基于模糊遗传算法的中低压配电网络联合规划

【作者】 汪卫华；

【导师】 杨期余；

【作者基本信息】 湖南大学 ， 电力系统及其自动化， 2002， 硕士

【摘要】 近几年国家投入巨资进行城网改造，使高压输、配电网的供电能力大大加强，但长期以来因为对中、低压配电网络缺乏足够的重视，致使目前中、低压配电网存在的问题还较多。本文对中、低压配电网电能损耗长期高居不下、电压质量差的问题进行了分析，指出了当前配电网规划存在的问题和配电模式的不合理。分析了现有配电网络规划不同数学模型的优劣性。提出了适合于配电网潮流计算的配电网结构存储方法。从理论上分析了配电网的供电能力，指出了在现有配电模式下配电网的供电能力是比较差的，提出了小容量变压器、多布点、缩短低压供电线路的配电模式，并将这一配电模式与现有配电模式下的常用降损节能措施进行了分析比较，证实了采用这一配电模式的优越性。通过研究还提出对国家标准DL/559—1996的6.5条的修改意见。在已往的电网规划中都只考虑同一电压等级下的网络结构优化，即只考虑同一电压等级下的线路走向和导线截面大小。本文从整体的角度考虑中压和低压配电网络的联合规划，不仅考虑了线路走向和导线截面大小，而且考虑了变压器的布置位置和容量，这是一个比单纯的网架规划更复杂的非线性组合优化问题。本文引入了遗传算法来解决这一问题，提出了采用多条染色体表示一组方案的方法，并对遗传操作过程中的交叉率和变异率进行了模糊控制，有效的加快了搜索速度，避免了不成熟收敛。计算实例表明本文的方法是可行的、有效的。更多还原

【Abstract】 Our country has largely invested in reconstruction of city electric power network in past years. It strength the supply ability of high-voltage network. But there are still many problems in middle and low voltage network result from the neglect of it. In this paper problem that high power loss and bad voltage quality in distribution network is analyzed. The defect of present distribution network planning and distribution model is pointed out. A new distribution model that small capacity transformer and short low voltage line is presented after analyzing the power supply ability of distribution network. It is found that this method is better than that of past through comparison between them. The advice that the fifth item of standard DL/T559-1996 should be modified is also presented. In the past electric power planning is considered only under the same voltage level. In this paper global joint planning for middle and low voltage network is considered. Both line arrangement and cross section and transformer arrangement and rate are considered. It is a non-line combined optimum problem more complex than single network planning. Genetic algorithm is adopted to solve this problem. The method using several chromosomes express a scheme is presented. Crossover rate and mutation rate are automatically adjusted by fuzzy control to quicken search procedure and avoid immature convergence. The result of typical example shows that these measures are feasible and efficient.更多还原