This paper proposes a frequency-smoothing scheme of a doubly-fed induction generator (DFIG) that can significantly eliminate the frequency fluctuations caused by continuously fluctuating wind speeds. To achieve this, a proportional-integral (PI) control loop depending on the frequency deviation instead of a proportional control loop used in conventional schemes is added to the maximum power point tracking loop. The P control loop in the proposed frequency-smoothing scheme eliminates the alternating component in the frequency deviation, whereas the I control loop eliminates the slowly-varying component. The gains for the P control loop and I control loop are suggested for effectively using the rotating masses of a DFIG while avoiding over-deceleration of the rotor speed. The simulation results evidently demonstrate that the proposed scheme nearly removes the frequency deviation under various wind conditions, by using the proposed PI control loop, especially in high penetration levels of wind.

中文翻译：

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基于 PI 控制环的双馈感应发电机频率平滑


本文提出了一种双馈感应发电机（DFIG）频率平滑方案，可以显着消除风速连续波动引起的频率波动。为了实现这一点，在最大功率点跟踪环路中添加了一个取决于频率偏差的比例积分（PI）控制环路，而不是传统方案中使用的比例控制环路。所提出的频率平滑方案中的 P 控制环消除了频率偏差中的交变分量，而 I 控制环消除了缓慢变化的分量。建议使用 P 控制环和 I 控制环的增益，以有效利用 DFIG 的旋转质量，同时避免转子速度过度减速。仿真结果明显表明，通过使用所提出的 PI 控制环，所提出的方案几乎消除了各种风力条件下的频率偏差，特别是在风的高渗透水平下。