Crowbar保护在双馈异步风力发电系统电网故障穿越中的应用

摘要

For the increasing rate of wind generation capacity ,higher requests are brought to the capacity of low voltage ride through for the wind generation on grid. Based on the grid connection guidelines of wind turbine,the operation of DFIG(Doubly-Fed Induction Generator) wind turbine during grid voltage sag is analyzed and it is proposed to apply Crowbar circuit in the protection of rotor excitation source and generator. The wind farm model is built with Matlab/Simulink to validate its effectiveness. Simulative results show that the circuit ensures the safety of system components by limiting the maximum currentgenerated by the rotor circuit during voltage sags,and the AC excitation DFIG can operate in connection with grid to stabilize the grid voltage during fault.%随着风电装机容量的增大,对风电机组并网的低电压穿越能力提出了更高的要求.在分析现行风电机组并网导则的基础上,对双馈异步风力发电机组在电网电压跌落情况下的运行状况进行理论分析,提出采用Crowbar电路来保护转子励磁电源和发电机自身的方案.在Matlab/Simulink建立的风电场模型中进行仿真以验证其有效性.仿真结果表明,该电路可以有效限制电压跌落时转子回路产生的最大电流,保证系统各元件的安全;同时也证明了该方案可以实现故障期间交流励磁双馈异步风力发电机不脱网运行,并能起到稳定电网电压的积极作用.