Li Junna, Shi Haoliang, Wang Yongliang, Ge Jianwei, Wu Fangzheng, Huang Qixiang, Zhang Yiting, Li Qisheng
State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710024, People's Republic of China.
Rev Sci Instrum. 2024 Jul 1;95(7). doi: 10.1063/5.0213784.
This paper presents three methods aimed at enhancing the flashover voltage of the supporting insulator in a Tesla transformer. These methods include optimizing the maximum electric field on the insulator surface, adjusting the overall structure of the insulator, and changing the surface structure of the insulator. Ten insulator samples with different structures were designed based on electric field simulation. Subsequent experiments were conducted to validate the effectiveness of these methods in improving flashover voltage. On this basis, the supporting insulator of the Tesla transformer was redesigned, leading to an increased output voltage. The results are summarized in the following. First, optimization of the shielding rings of the cathode and anode reduces the electric field at the triple junction, which significantly increases the flashover voltage. Second, extending the inclination starting position of insulators with the same inclination angle effectively reduces the surface electric field intensity and increases the flashover voltage. Third, increasing the inclination angle within a certain range while keeping the inclination starting position constant extends the creepage distance and enhances the flashover voltage. However, excessively large inclination angles may lead to a decrease in flashover voltage due to excessive normal electric field. Fourth, grooving on the insulator surface at appropriate locations can inhibit the development of the streamer and improve flashover voltage. Finally, the supporting insulator of the Tesla transformer was redesigned based on these results, elevating the output voltage from 750 kV to over 1 MV.
本文提出了三种旨在提高特斯拉变压器中支撑绝缘子闪络电压的方法。这些方法包括优化绝缘子表面的最大电场、调整绝缘子的整体结构以及改变绝缘子的表面结构。基于电场模拟设计了十个不同结构的绝缘子样品。随后进行了实验，以验证这些方法在提高闪络电压方面的有效性。在此基础上，对特斯拉变压器的支撑绝缘子进行了重新设计，从而提高了输出电压。结果总结如下。第一，优化阴极和阳极的屏蔽环可降低三相交界处的电场，这显著提高了闪络电压。第二，延长相同倾斜角度的绝缘子的倾斜起始位置可有效降低表面电场强度并提高闪络电压。第三，在保持倾斜起始位置不变的情况下，在一定范围内增大倾斜角度可延长爬电距离并提高闪络电压。然而，过大的倾斜角度可能会由于法向电场过大而导致闪络电压降低。第四，在绝缘子表面的适当位置开槽可抑制流光的发展并提高闪络电压。最后，基于这些结果对特斯拉变压器的支撑绝缘子进行了重新设计，将输出电压从750 kV提高到了1 MV以上。
