分布式电源接入对配电网电压稳定性的影响研究

发布时间：2018-08-03 11:07

【摘要】：随着人们生活水平的不断提高,配电网负荷也在急剧增长,这意味着配电设备的运行状态越来越接近于极限运行状态,配电网承受负荷增长的能力越来越低,与此同时,大量分布式电源接入配电网,这使得配电网的运行更加复杂,配电网的电压稳定面临挑战。因此,有必要对分布式电源接入对配电网电压稳定性的影响进行研究和分析,为分布式电源高渗透率接入配电网提供理论基础和决策参考。本文在改进连续潮流算法的基础上,开展了不同类型的分布式电源在不同并网条件下对配电网静态电压稳定性的影响研究,主要完成工作如下：给出了灵敏度矩阵和戴维南等效阻抗矩阵的定义,建立了含分布式电源的配电网中各电力元件的详细模型,同时将PQ节点和PV节点的双向转换逻辑考虑在内,形成了一种针对含分布式电源的配电网潮流计算的基于灵敏度矩阵的前推回代潮流算法。根据配电网的结构和运行特性提出了一种针对配电网电压稳定分析的三相连续潮流算法。算法主要完成了预测环节和校正环节两方面的改进,其中预测环节采用了拉格朗日二阶插值算法对配电网的下一个运行状态进行预测,有效提高了预测环节的预测速度和计算精度；校正环节采用基于灵敏度矩阵的前推回代算法对预测结果进行校正,解决了牛顿-拉夫逊潮流算法应用到配电网中存在对初值敏感、收敛性差等的问题。在此基础上,采用局部参数化方法追踪配电网各节点的PV曲线,从而准确计算出配电网的静态电压稳定裕度。以改进连续潮流算法为分析工具,将不同类型的分布式电源以不同的并网容量、并网位置和并网方式接入配电网,通过实例计算含不同类型的分布式电源在不同并网条件下的配电网的静态电压稳定裕度完成了分布式电源接入对配电网静态电压稳定性的影响分析,所得结论为配电网中分布式电源的运行、规划起到一定的指导作用。从配电网电压安全的角度出发,采用优化方法,在分析分布式电源接入对配电网静态电压稳定性影响的基础上,形成了以分布式电源有功功率最大为上层优化目标,以满足配电网静态电压稳定裕度、节点电压和支路电流等约束条件为下层优化目标的双层优化模型。算法结果表明所提出的准入功率计算模型的有效性。
[Abstract]:With the continuous improvement of people's living standard, the load of distribution network is also increasing rapidly, which means that the operating state of distribution equipment is more and more close to the limit operation state, the ability of distribution network to bear the load growth is becoming lower and lower, at the same time, A large number of distributed power sources are connected to the distribution network, which makes the operation of the distribution network more complex, and the voltage stability of the distribution network faces challenges. Therefore, it is necessary to study and analyze the influence of distributed power access on the voltage stability of distribution network, so as to provide the theoretical basis and decision-making reference for the distribution network with high permeability of distributed generation. Based on the improved continuous power flow algorithm, this paper studies the influence of different types of distributed power generation on the static voltage stability of distribution network under different grid-connected conditions. The main work is as follows: the definition of sensitivity matrix and Thevenin equivalent impedance matrix are given, and the detailed models of each power element in the distribution network with distributed generation are established. Considering the bidirectional conversion logic of PQ node and PV node, a forward backward power flow algorithm based on sensitivity matrix for power flow calculation of distribution network with distributed generation is proposed. According to the structure and operation characteristics of distribution network, a three-phase continuous power flow algorithm for voltage stability analysis of distribution network is proposed. The algorithm mainly improves the prediction and correction, in which the Lagrange second-order interpolation algorithm is used to predict the next running state of the distribution network. The prediction speed and accuracy are improved effectively, and the prediction results are corrected by using the forward and back algorithm based on sensitivity matrix. Newton-Raphson power flow algorithm is used to solve the problems of sensitivity to initial value and poor convergence in distribution network. On this basis, local parameterization method is used to track PV curves of each node in distribution network, and the static voltage stability margin of distribution network is calculated accurately. With the improved continuous power flow algorithm as the analysis tool, different types of distributed generation are connected to the distribution network with different grid-connected capacity, grid-connected position and grid-connected mode. By calculating the static voltage stability margin of distribution network with different types of distributed power supply under different grid-connected conditions, the influence of distributed power access on the static voltage stability of distribution network is analyzed by an example. The conclusion can be used as a guide for the operation of distributed generation in distribution network. Based on the analysis of the influence of distributed power access on the static voltage stability of distribution network, from the point of view of voltage security of distribution network, the optimization goal of maximum active power of distributed power supply is formed by using the optimization method, which is based on the analysis of the influence of distributed power access on the static voltage stability of distribution network. The bilevel optimization model is designed to satisfy the static voltage stability margin, node voltage and branch current constraints. The results show that the proposed model is effective.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM712

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