城市高压配电网负荷转供控制策略研究

发布时间：2018-04-04 02:56

本文选题：高压配电网　切入点：负荷转供　出处：《西南石油大学》2017年硕士论文

【摘要】：国民经济的迅猛发展,伴随着城市负荷的快速增长,使得城市负荷密度大幅度提高,然而滞后的高压配电网的工程建设与负荷的实际增长产生了脱节,在迎峰度夏或度冬等大负荷期间,城市高压配电网的负载分配极不均衡,在运行期间易造成主变过载,输电断面阻塞等情况,影响高压配电网的安全稳定运行,这种情况下,地区调度员往往会进行频繁的甚至于大面积的负荷转供操作。现实中由于缺乏足够的理论指导,他们在进行转供的时候,多是基于经验或试凑的方式将负载率高的某些220kV变电站所带的负荷转移到其他有联络关系的负载率较低的主变上去。但在面对结构越来越复杂,负荷越来越重的城市高压配电网,调度员显得把控力不足。因此,急需提出一种有效的高压配电网负荷转供策略以辅助调度员进行决策。本文从模型和算法着手,对高压配电网的负荷转供问题进行了研究分析。负荷转供也属于重构优化研究范畴,传统的重构问题多是以中低压配电网为研究对象,以基于开关0-1状态变量进行重构建模。但由于高压配电网与中压配电网相比有明显的结构性,可控性差异,因此,中低压配电网的重构策略对高压配电网并不适用。本文从高压配电网的拓扑结构特点出发,根据其站内站间的联络关系,抽象出了功能单元,并将相互之间有联系的功能单元划分成一个单元组,改变组内的拓扑结构,就间接的改变了各电源点的负载率,因此,以单元组为对象进行重构建模。这样就将重构整个网络的开关问题转化成了单元组拓扑状态选择问题,实现了降维.为了选择出合适的可行拓扑状态,提出了一种负荷转供的分层优化模型,在上层优化模型中,形成一种各单元组的负载预分配方案,计算均衡度,再在下层优化模型中,枚举单元组的可行拓扑状态,并找出最贴近上层的拓扑状态,利用优化算法的迭代更新机制,找到主变负载均衡的情况下最贴近他的实际拓扑状态。高压配电网的负荷转供模型求解是一个复杂的优化问题,选择智能算法求解这一问题是一种有效的策略,本文采用了近年来新兴的一种智能优化算法—教与学优化算法(TLBO),该算法具有参数少,原理简单,易于编程且收敛速度快的优点,在求解优化问题时,显示了十足的优势。为了避免在求解高维的复杂优化问题时陷入局部最优解,本文在基本的算法中引入了差分进化算法(DE)的交叉操作,以提高算法的搜索精度,与其他的智能算法进行了验证分析比较,结果表明改进算法的有效性。并将该算法用于负荷转供优化模型的求解。最后,利用提出的模型和算法,对某城市高压配电网局部系统进行了算例分析,验证了转供策略的有效性。
[Abstract]:The rapid development of the national economy, with the rapid growth of the city makes the city load, load density is greatly increased, but the actual growth of engineering construction and the load of high voltage distribution network lag produced in line, during the peak summer or winter, high load and load distribution of city high voltage distribution network is not balanced, easy to the main transformer caused by overload during operation, transmission section blocking etc., affect the safe and stable operation of high voltage distribution network, in this case, the dispatcher will often frequent the area even in large area for load transfer operation. In reality due to the lack of sufficient theoretical guidance, they in turn for the more some of the 220kV substation based on experience or try the high load rate of the load transfer to other contact load main transformer low up. But in the face of more and more complex structure, negative City high voltage distribution network load more and more heavy, the dispatcher is to control the power shortage. Therefore, it is urgent to put forward a decision for high voltage distribution network load transfer for effective strategies to assist the operator in this paper. From the model and algorithm to the high voltage distribution network for load transfer problems are analyzed. The load transfer is the research category of optimization reconstruction, reconstruction of the traditional is in low voltage distribution network as the research object, to switch 0-1 state variables based on the reconstruction model. But because of the high pressure distribution network and distribution network than the obvious structural controllability, difference, therefore, the reconstruction strategy of low voltage distribution network is not suitable for high voltage distribution network this paper. From the topology characteristic of the high voltage of power network, according to the contact relationship between the station station, abstracted functional units, and will have the relationships between functional units into a Unit group, change the topology within the group, he indirectly changed the load rate of the power point, therefore, to reconstruct the unit group as the object modeling. This will transform the entire network reconfiguration switch to select the topology state element group, realize dimensionality reduction. In order to choose a feasible topology suitable condition the proposed a hierarchical optimization model for load transfer, in the upper level optimization model, the formation of a pre load distribution scheme of each unit group, calculate the equilibrium degree, then in the optimization model, the feasible topology state enumeration unit group, and find out the most close to the top of the topological state, using iterative optimization algorithm the update mechanism, find the main transformer load balance under the condition of the most close to his actual state. The topology of high voltage distribution network for load transfer model is a complex optimization problem, intelligent algorithm to solve this problem is An effective strategy in this paper, a new intelligent optimization algorithm and optimizing the teaching method (TLBO), the algorithm has less parameters, simple principle, easy programming and fast convergence, in solving the optimization problem, show full advantage. In order to avoid falling into local optimal solution in solving complex high dimensional optimization problems, in this paper the basic algorithm introduces differential evolution algorithm (DE) of the crossover operation, to improve the search accuracy, compared with other intelligent algorithms is verified, results show the effectiveness of the improved algorithm. And this algorithm is used to solve the load transfer optimization model. Finally, using the proposed model and algorithm, the local system of a city high voltage distribution network is analyzed and verified the effectiveness of the transfer strategy.

【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM727.2

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