电力系统保护与控制2025，Vol.53Issue(12)：1-12,12.DOI:10.19783/j.cnki.pspc.241067
基于动态状态估计的海风柔性低频输电系统海缆纵联保护
Pilot protection of submarine cables in flexible low frequency transmission systems for offshore wind power based on dynamic state estimation
摘要
Abstract
Flexible low frequency AC transmission technology combines the advantages of both conventional AC power frequency and DC transmission,offering significant potential for application in medium-to-long distance offshore wind power connection.However,in such scenarios,wind power is transmitted through long-distance submarine cables.In the event of a cable fault,the fault current characteristics are influenced by the controlled power sources at both ends,leading to a decline in the performance of current differential protection.Additionally,the long low-frequency period,coupled with the effect of the distributed capacitance of the long submarine cable,results in slow fault discrimination for the protection system.This can cause wind turbines to disconnect from the grid,threatening grid security and stability.To address this,a pilot protection scheme for submarine cables in offshore wind power flexible low frequency transmission systems is proposed based on dynamic state estimation.A submarine cable model is established considering the structure of each metallic layer of a three-core submarine cable and its distributed capacitance.By utilizing the redundancy characteristics of dynamic state estimation of instantaneous values,the speed and reliability of the proposed protection method are improved.A protection criterion is constructed based on the matching degree between the developed cable model and the physical cable.Simulation results show that the proposed protection method can reliably discriminate various internal and external faults within 5 ms and exhibits strong tolerance to transition resistance and interference.关键词
海上风电/柔性低频输电系统/三芯海缆/动态状态估计/纵联保护Key words
offshore wind power/flexible low frequency transmission system/three-core submarine cable/dynamic state estimation/pilot protection引用本文复制引用
李猛,卫云辉,张豆豆,王昊月,聂铭,和敬涵..基于动态状态估计的海风柔性低频输电系统海缆纵联保护[J].电力系统保护与控制,2025,53(12):1-12,12.基金项目
This work is supported by the General Program of National Natural Science Foundation of China(No.52377070). 国家自然科学基金面上项目资助(52377070) （No.52377070）
