Prytyskach I. Models and methods of power transformers diagnosis in electric networks with voltage 6–110 kV

The object of research: process of power transformers diagnosis in electric networks with voltage 6-110 kV. The purpose of research: to develop new and to improve existing models and methods of power transformers diagnosis to improve their durability and level of maintenance service during the operation of electric networks with voltage 6-110 kV. Methods of research: mathematical modeling, dynamic state estimation, cluster analysis, digital signal processing, differential equations solving using computer simulation. Theoretical and practical results and innovations: mathematical models of dynamic assessment of transformer diagnostic parameters were developed for the first time based on the Kalman filter; mathematical models for determining the transformer diagnostic parameters were improved due to thermal and moisture models parametric identification, which increases the reliability of transformers defects detection; method for determining the statistical characteristics of the load process was improved through the use of cluster analysis to identify the consumers work mode, allowing to increase the transformers load capacity evaluation reliability; method for stochastic evaluation of transformers load capacity was developed to ensure the effective application of technical criteria based on the results of load simulation, which ensures a higher level of assessment results reliability for admissibility of certain transformers work modes. A subject degree of introduction: the results of studies are used for educational purposes in NTUU "KPI" and ZNTU and transferred for use in LLC "Electrosfera", Kyiv and LLC "NDI Peretvoryuvach", Zaporizhzhya. Effectiveness of implantation: increase of the credibility of power transformer diagnosis. Sphere of use: electric networks with voltage 6–110 kV.