Electric Field Distribution and Switching Impulse Discharge under Shield Ball Surface Scratch Defect in an UHVDC Hall
1
Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defense, North China Electric Power University, Baoding 071003, China
2
China Electric Power Research Institute, Beijing 100192, China
*
Author to whom correspondence should be addressed.
Energies 2018, 11(6), 1408; https://doi.org/10.3390/en11061408
Received: 4 May 2018 / Revised: 24 May 2018 / Accepted: 28 May 2018 / Published: 31 May 2018
(This article belongs to the Section Energy Sources)
The dimension and surface state of shielding fittings in ultra high voltage direct current (UHVDC) converter station valve halls have a great influence on their surface electric field and switching impulse characteristics, which are important parameters confirming the air gap distance in the valve hall. The characteristics of impulse discharge under different lengths, dent degrees and burrs around the scratches of Φ1.3 m shield balls with a 2 m sphere-plane gap length were tested, in the UHVDC testing base of the Hebei Electric Power Research Institute. The discharge characteristics under the influence of the surface scratches of the shield ball were obtained. The results demonstrate that the discharge voltage of sphere-plane gap decreases obviously when there are unpolished scratches on the surface of the shield ball. However, when the scratches are polished, the discharge voltage has no significant impact. At the same time, a 1:1 full-scale impulse test model was established based on the finite element method. The electric field intensity and the space electric field distribution of the shield ball were obtained under the influence of scratches with or without burrs. The results of the simulation show that when the surface of the shield ball is smooth, the electric field distribution around it is even. The electric field intensity on the surface of the shield ball increases obviously when there are burrs around the scratches. When there is no burr around the scratches, the length and depth of the scratches have no obvious effect on its electric field distribution. Meanwhile, calculation results are consistent with test results. The results can provide an important basis for the design and optimization of shielding fittings, and technical support for its localization.
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Keywords:
ultra-high voltage; shield ball; sphere-plane air gap; positive polarity; switching impulse
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MDPI and ACS Style
Geng, J.; Qin, Y.; Lv, F.; Yao, X.; Ding, Y. Electric Field Distribution and Switching Impulse Discharge under Shield Ball Surface Scratch Defect in an UHVDC Hall. Energies 2018, 11, 1408. https://doi.org/10.3390/en11061408
AMA Style
Geng J, Qin Y, Lv F, Yao X, Ding Y. Electric Field Distribution and Switching Impulse Discharge under Shield Ball Surface Scratch Defect in an UHVDC Hall. Energies. 2018; 11(6):1408. https://doi.org/10.3390/en11061408
Chicago/Turabian StyleGeng, Jianghai; Qin, Yuchen; Lv, Fangcheng; Yao, Xiuyuan; Ding, Yujian. 2018. "Electric Field Distribution and Switching Impulse Discharge under Shield Ball Surface Scratch Defect in an UHVDC Hall" Energies 11, no. 6: 1408. https://doi.org/10.3390/en11061408
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