CAJ | 학술논문

双馈风电机组的规模化应用使电力系统的故障暂态特性发生变化。为了保障电力系统规划设计和保护控制的顺利实施，必须充分掌握双馈感应发电机(doubly fed induction generator，DFIG)输出短路电流的特征。目前双馈感应发电机的暂态分析尚未计及变流器励磁控制的影响，使双馈风电机组短路电流还难以准确分析和计算。针对DFIG转子侧变流器励磁控制与发电机电磁过程的复杂暂态耦合，通过构建包含变流器调控过程及发电机电磁暂态的转子回路动态模型，重点分析了电网对称短路冲击作用下DFIG的暂态扰动及其传递特性，推导了计及励磁调节作用的DFIG定转子短路电流简化表达式，分析了励磁控制下DFIG短路电流的特征以及控制方式对暂态行为的影响，利用时域仿真验证了理论分析的正确性。
쌍궤풍전궤조적규모화응용사전력계통적고장잠태특성발생변화。위료보장전력계통규화설계화보호공제적순리실시，필수충분장악쌍궤감응발전궤(doubly fed induction generator，DFIG)수출단로전류적특정。목전쌍궤감응발전궤적잠태분석상미계급변류기려자공제적영향，사쌍궤풍전궤조단로전류환난이준학분석화계산。침대DFIG전자측변류기려자공제여발전궤전자과정적복잡잠태우합，통과구건포함변류기조공과정급발전궤전자잠태적전자회로동태모형，중점분석료전망대칭단로충격작용하DFIG적잠태우동급기전체특성，추도료계급려자조절작용적DFIG정전자단로전류간화표체식，분석료려자공제하DFIG단로전류적특정이급공제방식대잠태행위적영향，이용시역방진험증료이론분석적정학성。
The large-scale application of doubly-fed wind turbines has significantly changed the fault transient characteristics of power systems. The short-circuit current contributed by doubly-fed induction generator (DFIG) should be fully understood to ensure the implementation of the planning and protection of power system. However, the impact of the converter excitation control has not been fully assessed, thus resulting in greater difficulty in the analysis and calculation of short-circuit current. This study presents a detailed analysis of short-circuit current of a DFIG, with focus on the complex coupling between the excitation control and electromagnetic process. The transient disturbances and their transitive relation in a DFIG under symmetrical short circuit are analyzed by constructing the dynamic model of rotor circuit. The expressions of rotor and stator short-circuit currents are deduced for the simplified calculation and analytical analysis. The characteristics of the short-circuit current of DFIG under the excitation control are analyzed and the impacts of control mode on the transient behavior are presented. The time-domain simulation is adopted to verify the validity of the theoretical analyses.