500kV主变差动保护TA问题分析及改进Problem Analysis and Improvement of TA for 500 kV Main Transformer Differential Protection
王建成,张涛,张建成,刘崇都,王欣,吴军轶
WANG Jiancheng,ZHANG Tao,ZHANG Jiancheng,LIU Chongdu,WANG Xin,WU Junyi
摘要(Abstract)：
差动保护"抗饱和"软件抓住1/5周波内TA(电流互感器)线性传变完成程序鉴别,这对采用高漏磁TPY级TA的主变差动保护防误动无疑上了一道"双保险"。但500 k V重合闸扰动下的无剩磁限制5P25级TA很难提供出大于1/5周波的线性传变,极易造成500 k V主变差动保护鉴别区内外故障出错而引发误动。分析了秦山核电厂4台主变差动保护所用20个5P级TA存在的问题,依据相关规范进行计算校核,优化调整TA特征参数,拓宽瞬态下TA线性传变时限,满足"抗饱和"软件鉴别区内外故障的判别条件。
Saturation-resistance software for differential protection caught TA(current transformer) linear transfer in one-fifth of the cycle to finish the verification of programme,which undoubtedly gives double insurance to "anti-maloperation" of main transformer differential protection that adopts high flux leakage TA of TPY class.But no-limited-leakage-flux TA with 5P25 class under the distortion of 500 k V auto-closure is difficult to provide linear transfer with its cycle not larger than 1/5,resulting in faults in and out of 500 k V main transformer differential protection region and maloperation.Problems in twenty 5P-class TAs for differential protection of four main transformers in Qinshan Second Nuclear Power Plant are analyzed and characteristic parameters of TA are optimized through calculation and verification in line with relevant regulations;time limit of TA linear transfer in transient state is expanded to meet the judgment requirements that saturation-resistance software needs to identify internal and external faults.
关键词(KeyWords)：
电流互感器;差动保护;越级误动;额定二次极限电动势;保护二次等效电动势;暂态系数;比例制动特性
TA;differential protection;over-reach maloperation;rated secondary limiting electromotive force;protection secondary electromotive force;transient factor;ratio brake characteristic
基金项目(Foundation):
作者(Author):
王建成,张涛,张建成,刘崇都,王欣,吴军轶
WANG Jiancheng,ZHANG Tao,ZHANG Jiancheng,LIU Chongdu,WANG Xin,WU Junyi
DOI: 10.19585/j.zjdl.2015.10.003
参考文献(References)：
- [1]王建成.秦山核电500 kV输电系统风险点及预控[J].浙江电力,2014,33(12):15-21.
- [2]王维俭,侯炳蕴.大型机组继电保护理论基础[M].北京:水利电力出版社,1989.
- [3]DL/T 864-2012大型发电机变压器继电保护整定计算导则[S].北京:中国电力出版社,2012.
- [4]DL/T 866-2004电流互感器和电压互感器选择及计算导则[S].北京:中国电力出版社,2004.
- [5]王建成,王欣,刘光明,等.秦山核电基地大电机试验平台技术方案分析、计算及论证[J].中国电业,2015(4):46-51.
- [6]王建成.500 kV增容导线在核电机群出线段的应用[J].电力建设,2012,11(33):23-27.
- [7]王建成.秦山第二核电厂水压试验、非核蒸气冲转电源容量校核运行方式的论证及实施[J].继电器,2007,12(35):420-424.