基于无线传感网络和GPS的电容器介损角的在线监测

Power capacitor online monitoring system based on wireless sensor network and GPS clock module

目前变电站电容器的在线监测主要是针对电容器组展开的,只能确定某组发生故障,难以确认故障的具体电容器。研究围绕变电站的各台电容器的故障诊断开展在线监测。鉴于各层电容器存在高电位差无法使用电缆实现信号传输,而使用光纤投资又高的问题,设计并实现了一种基于Zigbee无线传感网络的电容器在线监测系统。在无线监测方案中,电容器电流、电压信号的精确同步采样是技术难点。提供了一个基于GPS授时模块秒脉冲的精确对时机制,实测同步误差小于1μs,这样可使介损角测量误差小于0.34'。针对变电站PT型号不统一问题,还提出了一种PT角差的估算方法。最后通过实验分析,提出的系统达到了在线监测要求,并在晋中某变电站投入应用。

The existing capacitor online monitoring system in transformer substation is mainly aimed at capacitor group. In this kind of system, the capacitor group malfunctions can be found, but individual capacitor failure is diffi- cult to be found. The online monitoring and fault diagnosis of individual capacitor is studied. In consideration of high potential difference between capacitor group layouts, it＇s difficult to realize communication based on wired lines, and the use of optical fiber will increase system investment. A capacitor monitor system base on wireless sensor network is presen- ted. In wireless monitor system, the capacitor current signal and voltage signal must he accurately synchronously sam- pied. A clock module based on GPS is provided in the research, with which the synchronous error is less than 1 microse- cond. The measuring error of dielectric loss angle is less than 0. 34＇ based on this clock module. The PT model is not u- nified in different substation, a estimation nuthod of PT angleerror is presonted. By the experimental analysis, the moni- toring system has reached the design requirement, and the system has been successfully applied in Jinzhong substation.