摘要
研究了Crowbar投入、退出时间对双馈感应风力发电机低电压穿越性能的影响,并在Matlab/Simulink仿真平台上搭建了含Crowbar保护电路的DFIG模型,验证了Crowbar投切时间对DFIG低电压穿越的影响,保证故障发生时,Crowbar电路按设定的投切时间工作,短路电流能根据电流的变化规律快速衰减,转子电阻电压不超过直流母线电压;采用阈值投入延时切出的方案,防止Crowbar保护在电网故障时多次投切。仿真结果表明,经过适当的延时切除Crowbar电路可以避免Crowbar电路多次动作和转子再次过电流,能很好地保护风电机组,提高其低电压穿越能力。结果显示,低电压穿越效果很大程度上受退出时间影响。
The impact of Crowbar switching time on the doubly fed induction generator low voltage ride through capability was studied in this paper,and the model under the protection of Crowbar was built in Matlab/Simulink simulation platform. The impact of Crowbar switching time on the DFIG low voltage ride through was verified by changing the Crowbar switching time to ensure the short circuit current attenuate rapidly in accordance with the regularity of current change when Crowbar circuits work, and to ensure the voltage in the rotor resistance won＇ t exceed the DC bus voltage at the same time. A Crowbar protection control strategies in which the Crowbar protection would work when the Current reached a certain value and exit after a certain delay in order to avoid the Crowbar protection switching several times when power system faults happened. The research showed that Crowbar device could provide a pathway for surge current of the rotor when the voltage dips. And Crowbar device could limit the increasing of the rotor current. So it can protect the DFIG efficiently. The result of LVRT was affected by the exit time to a large extent.
出处
《华北电力技术》
CAS
2015年第1期25-28,32,共5页
North China Electric Power
