一种提升LVRT能力的DFIG控制策略及故障特征分析  

A DFIG CONTROL STRATEGY AND FAULT CHARACTERISTIC ANALYSIS FOR IMPROVING LVRT CAPABILITY

作　　者：刘洪金 杨炳元[1] 粱佳宇 蔡文超 Liu Hongjin;Yang Bingyuan;Liang Jiayu;Cai Wenchao(College of Electric Power,Inner Mongolia University of Technology,Hohhot 010051,China;Inner Mongolia Electric Power Research Institute,Hohhot 010020,China)

机构地区：[1]内蒙古工业大学电力学院,呼和浩特010051 [2]内蒙古电力科学研究院,呼和浩特010020

出　　处：《太阳能学报》2021年第4期445-453,共9页Acta Energiae Solaris Sinica

基　　金：内蒙古自然科学基金(2018LH05032)。

摘　　要：为降低传统控制策略下电网发生严重故障期间转子侧撬棒电路投入运行对低电压穿越和继电保护的影响,在分析电网故障撬棒电路投入双馈感应风力发电机(DFIG)暂态故障特征的基础上,提出一种转子侧撬棒电路自适应切除控制策略。电压深度跌落撬棒电路投入后,定子故障电流中的衰减转速频率交流分量为故障初期的主要分量,在衰减转速频率交流分量衰减完毕后切除撬棒电路恢复励磁,能够保证变流器在安全工作的同时,利用DFIG自身的无功调节能力向电网提供更多无功支撑,提升低电压穿越性能,并能够提高电网发生短路故障时基于工频量保护的可靠性。通过RTDS平台仿真分析验证控制策略的有效性。In order to reduce the impact of the rotor-side crowbar on the low-voltage ride-through and relay protection during serious fault of the grid under the traditional control strategy,an adaptive removal of rotor-side crowbar control strategy is proposed based on transient fault analysis of DFIG.When the voltage drops deeply with the Crowbar circuit,the attenuated speed frequency AC component of the stator fault current is the main component at the beginning of the fault.After this current being attenuated completely,the excitation is restored with the removal of Crowbar,and the security of the converter operation is ensured.More reactive power is provided to the grid using DFIG to improve the low voltage ride through performance,and improve the reliability of relay protection based on the power frequency when short circuit occurs in the power grid.The effectiveness of the control strategy is verified by RTDS.

关 键 词：双馈感应发电机 撬棒电路保护 低电压穿越 短路电流 继电保护 

分 类 号：TM614[电气工程—电力系统及自动化]