1000 kV电力变压器的抗震性能

Seismic Performance of a 1 000 kV Power Transformer

为得到特高压电力变压器的地震响应,以特高压工程中常用的1台1000kV电力变压器为对象,建立了有限元模型。有限元分析得到了1000kV变压器的模态特性和地震响应。发现地震作用中电力变压器箱体与侧壁上L形升高座之间有强烈的动力相互作用效应,这种动力相互作用放大了安装在L形升高座上的1100kV套管受到的地震作用。为了减小这种动力相互作用影响,用3种方式加固1000kV变压器箱体侧壁上的L形升高座,分析比较了不同加固方式对1000kV变压器抗震性能的影响。与未加固的变压器相比,安装在加固的L形升高座上的1100kV套管基本振动频率最大增大60%,在幅值0.3g标准地震作用下的1100kV套管顶部的最大位移和加速度最大分别减小75%和35%,1100kV套管根部的剪力和弯矩响应最大分别减小40%和30%。加固1000kV变压器箱体侧壁上的L形升高座是一种简单有效提高变压器抗震性能的措施。

In order to evaluate seismic response of ultra-high voltage(UHV) power transformers, a finite element model was developed for a 1000 kV power transformer, whose type transformer is commonly used in UHV transmission and transformation projects. Modal characteristics and seismic response of the 1000 kV transformer were obtained through the finite element analysis. There is a strong dynamic interaction between the 1000 kV transformer tank and L-shaped turret under earthquake action, and this type dynamic interaction magnifies the earthquake motions for the 1100 kV bushing mounted on the top of the L-type turret. To reduce the effect of the dynamic interaction on the seismic response of the 1100 kV bushing, three seismic strengthening methods were used to reinforce the L-type turret, and effects of the reinforcement types on the seismic response of the 1000 kV transformer were compared. Compared to the un-reinforced 1000 kV transformer, the maximum natural vibration frequencies of 1100 kV mounted on the reinforced L-type turret increased by 60%, the maximum relative displacement and acceleration responses at the top of the 1100 kV bushing reduced by 75% and 35%,and the maximum shear force and bending moment response at the base of the 1100 kV of bushing decreased most by 40% and 30%, respectively. Therefore, the reinforcement of the L-type turret installed on the transformer tank sidewall is a simple and effective measure to enhance seismic performance of 1000 kV transformers.