双馈感应风力发电机实现LVRT仿真研究

Simulation Research of Doubly Fed Induction Wind Generator to Achieve LVRT

在基于双馈电机的并网风力发电系统中,一般采用附加转子侧撬棒电路的方法来实现低电压过渡。当电网电压发生严重短暂跌落故障时,可以同时附加直流侧卸荷电路以更好地实现低电压穿越。为实现低电压运行,撬棒电阻值的选取至关重要。在考虑最大转子故障电流和直流母线钳位效应的双重因素下,给出了双馈式风电机组撬棒保护电阻取值约束式,并讨论了DFIG附加两种保护电路后具体的低电压穿越控制策略。对2MW DFIG风力发电系统进行仿真,结果表明,在选择合适的保护电阻基础上,通过对保护电路的合理控制,附加撬棒电路和直流侧卸荷电路可以有效帮助DFIG实现低电压穿越运行。

For the doubly-fed induction generator（DFIG） based wind turbines,crowbar is a commonly used protection method to implement the low voltage ride-through（LVRT） capability.In the case of deep and short voltage dip,DC damp circuit can be used at the same time in order to enhance the LVRT performance better.Considering the importance of the value of crowbar resistor in this process,a crowbar resistance design method based on the faulty rotor current and the dc-link voltage was proposed,and the specific LVRT control strategy was discussed in this paper.A typical 2MW DFIG system was used,the analysis and simulation results show that,with the help of appropriate protective resistor and the reasonable control strategy,the additional protection devices can effectively help wind generator provide LVRT capability.