基于等效转子电压的双馈感应发电机灭磁控制

针对电网电压故障引起的双馈感应发电机磁链弱阻尼振荡问题，提出一种采用等效转子电压的双馈感应电机灭磁控制策略。分析电网电压故障激起的双馈感应电机定子磁链的暂态过渡过程，建立定子磁链状态方程；通过求解状态方程的特征根和定子磁链的振荡频率及阻尼比，在转子电压前馈补偿项的基础上引入定子磁链的微分反馈项，得到等效转子电压参考值，并研究了其改善磁链欠阻尼特性和加快暂态磁链衰减的机理。最后，双馈感应发电机的仿真结果表明，本文方法可以较好地抑制故障期间的磁链振荡冲击，有利于双馈风电机组故障穿越能力的提高。

Demagnetization Control of Doubly fed Induction Wind Generators Based on Equivalent Rotor Voltage

In order to solve underdamping oscillation of doubly fed induction generator (DFIG) aroused by grid fault,a flux damping control method for DFIG based on equivalent rotor voltage was proposed.State equation of the stator flux linkage was established.The oscillation frequency and damping ratio of stator flux linkage by means of solving the characteristic root was analyzed.The rotor voltage feedforward compensation with the addition of the stator flux linkage derivative feedback compensation could get equivalent rotor voltage reference.The mechanism about how to improve underdamping character of stator flux linkage and accelerate the speed of attenuation of transient flux dc component was proposed.The simulation results demonstrated that the proposed method suppressed the oscillation of the stator flux linkage and enhanced the DFIG voltage fault ride through capability.