摘要
目前计及撬棒保护动作的双馈风机(DFIG)短路电流特性的相关研究,一般是假设撬棒(Crowbar)保护在故障瞬间动作,实际上由于控制系统的原因,撬棒保护故障瞬间并不会瞬时动作,而是具有一定的延迟。针对这一实际问题,以撬棒保护动作时刻为分界点,将故障过程分为两个阶段,以转子磁链作为两个阶段的桥梁进行衔接,将第一阶段转子磁链的末值作为第二阶段转子磁链的初值;同时针对现有文献转子磁链频率含量并未完全统一的问题,分析了故障前后定、转子磁链的频率分量,采用拉氏和反拉氏变换法推导了转子磁链解析式;在此基础上通过故障分量法和故障全量法推导了双馈风机短路全电流表达式。最后在Matlab/Simulink平台上建立DFIG电磁暂态仿真模型,仿真证明了DFIG短路全电流计算表达式的正确性,并分析了撬棒保护动作时间对短路电流的影响。
At present,the research on short-circuit current characteristics of DFIG considering Crowbar protection generally assumes that Crowbar protection acts at the moment of fault.In fact,the Crowbar protection does not act instantaneously at the moment of fault because of the control system,but has a certain delay.In view of this practical problem,this paper divides the fault process into two stages,adopts the rotor flux linkage as a bridge between the two stages,and takes the last value of the first stage rotor flux linkage as the initial value of the second stage rotor flux linkage.In addition,the frequency components of stator and rotor flux linkage before and after fault are analyzed,and the analytical expressions of rotor flux linkage are deduced by Laplace and inverse Laplace transformations.Finally,the electromagnetic transient simulation model of DFIG is established on Matlab/Simulink platform.The simulation results verify the correctness of the expression of short-circuit full current of DFIG,and the effect of Crowbar protection action time on short-circuit current is also analyzed.
作者
范小红
安德超
孙士云
孙德娟
王杨
Fan Xiaohong;An Dechao;Sun Shiyun;Sun Dejuan;Wang Yang(Faculty of Electric Power Engineering Kunming University of Science and Technology Kunming 650500 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2019年第16期3444-3452,共9页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(51367009)
关键词
双馈风机
撬棒保护
动作时间
转子磁链
短路电流
Doubly fed induction generator
Crowbar protection
action time
rotor flux linkage
short-circuit current
