避雷器泄漏电流测量原理分析及内置式监测装置研制

Analysis of Measurement Principle of Leakage Current of MOA and Development of Built-in Monitoring Device

为了明晰当前多种避雷器泄漏电流测量原理的优缺点,选择准确度更高、适用性更好的测量原理,并解决传统在线监测装置对避雷器早期性能劣化不敏感且不能避免外套污秽电流干扰的问题。文中对全电流法、阻性电流基波法、容性电流补偿法、谐波分析法共4种泄漏电流分析法及其测量干扰因素进行了分析。认为对于110 kV及以上交流电力系统,由于电网谐波干扰较小,建议采用谐波分析法作为避雷器在线监测装置的泄漏电流分析方法更为准确可靠。文中在采用谐波分析法的基础上提出了一种内置式避雷器在线监测装置,在避雷器元件腔室中内置温湿度及电流传感器,采集避雷器芯体温湿度以及泄漏电流等监测数据,多维化实时评估避雷器运行状态。相比传统避雷器监测装置,内置式监测装置从设计原理上提高了测量的准确性,且通过了运行可靠性验证,是一种更加有效的状态监测手段。

For clarifying the pros and cons of the presently various measurement principles of the leakage current of the arrester,selecting the measurement principle with higher accuracy and better applicability,and solving the problem that the traditional online monitoring device is not sensitive to the early performance deterioration of the arrester and can not avoid the interference of the polluted current of the outer coat,such four current analysis methods as the full current method,the resistive current fundamental wave method,the capacitive current compensation method and the harmonic analysis method and their interference factors are analyzed in this paper.It is considered that for the AC power system at 110 kV and above,due to the small harmonic interference of the power grid,the use of the harmonic analysis method as the leakage current analysis method of the online monitoring device of the arrester is more accurate and reliable.A kind of built-in online monitoring device of the arrester based on the harmonic analysis method is proposed in this paper.The temperature and humidity as well as current sensors are built into the cavity of the arrester element,the monitoring data of the temperature and humidity of the arrester core and the leakage current are collected,and the operation state of the arrester is assessed in a multidimensional real-time manner.Compared with the traditional monitoring device of the arrester,the built-in monitoring device improves the accuracy of the measurement in terms of the design principle,has passed the operation reliability verification,and is a more effective state monitoring method.