计及RSC控制的DFIG短路电流直流分量解析表达

现有文献针对计及转子变流器(RSC)控制的双馈感应风电机组(DFIG)定子短路电流解析表达,将定子磁链当作一阶直流衰减分量或忽略功率外环控制。基于DFIG电压、磁链和RSC控制方程,得到定子电流关于定子电压和定子功率的传递函数,提出定子电流的精确解析表达式。基于RSC内、外环PI参数关系,推导直流分量衰减时间常数和角频率关于PI参数的表达式。分析了RSC内外环PI参数对定子电流直流衰减分量的影响。仿真结果验证了解析表达式的准确性,为PI参数选取和保护装置测量、整定提供依据。

ANALYTICAL EXPRESSION OF DC COMPONENT OF SHORT-CIRCUIT CURRENTS OF DFIG CONSIDERING RSC CONTROL

In existing literatures,the analytical expressions of the stator short circuit currents of the doubly fed induction generator(DFIG)considering the rotor side converter(RSC)control are derived either by assuming that the stator flux as the first order decaying DC component or by neglecting the outer-loop power control. Based on the voltage,flux-linkage equations of the DFIG and the RSC control equations,the stator current transfer functions concerning the stator power reference value and stator voltage is obtained,and then the accurate analytical expressions of the stator currents are derived. Based on the relationship between the PI parameters of the inner and outer loop control of the RSC,the decaying time constant and angular frequency of the decaying DC component analytical expressions about the proportional parameters are derived. The effects of the PI parameters of the inner and outer loop control to the RSC on the decaying DC components of the stator currents are analyzed. Simulations results verify the accuracy of the analytical expressions.