电力系统保护与控制2026，Vol.54Issue(3)：99-108,10.DOI:10.19783/j.cnki.pspc.250500
双极柔性直流系统阀交流侧接地保护研究
Study on grounding protection of the valve AC side in bipolar VSC-HVDC systems
摘要
Abstract
To address the issue that fault currents caused by grounding faults on the valve AC side of bipolar VSC-HVDC systems have no natural zero-crossing points,the characteristics of fault currents at both the faulty and healthy terminals after converter blocking at the faulty end are analyzed.Analytical expressions are derived,and a criterion and corresponding protection scheme for the healthy terminal to identify grounding faults on the opposite side are obtained.Since arc currents that reverse and pass through a zero crossing are beneficial for restoring the dielectric strength of the arc gap in AC circuit breakers,the impact of reducing DC voltage after a fault on the reverse zero-crossing behavior of valve AC-side fault currents is investigated.Based on this,a protection scheme is proposed in which,after the healthy terminal is taken out of operation,the non-grounded pole on the DC side of the faulty terminal is grounded through a resistor.The expressions for the current limiting resistor and the valve AC-side fault currents are derived.Finally,simulations are performed on the PSCAD/EMTDC platform.The results demonstrate that grounding the non-grounded pole through a resistor can not only enable reverse zero-crossing of valve-side fault current of the converter transformer,but also effectively prevent the occurrence of three-phase short circuits in the converter transformer.关键词
双极柔性直流输电/模块化多电平换流器/接地故障/偏向于时间轴一侧的故障电流/继电保护Key words
bipolar VSC-HVDC/modular multilevel converter/grounding fault/fault current biased to one side of the time axis/relay protection引用本文复制引用
盛诗意,徐习东,李峰,陈丹青,罗澍忻..双极柔性直流系统阀交流侧接地保护研究[J].电力系统保护与控制,2026,54(3):99-108,10.基金项目
This work is supported by the Major Project of National Natural Science Foundation of China(No.62293500). 国家自然科学基金重大项目资助(62293500) （No.62293500）
南方电网公司科技项目资助(GDKJXM20231022) （GDKJXM20231022）
