Theoretical Study On Condition Assessment Methods Of Large Power Transformer

Power transformer is one of the most important devices of power system. Its operating condition has important effects on the security, stability and economic operating of power system. Therefore, assess its operating condition scientifically has important meaning for develop reasonable maintenance strategies and improve its operating reliability.The effect of thermal stress, electrical stress and mechanical stress on transformer life has been studied in this paper. Based on the study of transformer hot spot temperature estimating, a reliability assessment model based on hot spot temperature estimating has been presented. Through laboratory experiments, the cumulative effects of impulse voltage on oil-paper insulation has been studied, which will provide theoretical support for future assessments. Through simulation, a stress-strength interference model of winding reliability assessing has been presented, which is used to assess its winding reliability when short circuit.These models and conclusion have some reference value for assessing power system reliability.