高压换流变阀侧SF_6气体套管外绝缘结构设计

Design of SF_6 Gas Bushing External Insulation Structure on High Voltage Converter Transformer Valve Side

高压换流变阀侧套管是实现换流变压器与阀塔电气连接的重要设备,文中主要针对其外绝缘结构设计进行讨论。研究内容主要分为3部分:讨论了换流变套管的实际运行环境和承受的电压、电流波形特征;对换流变套管从空心复合绝缘子、套管均压罩、套管尾部3方面进行了设计和分析;建立了换流变套管三维电场仿真计算模型,在实际运行环境下对其外绝缘性能进行计算分析。研究结果表明:套管主绝缘宜采用电容式结构,且套管端部应装配苹果型均压罩;套管空心复合绝缘子的绝缘距离设计为7 490 mm,且尾部的绝缘距离设计为3 110 mm;在实际运行环境下,端部均压罩最大场强出现在下端面,其值为2386 V·mm^(-1)。文中的计算结果可为高压直流输电工程用换流变套管外绝缘设计提供一定的理论依据。

The converter transformer valve side bushing is an important equipment to realize the electrical connection between the converter transformer and the valve tower. The paper mainly discusses the design of the external insulation structure. The research content is divided into three parts, the actual operating environment and the characteris-tics of the voltage and current waveforms of converter transformer bushing are discussed. The design and analysis of the hollow composite insulator, corona ring and tail end of the bushing has been done. The three dimensional electric field simulation model has been set up to calculate and analyze the external insulation performance of the bushing. The results show that the main insulation of the bushing is fit to the capacitive structure, and the end of the bushing should be equipped with apple type corona ring. The insulation distance of the hollow composite insulator is designed as 7 490 mm. The insulation distance of the bushing tail is designed as 3110 mm. In the actual operating environment, the maximum field strength of the corona ring appears on the lower end surface, and the value is 2 386 V-mm^-1. The results of the paper can provide the theoretical basis for the design of the external insulation of the converter transformer bushing used in the HVDC transmission project.