变电站电容型设备在线监测系统设计与应用

Design and Application of Online Monitoring System for Substation Capacitive Equipments

以有源零磁通电流互感器获取电容型设备及氧化锌避雷器微弱泄漏电流,以IRIG-B码为同步采样时钟,实现100 ns的高精度同步采样。在此基础上通过对现场可编程门阵列编程生成B码解码、模拟/数字转换控制、测频、雷击计数、温湿度采集等多个逻辑模块,围绕FFT IP核设计并实现多通道模拟信号采样、存储及快速傅立叶变换运算功能,在提升测量精度的同时,有效降低了装置的硬件成本。装置试验及现场运行数据表明:装置可以满足电力系统在线监测精度要求,并具有较高的稳定性和可扩展性。

Weak leakage current of capacitive equipments and zinc oxide arrester is obtained by using active zero flux current transformer（ CT）,and high-precision synchronous sampling of 100 ns is realized by taking Inter Range Instrumentation Group-B（ IRIG-B） as the synchronous sampling clock. On the above basis,field programmable gate array（ FPGA） is used to produce multiple logic modules such as IRIG-B decoding,analog to digital converter（ ADC） control,frequency measurement,lightning counting,temperature and humidity acquisition,and so on. Particularly by designing and realizing functions including multi-channel simulating signal sampling,storage and fast Fourier transformation（ FFT） around FFT IP core,it is able to improve measurement accuracy as well as effectively reduce hardware costs of the device. Experimental and field operation data indicate that this device is able to satisfy requirements for online monitoring precision of the power system and has higher stability and scalability.