多类型故障影响下柔直线路故障机理分析及单端保护方法  

Fault Mechanism Analysis and One-terminal Protection Method of Flexible DC Transmission Line under the Influence of Multi-type Faults

作　　者：慕宗君 邱俊宏 李振兴[2] 王卫东 刘登鑫 胡斌 MU Zongjun;QIU Junhong;LI Zhenxing;WANG Weidong;LIU Dengxin;HU Bin(Xuji Electric Co.,Ltd.,Xuchang 461000,China;College of Electrical Engineering&New Energy,Three Gorges University,Yichang 443002,China)

机构地区：[1]许继电气股份有限公司,河南许昌461000 [2]三峡大学电气与新能源学院,湖北宜昌443002

出　　处：《中国电力》2025年第1期107-114,共8页Electric Power

基　　金：国家自然科学基金资助项目(52077120)。

摘　　要：多端柔性直流输电线路保护存在多种故障类型,易受过渡电阻、噪声等因素的影响。为此,提出一种应用单端电压梯度能量值的柔直线路全线速动保护方法,仅基于单端测量电压即可保护线路全长。分析了柔性直流线路区内外的电压故障特征,并引入改进电压梯度算法构建保护启动判据,进一步构建基于能量值比较的全线故障保护判据,基于正负极能量比在单极或极间故障下所处范围不同实现故障选极。仿真验证表明:所提方法能够快速完成区内外故障识别、故障极判断,并具有良好的抗噪性和耐高阻能力。Multi-terminal flexible DC transmission line protection faces various fault types and is susceptible to factors such as transition resistance and noise.To address this,a fast-action protection method for the entire flexible DC line using single-ended voltage gradient energy values is proposed,which can protect the entire length of the line based solely on single-ended measured voltage.The voltage fault characteristics inside and outside the flexible DC line are analyzed,and an improved voltage gradient algorithm is introduced to construct a protection initiation criterion.Furthermore,a full-line fault protection criterion based on energy value comparison is constructed,and fault pole selection is achieved based on the different ranges of positive and negative energy ratios under unipolar or inter-pole faults.Simulation verification shows that the proposed method can quickly identify faults inside and outside the zone,determine the fault pole,and exhibits good noise immunity and high resistance tolerance.

关 键 词：柔性直流线路 单端保护 改进电压梯度 故障区判别 

分 类 号：TM721.1[电气工程—电力系统及自动化]