配电网无功优化的分时段控制策略

为改善电压、降低损耗、简化控制，根据负荷水平及其变化趋势，对已装有补偿电容和在变电站装有有载调压变压器的配电网，提出了分时段优化控制的策略，开发了次日运行中电容器投切和调压变压器变比调节的模型和算法。应用改进的退火选择遗传算法，该算法对于每一负荷时段可得出该段的最优运行方式；计算一天所有负荷段即得出次日电容器投切和调压变压器变化调节的运行表。该模型易于满足电容器投切和变压器调节次数的限制。文中还分析了有载调压变压器调节电网电压水平的作用和变压器铁耗的影响。算例结果表明该算法不但能有效地降低电能损耗，而且控制简单。

TIME-INTERVAL BASED CONTROL STRATEGY OF REACTIVE POWER OPTIMIZATION IN DISTRIBUTION NETWORKS

This paper describes a new reactive power optim ization strategy for improving voltage quality,reducing active power losses and simplifying control operations of the distribution systems equipped with on- load tap changer at substations and EE.shunt capacitors.Thus the time- interval control strategy is based on load level and its changing trends.The algorithm, to find proper dispatch schedule for on- load tap changer and shunt capacitors of the next day,is developed.An im proved genetic algorithm with annealing selection is integrated to determ ine the best schedule of each load level. After calculating all load level stages of the next day,a schedule table will be produced for the operation guidance. Moreover,this algorithm can meet constraints of maxim um allowable number of switching operations easily. In particular,effects of voltage and iron loss level of distribution networks in question are also taken into account.Num erical examples show the proposed m ethod can not only effectively reduce power losses and improve voltage quality,but also greatly sim plify control operations.