电网电压不平衡和畸变的双馈风电锁相环研究与设计

Research and Design of PLL for DFIG-Based Wind Power with Unbalanced and Distortion Grid Voltage

论述了双馈风电并网的锁相环(PLL)技术。针对基于传统PI-PLL技术,以双同步旋转坐标系建立电网电压不平衡和畸变数学模型,采用2ω陷波器的PLL,试验验证不能够完全消除2ω谐波的问题,提出了二种改进的解耦DDSRF-PLL算法:基于串联陷波器的DDSRF-PLL和基于反Park变换的DDSRF-PLL算法。通过DSP28335编程试验表明,基于反Park变换的DDSRF-PLL能更精确地锁定相角,更稳定,动态响应速度快。

This article discussed PLL technique for doubly-fed wind power grid connected which is based on traditional PI-PLL. It establishes a mathematical model of power grid unbalance and distortion grid voltage with DDSRF. The PLL of 2xoNF is used, and the experimental verification shows that it is not able to completely eliminate the pulse and can＇ t remove the harmonic. Therefore ,the article put forward two kinds of improved decoupling DDSRF-PLL models. The models are respectively based on notch filter and reverse Park DDSRF-PLL algorithms. The result through DSP28335 programming indicates that the reverse Park method can lock phase angle more precisely,is more stable and has faster dynamic response.