无功补偿及其对电力系统电压稳定性影响的分析

【作者】 杨腾栋；

【导师】 彭志炜；

【作者基本信息】 贵州大学 ， 电力系统及其自动化， 2007， 硕士

【摘要】 电压是电能质量的重要指标之一，网损是电力企业的一项重要综合性技术经济指标。长期以来电力系统网络损耗问题比较突出，而无功补偿是降低线损的有效手段。随着电力系统负荷的增加，对无功功率的需求也日益增加。在电网中的适当位置装设无功补偿装置成为满足电网无功需求的必要手段。提高电压质量、降损节能是供电企业当前的工作重点之一。对电网给予合理的无功补偿，能够有效地维持系统的电压水平，降低有功网损，提高网络输送容量满足负荷的无功需求。论文首先从无功功率不足带来的危害说明无功补偿的必要性，从节约能源的角度说明无功补偿的重要性，然后论述了无功补偿的发展历史和发展现状，介绍了无功补偿原理，分析了电压失稳的机理和电压稳定的分析方法。电力系统稳定问题的物理本质是系统中功率平衡问题，无功的缺额是电压失稳的本质原因。节点负荷功率的变化会引起电力系统的运行状态发生变化。当节点负荷增加到一定值时，系统结构稳定性就会发生变化，出现分叉现象。本文基于分叉理论、诱导向量场和数值计算方法提出一种改进确定电压稳定分叉值的方法，可以求出系统的静态分叉点和系统的节点负荷临界值。该方法还可以避免在临界点附近收敛困难的问题。通过对一个IEEE₃0节点的系统证明了该方法的有效性。并且应用这种改进方法对IEEE₃0节点的系统在无功补偿方式下进行了无功补偿对电力系统电压稳定性影响的分析。更多还原

【Abstract】 Voltage is one of important quality index of electric power system. Power loss is an important synthesis technical and economic index of power companies. In the past several years, the problem of power loss is very serious. However, reactive compensation is an effective method to save power loss. Due to increasing loads of electric power system, demand of reactive power was also increasing. It became necessary means that reactive power compensation devices were installed in proper position of electric network. Currently, improving voltage quality and saving power loss have been job emphasis of power companies. The reasonable reactive power compensation of distributing net can effectively maintain the voltage level, decrease the network loss and raise the transmission capacity.At first the necessity of reactive compensation aiming directly at the harm of reactive power is illustrated in this paper. And the importance of reactive compensation focusing on energy sources is emphasized. The paper also states the history and the present situation of reactive compensation according to the facts of china, introduce the principle of reactive compensation and analyzes the mechanism of the voltage stability. The physical essence of the power system stability issue is the power balance .The lack of reactive power is the reason of the voltage unstability. When nodes load increases, the system’s run state will change also. When the load increase to a critical point, the power system’s structural stability will change, the power system will appear bifurcation phenomenon. Based on the bifurcation theory and induced vector field conception, this paper give an algorithm which can search for the static bifurcation points and the critical point of node’s load. This algorithm avoids the difficulty happen near the bifurcation point. Used this algorithm to calculate and analysis a IEEE power system that have thirty nodes, it testify this algorithm is valid. Apply this algorithm to calculate and analysis a IEEE₃0 power system that have reactive compensation, it analyzes that the reactive compensation affect voltage stability of power system.更多还原