Temperature Rise Characteristics of Vertical Grounding Electrodes of Ultra-High Voltage DC ± 800 kV Pu'er Converter Station

2018 International Conference on New Energy and Future Energy System

Yang, D.^1 ; Zou, Z.L.^1 ; Chen, W.^1 ; Li, S.D.^2 ; Xie, Z.C.^1

China Southern Power Grid, Extra High Voltage Power Transmission Company, Maintenance and Test Center, Guangzhou

510663, China^1

School of Electrical Engineering, Wuhan University, Wuhan

430072, China^2

关键词: Calculation models;    Current distribution;    Design and operations;    Grounding current;    Ultra high voltage;    Ultra high voltage direct currents (UHVDC);    Vertical electrodes;    Vertical grounding electrode;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/188/1/012109/pdf
DOI  :  10.1088/1755-1315/188/1/012109

来源: IOP

【 摘 要 】

The vertical grounding electrode (VGE) is a new type of grounding design of ultra-high voltage direct current (UHVDC) power transmission project, which can greatly reduce the grounding area. The main structure of VGE is several or dozens of vertical electrode wells connected with each other by cables to form a conductor system. However, the ends of the VGE temperature may rise severely due to the non-uniform grounding current of each electrode. In serious cases, cable failures or other accidents may occur. In order to investigate the VGE temperature rise characteristics of the UHV ±800kV Pu'er Converter Station in China, firstly a single VGE was simulated in the laboratory. Measurements of the single VGE temperature rise were compared with the calculations by finite element method (FEM) to verify the validity of the algorithm. Then the calculation model was utilized to compute the current distribution of each VGE of Pu'er Converter Station, and a current balance design was proposed in this paper. Calculations demonstrated that the maximal temperature rise of the VGE was 31 °C, which was lower than the design limit. This paper may provide some useful reference for the design and operation of the UHVDC vertical ground electrodes.