Topological study on electrode wells of vertical grounding electrodes of UHVDC

Abstract

The main body of vertical grounding electrodes of an ultra-high-voltage direct current (UHVDC) converter station is dispersed electrode wells, due to the shielding effect between electrode wells, the arrangement of which is a problem that needs to consider the electrical performance, the area, and the economy. The vertical grounding electrode simulation calculation model is built based on the boundary element numerical calculation software. It is found that the single circular ring is an ideal topology structure of the electrode wells, and the double circular ring structure can be adopted when the area is limited. When the double-circle structure is adopted, current flowing through each electrode well on the inner circle is obviously lower than that on the outer circle because of the stronger shielding effect. The design proposal to increase the depth of electrode wells on the inner circle to make the distribution of current more uniform is proposed. The electrical performance difference between the arrangement of standard circular and the irregular circular is studied, and suggestions for the arrangement of irregular circular are given. The research conclusion can be used as a reference for design of vertical grounding electrodes.

Keywords

• electromagnetic shielding
• earth electrodes
• boundary-elements methods
• HVDC power convertors
• HVDC power transmission
• current distribution
• power transmission protection
• standard circular
• irregular circular
• current distribution
• outer circle
• topology structure
• single circular ring
• boundary element numerical calculation software
• vertical grounding electrode simulation calculation model
• electrical performance
• shielding effect
• UHVDC converter station
• topological study
• double circular ring structure
• electrode wells
• ultra-high-voltage direct current converter station