大型变压器铁芯接地在线监测技术的研究

变压器铁芯在正常运行中只能有而且必须有一点接地,必须预防和及时发现变压器铁芯多点接地故障并迅速做出处理,防止事故扩大。以电流检测法为基础开发了变压器铁芯接地微机在线监测系统,该装置能够对变压器铁芯接地电流进行在线监测,经电流互感器转换为变压器铁芯接地线中的电流信号,首先被转换成模拟电压信号,然后被采集卡转换成数字信号,输入到工控机,工控机对信号进行分析和处理,在发生故障时给出报警信号。

Study on Online Monitoring Technology to Core Earthing of Large Transformer

The transformer core must be earthing in one point and only one point,so multi-points earthing fault of transformer core has to be prevented,found out in time and treated quickly in order to avoid the fault to be extended.Based on the current checking method,a micro computer transformer core earthing online monitoring system is already developed,the earthing current of transformer core could be monitored on-line by it.The current signal in transformer core earth lead is transformed firstly to simulated voltage signals by means of CT,then transformed to digital signals by the collection card,which will be inputed into the process computer to do analysis and treatment,an alarm signal could be given when a fault is happened.