How to Evaluate the Aging and Lifespan of Oil-immersed Transformer

Introduction: According to transformer aging mechanism and referring to relevant studies at home and abroad, the paper evaluates the aging and residual life of 330kV power transformer by means of measuring the degree of polymerization (DP) of insulation paperboard. The result shows that DP of power transformer insulation paperboard is a correct, reliable and effective criteria for determining the aging degree of insulation. 

Key words: 330kV, oil-immersed transformer, insulation paperboard, degree of polymerization (DP), aging, lifespan, evaluation  

Introduction  

As installed capacity grows rapidly, the reliability of power supply needs to be higher and higher correspondingly. Hence, it is necessary to determine working condition of power transformer, which operates for a long time. The lifespan of oil-immersed transformer is determined by insulation aging degree but transformer oil can regenerate or be replaced during operation. Therefore, aging and lifespan of power transformer mainly depends on insulation board and its actual conditions. The paper evaluates the aging and residual life of power transformer by means of measuring the degree of polymerization (DP) of insulation paperboard.