Regularity of Current Dispersal in Different Kinds of Grounding Electrode

This paper analyzes the regularity of ±800 kV HVDC grounding current dispersal in 3 common types of Grounding Electrodes by simulating the surface potential and current density. When HVDC system is in single pole operation mode then a large amount of current can be dissipated from grounding system. Firstly, a single line ±800 kV HVDC transmission system is built in this paper to simulate the grounding current. The measured stable grounding current is 3000A. Secondly, a grounding electrode current dispersal model is designed and then inserted 3000A current in horizontal, cross and circle electrodes. After the analysis of simulations, it is proved that horizontal electrode has the highest surface potential and current density. Although circle electrode has the best surface potential and current density distribution near the electrode but the value of surface potential and current density is higher than the cross electrode after 300m. This study provides valuable suggestions for design of HVDC grounding electrodes.