故障暂态对小电阻接地系统零序电流保护的影响  

Influence of Fault Transients on the Zero Sequence Protection in Low-resistance Grounding System

作　　者：刘钟淇 王顺超[2] 冯江哲 孙通 

机构地区：[1]龙源(北京)风电工程技术有限公司,北京100034 [2]电力规划设计总院,北京100120

出　　处：《风力发电》2015年第3期16-20,共5页Wind Power

摘　　要：为实现单相接地故障的准确切除，主变低压侧采用小电阻接地方式的风电场逐渐增多，如何正确配置零序电流保护成为一个关键问题。由于Z型接地变压器存在一定的零序阻抗，在单相接地故障初期，系统存在一个电磁暂态过程，对零序电流保护可靠性和灵敏性会产生较为显著的影响，有可能造成保护的误动作。为研究此问题，本文建立了计算故障暂态过程的简化电路模型，并提出了计算暂态过程的关键参数的数学方法，以及依据计算结果调整零序电流保护整定值的基本策略。In order to clear the single-phase grounding fault quickly, low-resistance grounding system becomes more and more common in wind farms. How to set up the zero-sequence protection for the collector system becomes a key issue. Due to the high zero-sequence impedance of Z winding grounding transformer, there exists an electromagnetic transient When single-phase grounding fault happens. The electromagnetic transient might have a significant impact on the zero- sequence protection and even leads to the malfunction of the protection. To study this problem, a simplified electric circuit model is established in this paper, and a mathematical framework for calculating the key parameter of the transient is proposed. Finally, the method of adjusting the zero-sequence protection is proposed.

关 键 词：风电场 小电阻接地系统 电磁暂态 零序电流保护 

分 类 号：TM862[电气工程—高电压与绝缘技术]