【作者】 刘伟良；

【导师】 黄纯；

【作者基本信息】 湖南大学 ， 电力系统及其自动化， 2005， 硕士

【摘要】 如何科学利用和优化配置配电网络的无功资源,降低运行损耗,提高供电质量,越来越受到关注和重视。配电网络电压/无功优化可以有效地解决上述问题。现今,针对配电网的电压/无功优化研究主要是在局部优化方面,所以针对多电压等级配电网络的电压/无功优化全局问题进行深入的研究具有很强的现实意义。 本文工作的重点在以下三个方面:首先,针对计算配电网络潮流的前代后代法进行了几个方面的改进;然后,提出了基于线性规划内点法的电压/无功优化控制模型和算法;其次,将遗传算法应用到配电网的无功优化中。 针对前代后代法在处理环路和PV节点方面的不足,本文提出了一种基于叠加原理的用于计算环状配电网潮流的改进算法,通过不断修正解环点支路功率达到整体收敛;而用修正PV节点无功的方法处理PV节点问题。另外,还提出了一种基于节点邻接表的节点编号方法。 对于电压/无功全局优化问题,针对高中压配电网的特点,将问题分解成电容器投切和变压器分接头调整两个子问题,通过这两个子问题的交替优化来得到最终解,适当简化电压约束从而提高了求解速度。采用原对偶路径跟踪法求解逐次线性化了的电容器投切优化问题时,采用了一些如模型的等值变换、内点法初始可行解的求法、归整改进措施。变压器调整则采用逐步调整策略来实现电压控制和减少调整次数。 在基本遗传算法(SGA)的基础上,提出改进型遗传算法用于配电网无功优化计算。模拟退火选择保证了群体的多样性和避免陷入局部最优;用自适应交叉和变异率来确保迭代稳定和促进全局最优;采用十进制编码、并逐代记录最优个体来加快计算速度。更多还原

【Abstract】 How to utilize and distribute reactive power resources rationally and scientifically, reduce and operating losses, improve power supply quality, is being paid more and more attention. Voltage/reactive power optimization in distribution network can solve the above-mentioned problems. Now, the researches of voltage/reactive power optimization in distribution network are local optimization. So that to the distribution network especially many voltage grade voltage, carrying on deep research about voltage/reactive power optimization problem in distribution network have many practical meanings.The focal point of the work of this paper is in the three following respects: First of all, forward/backward sweep method is improved on some aspects to calculate power flow of distribution network; Secondly, model and algorithm about voltage/reactive power optimization is proposed based on linear programming interior-point; Last, genetical algorithms is applied in distribution network voltage/reactive power optimization.Aiming for the disadvantages of the forward/backward sweep method in dealing with meshed distribution networks and PV nodes, an improved power flow algorithm based on the superposition principle for meshed distribution networks through revising power flow of the unlinked point continuously and correcting the reactive power of the PV nodes are proposed in this paper. Moreover, a bus-labeling method based on the adjacent nodes table is presented.Considering the characteristics of the high-medium voltage level distribution networks, the voltage/reactive power optimization (VRPO) is divided into two sub-problems: switching capacitors and adjusting tap ratios of transformers. The final result of the VRPO is gotten by alternatively solving the two sub-problems together. The algorithm is fastened by simplifying the constraints of node-voltages. Capacitor switching is formulated with the successive linear primal-dual interior-point programming algorithm which is improved in some aspects: transforming the model equivalently, solution the initial interior-point and integer problem etc. While taps adjusting is processed through the step-adjusting strategy to control the voltage and to reduce the tap-changing times.更多还原