风电系统距离Ⅲ段保护动作特性分析  

Operation Characteristics Analysis of Zone 3 Distance Protection in Wind Power Systems

作　　者：李生虎[1] 贾树森[1] 孙莎莎[1] 

机构地区：[1]合肥工业大学电气与自动化工程学院,安徽省合肥市230009

出　　处：《电力系统自动化》2011年第5期31-35,41,共6页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(50707006);教育部新世纪优秀人才支持计划资助项目(NCET-08-0765)~~

摘　　要：研究了异步发电机对输电线路距离Ⅲ段保护动作特性的影响。基于设定的定子电压,给出异步发电机理论阻抗。建立区分定、转子回路的风电系统潮流算法,计算异步发电机实际阻抗。根据风电系统节点电压对输入机械功率的灵敏度,以及保护动作裕度对节点电压的灵敏度,建立保护动作裕度对输入功率的线性关系。计算结果表明:异步发电机呈现负电阻、正电抗特性,使得线路远风电场节点测量阻抗类似反向故障;输入机械功率增加和定子电压降低,将减小异步发电机阻抗模值,降低保护动作裕度;风电场附近负荷增长,可能大幅降低线路远风电场节点距离Ⅲ段保护动作裕度。The impact of induction generators on operation characteristics of zone 3 distance protection is studied.The theoretical impedance of a induction generator is quantified with fixed stator voltage.The actual impedance is derived with a newly proposed load flow model which differentiates the stator and the rotor circuits.From the sensitivity model of bus voltage to mechanical input power,and that of operation margin of zone 3 relay to bus voltage,the linear relationship of operation margin to input wind power is derived.Numerical results show that： the induction generator has a characteristic of negative resistance and positive reactance,yielding the apparent impedance of the far-end wind farm bus similar to the backward fault;the increment of mechanical input power corresponds to lower stator voltage,lower machine impedance magnitude,and lower operation margin;the load increment near wind farms may notably decrease the operation margin of zone 3 impedance relay of the far-end wind farm bus.

关 键 词：距离Ⅲ段保护 异步发电机 动作裕度 灵敏度模型 风电系统 

分 类 号：TM315[电气工程—电机]