Reliability Evaluation of Multi-Area Integrated Electricity-Gas Systems Based on the Improved Uniform Design

Reliability evaluation of the integrated electricity-gas system (IEGS) is an essential part of maintaining a continuous and stable energy supply. However, the task is extremely time-consuming since there are numerous system states considering the random outages of components, and each system state corresponds to a sample that needs to be analyzed. In this paper, the uniform design method (UDM) is customized to improve the computation efficiency of multi-area IEGS reliability evaluation. The UDM selects system states based on the proactive design rather than on the state enumeration or random sampling. Based on UDM, the selected samples have good uniformity and dispersion in the sample space which contributes to the reliability evaluation accuracy when the number of chosen samples is limited. Moreover, spectral clustering is applied to assist UDM to improve the representativeness of the selected samples. And an extended network flow method is proposed to calculate the clustering features efficiently. Last, comprehensive reliability indices are constructed to measure the reliability level of the multi-area IEGS, through which the impacts of cross-energy failure propagation and the advantages of cross-area energy sharing on reliability are also quantified. Case studies have been conducted to verify the validity of the proposed methods.