基于组合赋权和BP神经网络的500kV交流输电线路电磁环境评估方法研究

Study of 500kV AC transmission line electromagnetic environment evaluation method based on combination empowerment and BP neural network

针对超高压输电线路日益突出的电磁环境问题,研究了基于BP神经网络原理的输电线路电磁环境评估方法。在国内外现有规定和推荐标准的基础上制定了跨越居民区、公路和农田等不同地区的超高压输电线路电磁环境等级标准。以华中电网500kV交流输电线路的实测数据为例,运用组合赋权的思想确定了工频电场、工频磁场、无线电干扰和可听噪声的权重,并将这四项指标作为输入变量,电磁环境评估等级作为输出变量,建立三层结构的BP神经网络评估模型。模型中考虑了单个地区的电磁环境评估和不同地区人口权重修正的整条线路电磁环境综合评估。评估结果表明,基于BP神经网络电磁环境评估方法能够较准确地评估500kV交流输电线路附近的电磁干扰情况,可为输电线路电磁环境评估提供参考。

In view of the increasingly prominent problem of electromagnetic environment for the ultra high voltage transmission line,the paper studies the electromagnetic environment evaluation method of UHV transmission line which is based on the BP neural network theory. On the basis of the existing regulations and recommendations at home and abroad,the electromagnetic environment grading standards of EHV transmission lines across residential areas,roads,farmland are established. Using the measured data of Central China Power Grid 500 kV line as an example,the weights of power frequency electric field,power frequency magnetic field,radio interference and audible noise are determined on combined weights,and these four indicators are used as input variables and electromagnetic environment assessment level as the output variable,the BP neural network of three layers structure evaluation model is set up. The evaluation system includes the electromagnetic environment evaluation of a single and the whole transmission lines which across different regions and considering population weight correction. Evaluation results show that the electromagnetic environment evaluation method based on BP neural network can accurately assess the electromagnetic interference of 500 k V line and can be used as a reference for EHV transmission line electromagnetic environment assessment.