第 41 卷 第 6 期 电 网 技 术 Vol. 41 No. 6
2017 年 6 月 Power System Technology Jun. 2017
文章编号:1000-3673(2017)06-2020-07 中图分类号:TM 76 文献标志码:A 学科代码:470·40
基于变压器电流直流分量衰减特性的
励磁涌流识别方法
郑彬
1
,滕文涛
1
,项祖涛
1
,邓帅荣
2
,周佩朋
1
,李岩军
1
,班连庚
1
,詹花茂
3
(1.电网安全与节能国家重点实验室(中国电力科学研究院),北京市 海淀区 100192;
2.重庆大学 电气工程学院,重庆市 沙坪坝区 400044;
3.华北电力大学 电气与电子工程学院,北京市 昌平区 102206)
A Novel Inrush Current Distinguishing Scheme Based on DC Component
Decaying Characteristics of Transformer Current
ZHENG Bin
1
, TENG Wentao
1
, XIANG Zutao
1
, DENG Shuairong
2
,
ZHOU Peipeng
1
, LI Yanjun
1
, BAN Liangeng
1
, ZHAN Huamao
3
(1. State Key Laboratory of Power Grid Safety and Energy Conservation(China Electric Power Research Institute), Haidian District,
Beijing 100192, China; 2. School of Electrical Engineering, Chongqing University, Shapingba District, Chongqing 400044, China;
3. School of Electrical and Electronic Engineering, North China Electric Power University, Changping District, Beijing 102206, China)
1
ABSTRACT: In order to distinguish inrush current and fault
current effectively to ensure reliability of transformer
protection, based on difference of DC component decaying
characteristics between magnetizing inrush current and fault
current, this paper proposes a novel magnetizing inrush
currents distinguishing scheme, using export circuit breaker
current of transformer as detection signal to identify inrush
current and fault current by setting decay rate of DC
component and fundamental component amplitude ratio as a
logical criterion. This paper analyzes above-mentioned
difference and influences of system short-circuit capacity,
transformer rated capacity, core remanence and other factors.
Through typical simulation and field data verification, the
inrush current distinguishing method is proved effective and
reliable, suitable to case of circuit breaker without closing
resistor installed. This scheme possesses advantages of clear
principle, less necessary data, easy implement and promising
engineering applications.
KEY WORDS: transformer; magnetizing inrush current; fault
current; DC component; decay characteristic; distinguishing
method
摘要:为有效区分励磁涌流与短路电流,确保变压器保护的
可靠性,针对变压器励磁涌流与短路电流直流分量衰减特性
的差异,提出了一种新的励磁涌流识别方法。该方法以变压
基金项目:国家电网公司科技项目(SGNX0000DKJS1500066)。
Project Supported by Science and Technology Foundation of State
Grid Corporation of China (SGNX0000DKJS1500066).
器高压侧和中压侧出口断路器电流作为识别励磁涌流与短
路电流的信号源,将电流直流分量与基波分量幅值比的衰减
速率设置为判据,可以辨识出励磁涌流与短路电流。基于典
型建模仿真分析了励磁涌流与短路电流直流分量衰减特性
的差异,以及不同系统短路容量、变压器额定容量、铁心剩
磁等因素的影响。经典型仿真结果及工程现场实测数据验证,
该方法有效,适用于断路器未加装合闸电阻的情况,并具有
原理清晰、所需测量数据少、简单易实现等优点,为新型继
电保护装置开发及工程应用提供了参考。
关键词:变压器;励磁涌流;短路电流;直流分量;衰减特
性;识别方法
DOI:10.13335/j.1000-3673.pst.2016.2219
0 引言
近年来,我国的特高压电网一直处于高速发展
阶段,“六交五直”的特高压混联电网预计将于 2016
年底初步形成
[1-2]
。变压器作为特高压电网中的核心
元件之一,对其主保护的可靠性与速动性都提出了
更高的要求。纵差保护具有原理简单、动作灵敏的
特点,被广泛用作变压器的主保护,但其正确动作
率普遍偏低。造成变压器保护误动的原因有很多,
其中励磁涌流占很大比重,如何准确识别励磁涌流
与内部故障的短路电流一直是变压器保护的一个
重要研究课题
[3-7]
。
目前,实际工程中应用的变压器差动保护主要
采用二次谐波制动原理或间断角原理来识别励磁
涌流,但二者均存在一定的局限性:二次谐波制动