基于相角差余弦值奇异熵的远海风电交流汇集线路单端量保护原理  

Single-ended protection principle for offshore wind power AC collection lines based on the singular entropy of the cosine value of phase angle difference

作　　者：戴志辉[1] 韩哲宇 李杭泽 DAI Zhihui;HAN Zheyu;LI Hangze(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Resources,North China Electric Power University,Baoding 071003,China;State Grid Tianjin Electric Power Company Chengxi Power Supply Branch,Tianjin 300110,China)

机构地区：[1]新能源电力系统全国重点实验室(华北电力大学),河北保定071003 [2]国网天津市电力公司城西供电分公司,天津300110

出　　处：《电力系统保护与控制》2025年第4期1-13,共13页Power System Protection and Control

基　　金：国家自然科学基金项目资助(51877084)。

摘　　要：海上风电柔直送出系统两侧电力电子设备均采用负序抑制控制策略。交流汇集线路故障时,两侧故障电流相角和幅值都发生较大变化,使传统工频量距离保护可靠性降低。为此,首先阐述了海上风电交流汇集系统结构,并分析负序抑制策略实现方法。其次,考虑电容电流分析传统距离保护适应性,并分析不同故障下相电流与其超前相电流相角差值余弦值的变化情况。在此基础上,利用Hankel矩阵反映特征量突变程度,提出一种基于相角差余弦值奇异熵的交流汇集线路单端量保护原理。最后,基于PSCAD/EMTDC搭建海上风电系统模型,分析并验证所提保护方案的有效性。结果表明,所提保护方案动作灵敏,可靠性高,能耐受20 dB噪声和100Ω过渡电阻。In offshore wind power flexible DC transmission systems,negative sequence suppression control strategy is adopted on both sides of the power electronic equipment.When a fault occurs on the AC collection line,the phase angle and amplitude of the fault current on both sides change significantly,which reduces the reliability of the traditional power frequency based distance protection.To address this issue,the structure of the offshore wind power AC collection system is described first,and the implementation method of the negative sequence suppression strategy is analyzed.Secondly,the adaptability of traditional distance protection is evaluated by considering the capacitive current,and the cosine value of the phase angle difference between the phase current and its leading phase current under different faults is analyzed.Based on this,the Hankel matrix is used to reflect the mutation degree of the characteristic quantities,and a single terminal protection principle for AC collection lines based on the singular entropy of the cosine value of the phase angle difference is proposed.Finally,an offshore wind power system model is built in PSCAD/EMTDC,and the effectiveness of the proposed scheme is verified.The results show that the proposed method is highly sensitive,reliable,and is capable of withstanding 20 dB noise and 100Ω transition resistance.

关 键 词：采样算法 单端量保护 奇异熵 接地故障 海上风电 

分 类 号：TM7[电气工程—电力系统及自动化]