A Novel Resistance Network Node Potential Measurement Method and Application in Grounding Grids Corrosion Diagnosis

In this paper, a novel resistance network node potential measurement technique based on 16-channel cycle method is presented, and a grounding grids corrosion diagnosis measurement system with 16 channels is built from this method. Through this measurement system, 1680 valid potential data and 1560 effective branch voltage data can be collected in one measurement by only 16 risers on the grounding grid. The stability error of the excitation current source is less than 0.15%, and the error of the applicable acquisition data is about 1% according to system data tests. Built on the measurements, an underdetermined sensitivity equation for solving the increasing multiple of branch resistance is put in place to determine the corrosion status of grounding grids. The experimental results show that the plenty of data is necessary when solving the underdetermined equation and also show that the system is under a high stability, high accuracy, and can comply with the requirements of corrosion diagnosis for grounding grids.