计及撬棒保护的双馈风电机组不对称短路电流特性分析  

Unsymmetrical short circuit current analysis of doubly fed induction generators with crowbar protection

作　　者：郑涛 魏占朋 李娟 王皓靖[2] 

机构地区：[1]新能源电力系统国家重点实验室华北电力大学,北京102206 [2]华北电力科学研究院有限责任公司,北京100045

出　　处：《电力系统保护与控制》2014年第2期7-12,共6页Power System Protection and Control

基　　金：国家高技术研究发展计划(863计划)资助项目(2012AA050208)~~

摘　　要：电网故障时,双馈式感应风电机组(DFIG)在机端电压深度跌落过程中表现出的电磁暂态特性十分复杂。计及撬棒保护的DFIG不对称短路特性研究较少,为了准确描述机端电压深度跌落过程中DFIG不对称短路电流变化特性,基于空间矢量和序分量法,建立了双馈感应电机的正、负序数学模型。在考虑双馈风电机组不同初始运行功率的情况下,通过数学解析的方法推导了撬棒保护电路投入后定转子正、负序磁链的计算表达式,在此基础上得到了定、转子电流的解析表达式。该方法同样适用于对称性故障时DFIG短路电流的解析计算。最后,通过Matlab/Simulink仿真软件验证了双馈风电机组机端发生对称和不对称电压跌落时定子电流解析计算表达式的准确性。Electromagnetic transient characteristics of doubly fed induction generator （DFIG） are very complex during the terminal voltage severely dips. One issue that has not received much attention so far is the contribution of DFIG to the asymmetrical short-circuit fault. In order to describe the DFIG＇s asymmetrical short-circuit current characteristics accurately, positive and negative sequence vector model of DFIG are established based on space vector theory and sequence component method. Considering the different initial operating power of DFIG the accurate mathematical expressions of the stator and rotor flux after crowbar insertion is deduced through mathematical analysis. After that, then the accurate expressions of the stator and rotor short circuit current are derived. The method is also suitable for the calculation of DFIG short circuit when symmetrical fault occurs. Finally, the mathematical expressions of stator current are verified according to the standard DFIG model in MATLAB/SIMULINK under the cases of symmetrical and asymmetrical voltage dips respectively.

关 键 词：双馈风电机组 不对称故障 撬棒保护 短路电流特性 故障分析 

分 类 号：TM315[电气工程—电机]