引用本文: | 刘尧,韩伟,李琼林,等.基于二次谐波复合闭锁的零序过流保护新方案[J].电力系统保护与控制,2019,47(19):113-121.[点击复制] |
LIU Yao,HAN Wei,LI Qionglin,et al.A new scheme of zero sequence overcurrent protection based on secondary harmonic compound blocking[J].Power System Protection and Control,2019,47(19):113-121[点击复制] |
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摘要: |
首先阐述分析了零序涌流的产生机理及特点。其次针对其会导致零序过流保护误动的问题,提出了一种基于二次谐波复合闭锁的零序过流保护新方案。通过比较零序电流的二次谐波含量及其变化率,即可辨识短路电流和励磁涌流,且能够不受CT饱和的影响。设计采用计数装置来具体实现二次谐波变化率的监测,并给出了相应的整定和计数原则。结合零序过流保护整定电流及动作时间,形成了新的零序过流保护方案。所提方案原理简单清晰,易于实现,有一定的工程应用基础。通过在PSCAD/EMTDC中搭建220 kV系统模型,验证了新方案在不同场景下的有效性。 |
关键词: 励磁涌流 零序过流保护 二次谐波 复合闭锁 计数装置 |
DOI:10.19783/j.cnki.pspc.181343 |
投稿时间:2018-10-29修订日期:2018-12-10 |
基金项目:国家电网公司总部科技项目资助“混合多端直流输电线路故障与自适应重合方法研究”(52170218000M) |
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A new scheme of zero sequence overcurrent protection based on secondary harmonic compound blocking |
LIU Yao,HAN Wei,LI Qionglin,ZHOU Ning,LIN Xiangning |
(State Grid Henan Electric Power Research Institute, Zhengzhou 450052, China;State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China) |
Abstract: |
Firstly, the generation mechanism and characteristics of zero-sequence inrush current are analyzed. Secondly, a new zero-sequence overcurrent protection scheme based on second harmonic compound blocking is proposed to solve the problem that zero sequence overcurrent protection will malfunction. By comparing the second harmonic content of zero sequence current and its change rate, the new method can identify short circuit current and inrush current, which can be unaffected by CT saturation. This paper designs a counting device to monitor the change rate of the secondary harmonic and gives the corresponding principles of setting and counting. Combined with zero sequence overcurrent protection setting current and action time, a new zero sequence overcurrent protection scheme is proposed, which is simple, clear and easy to implement. In addition, it has a certain engineering application foundation. This paper verifies the effectiveness of the new scheme in different scenarios by building a 220 kV system model in PSCAD/EMTDC. This work is supported by Science and Technology Project of State Grid Corporation of China (No. 52170218000M) “Research on Hybrid Multi-DC Transmission Line Fault and Self-adaptive Reclosing Method”. |
Key words: inrush current zero sequence overcurrent protection second harmonic compound blocking counting device |