覆冰架空导线舞动跳闸概率计算新方法

覆冰导线的舞动严重威胁着电力系统安全稳定运行，如何准确地计算覆冰导线舞动导致的输电线路跳闸的概率成为备受关注的研究课题之一。提出了基于舞动运动方程、气象信息及故障信息相结合的覆冰导线舞动的跳闸概率计算新方法。首先由风速与冻雨量的历史样本获得风速与冻雨量的概率分布函数，然后根据牛顿定律建立了覆冰导线的单自由度舞动模型；进而，采用里茨-伽辽金方法求解舞动模型，获得了以风速和覆冰厚度为自变量的舞动幅值解析表达式；基于已获得的风速与冻雨量的概率分布函数，获得与二者为函数关系的覆冰厚度的概率分布函数，进而获得舞动幅值的概率分布函数；最后，根据覆冰舞动跳闸的历史故障记录所获得的泊松分布求得覆冰导线舞动幅值越限及短路故障的联合概率，结合贝叶斯公式获得舞动幅值越限条件下的覆冰导线舞动跳闸概率。算例证明了该方法的正确性及有效性。

A New Method for Calculation of Transmission Line Tripping Probability Caused by Galloping of Iced Overhead Conductor

The galloping of iced conductors seriously threatens the safety and stability of power systems, so it has become a focus for research to accurately calculate the transmission line tripping probability caused by the galloping of iced conductors. A new tripping probability calculation method is proposed based on the galloping equation, meterological information and fault information. Firstly, the probability distribution functions of wind speed and frozen rainfall are obtained using their respective historical samples; next, a single-degree-of-freedom galloping model of iced conductors is built according to the Newton law; and then, the Ritz-galerkin method is utilized to solve the galloping model to acquire the analytical expression of the galloping amplitude with the wind speed and icing thickness as independent variables; furthermore, the probability distribution function of icing thickness, which is the function of wind speed and frozen rainfall, is calculated using the probability distribution functions of wind speed and frozen rainfall, and then the probability distribution function of galloping amplitude is also calculated; finally, according to the Poisson distribution obtained by the historical fault records of galloping-caused tripping, the joint probability for the over-limit of galloping amplitude and the short-circuit fault is obtained, and the galloping-caused tripping probability of iced conductors is calculated using the Bayesian formula under the condition of over-limit of galloping amplitude. Case study has proved the effectiveness of the proposed method.