自动定向式变电站局部放电监测定位方法研究

Research on partial discharge monitoring and localization method in an automatic directional way in substations

局部放电监测对发现绝缘缺陷与减少设备绝缘击穿故障均有重要意义,但是目前基于固定天线阵列装置的局部放电信号监测定位方法还不能实现空间上多维度、大范围的高准确度监测。为此设计了一种包含机械结构与天线阵列的自动定向装置,并提出适用的局部放电监测定位方法。所述局部放电监测定位系统首先根据信号特征通过N-Q-Φ等图谱判别局部放电信号,再从空间几何关系角度确定输送给机械结构的控制信号,从而控制定向装置不断调整天线阵列指向,并在闭环调节下使信号时间差最终控制在预设阈值以内。此时阵列中央的激光头所指即为局部放电源位置,完成了局部放电源的监测定位。之后建立局部放电监测定位实验系统,并对上述方法进行测试。结果表明,实验系统能有效发现局部放电信号,并能准确快速地定位局部放电源位置,这对实现局部放电大范围监测与定位有重要意义。

The partial discharge(PD)monitoring is of great signifcance for the discovery of insulation defect and the reduction of equipment insulation breakdown fault.However,recent PD monitoring and localization methods based on fixed antenna array still cannot achieve multi-dimensional,large-scale and high-precision monitoring.Therefore,an automatic directional equipment including a mechanical structure and an antenna array is designed and a monitoring and localization method suited to the equipment is proposed.First,the PD monitoring and localization system distinguishes PD signals according to characteristics of signals by N-Q-Φand other graphs.And then the control signals delivering to the mechanical structure can be determined from the perspective of spatial geometric relationships.Thus the orientation of the antenna array can be adjusted through the mechanical structure.Gradually the time difference will be controlled within a preset threshold under the closed loop regulation.At this time where the laser pointer in the center of this array pointed is the PD source.Finally the monitoring and localization of the PD source is completed.Then a monitoring and localization experiment system is established to test the above method.The results show that the experiment system can detect the local discharge signal effectively and locate the PD source accurately,which is of important meaning for the realization of large-scale PD monitoring and localization.