摘要
研究一种不平衡负载下离网型双馈电机的定子端与转子端变换器协调控制策略。在系统数学模型的基础上,对转子端变换器提出了一种直接电压控制方案,为了提高系统的动态响应和鲁棒性,设计了一种基于扩张状态观测器的转子电流控制方案,即通过扩张状态观测器估计系统总扰动,并以前馈方式消除该扰动。针对负载不平衡问题,通过在定子端采用三相四脚变换器对定子电流的零、负序分量进行补偿,消除了不平衡负载对双馈感应电机的不利影响,改善了发电系统的电能质量。为了减少控制器的计算负担,对定子端变换器交流侧的电流采用比例-谐振(PR)控制,有效地避免了繁琐的正、负序分离计算,简化了控制算法。仿真和实验结果验证了该方案的正确性及可行性。
This paper studies a coordinated control scheme for the stator-side and rotor-side converters of the stand- alone doubly fed induction generator （DFIG） under unbalanced load condition. According to the space-vector mathe- matical model of the stand-alone system, in the rotor-side converter, a direct voltage control method is presented to provide excellent voltage profile for the load. Then, to enhance the system dynamic response and robustness, the rotor current control method is designed based on the extended state observer;and the extended state observer is used to estimate the total disturbance of the system, which will be eliminated in a feed-forward way. Meanwhile, aiming at the unbalanced load problem, in the stator-side, a three-phase four-leg converter functioning as the stator-side converter is used to compensate the negative and zero sequence components of the stator current, which eliminates the undesired effect of the unbalanced loads on doubly fed induction generator and improves the system power quality. To reduce the computational burden for the controllers, the proportional resonant （PR） control is utilized in the AC current loop of the stator-side converter, which effectively avoids the tedious calculation for the positive and negative sequence de- composition, and simplifies the control algorithm. Simulation and experiment results verify the correctness and feasi- bility of the proposed control scheme.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2013年第8期1886-1893,共8页
Chinese Journal of Scientific Instrument
基金
国家自然科学基金(61174125)资助项目
关键词
双馈感应电机
比例-谐振控制器
不平衡
三相四脚变换器
离网型风力发电系统
doubly-fed induction generator
proportional resonant controller
unbalance
three-phase four-leg convert- er
stand-alone wind power system
