基于谐波阻尼的双馈感应发电机定子谐波电流抑制改进策略

Harmonic Damping Based Improvement Strategy for Suppressing Stator Harmonic Current of Doubly-fed Induction Generator

通过建立电网电压谐波下双馈感应发电机(DFIG)的数学模型,分析了电网电压谐波对DFIG性能的影响,以抑制定子电流5次和7次谐波为目标,在转子电流内环采用比例—积分—谐振(PIR)调节器的基础上,引入定子谐波电流闭环控制策略,避免了常规谐波抑制策略转子电流指令计算对发电机参数的依赖。随着定子谐波电流环R调节器增益系数的增大,对定子电流中的谐波抑制越明显,但是抗扰动能力下降,通过引入谐波阻尼控制,在最大限度抑制定子电流谐波的基础上增强了系统的抗扰动能力,提高了系统的鲁棒性,加快了系统的动态响应。并从稳态特性和动态特性角度分析了参数变化对系统的影响。最后通过仿真和实验验证了所提控制策略的有效性。

Based on the mathematical model of doubly‐fed induction generator （DFIG） under harmonically distorted grid voltage conditions , the impact of power grid voltage harmonic on DFIG operation performance is analyzed . In order to suppress the 5th and 7th harmonics of stator current , the closed‐loop control strategy of stator harmonic current is introduced based on the rotor current loop with proportional‐integral‐differential （ PIR ） regulator , avoiding the dependence of rotor current command calculation in conventional harmonic suppression control strategy on generator parameters . With the increasing of R regulator gain coefficient in stator harmonic current loop , the suppression on stator harmonics is more obvious , but it will decrease the anti‐power disturbance . By introducing the harmonic damping control , the system anti‐disturbance ability is enhanced on the basis of maximum suppressing stator current harmonics . Consequently , the system robustness is improved , and the system dynamic response is accelerated . Considering dynamic and steady state characteristics , the influence of parameters change on the system is analyzed . The effectiveness of the proposed control strategy is validated by the experiment and simulation .