MAINTENANCE STRATEGY OF POWER TRANSFORMERS IN RURAL ELECTRIC NETWORKS OF 10 KV ACCORDING TO RESULTS OF DIAGNOSTICS
The analysis of statistical material of technical state evaluation of power transformers of 10/0,4 kv is made. The factors which influence on the efficiency of power equipment are defined. The results of experimental research in case of failure of power transformers 10/0,4 kv in rural electric networks are given. The classification of failure is represented according to the elements, reasons and months of the year. The results of diagnostics of long-working transformers are examined and the evaluation of the technical state is made. It is found that the vain failure is the spire circuit which can exist for a long time without influence on the electricity and increasing expenses for servise of power transformers in case of their maintenance. Non-failure operation of the internal insulation (main, spiral), failure of which is 70,8% of the part of spiral is 55,2%. The break-down of insulation in case of internal overstrain is 34,4%, in case of storm is 20, 8%. The overstrains and the influence of the environment as a rule cause spire circuit of high voltage winding, which lead to worsening of windings of the relative body. The strategy of transformers maintenance according to the evaluation of the technical state on the basis of the results of the diagnostics is offered. The structure of the efficient strategy of technical servise of power transformers 10/0,4 kv is defined and the plan containing the next main elements is made: functional modeling of research of the transformers according to regional (climate) peculiarities of exploration and taking Technical Servise and Technical Regulations in real condition; determination of the economic optimal criterion for all the alternative approaches (there are 3 approaches in the article); optimisation of economic optimal criterion of the alternative approaches and the choice of the controlling influence on the object under research on the basis of minimization; realization of the system of Technical Servise and Technical Regulations of the power transformers according to the real state.