局部放电联合检测中光-电信号与放电量关联关系的修正

Correction of the Relationship between Optical-Electrical Signal and Charge Quantity in Partial Discharge Combined Detection

基于实验室搭建的局部放电光-电信号联合检测平台,进行了4种典型缺陷下局放模拟检测实验,获取了局放的光信号和电信号。分析了两类局部放电信号与SF6气体绝缘模拟腔体内部的视在放电量之间的关系,同时,根据现场试验中,真实存在的一些影响因素对结果进行了修正,分别从不同气压下超高频(ultra high frequency,UHF)检测信号与视在放电量之间的关系和不同尺寸绝缘缺陷下光测法信号与视在放电量之间的关系两方面进行了修正。获取了气压对UHF信号影响的修正公式,取模拟腔体内气压0.3 MPa时,对修正值与实际测量值进行比较,得到除自由金属微粒缺陷(相对误差为14. 4%)外,其他缺陷的相对误差均小于5%;获取了不同缺陷尺寸下对光测法信号影响的修正公式,选取各类缺陷的最小尺寸,对修正值与实测值进行比较发现,除自由金属微粒缺陷外,其他缺陷的相对误差均小于10%,验证了修正结果的可靠性。

Based on the partial discharge(PD)combined detection platform in the laboratory,the experiments under the four typical defects are performed,and the PD optical signals and PD electrical signals are obtained.The relationship between the two types of PD signals and the charge quantity in the SF 6 insulated simulation cavity is analyzed.According to the actual influence factors in the field test,the results were corrected.The relationship between ultra high frequency(UHF)signal and charge quantity under different pressures are revised,the relationship between optical method and charge quantity under different size of insulation defects are also revised.A correction formula for the effect of air pressure on the UHF signal is obtained.When the pressure in the simulation cavity is 0.3 MPa,the correction value is compared with the measured value.Except for the free metal particle defect(relative error is 14.4%),the relative error of other defects is less than 5%.A correction formula for the effect of different defect sizes on the optical signal is obtained,and the minimum size of each type of defect is selected to calculate the correction value.Comparing with the measured values,it is found that the relative errors of other defects except the free metal particle defects are less than 10%,which verifies the reliability of the correction result.