A supply risk assessment method for integrated energy systems considering multiple failure states of pipelines

With the increasing coupling between different systems, the risk of failure propagation in integrated energy systems (IESs) is consequently increased. At present, the multiple failure states in natural gas pipelines are not considered in most existing failure propagation assessment methods. Therefore, this paper proposes a failure propagation impact assessment method for the IESs that considers the multiple failure states of natural gas pipelines and the dependent characteristics of different systems. First, the multi-state failure model and coupling equipment model of natural gas pipeline are established. Based on the redispatch models of systems, the failure propagation flow of IES system under different coupling levels and different pipeline failure states is analyzed. Then, assesses the impact of these failures using assessment metrics. Finally, the effectiveness of the proposed method is validated in an IES. Numerical results show that compared with using the two-state model, the total load shedding of the IES is decreased by about 50 % by adopting the multi-state model. Also, it is validated that with the consideration of electric-driven compressors and electric-driven gas sources, the failures in power system have more significant impacts on the reliability of natural gas system, which is more correspondent to the actual failure propagation of IESs.