【作者】 摄伟；

【导师】 刘健；

【作者基本信息】 西安科技大学 ， 电力系统及其自动化， 2008， 硕士

【摘要】 电力系统无功优化是保证电力系统经济运行的一项有效手段,也是提高电压质量的重要措施。本文对基于禁忌搜索算法的区域电网无功优化算法进行了研究并实现了通用应用软件。针对某一确定时刻的电力系统无功优化问题,建议了一种改进禁忌搜索算法,建立了综合考虑网络损耗和电压质量两方面因素的目标函数,以电压约束、电气极限约束和控制约束为约束条件,以变压器档位、电容容量和发电机的端电压为控制变量,解向量采用十进制编码,并采用扩展邻域搜索策略,以便于更容易跳出局部最优解。基于禁忌搜索算法,提出了一种根据预测负荷曲线进行一天内无功优化的改进方法。该算法将时间分段中的起始点和该分段中的控制变量一同构成解向量,从而避免了先进行时间分段的优化,后进行无功优化的二次优化,达到了从整体上进行优化的效果;当邻域解普遍陷入不符合电压约束条件的不可行解区域时,将目标函数切换为以当前电压偏离额定电压最小为目标,确保搜索可以正常进行并逐渐进入可行解区域。当邻域解普遍回到可行解区域后,将目标函数重新切换回以全天内电能损耗最小为目标。上述切换目标函数的措施,有效地确保了优化搜索不会因陷入不可行区域而终止。采用VC++6.0实现了基于上述算法的通用应用程序,并应用于SCADA系统中。采用IEEE6节点、IEEE14节点和IEEE30节点系统作为算例进行测试,结果表明本文提出的算法是可行的和有效的。更多还原

【Abstract】 Optimization of the reactive power in power system is an effective means to guarantee the economic operation and high voltage quality. Improved approaches based on Tabu search algorithm are investigated and the corresponding application software is programmed.As for the problem of reactive power optimization at a certain instant, an improved Tabu search algorithm is suggested. The index considering both losses reduction and high voltage quality is established. The constraints include voltage requirements, electrical limitations of apparatus and control restrictions. The transformer taps, capacitor capacity and generator terminal voltage are used as the control variables. The solution vector is decimal coded. An expanding neighborhood searching approach is used to escape from the local optimal solution.Based on Tabu search algorithm, an improved reactive power optimization within a day using the load forecasting results is presented. The solution is composed of the beginning time and the control variable of each time-interval. It can avoid the problem of twice optimization process, in which, the time-intervals are optimized at first and the reactive power is optimized based on each time-interval. So, the proposed method has the performance of optimizing the reactive power and time intervals simultaneously. In the cases of the neighborhood solutions falling into infeasible area, i.e., the voltage constraints are not satisfied, the index is switched to the voltage quality, so as to guarantee the searching process can work and gradually reach the feasible area. Once neighborhood solutions returning to feasible area, the index is switched back to losses reduction during the whole day.The application software based on above approaches are realized on the platform of VC++6.0, which has been used in the SCADA systems. IEEE4 system, IEEE14 system and IEEE30 system are used as test examples. The results of testing show that the proposed approaches and the application software are feasible.更多还原