高压电气设备泄露电流检测传感器的研究

Divulge current transducer for high-voltage electric equipment

电力设备绝缘在线监测技术已成为保证安全发电和供电、及时发现事故隐患、减少停电检修、提高供电可靠性的重要技术手段 ,高压设备绝缘在线监测的关键技术是泄露电流的采集 .为此分析了单匝穿芯式与多匝串入式传感器的结构原理 ,从变电所被测高压设备性能以及现场情况出发 ,阐述了单匝穿芯式传感器本身具有信号弱、稳定性差及难以长线传输等缺点 ,因此传感器设计时应采用多匝串入式 ;并对目前通用的三种铁芯材料即冷轧硅刚片、坡莫合金和超微晶合金的性能进行比较 ,分析了各种参数对传感器特性的影响 ,得出采用坡莫合金为铁芯材料可以增强输出信号幅值 ,减少误差 ,利于补偿 ;通过LDHL— 2 5 0型漏电流传感器试验数据 ,对传感器特性进行了分析 ;指出影响传感器精度的主要因素 ,并提出对传感器误差减匝补偿。

The on line monitoring of high voltage equipment is an important technique to ensure safe generation and transmission of electricity and finding out hidden trouble in a fimely manner. And the key to on line monitoring of high voltage equipment is the detection of divulge current. The structures of these two types of transducers, single circle passing through transducer(SCPTT) and multi circles serial transducer(MST) are analyzed. Because the signal of SCPPT is weak and its stability is unfavorable, MST is applied as the transducer is designed. By comparing material performance of cold rolled silicon, Permalloy and nanocrystalline alloy and analyzing the influence of all parameters to the performance of transducer, Permalloy is found to be the most suitable material for the transducer. According to the experiment data of LDHL-250 transducer, the performance of transducer is analyzed and most of the factors which influence the precision of transducer are identified. Furthermore, three methods used for error compensation, including decreasing circles, differential method and software method, are suggested.