多OLTC协调动作对电压稳定影响的定量评估方法  

Quantitative evaluation method of voltage stability affected by multi-OLTC coordination

作　　者：李国强 刘光晔[1] 侯龙宇 金龙 杨亚乔 LI Guoqiang;LIU Guangye;HOU Longyu;JIN Long;YANG Yaqiao(College of Electrical and Information Engineering, Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学电气与信息工程学院

出　　处：《电力自动化设备》2019年第7期154-160,共7页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(51577053)~~

摘　　要：为定量评估复杂系统中多台有载调压变压器(OLTC)调节对系统电压稳定的影响,根据非线性方程极值分析原理,推导出了网络传输功率极限的必要条件,提出可以评价负荷节点电压稳定性的法向阻抗模裕度指标(NIMMI)。基于法向动态等值阻抗模,提出了可以动态跟踪系统节点间联系紧密性程度的电气耦合系数指标。针对含OLTC的非线性电力系统特点,考虑变比的影响,在牛顿-拉夫逊法求解潮流方程组的基础上,对初始状态下使潮流计算收敛的雅可比矩阵进行修正,计算节点动态等值参数,并进一步提出了计及负荷特性和OLTC调压效应的NIMMI。所提出的NIMMI能精确地量化分析复杂系统中多OLTC协调动作对电压稳定的综合影响,可以作为全网OLTC协调动作方案及变比调节范围的合理性评价依据。电气耦合系数指标能准确有效地识别出电压失稳速度较快的关键节点。最后,通过IEEE14节点系统的仿真结果验证了分析方法的有效性和正确性。In order to quantitatively analyze the effect of OLTC(On-Load Tap Changer) regulation on voltage stability in complex systems,according to the principle of extremum analysis of nonlinear equations,the necessary conditions for the network transmission power limit are deduced,and the NIMMI(Normal Impedance Modulus Margin Index) is proposed to analyze the voltage stability of load nodes. Based on the normal dynamic equivalent impe-dance,the electrical coupling coefficient index that can dynamically track the degree of contact tightness between nodes of the system is proposed. Considering the characteristics of nonlinear power system with OLTC,taking into account the effect of transformation ratio,based on the Newton-Raphson method for solving the power flow equations,the Jacobian matrix for the convergence of load flow calculation in the initial state is modified to calculate the dyna-mic equivalent parameters of nodes,and the NIMMI which takes into account load characteristics and OLTC voltage regulation effects is further proposed. The proposed NIMMI can accurately quantify and analyze the comprehensive influence of multi-OLTC coordinated action on the system voltage stability in a complex system,and can be used for assessing the rationality of the OLTC coordinated operation scheme and transformation ratio adjustment range of the entire network. The electrical coupling coefficient index can identify the key nodes with fast voltage instability accurately and effectively. The simulative results of the IEEE 14-bus system verify the effectiveness and correctness of the proposed analysis method.

关 键 词：电力系统 电压稳定 法向阻抗模裕度指标 有载调压变压器 动态等值 

分 类 号：TM761[电气工程—电力系统及自动化]