Linguistic mathematical model for assessing the technical condition of high-voltage circuit breakers based on monitoring data

Purpose. To develop a comprehensive linguistic mathematical model for determining the service life and failure probability of high-voltage circuit breakers based on the assessment of the technical condition of individual functional units using parameters obtained in Online and Offline monitoring modes. Methodology. For the technical condition assessment of high-voltage circuit breakers, artificial intelligence methods based on fuzzy set theory and linguistic modeling were applied. Multiparameter aggregation of diagnostic parameters was performed using hierarchical fuzzy inference based on the Mamdani algorithm. The weighting coefficients of the hierarchical structure were determined on the basis of expert assessment using an approach that combines fuzzy logic and the pairwise comparison method (Saaty method). To assess the risk of normal operating condition violation in the electric power system subsystem, probabilistic-statistical modeling methods of power system operating conditions (Monte Carlo method) were applied. Findings. A set of key diagnostic parameters of the functional units of SF6 circuit breakers was formed to determine the consumed service life and failure probability based on monitoring data. A hierarchical structure of an expert system for aggregated assessment of the technical condition was constructed. A linguistic mathematical model for determining the service life and failure probability based on multiparametric aggregation of the states of individual functional units was developed. Weighting coefficients of diagnostic parameters and functional units were determined using a hybrid approach. Using a sample of operating SF6 circuit breakers, simulation of the developed mathematical model was performed to determine the service life, failure probability and to identify defective units. Probabilistic-statistical modeling of a power system subsystem was carried out to assess the risk of violation of the normal operating mode under various contingency scenarios. Quantitative risk levels were obtained and the fleet of high-voltage circuit breakers was ranked according to maintenance priority. Originality. Based on the constructed hierarchical structural schemes for determining the levels of technical condition factors of individual functional units, linguistic mathematical models for determining the consumed service life and failure probability of functional units and of the high-voltage circuit breaker as a whole were developed. Practical value. The developed software can be used as part of a computational complex for the analysis of operational risks in electric power systems. It implements the task of comprehensive assessment of the technical condition of high-voltage circuit breakers based on monitoring results in Online and Offline modes. It enables the development of a strategy for further operation and the substantiated determination of priorities for decommissioning or replacement. It provides a quantitative assessment of the risk of emergency situations arising from failures or planned or unplanned decommissioning.