一种抑制双馈风机故障电流频率偏移的有效方法  

An effective method for suppressing frequency offset of double-fed induction generator fault current

作　　者：蔡文超 杨炳元[1] 高敏 李超 Cai Wenchao;Yang Bingyuan;Gao Min;Li Chao(School of Electric Power,Inner Mongolia University of Technology,Hohhot 010080,China)

机构地区：[1]内蒙古工业大学电力学院,内蒙古呼和浩特010080

出　　处：《可再生能源》2018年第11期1663-1669,共7页Renewable Energy Resources

基　　金：内蒙古工业大学重点基金项目(ZD201519)

摘　　要：随着风机装机容量的增加,双馈感应风机(doubly-fed induction generator,DFIG)的故障特性对继电保护的影响越来越大,其不同的Crowbar控制策略会导致不同的故障特性。在深入分析DFIG暂态电流特征和Crowbar作用后转子短路电流变化的基础上,结合其定、转子电流的对应关系,提出一种优化的Crowbar控制策略。电网故障期间内Crowbar电路分时段投切,既能满足DFIG的低电压穿越要求,又能改善其故障电流频率偏移的程度。有效地减少了电流差动保护、距离保护及方向元件、选相元件的错误动作,在根源处减轻基于工频量的傅氏算法出现偏差对继电保护造成的影响。最后利用RTDS平台,以内蒙古某风场为依托,验证所提控制策略的有效性和可行性。With the increase of installed capacity of wind turbines, the fault characteristics of doubly-fed induction generators（DFIG） have a greater impact on relay protection. Different Crowbar control strategies lead to different fault characteristics. After an in-depth analysis of the DFIG transient current characteristics and rotor short-circuit current changes after the Crowbar effect, combined with the corresponding relationship between stator and rotor currents, an optimized Crowbar control strategy is proposed. The Crowbar circuit in a period of time during the fault of the power grid is divided into periods, which not only can meet the low voltage ride-through requirement of the DFIG but also can improve the degree of the fault current frequency offset. Effectively reduce the current differential protection, distance protection and directional components, phase-selection components of the wrong action. The influence of the deviation of the Fourier algorithm based on the amount of power frequency on the protection of the relay is mitigated at the root. Finally, using RTDS platform to rely on a wind field in Inner Mongolia, the effectiveness and feasibility of the proposed control strategy were verified.

关 键 词：双馈感应风机 CROWBAR电路 控制策略 故障特性 频率偏移 

分 类 号：TK84[动力工程及工程热物理—流体机械及工程] TM614[电气工程—电力系统及自动化]