山东电力高等专科学校学报

在不拆一次引线的情况下，采用传统方法测量三节结构金属氧化物避雷器的I_0.75时，中节避雷器I_0.75的测量误差大。通过试验确定了中节避雷器I_0.75测量误差大的主要原因，即试验过程中高压法兰与低压试验引线之间的杂散电流经过试验引线流经电流表，使电流表的示数变大。在此基础上，提出了在低压试验引线加屏蔽层的方法，以减小杂散电流对三节结构金属氧化物避雷器中节I_0.75测量的影响。试验结果表明，低压屏蔽电流法可有效提升三节结构金属氧化物避雷器中节I_0.75测量的准确性。

The I_0.75 measurement error of the middle section of the surge arrester is large when measuring the I_0.75of the metal oxide arrester with three sections using conventional method without removing the primary leads.The main reason for the large I_0.75measurement error of the middle section of the surge arrester is determined by tests,i.e.,the stray current between the high-voltage flange and the low-voltage test lead flows through the ammeter via the test lead during the test,which increases the reading of the ammeter.On this basis,the method of adding the shielding layer on the low-voltage test lead is proposed to minimize the effect of stray current on the I_0.75measurement of the middle section of the metal oxide arrester with three sections.The test results show that the low-voltage shielding current method can effectively improve the accuracy of I_0.75measurement of the middle section of metal oxide arrester with three sections.