基于定子串联阻抗的DFIG低电压穿越控制策略

Low Voltage Ride Through Control Strategy of Doubly Fed Induction Generator Based on Stator Series Impedance

针对双馈感应风力发电机(DFIG)撬棒保护实现故障穿越的不足,从电网电压跌落期间机组的整体需求出发,提出一种基于定子串联阻抗的DFIG低电压穿越综合控制策略。分析了定子串联阻抗控制策略改善DFIG故障穿越的机理,给出了串联阻抗阻值的整定方法。在转子侧换流器中附加无功补偿控制策略,充分发挥了定子侧的无功支撑能力,加快电网电压的恢复。仿真结果表明:所提的综合控制策略增强了DFIG的故障穿越能力,抑制了转子电流、直流母线电压、电磁转矩的冲击,同时能够满足无功支撑的需求,克服了传统撬棒保护的不足,兼顾了故障结束后机组的稳定运行。

Aiming at the shortcomings of doubly fed induction generator(DFIG)crowbar protection,based on the overall demand of the unit during the voltage drop,a DFIG low voltage ride through integrated control strategy based on stator series impedance was proposed.The mechanism of stator series impedance to improve DFIG fault ride through was analyzed,and the setting method of series impedance resistance was given.Additional reactive power compensation control strategy was adopted in rotor side converter,the stator side of the reactive support capacity was given full play,the grid voltage recovery was sped up.The simulation results show that the proposed integrated control strategy enhances the fault ride through capability of DFIG,the rotor current,DC bus voltage and electromagnetic torque are suppressed,At the same time,it can meet the needs of reactive power support,overcome the shortcomings of the traditional Crowbar protection,and take into account the stability of the unit after the end of the operation.