110 kV交流避雷器整支大电流冲击耐受能力研究

High-Current Impulse Withstand Capability of 110 kV AC Arrester

为了明晰110 kV交流避雷器4/10μs大电流冲击耐受能力现状及其失效的原因,验证整支避雷器与其电阻片作为试品的等价性,提出抽检试验评价规则建议,提升入网避雷器质量。本研究以110 kV(66 kV)交流系统及线路用瓷外套、复合外套“管型设计”和复合外套“缠绕型设计”避雷器为研究对象,在对比分析现行国家标准及电力行业标准差异的基础上,采用试验手段研究整支避雷器及其核心元件电阻片的大电流冲击耐受能力;对比不同结构的避雷器、同一避雷器与其电阻片之间大电流冲击耐受能力的差异。研究发现整支避雷器的大电流冲击耐受性能与其电阻片性能不等价。设计A结构避雷器的大电流耐受性能较设计B结构(同电阻片尺寸时)更有保障。分析大电流冲击耐受试验前后试品电气参数变化规律,发现110 kV(66 kV)交流避雷器耐受大电流失效的主要表现是冲击后试品工频参考电压和残压变化率超标,外观损坏导致的避雷器失效占比较少。对于110 kV(66 kV)交流避雷器的大电流冲击耐受抽检试验,建议采用DL/T 815-2021标准的判定规则;建议设计A结构的避雷器可使用电阻片或整支避雷器(避雷器本体)作为试品,使用整支避雷器试品通过试验可给予更高的质量评级;设计B结构的避雷器建议使用整支避雷器(避雷器本体)作为试品。

In order to clarify the current status and the cause of the failure of the 4/10 μs high current impulse withstand of the 110 kV AC arrester,and to verify the equivalence of the whole arrester and its resistors as test samples,some suggestions on the evaluation rules of sampling test are put forward to improve the quality of the arrester connected to the grid.The author takes the porcelain-housed and polymer-housed arrester of “Tube design” and “Wrapped design” for 110 kV(66 kV) AC power system as the research object.Based on the comparison of the differences between the current national standards and the power industry standard,and test is conducted to study the high-current impulse withstand capability of the whole arrester and its core element resistors.Comparing the difference in high current impulse withstand capability between the whole arresters of different structures and the arrester with its resistors.It is found that the high current impulse withstand capability of the whole arrester is not equivalent to the performance of its resistor.The high current impulse withstand capability of the arrester designed with structure A is more guaranteed than that designed with structure B(the same size as the resistor).The variation of electrical parameters of 110 kV(66 kV) AC arrester before and after the high current impulse withstand test are analyzed,which found that the main manifestation of high-current failure tolerance is the power frequency reference voltage and residual voltage change rate of the test product exceed the standard after the impulse,and the failure of arrester caused by appearance damage is relatively small.For the sampling test of 110 kV(66 kV) AC arrester with high current impulse withstand capability,it is recommended to adopt the judgment rule of DL/T 815-2021 standard;It is suggested that the arrester of structure A can use the resistor or the whole arrester(SVU) as the test sample,and a higher quality rating can be given if the whole arrester test passed;It is recommended to use the whole arrester(SVU) as the test sample for the arrester of structure B.