Abstract: The site geotechnical engineering characteristics of Tangshan Caofeidian Coalfired Heatsupply Power Plant of China Resources were introduced. The cathode protection mode of electric grounding grid and its design calculation method were analyzed. The effects of cathode protection were tested systematically. The test result shows that to select magnesium alloy sacrificial anode in cathode protection of grounding grid can get designed protective potential and can obtain better anticorrosive effect.

Key words: grounding grid, cathode protection, magnesium alloy, sacrificial anode, corrosiveness, test pile