变压器套管多参量在线监测装置研制与应用

Development and Application of Multi-parameter On-line Monitoring Equipment for Transformer Ushing

少油设备对电网安全运行至关重要,近年来,因变压器套管故障引起的电网事故时有发生。为了诊断套管运行状态,避免套管故障引发严重电网事故,开发了套管油中溶解氢气、油压、油温多参量在线监测装置,包括信号采集、汇控柜和数据分析3个单元。研制了一种无油气分离膜、基于钯合金薄膜技术的新型氢气传感器,对传感器的结构进行了微型化、低功耗设计,在芯片表面沉积了Si3N4保护膜,提高了传感器的测量精度和使用寿命。研制了氢气、油温、油压三合一传感器,具有小型化、轻量化、易于安装等优势。测试结果表明:传感器氢气测量范围为0~5 000μL/L,测量精度可达10%或15μL/L(取数值较大者);压力测量范围为0~1.0 MPa,分辨率0.1 kPa,精度可达0.25级;温度测量范围为-40~+105℃,精度为±1℃。装置测量性能完全满足变压器套管在线监测要求,已在330 kV变电站挂网运行,可对套管状态进行实时在线监测,将套管的早期潜伏性故障消除在微弱的萌芽状态。

Oil-less equipment is very important for the safe operation of power grid.In recent years,power grid accidents caused by transformer bushing faults occur frequently.In order to diagnose the running state of bushing and avoid serious power grid accidents caused by bushing failure,an on-line multi-parameter monitoring device for dissolved hydrogen,oil pressure and oil temperature in bushing oil was developed,including three units:signal acquisition,control cabinet and data analysis.A new hydrogen sensor without oil-gas separation membrane and based on palladium alloy film technology was developed.The structure of the sensor was designed with miniaturization and low power consumption.Si3N4 protective film was deposited on the chip surface,which improved the measurement accuracy and service life of the sensor.A three-in-one sensor for hydrogen,oil temperature and oil pressure has been developed,which has the advantages of miniaturization,lightweight and easy installation.The test results show that the hydrogen measurement range of the sensor is 0~5000μL/L,and the measurement accuracy can reach 10%or 15μL/L(with larger values);the pressure measurement range is 0~1.0 MPa,the resolution is 0.1 kPa,and the accuracy can reach 0.25 grade;and the temperature measurement range is-40~105℃,and the accuracy is±1℃.The measurement performance of the device fully meets the requirement of on-line monitoring of transformer bushing.It has been put into operation in 330 kV substation.It can monitor the bushing status on-line in real time and eliminate the early latent fault of bushing in the weak budding state.