瓷套管避雷器的多体动力学模型与地震响应分析

为了在优化设计减震装置时减少计算工作量提高计算效率,针对特高压瓷套管避雷器,提出一种新颖的建立低自由度动力学模型的方法。首先,根据试验结果定量分析特高压避雷器的瓷套管与法兰胶装连接处的弹性特性,表明抗弯刚度沿着避雷器的轴向分布很不均匀,为可以离散化弹性特性从而建立避雷器的多体模型奠定基础。其次,将避雷器的每节瓷瓶单元看作刚体单元,设备整体的抗弯特性用法兰连接处的回转弹簧模拟,利用多体动力学理论,建立避雷器设备的多刚体—铰链—回转弹簧模型,并利用铰接点坐标法推导了该系统在地震动激励下的运动方程。最后,以1 000 kV某型号避雷器为算例,进行了静力分析和地震响应时程分析,计算结果与试验结果对比显示二者吻合地很好。结果表明:所提出的避雷器多体模型,形式简单,自由度个数与瓷套管单元个数相等,通常不大于6；利用该方法,方便建立加装减震装置的避雷器设备的动力学模型。该方法还容易推广应用到变电站中其他瓷立柱式电气设备的抗震分析中。

Multibody dynamics model and seismic response analysis for porcelain-housed arrester

To reduce the computational cost and improve the computational efficiency in optimal design of seismic isolation device for ultra-high voltage (UHV) porcelain-housed surge arresters, this paper proposes a novel modeling method for lower degrees of freedom for arresters. The characteristic of the elasticity at the cementing joint between porcelain housing and metallic flange was firstly investigated quantitatively based on test data. It shows that the flexural rigidity distributed unevenly along the axial direction of the arrester, which provides basis for the discretization of elasticity characteristics and the establishment of the multibody model of the arrester. Then, each porcelain unit was taken as a rigid body, and the flexural behavior of the overall system was simulated by torsional springs at flange cementing joint. A model of multibody system with pin-joints and torsional springs was constructed based on the multibody dynamics theory. The joint coordinate method was adopted to derive the governing equations of motion for the multibody system under seismic excitation. Lastly, a 1 000 kV porcelain arrester was modeled by the proposed method, and static analysis and seismic response history analysis were performed. Comparison between calculated results and test results showed a good agreement. Results show that the numbers of degrees of freedom of the multibody system for an arrester was equal to the numbers of its porcelain units, which is usually less than 6. Due to its simplicity in form, it is easy to construct the model of isolated arresters equipped with seismic isolation device by the proposed method. The method can also be easily extended to the seismic analysis of similar column-type porcelain electrical equipment in substation.