基于Crowbar保护电路的双馈风电系统高电压穿越

针对电网电压发生骤升故障时造成的电网不稳定运行,在双馈机组转子侧加入Crowbar保护电路,增加双馈风电系统高电压穿越的能力。通过建立电网电压骤升时双馈风电机组投入Crowbar保护电路后的数学模型,并从磁链角度推导出转子侧暂态电流及其最大估算值,根据短路电流和直流侧母线耐受电压的大小,确定Crowbar电路串联的电阻值、切入和退出时间,加速系统暂态电流的衰减,实现双馈系统的高电压穿越。Matlab/Simulink仿真结果表明:控制方案增强了双馈发电系统稳定运行的可靠性,并提高了双馈风力发电系统的高电压穿越能力。

High voltage ride through for doubly fed wind power system based onCrowbar protection circuit

Aiming at the power grid voltage occurring swell faults causing the power grid unstableoperation, the Crowbar protection circuit is added to the rotor side of the doubly fed unit to increase thehigh voltage ride through capability of the doubly fed wind power system. By the establishment of themathematical model after the doubly fed wind power units put into Crowbar protection circuit duringpower grid voltage swell, from the angle of flux derived rotor transient current and maximum estimatedvalue. According to the short- circuit current and DC bus voltage tolerance size, determines theCrowbar series circuit resistance value, entry and exit time, accelerates the attenuation of transientcurrent, achieveshigh voltage ride through of the doubly fed wind power system. Matlab/Simulinksimulation results show that the control scheme can improve the reliability of the doubly fed generatorsystem and improve the high voltage ride through capability.