三相不平衡配电网线性潮流模型及最优潮流研究

论文总字数：26549字

摘 要

随着配电网规模增大，电网用户数量增加，加上大量诸如风机光伏等可再生能源的高比例并网，配电网呈现三相不平衡严重、集中和分布式发电并行，不同区域间弱环耦合等特点。研究配电网在三相不平衡条件下的潮流分布和最优运行域，对配电网的安全运行和优化调度具有重要意义。本文在计及配电网的三相不平衡特征的条件下，分别展开三相不平衡配电系统的潮流计算分析和最优运行域求解，主要工作为：

第一，基于节点注入模型，构建了三相不平衡配电网的潮流模型，介绍了三相导纳矩阵构建的过程，并对相应的求解算法进行研究。从传统角度基于牛顿法进行求解计算，从线性化角度基于复平面下的线性近似方法，求得线性潮流计算模型的近似解，由于线性近似方法解开了电压与无功间的耦合，无需迭代，使计算速度大大提升。

第二，在最优潮流方面，基于经典优化理论分别建立了无功优化模型和有功无功协调优化模型，使用内点法寻找配电网运行的最优解，并在上述线性化近似方法的基础上，将优化模型改进为线性无功优化模型和线性化协调优化模型，将优化模型进行线性化提高了模型的凸性，使得寻找到的解为全局最优，且减少了计算收敛时间。

关键词：配电网；三相不平衡；线性潮流计算；无功优化；协调优化

Abstract

As the scale of the distribution network increases, the number of users increases, and a large number of renewable energy sources such as wind turbines and photovoltaics are connected to the grid, resulting in features such as serious three-phase imbalance in the network, centralized and distributed power generation in parallel, weak loop coupling among different regions. Studying the power flow and optimal operating domain of the distribution network under three-phase unbalanced conditions is of great significance to the safe operation and optimal scheduling of the distribution network. In this paper, under the condition of considering the three-phase unbalance characteristics of the distribution network, the power flow calculation analysis and the optimal running domain solution of the three-phase unbalanced power distribution system are respectively developed. The main work is as follows:

Firstly, based on the node injection model, the power flow model of the three-phase unbalanced distribution network is constructed. The process of constructing the three-phase admittance matrix is ​​introduced, and the corresponding algorithm is studied. From the traditional point of view, the Newton method is used to solve the calculation. From the linearization angle based on the linear approximation method under the complex plane, the approximate solution of the linear power flow calculation model is obtained. Since the linear approximation method solves the coupling between voltage and reactive power, no iteration is needed, so that the calculation speed is greatly improved.

Secondly, in terms of optimal power flow, based on the classical optimization theory, the reactive power optimization model and the active and reactive power coordination optimization model are respectively established. The interior point method is used to find the optimal solution of the distribution network operation. Based on the above linear approximation method, the improvement of the optimization model to the linear reactive power optimization model and the linearized coordinated optimization model are proposed, linearizing the optimization model improves the convexity of the model, making the found solution globally optimal and reducing the computational convergence time.

KEY WORDS: Three-phase unbalance; Linear power flow calculation; Reactive power optimization; Coordinated optimization

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1课题研究的背景及意义 1

1.1.1课题的研究背景 1

1.1.2课题的研究意义 1

1.2课题的研究现状 2

1.2.1配电网确定性潮流计算方法 2

1.2.2配电网最优运行域的研究 3

1.3论文的主要工作 4

第二章 三相不平衡配电网潮流分析 6

2.1引言 6

2.2节点注入模型 6

2.3三相不平衡配电网潮流模型 7

2.4三相不平衡配电网潮流求解算法 8

2.4.1牛顿-拉弗逊算法 8

2.4.2线性化近似潮流算法 11

2.5算例分析 12

2.5.1牛顿-拉弗逊算法验证 13

2.5.2线性化潮流近似算法验证 13

2.6本章小结 14

第三章 三相不平衡配电网的最优潮流及无功优化 15

3.1引言 15

3.2最优潮流在配电网优化运行中的意义 15

3.2.1最优潮流对配电网潮流分布的影响 15

3.2.2最优潮流对配电网电压的影响 15

3.2.3最优潮流对配电网有功网损的影响 16

3.3经典最优潮流模型 16

3.3.1变量集合 16

3.3.2目标函数 16

3.3.3约束条件 17

3.4无功优化模型 17

3.4.1经典无功优化模型 17

3.4.2基于线性化潮流模型的无功优化模型 18

3.5求解算法 19

3.6算例分析 19

3.6.1经典无功优化模型求解 19

3.6.2线性化无功优化模型求解 22

3.7本章小结 24

第四章 三相不平衡配电网的有功无功协调优化 25

4.1引言 25

4.2有功无功协调优化模型 25

4.2.1经典协调优化模型 25

4.2.2基于线性化潮流模型的协调优化模型 26

4.3算例分析 27

4.4本章小结 29

第五章 总结与展望 30

5.1总结 30

5.2展望 30

参考文献 32

致 谢 34

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