减小架空输电线路不平衡度的研究和措施

Research and Countermeasure of Reducing Imbalance of Overhead Transmission Line

输电线路因线间及对地位置不对称,造成线路参数不平衡,影响线路输送电能质量及电网安全运行。通过对影响线路不平衡度因素(包括相序排列方式、相间距离、输送功率、运行电压及大地导电率等)的计算分析,并对上述因素的所占比例、影响大小进行统计分析得出结论:针对影响电流不平衡度的最大因素比选合适的相序排列方式可有效降低电流不平衡度。通过技术经济比较、综合分析优化相序排列方式,在对比选优相序排列方式下通过软件计算并综合考虑投资与线路电流不平衡度减小至满足要求范围内的最佳相序排列。通过上述研究分析,采取有效措施以减小输电线路电流不平衡度,从而产生良好的社会效益及经济效益。

The imbalance of transmission line parameters caused by asymmetry between line to line or line to earth could affect quality and operation of power grid. The unbalance factors including the phase sequence, phase distance, transport power,running voltage and ground conductivity etc. were analyzed. Statistical analysis conclusion was given through the factors affecting proportion and arrangement. According to the influence of current unbalance factor analy- sis, selecting a proper phase sequence could effectively reduce the current unbalanced degree. By comparison of tech- nology and economy, comprehensive analysis of the optimization phase order arrangement, in contrast to selection phase sequence by software calculation and considering the investment and the line current unbalance was reduced to meet the requirements of the best sequence. Through these research and analysis, effective countermeasures were point out to reduce the transmission line current imbalance for good economic and social benefits.