摘要
随着分布式电源广泛接入配电网,传统三段式电流保护方案的性能严重劣化。单端暂态量边界保护由于具备不依赖电源特性等突出优势,有望成为改善主动配电网保护配置性能的有效方案,但其需依附于线路边界强健的滤波作用。为此,该文研究发现,可利用智能变电站和智能开闭所中电子式电压互感器、金属氧化物避雷器与其余设备杂散电容共同作为线路边界,其优异的高频滤波作用能够为暂态量保护方案的设计奠定基础;其次,利用区内外故障时电压行波高频频带能量差异构造保护判据,并基于整定门槛与动作时序的合理配合形成单端暂态量阶段式保护方案;最后,基于PSCAD仿真平台验证所提方案的有效性、灵敏性与可靠性,其可与电流保护方案协同互济以强化主动配电网继电保护方案的动作性能。
As a large number of distributed generations are connected to the distribution networks,the performance of traditional three-stage current protection deteriorates seriously.The non-unit transient-based boundary protection is expected to be an effective scheme to improve the relay protection performance of active distribution networks due to its outstanding advantages,such as being independent of power supply property.However,the effectiveness of this approach relies heavily on the strong filtering effect achieved at the line boundary.Therefore,this paper presents that the electronic voltage transformer,the metal-oxide arrester,and the remaining apparatus’s stray capacitance of the smart substation and smart switching station can be used together as the line boundary.The excellent high-frequency filtering characteristics of this arrangement can serve as a foundation for the design of non-unit transient-based boundary protection.Then,the protection criterion is constructed due to the difference in the energy of the high-frequency band of the inside-zone and outside-zone fault voltage traveling waves.Based on the reasonable coordination of the setting threshold and the action sequence,a non-unit transient-based two-stage protection is formed.Finally,the proposed protection scheme is performed based on the PSCAD platform to verify its effectiveness,sensitivity,and reliability,which can be coordinated with three-stage current protection to enhance the protection performance in the active distribution network.
作者
吴宇奇
黎钊
肖澍昱
黄梓欣
李正天
魏繁荣
林湘宁
WU Yuqi;LI Zhao;XIAO Shuyu;HUANG Zixin;LI Zhengtian;WEI Fanrong;LIN Xiangning(State Key Laboratory of Advanced Electromagnetic Engineering and Technology(Huazhong University of Science and Technology),Wuhan 430074,Hubei Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2024年第12期4666-4681,I0007,共17页
Proceedings of the CSEE
基金
国家重点研发计划项目(2021YFB2401000)
国家电网有限公司科技项目:基于自主芯片的变电站高可靠性保护与监控技术(SGSDDKK00WJJS2200105)。
关键词
配电线路
单端暂态量保护
线路边界
电子式电压互感器
金属氧化物避雷器
智能变电站
distribution lines
non-unit transient-based protection
line boundary
electronic voltage transformer
metal-oxide arrester
smart substation
