摘要
现有变压器内部故障防护方法仍有不足,大型电力变压器爆燃事故时有发生。针对变压器轻微缺陷发展为严重缺陷、最终发生电弧击穿的全过程,文中提出构建大型电力变压器安全运行三级防线:第一级为轻微缺陷的检测和预警,文中分析了各类缺陷检测方法的现状,并初步提出了基于多点温度的热缺陷辨识方法;第二级为严重放电缺陷阶段的主动保护,在发生贯穿性电弧故障之前动作跳闸,文中通过放电试验研究了严重放电缺陷的脉冲电流、特高频及声信号特征,提出了基于多参量的变压器主动保护方案和新型轻瓦斯保护方案;第三级针对电弧故障提升传统变压器保护技术的灵敏性和快速性,为此文中提出了估算变压器主磁链的铁芯饱和判别技术,构建了基于漏磁幅值及对称性差异的匝间故障高灵敏度保护方案。文中对变压器主动保护技术的探索和所提出的三级防线故障防护体系对于提升变压器安全运行水平具有重要意义。
The existing protection methods for transformer internal faults are still imperfect,and explosion accidents of largecapacity power transformers occur from time to time.In view of the whole evolving process from minor defects to serious defects and finally arc breakdown in the transformer,the paper proposes to build three defensive lines for the safe operation of largecapacity power transformers.The first line is the detection and early warning of minor defects.The paper analyzes the current status of various defect detection methods and preliminarily proposes a thermal defect identification method based on multi-point temperature.The second line is the active protection in the stage of serious discharge defects,which trips before the occurrence of penetrating arc fault.The paper studies the characteristics of pulse current,ultra high frequency and acoustic signal of serious discharge defects through discharge tests,and proposes an active transformer protection scheme based on multiple parameters and a new Bucholz protection scheme.The third line is to improve the sensitivity and rapidity of traditional transformer protection technologies for arc faults.Therefore,the paper proposes core saturation discrimination technique for estimating the main magnetic flux of the transformer,and constructs an inter-turn fault protection scheme with high sensitivity based on the amplitude and symmetry difference in magnetic flux leakage.The exploration of active transformer protection technology and the proposed fault protection system of three defensive lines are of great significance for improving the safe operation level of transformers.
作者
郑玉平
郝治国
薛众鑫
郝建
潘书燕
龚心怡
ZHENG Yuping;HAO Zhiguo;XUE Zhongrin;HAO Jian;PAN Shuyan;GONG Xinyi(NARI Group Corporation(State Grid Electric Power Research Institute),Nanjing 211106,China;State Key Laboratory of Smart Grid Protection and Control,Nanjing 211106,China;School of Electrical Engineering,Xi'an Jiaotong University,Xi'an 710049,China;State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University),Chongqing 400044,China)
出处
《电力系统自动化》
EI
CSCD
北大核心
2023年第20期1-12,共12页
Automation of Electric Power Systems
基金
国家自然科学基金资助项目(U1866603)
国家电网公司科技项目(5100-202340030A-1-1ZN)。
关键词
电力变压器
主动保护
安全运行
缺陷辨识
匝间故障
power transformer
active protection
safe operation
defect identification
inter-turn fault
