基于高压侧测量的输电线绝缘子泄漏电流在线监测系统

设计了一种基于MSP430高压侧绝缘子泄漏电流在线监测系统，采用一段时间内泄漏电流的峰值最大值、峰值平均值和脉冲数等参数作为污秽程度划分的依据，详细介绍了基于反馈补偿型泄漏电流传感器的设计，实现电流传感器的高线性化，提出用电流互感器直接从高压负载电流中获取系统供电能量的思想，分析了干扰噪声对泄漏电流信号峰值提取的影响，在软件设计中，引入了小波变换算法对信号进行降噪处理的方法。实验测试表明，通过对实时监测记录的历史数据进行综合分析和统计，能够对绝缘子的污秽程度做出正确的划分，并实现绝缘子污秽过度报警功能，从而减少了污闪发生的概率，提高了供电系统可靠性。

ON-LINE MONITORING SYSTEM ON MEASURING LEAKAGE CURRENT NEAR HV SIDE FOR ELECTRICAL TRANSMISSION LINE INSULATORS

A novel on-line monitoring system is presented based on MSP430 designed to measure insulators' leakage current near high voltage (HV) side. The system adopts the parameters such as the maximal peaks, the average peaks and the number of large current pulses of the leakage currents in a period to differentiate the contamination degree of insulators. Hence, a new kind of leakage current sensor based on the principle of feedback compensation is described in details. The design of this structure keeps the sensor holding high linearity. Then the power supply of the on-line device directly obtains from the transmission line through switching and linear DC/DC converter. This paper also analyzes the effect of noise signal on detecting the peaks of leakage currents, and a wavelet transform algorithm is introduced to denoise. Field tests show that it can properly predict the contamination degree of the insulators and offer the pre-alert information when the contamination exceeds the threshold, through analyzing the data acquired from historical real-time records. Thus, the probability of flashover can be reduced and the reliability of the whole power supply system can be improved.