双馈风机三相短路电流特性分析  

Analysis of three-phase short-circuit current characteristics of doubly fed induction generator

作　　者：范小红 孙士云[1] 孙德娟 海世芳 王杨[1] FAN Xiaohong;SUN Shiyun;SUN Dejuan;HAI Shifang;WANG Yang(Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]昆明理工大学

出　　处：《电力系统保护与控制》2019年第18期38-48,共11页Power System Protection and Control

基　　金：国家自然科学基金项目资助(51367009)“多视角下重合时序的策略整定、风险评估及其协调优化研究”~~

摘　　要：双馈风机(DFIG)短路电流特性与传统电机相比存在显著差异。根据机端电压的跌落程度,分析了计及Crowbar保护动作和计及RSC控制两种情况下DFIG的短路电流特性。针对撬棒(Crowbar)保护动作后转子磁链的频率含量以及定、转子电流的解析表达式并未完全统一的问题,建立了DFIG数学模型,分析Crowbar保护动作后DFIG定、转子磁链的暂态过程。在此基础上采用拉氏和反拉氏变换法推导了转子磁链的表达式,通过数学解析的方法得到了计及Crowbar保护动作的DFIG定、转子电流计算表达式。同时根据DFIG数学模型和转子侧变流器(RSC)控制模型,采用解微分方程法详细地推导了计及RSC控制的双馈风机定、转子短路电流的表达式。最后在Matlab/Simulink平台上建立DFIG电磁暂态仿真模型。仿真验证计及Crowbar保护和计及RSC控制两种情况下DFIG短路电流表达式的正确性,进而分析了电压跌落程度、Crowbar阻值以及PI控制参数对短路电流的影响。The short-circuit current characteristics of Doubly Fed Induction Generator(DFIG)are significantly different from those of conventional motors.According to the voltage drop of the motor,the short-circuit current characteristics of DFIG,taking into account Crowbar protection action and RSC control,are analyzed in this paper.Aiming at the problem that the frequency content of rotor flux linkage and the analytical expressions of stator and rotor current are not completely unified after Crowbar protection action in the existing literature,this paper establishes a DFIG mathematical model and analyzes the transient process of stator and rotor flux linkage of DFIG after Crowbar protection action.On this basis,Lagrangian and anti-Lagrangian methods are adopted.The expression of rotor flux linkage is deduced by transformation method,and the calculation expressions of DFIG stator current and rotor current considering Crowbar protection action are obtained by mathematical analysis method.At the same time,according to the mathematical model of DFIG and the control model of Rotor-Side Converter(RSC),the expressions of stator current and rotor current of DFIG with RSC control are deduced in detail by solving differential equation methods.Finally,the electromagnetic transient simulation model of DFIG is established on Matlab/Simulink platform.The simulation results verify the correctness of the short-circuit current expression of DFIG considering Crowbar protection and RSC control,and then analyze the influence of voltage sag,Crowbar resistance and PI control parameters on short-circuit current.

关 键 词：双馈风机 Crowbar保护 转子磁链 RSC控制 短路电流 

分 类 号：TM6[电气工程—电力系统及自动化]