Automatic maintenance of substation ground resistance

The main purpose of power system substation grounding system is to maintain reliable operation and provide protection for personnel and apparatus during fault condition. However, in practice, ground resistance value of the substation often did not meet the required value. It can result in serious failures such as apparatus malfunction and lost revenue This paper presents a prototype for automatic monitoring and maintenance of those grounding systems. It basically consists of a PC, terminal measurement unit, data acquisition unit, and relay board. It measures the grounding resistance and has the ability to actuate a fluid sprinkler system at the substation grounding system thus improving and maintaining substation grounding system resistance at an acceptable level. This system will ultimately increase the reliability and efficiency of a substation particularly when under transient overvoltage due to switching and lightning phenomena by reducing lethal ground potential rise