DEVELOPMENT AND APPLICATION OF A PORTABLE ELECTROCHEMICAL DEVICE FOR DIAGNOSE OF GROUNDING GRID CORROSION
Zhigang Qiu · Fushi kexue yu fanghu jishu · 2009
The galvanostatic technique was adopted to diagnose the corrosion situation of grounding grid for electric substation.A portable computerized system was constructed to implement the in-field measurement,which consists of current limiting probe,potentiostat,data acquisition card,laptop and data processing software.The probe was designed to solve the current distribution problem,the data processing software was developed to eliminate the noise and the IR drop by wavelet filtering and Levenberg-Marquardt fitting respectively.The measurement procedure involve inserting the probe into the soil right above the target grounding grid,detecting the galvanostatic charge curve and finally obtaining the polarization resistance Rp as an evaluating parameter.The system was applied at several electric substations and showed good performance in these practical applications.