水份含量对变压器油纸绝缘系统回复电压参数影响规律的研究

油浸式电力变压器中的油纸绝缘系统受潮会加速固体绝缘材料老化,严重影响其运行寿命,因此评估变压器绝缘纸板中的水份含量对确保变压器安全可靠运行具有重要意义.基于回复电压的极化谱方法是一种无损的绝缘诊断方法,已经被用来评估变压器的绝缘状态.笔者研究了不同充电时间下水份含量变化对回复电压参数的影响规律.结果表明,回复电压最大值...

Influence of Moisture Content on Parameters of Return Voltage Measurement in Oil-paper Insulation System of Transformer

Once the oil-paper insulation system in oil-immersed transformer is affected with damp,the aging of solid insulation materials will be accelerated and the operation life will be seriously influenced.Therefore,the assessment of moisture content in insulating paper board of transformer makes great sense for the safe and reliable operation of transformer.As a non-destructive insulation diagnostic technique,the polarization spectral method which is based on return voltage measurement has been employed to assess the state of insulation of the transformer.In this paper,the effect of moisture content change under different charging time on the parameter of return voltage is studied.The result shows that with the increase of moisture content in insulation system the maximum value of return voltage and initial slope increase in second-order linear form,while the central time constant presents an opposite trend.The central time constants vary obviously with the change of moisture constant,so it is considered as a reliable indicator to evaluate moisture content and moisture level in oil-paper insulation system of transformer.