Dependability Model of Electric Power Systems for Assessing Smart City Energy Sustainability

The sustainable development of smart regions directly depends on the dependability and resilience of critical energy grids (CEGs) and their key components—electrotechnical systems (ETSs). Accurate and reliable assessment of ETS dependability is a critical factor in ensuring the sustainability of CEGs. The article presents a triplet-based decomposition model for complex electrotechnical systems, in which the system is represented as three-component blocks (triplets). The aim of the study is to reduce the dimensionality of the state space and simplify the Markov analysis of system sustainability and dependability under destructive impacts. Based on this model, the TRICAM method for triplet clustering and aggregation has been developed, combining structural decomposition and functional aggregation within a single stage of analysis. Unlike quasi-lumping methods, TRICAM implements a formalized three-state aggregation with clearly defined rules and preservation of the Markov structure, which simultaneously performs aggregation and structural decomposition and enables hierarchical model construction. The method maintains uniformity in the number of aggregated states and a fixed model dimensionality, eliminating exponential growth of the state space and simplifying implementation. TRICAM is particularly suitable for flat or hierarchically structured symmetric systems, making it an effective tool for the engineering analysis of electrotechnical systems. The results of the study demonstrate the potential contribution of the proposed method for ETS-CEG to regional sustainable development by reducing the risks associated with inaccurate and non-verifiable assessment of ETS dependability.