基于Crowbar保护控制的交流励磁风电系统运行分析

随着越来越多的交流励磁风力发电机接入电网运行,新的电网运行规则要求发电机在电网电压跌落时仍能保持不间断运行.为保护转子励磁电源和发电机,常采用Crowbar保护电路来限制电压跌落时转子回路的最大电流.文中通过仿真详细研究了电网故障时交流励磁风电系统的运行行为,就电压跌落程度及旁路电阻取值对Crowbar保护控制的影响以及采用Crowbar电路的系统运行特点进行了讨论分析.仿真结果验证了Crowbar电路的有效性,该方法可实现故障时交流励磁风力发电机不间断运行.

Analysis on the Operations of an AC Excited Wind Energy Conversion System with Crowbar Protection

With more and more AC excited wind turbines connecting to the power networks, the new gird code requires the generators to be capable of riding through a grid voltage dip. In order to protect the rotor-side converter and generator, a crowbar protection circuit is often connected to the rotor windings to limit peak currents in the rotor during a voltage dip. By analyzing the behaviors of an AC excited wind turbines during system faults, the effects of voltage dip and bypass resistor values on the Crowbar protection is analyzed. The performances of wind turbines with a Crowbar circuit are also discussed. The simulation results validate the effectiveness of Crowbar protection in terms of fault ride through capability.