基于电流合成矢量轨迹特性的双馈风电场主变压器差动保护  

Differential Protection of Main Transformer of Doubly-Fed Wind Farm Based on Current Synthesized Vector Trajectory Characteristics

作　　者：宋许鹏 杨小洋 樊征臻 SONG Xupeng;YANG Xiaoyang;FAN Zhengzhen(School of Mechanical and Electrical Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Jiaxun Feihong Intelligent Technology Institute,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)机械与电气工程学院,北京100083 [2]佳讯飞鸿(北京)智能科技研究院有限公司,北京100083

出　　处：《中国电力》2025年第2期9-21,共13页Electric Power

基　　金：中央高校基本科研业务费重点领域交叉创新项目(2022JCCXJD01)。

摘　　要：双馈风电场故障穿越的过程中,风电场侧提供的短路电流存在频率偏移现象,导致基于傅里叶算法的相量提取存在误差,二次谐波制动元件可能误动作,使得差动保护长时间闭锁。提出了一种基于电流合成矢量轨迹特性的新型时域保护方案。针对变压器区内故障和区外故障的本质差异,分别构造2种合成矢量,并根据各自合成矢量的轨迹特性设计保护方案。在PSCAD/EMTDC中搭建双馈风电场送出系统控制和保护的仿真模型。实验表明,所提方案能识别各种区内故障,且不受励磁涌流、区外故障伴随电流互感器(current transformer,CT)饱和以及区外故障伴随CT测量误差的干扰,最快15 ms即可动作且平均动作时间小于一个工频周波。During the fault ride-through process of the doubly-fed wind farms,the short-circuit current provided by the wind farm side exhibits frequency deviation,which leads to errors in the Fourier algorithm based phasor extraction.Additionally,the second harmonic restraint element may act incorrectly,leading to longterm blockage of the differential protection.This paper proposes a novel time-domain protection scheme based on the characteristics of the current synthesis vector trajectory.Based on the intrinsic differences between internal faults and external faults of transformers,two current synthesis vectors are constructed accordingly,and corresponding protection schemes are designed according to the trajectory characteristics of each synthesis vector.A simulation model of the control and protection of the delivery system of doubly-fed wind farms is constructed in PSCAD/EMTDC.Experimental results show that the proposed scheme can identify various internal faults and is not affected by the interference of magnetizing inrush current,current transformer(CT)saturation accompanying external faults and CT measurement errors accompanying external faults.The proposed scheme can operate in 15ms at the fastest and the average operation time is less than a fundamental frequency cycle.

关 键 词：双馈风电场 主变压器保护 合成矢量 励磁涌流 电流互感器饱和 

分 类 号：TM614[电气工程—电力系统及自动化] TM773