换流变压器出线套管极性反转电场计算分析

Analysis of electric field of valve-side outlet in convert transformer under polarity reversal voltage

换流变压器是高压直流输电系统中的重要设备之一,高压和特高压换流变压器设计制造的难点在绝缘技术,而绝缘的关键部位在阀侧出线装置。利用罚函数法构造了有限元状态方程,并通过数值方法进行求解。最后,讨论并分析了一个实际的±800 kV换流变压器出线套管模型在极性反转试验电压下绝缘结构中的瞬态电场分布,且通过对线性和非线性条件下的计算结果进行对比分析,考察了非线性对换流变压器出线套管极性反转电场分布的影响,为准确的进行换流变压器出线套管的绝缘结构设计提供依据。

Convert transformer is one of the most important equipments in the HVDC （high voltage DC） transmission system. The difficulty in the design of high voltage and ultra high voltage convert transformer is insulation technology, and the key part of insulation is in the valve-side outlet device. Finite element state equation can be got by means of penalty method, and by using the numerical methods to solve the equation. Finally, the transient electric field of a practical converter transformer＇ s valve-side outlet device under polarity reversal test voltage, was calculated and through the calculation results of linear to nonlinear, the influence of electric dependent conductivity on electric field distributions can be got, also the basis for the accurate designing of insulationis.