中文摘要：

为精简双馈感应发电机直流并网系统结构，在采用双变流器直流并网的基础上，进一步研究双馈电机无位置传感器控制策略。针对定子电压的非正弦性，定子侧变流器和转子侧变流器通过间接气隙磁链定向控制。为降低无位置传感器运行的参数依赖性，采用基于气隙磁链的模型参考自适应控制策略。以双馈电机数学模型为基础，采用小信号的分析方法，分析了无位置传感器策略的稳定性和对双馈电机参数变化的鲁棒性。最后构建了双馈风力发电机直流并网系统实验平台，对所提控制策略的正确性与可行性进行了实验验证。

英文摘要：

In order to simplify the complexity of doubly-fed induction generator （DFIG） system connected to DC grid, the sensorless operation technique is further studied on the basis of two converters. Aiming at that stator voltage is not sinusoidal, the stator side converter and the rotor side converter was controlled through the indirectly air-gap flux orientation. In order to reduce the dependency on the parameters, the model reference adaptive system based on air-gap flux was applied to achieve the sensorless operation. The small signal method was applied to analyze the stability of the sensorless operation and the robustness against the DFIG parameter variations on the basis of mathematical model of DFIG. Finally, the experi- mental system of DFIG connected to DC grid is developed to validate the sensorless operation technique.