特高压换流变压器套管电连接结构地震累积效应评估方法研究

Research on Evaluation Method of Seismic Cumulative Effect of Electrical Connection Structure of Valve-side Bushing in Converter Transformer

摘要:

地震作用下换流变压器套管会产生位移响应，响应剧烈时其尾端电连接结构可能产生损伤。为了研究地震作用下换流变压器阀侧套管电连接结构的损伤累积效应，文中以换流变压器套管表带触指型电连接结构作为研究对象，建立了精细化的有限元模型。通过有限元计算，可以得到重力和地震作用下表带页片和连接母头内壁的接触压强和位移响应。基于Archard磨损模型，提出了一种在地震作用下表带触指磨损深度的计算方法。以磨损深度作为地震损伤累积的指标，对不同地震强度下表带触指页片磨损的程度进行了对比分析，计算了多次地震作用下的累积磨损深度。发现随着地震强度提高，表带触指的接触压强变化不大，但摩擦行程有较高程度的增大，使得磨损深度也会进一步加深。在不同强度的地震作用下，磨损的分布呈现不均匀但规律的特点，磨损深度的最大值总是出现在最远离连接公头根部的表带的上方页片。重力作用对电连接结构不同部件的磨损差异影响很大。尽管单次地震作用下磨损深度总体较小，仍旧存在局部磨损破坏的可能，应当重视地震作用下的损伤累积效应。

Abstract:

The electrical connection structure of converter transformer bushing produces strong stress-displacement response under seismic action, which leads to damage inside it. In order to investigate the cumulative damage of electrical connection structure of valve-side bushing in converter transformer under different seismic effects, the corresponding finite element model is established by taking the electrical connection structure with strap contact of converter transformer bushing as the research object. The contact pressure and displacement response of inner wall of strap page and strap female head under gravity and seismic action are obtained by finite element calculation. Based on Archard wear model, a calculation method is introduced for the wear depth of strap contact under seismic action. Taking the wear depth as an index of cumulative seismic damage, the degrees of wear of different components under different earthquake intensities are compared and analyzed, and finally the cumulative wear depth under several seismic actions is calculated. It is found that as the earthquake intensity increases, the contact pressure of strap contact does not change much, but there is a great increase in friction stroke, which makes the friction depth deepen further. Under the seismic action of different intensities, the distribution of wear shows uneven but regular characteristics, and the maximum value of wear depth always appears in the upper page of strap furthest from the root of male head. Therefore, it is concludes that gravity has a great influence on the wear difference of different parts of electrical connection structure. At the same time, although the overall wear depth under a seismic action does not seem to be large, there is still the possibility of local wear damage under multiple earthquakes, so it should pay attention to the cumulative damage under seismic action.