DESIGN OF MULTI-CHANNEL CORROSION DETECTION SYSTEM FOR GROUNDING GRID IN SUBSTATION

To improve the efficiency and accuracy of corrosion detection of substation grounding grid, a multi-channel corrosion detection system was developed. Based on the Tellegen's theorem, the corrosion diagnosis model was established. The diagnosis model was solved to locate the corrosion branch of the grounding grid accurately by Monte Carlo algorithm and Particle Swarm Optimization algorithm. A grounding grid corrosion detection system with 16 measurement channels was developed using a switch matrix structure, which could measure 120 port resistances simultaneously. The model of the grounding grid was established using Visio. The host computer software was developed based on C#, to achieve the functions of human-computer interaction, computing and others. A field test was carried out in a 110kV substation in Tianjin city, two severely corroded branches were located effectively. The results show that the grounding grid corrosion detection system can locate the corrosion of the grounding grid accurately.