8.5kV特高压晶闸管低占比终端结构设计与研究

Design and Research on Terminal Structure of 8.5kV UHV Thyristor With Low Proportion

作为能量变换和传输的重要器件,大功率晶闸管在诸如高压直流输电等领域得到广泛应用。随着电网对输电功率容量的要求越来越高,提高晶闸管导通容量备受关注。但是,随着容量的提升,传统的直线斜角造型技术在保证角度足够小的同时,会减少较多的阴极有效导通面积。为解决此问题,提出了一种低占比终端结构的大功率晶闸管,该晶闸管采用折线造型技术,能够在终端结构侧做到更小的角度,达到与直线斜角造型技术同样的电场优化效果,还可以保证阴极有效导通面积。最后,通过Silvaco平台,建立8.5 kV晶闸管的TCAD模型进行分析,验证所提出的结构的可行性。

As an important device for energy conversion and transmission, high-power thyristors are widely used in fields such as high-voltage direct current transmission. With the increasing requirements of the power grid for the transmission power capacity,increasing the conduction capacity of the thyristor has attracted much attention. However, as the capacity increases, the conventional straight-line oblique angle modeling technology may reduce the effective conduction area of the cathode while ensuring that the angle is small enough. In order to solve this problem, a high-power thyristor with a low-occupancy terminal structure was studied. In this thyristor, a broken line shape was adopted to achieve a smaller angle on the terminal structure side to achieve the same electric field optimization as a line oblique angle. Meanwhile, the effective conduction area of the cathode could be ensured. Finally, a TCAD model of an 8.5 kV thyristor device was established and analyzed by using the Silvaco platform to verify the feasibility of the proposed structure.