simulate the annual operation of the natural gas transmission systems and calculate the relevant reliability indices of connection nodes for the electric power plants using natural gas. The analysis of a combined system based on the Hellenic electric power system and the natural gas transmission system is presented assuming alternative case studies while the impact of their interdependence is determined. These results are compared and useful conclusions are obtained.