基于apFFT的双馈风电场送出变压器差动保护方法  

Method of Differential Protection for Double-fed Wind Farm Outgoing Transformer Based on All-phase Fast Fourier Transform

作　　者：金恩淑 张宏鹏 胡晓晨 朱宏 JIN Enshu;ZHANG Hongpeng;HU Xiaochen;ZHU Hong(State Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology,Ministry of Education,Northeast Electric Power University,Jilin 132012,China)

机构地区：[1]现代电力系统仿真控制与绿色电能新技术教育部重点实验室(东北电力大学),吉林132012

出　　处：《高电压技术》2025年第4期1560-1568,共9页High Voltage Engineering

基　　金：国家自然科学基金(52277170)。

摘　　要：双馈风电场在低电压穿越策略下所输出的短路电流存在偏频特性,导致送出变压器传统差动保护动作延时过长。针对上述问题,首先,研究了低电压穿越策略下的双馈风机短路电流特性及其偏频特性对风电场送出变压器傅里叶工频算法提取二次谐波分量的影响;其次,分析了传统差动保护在双馈风电场送出变压器中的适应性;然后,提出了基于全相位快速傅里叶变换(all-phase fast Fourier transform,apFFT)的双馈风电场送出变压器差动保护新方法;最后,通过PSCAD/EMTDC仿真对所提方法进行了验证,结果表明,新方法不仅能够正确识别励磁涌流,而且提高了内部故障时差动保护的速动性。The short-circuit current provided by a double-fed wind farm under the LVRT strategy has a bias frequency characteristic,which leads to a long delay in the action of the conventional differential protection of the sending transformer.To address these problems,firstly,the short-circuit current characteristics of double-fed wind turbines under LVRT strategy and its bias frequency characteristics are analyzed,and the influence of the Fourier frequency algorithm on the extraction of the second harmonic component of the wind farm send-out transformer is investigated;secondly,the adaptability of the traditional differential protection in the send-out transformer of double-fed wind farms is analyzed;and then,a new differential protection method for the send-out transformer of double-fed wind farms based on the full-phase fast Fourier transform is proposed.Finally,the proposed method is validated by PSCAD/EMTDC simulation,and the results show that the new method can be utilized to not only correctly recognize the excitation inrush current,but also improve the rapidity of the differential protection in case of internal faults.

关 键 词：双馈风电场 送出变压器 全相位快速Fourier变换 间谐波 差动保护 励磁涌流 

分 类 号：TM614[电气工程—电力系统及自动化]