摘要
针对锁相环(phase-locked loop,PLL)与电网强耦合导致双馈风机(double-fed induction generator,DFIG)在弱电网下阻抗失配易引发振荡风险的问题,提出基于串联滞后校正PLL的DFIG阻抗重塑方法。首先,通过建立DFIG阻抗模型并分析其波特图,发现考虑电网阻抗才能准确评估潜在振荡风险。然后,在考虑电网阻抗情况下,将串联滞后校正环节引入PLL以补偿振荡频段相位裕度,并利用全通滤波器校正DFIG工频相位偏移以提升并网稳定性。最后,为验证所提方法的有效性,基于RT-LAB搭建半实物平台,为提高超宽频阻抗扫描效率,提出对数分布多频并行注入法进行阻抗扫描方法,其效率较传统方法提高47.2%;在低短路比下,所提重塑方法可将定子电压THD降至38%~48.9%,电流THD降至40%~59.6%,其谐波抑制性能优于传统重塑方法。
In view of oscillation risk,which is likely happen due to impedance mismatch of the doubly-fed induc-tion generator’s(DFIG)in weak grids due to the strong coupling between phase-locked loop(PLL)and grid,an im-pedance reshaping method of DFIG based on cascaded lagging compensation wideband characteristics of PLL is pro-posed.First,by setting up the impedance model of the DFIG and analyzing its Bode diagram,it is found that consid-eration of grid impedance can accurately assess potential oscillation risk.Subsequently,in case of considering grid impedance,a series lag link is introduced to the PLL to compensate the phase margin in the oscillation-prone fre-quency band.An all-pass filter is also applied to correct the power-frequency phase shift in the DFIG,thereby en-hancing grid connection stability.Finally,for validating the effectiveness of the proposed method,a hardware-in-the-loop(HIL)platform is set up based on RT-LAB.Moreover,for increasing the efficiency of ultra-wide band imped-ance scanning,a logarithmically distributed multi-frequency parallel injection method for impedance scanning is proposed,which,compared to conventional methods,improves scanning efficiency by 47.2%.Under conditions of a low short-circuit ratio(SCR),the proposed reshaping method reduces the stator voltage THD to a range of 38%to 48.9%and the current THD to a range of 40%and 59.6%,and its harmonic suppression performance is superior to the traditional reshaping approaches.
作者
徐恒山
陈雷
XU Hengshan;CHEN Lei(College of Electrical Engineering&New Energy,China Three Gorges University,Hubei Yichang 443002,China)
出处
《高压电器》
北大核心
2025年第11期149-161,共13页
High Voltage Apparatus
基金
宁夏自然科学基金项目(2024AAC03747)。
关键词
双馈风机
宽频振荡
弱电网
阻抗重塑
锁相环
doubly-fed induction generator
broadband oscillation
weak grid
impedance reshape
phase-locked loop(PLL)
作者简介
徐恒山(1989-),男,博士,硕士生导师,主要研究方向为新能源发电与并网、电力电子技术及应用,E-mail:xuhengshan@ctgu.edu.cn;通信作者:陈雷(2000-),男,硕士研究生,主要研究方向为新能源发电与并网,E-mail:3200043698@qq.com。
