Abstract: Abstract:Aiming at the concrete loca resource condition of the 2×60MW coalfired power plant in Combodia, considering the requirements to reduce the soil replacement amount, to control the cost rationally and to ensure the project duration, the concrete grounding scheme was put forward. According to the rule of the file IEEE 80—2000“Guide for Safety in AC Substation Grounding”, the permissible values of the step voltage and the contact potential were verified, and it was ensured that the grounding resistance in whole plant can meet the requirement of the project contract.

Key words: Keywords:oversea thermal power plant, soil resistivity, grounding resistance, step voltage, contact potential