置信域算法在输电线路覆冰不平衡张力计算中的应用及不平衡张力的影响因素

Application of Trust Region Algorithm in Calculation of Unbalanced Tension Caused by Ice Covered on Transmission Lines and Influencing Factors of Unbalanced Tension

输电线路覆冰不平衡张力计算是验算杆塔强度、检验各档导线应力和对地距离的前提条件。针对覆冰不平衡张力数学模型的高维、强非线性等特点,选用具有强鲁棒性的Trust Region优化算法完成模型求解。算例和大量仿真结果显示,该算法可得耐张段各档应力、档距增量和高差增量的高精度解。在模型和算法准确性得到验证之后,计算了不同冰区和覆冰不平衡率下最大不平衡张力百分比,进一步分析了不平衡张力随导线安全系数、悬垂串串长、档高差等因素的变化规律,可用于解决覆冰线路的优化设计、安全运行和事故分析等问题。

As the precondition of checking the calculation of tower strength and examining conductor stresses and clearances to ground of spans, the unbalanced tension of ice-covered transmission line should be computed. In view of such features of the mathematical model for unbalanced tension of ice-covered transmission line as high dimension and strong nonlinearity, the Trust Region optimization algorithm that possesses strong robustness is chosen to solve the model. Results of calculation and a lot of simulation show that using this algorithm the high-precision solutions of stresses of spans, increments of spans and increments of height differences can be obtained. After the validation of the model and the accuracy of the algorithm, the percentages of maximum unbalanced tensions in different ice areas and under different unbalance rates are computed, and the variation law of unbalanced tension with the factors such as safety coefficient, length of suspension insulator string and height differences of spans is further analyzed. Results of this research could be used to optimization design, safety operation and fault analysis of ice-covered transmission lines.