电网电压不对称骤升下双馈风力发电机改进控制策略  

An Improved Control Strategy for Doubly Fed Induction Wind Generators Under Unbalanced Grid Voltage Swell

作　　者：谢震[1] 张兴[1] 杨淑英[1] 宋海华[1] 曲庭余[1] 石权利[1] 

机构地区：[1]合肥工业大学电气与自动化工程学院,安徽省合肥市230009

出　　处：《中国电机工程学报》2013年第15期109-118,9,共10页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51277050;51077034);国家科技支撑计划(2011BAA07B05);国家青年科学基金项目(51107025);安徽省高校自然科学研究项目(2011AJZR0063)~~

摘　　要：双馈风力发电机在电网电压不对称骤升时,定子磁链中不仅会产生暂态直流分量,而且还会产生负序分量。为了抑制电网电压不对称骤升造成的定子电流不平衡,分析了电网电压不对称骤升下双馈发电机的电磁过渡过程,在采用基于双同步旋转坐标(synchronous reference frame,SRF)的转子变流器控制策略基础上,提出基于有源阻尼的转子变流器的双SRF改进控制策略,为提高电网电压不对称骤升时控制性能,在转子负序电流内环中引入虚拟电阻,有效抑制转子负序电流和电磁转矩的振荡;而在定子负序电流外环中引入有源阻尼,加快电网电压不对称骤升时对定子负序电流抑制的过渡过程,提高了系统动态响应的能力,可增强不对称电网电压骤升下双馈风力发电机不间断运行能力,最后通过仿真和实验验证了改进策略的可行性和有效性。Grid voltage unsyrnmetrical swell will cause transient DC flux components and negative sequence components in the doubly fed induction generator （DFIG） stator windings, which will create more serious stator and rotor current and torque oscillations even than voltage dips. This paper analyzed the dynamic behavior of DFIG during unsymmetrical voltage swell. The improved double synchronous reference frame control strategy based on the active resistance manages effective to suppress unbalance of the stator current, the rotor current control structure based on active resistance can suppress the rotor current and torque oscillation, the stator negative sequence current control structure based on active resistance can shorten oscillation transient time of the stator negative sequence current component during the unsymmetrical voltage swell, This paper proposed an improved SRF control strategy to enhance its high voltage ride through capability. This improved method was verified by Simulation and experimental results.

关 键 词：双馈风力发电机 有源阻尼 不对称骤升 高电压过渡 

分 类 号：TM74[电气工程—电力系统及自动化]