电网对称故障时双馈感应发电机不脱网运行的励磁控制策略

提出了一种电网对称故障时保持双馈感应风力发电机不脱网运行的新型励磁控制策略。在导出的发电机基本电磁关系的基础上，分析了电网对称故障时发电机的暂态物理过程。为保证故障期间双馈感应发电机转子侧变频器安全运行，新的励磁控制策略针对故障过程中发电机内部电磁变量的暂态特点，控制发电机漏磁链以抵消定子磁链中的暂态直流分量对转子侧的影响。与此同时，利用定子侧电阻对发电机进行灭磁。研究中建立了30kW双馈感应发电机励磁控制实验系统及计算机时域仿真模型。实验证明所提出的励磁控制策略效果显著，同时也检验了仿真模型的精确性。

Ride-through Control Strategy of a Doubly Fed Induction Generator for Symmetrical Grid Fault

A new excitation control strategy is proposed for the rotor side converter in a doubly fed induction generator(DFIG)to allow the system to ride through a symmetrical grid fault.The transient phenomena associated with the short circuit fault are investigated based on the electromagnetic characteristics of the DFIG system.It is shown that the leakage flux linkages and hence the currents of the generator should be controlled to counteract the undesirable effect of the transient DC component in the stator flux linkage that is caused by the fault.The voltage and current on the semiconductor devices in the rotor side converter are consequently attenuated,increasing the possibility of successful ride-through.The resistance present in the stator side circuit is utilized to demagnetize the machine.A 30 kW DFIG test rig is set up,and the proposed control strategy is validated by experiment.