不平衡电网电压下基于滑模变结构控制的双馈风电系统转子侧变流器控制策略  

Sliding-Mode Control for Rotor-Side Converters of DFIG-Based Wind-Power Generation System Under Unbalanced Grid Voltage Conditions

作　　者：张迪[1] 魏艳君[1] 杨宗丰 丁浩[1] 漆汉宏[1] 

机构地区：[1]燕山大学电气工程学院,秦皇岛066004

出　　处：《电工技术学报》2016年第17期121-131,共11页Transactions of China Electrotechnical Society

基　　金：河北省应用基础研究计划重点基础研究项目(13964304D);教育部高等学校博士学科点专项科研基金(20121333110007)资助

摘　　要：在两相静止坐标系下,建立了基于功率控制的双馈电机统一的数学模型,该模型在平衡和不平衡电网电压条件下均适用。采用基于滑模变结构的直接功率控制方法实现了对双馈风电系统转子侧变流器的控制,该方法控制结构简单,动态响应快,鲁棒性强。在不平衡电网电压条件下,提出了一种新型的功率优化补偿控制策略。该控制策略可直接对转子侧变换器的功率给定进行补偿,无需对定、转子电流进行正、负序分解,简化了系统控制结构;更重要的是其能有效降低定子电流扰动对功率补偿量的影响,系统鲁棒性得到明显提高。仿真和实验结果均证明了该控制策略的正确性和有效性。A general mathematical model for the double fed induction generator （DFIG） is presented based on power control in the two-phase static coordinate, which is suitable for either balanced or unbalanced grid voltage condition. Direct power control based on sliding-mode control is used to realize the control of DFIG＇ s rotor-side converter. The controller has advantages of simple structure, rapid response, and high robustness. A novel optimization control strategy is proposed for compensating power under unbalanced grid voltage conditions. The proposed control strategy is implemented by directly increasing power compensation to the power reference value, which eliminates the sequence component extraction of the stator and rotor currents. Therefore the control structure is simplified. More importantly, the proposed control algorithm can reduce the influence of the stator current disturbance on the power compensation, thus improves system robustness. Simulation and experiment results confirm the reliability and validity of the proposed control strategy.

关 键 词：双馈电机 转子侧变换器 滑模变结构控制 直接功率控制 不平衡电网电压 

分 类 号：TM46[电气工程—电器]