基于定子串联动态电抗的综合低电压穿越策略  

Comprehensive LVRT Strategy Based on Dynamic Stator Series Reactance

作　　者：姜惠兰[1] 贾燕琪 周陶 周照清 张驰[1] JIANG Huilan;JIA Yanqi;ZHOU Tao;ZHOU Zhaoqing;ZHANG Chi(Smart Grid Key Laboratory（Tianjin University）,Ministry of Education,Nankai District,Tianjin 300072,China)

机构地区：[1]智能电网教育部重点实验室(天津大学)

出　　处：《电网技术》2018年第11期3760-3767,共8页Power System Technology

基　　金：国家自然科学基金项目(51477115)~~

摘　　要：双馈异步风力发电机对电网电压扰动比较敏感,其低电压穿越技术仍是目前研究的热点问题。针对定子串联电抗穿越方式电抗取值小难以有效抑制故障过电流,取值大又限制转子侧变流器功率控制能力的矛盾,提出一种基于定子串联动态电抗的综合低电压穿越策略,在理论分析定子串联电抗值及切换时刻合理整定方法的基础上,制定了大、小电抗双模式切换的低电压穿越方案。为进一步提高穿越性能,大电抗模式下RSC采用暂态磁链主动衰减控制策略以尽快进入小电抗阶段,小电抗模式下RSC采用无功支撑为主、有功为辅的功率协调控制策略。仿真结果表明,所给出的穿越策略有效抑制了故障期间转子过电流,提高了DFIG的无功输出能力,同时降低了电压恢复期间的电抗切除冲击。Doubly-fed induction generator（DFIG） is sensitive to grid voltage disturbance, and corresponding low voltage ride-through（LVRT） technology is still a hotspot issue. To solve the contradiction between restricting rotor overcurrent and offering enough reactive power to power grid when using stator series reactance for LVRT, a new strategy using dynamic stator series reactance is proposed. After analyzing theoretically the setting method of series reactance value and reasonable switch time, a double-mode switching LVRT scheme is established. In order to further improve LVRT performance, active flux attenuation control strategy of rotor-side converter（RSC） is applied with big reactance, while power coordination output control strategy is applied with small reactance. Simulating result shows that the proposed scheme can effectively suppress the rotor overcurrent and improve control capability of reactive power output. The overcurrent caused by cutting off the series reactance after fault is also reduced.

关 键 词：双馈风力发电机 低电压穿越 定子串联动态电抗 磁链主动衰减控制 功率协调控制 

分 类 号：TM614[电气工程—电力系统及自动化]