摘要
随着直流工程输送容量、电压等级的不断提升,交直流故障耦合对西北送端电网造成的稳定问题愈发突出,给送端电网安全运行带来巨大的挑战,需对特高压直流安控系统进行研究和优化。为此,首先分析了送端电网特高压直流运行的稳定特性,从直流故障冲击引发的各类稳定性问题和交直流、新能源运行方式的耦合关系出发,提出了考虑多种直流故障类型分类、敏感因素分档、直流功率分级的精益化直流安控策略;在此基础上,基于不同地区切机对系统稳定性的影响,优化了直流故障后的切机顺序与切机量,并阐述了送端安控系统架构及故障后安控的动作顺序。所得成果已经在西北特高压直流工程中得到实际应用,有效降低了安控动作代价,提升了直流送出能力和系统稳定水平。
With the continuous improvement of DC project transmission capacity and voltage level,the stability problem caused by the coupling of AC and DC faults in the Northwest Grid is becoming prominent,which brings great challenges to the safety of the transmission network,and it is necessary to research and optimize the UHVDC safety control system.Consequently,we first analyzed the stability characteristics of the UHVDC operation of the transmission grid.Then,from the angles of the various stability problems caused by DC fault impact and coupling relationship between AC and DC and new energy operation modes,we proposed a DC safety control strategy considering multiple DC fault types classification,sensitive factor binning,and DC power classification.Finally,based on the impact of cutting machines in different regions on system stability,the sequence and amount of cutting after DC faults are optimized and explained.Moreover,the structure of the sending-end security control system and action sequence of safety control device after a fault are described.The results of this paper have been applied in the Northwest UHVDC project,thus the cost of safety control actions has effectively been reduced,and the DC output capability and system stability have been improved.
作者
任冲
牛拴保
柯贤波
霍超
陆海洋
REN Chong;NIU Shuanbao;KE Xianbo;HUO Chao;LU Haiyang(Northwest Branch of State Grid Corporation of China,Xi’an 710048,China;NR Electric Co.,Ltd.,Nanjing 211102,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2020年第9期3229-3237,共9页
High Voltage Engineering
基金
国家电网公司科技项目(多直流群送端系统运行特性、耦合机理及评价指标研究)。
关键词
UHVDC
安控策略
直流故障
运行方式判别
功率分档
UHVDC
security control strategy
DC faults
discrimination of operation mode
power classification
