一种变频变压的双频注入绝缘监测方法  

A dual-frequency injection insulation monitoring method based on frequency conversion and voltage conversion

作　　者：刘建辉 曾铁军[1] 王新林[1] LIU Jianhui;ZENG Tiejun;WANG Xinlin(School of Electrical Engineering,University of South China,Hengyang,Hu’nan 421000)

机构地区：[1]南华大学电气工程学院,湖南衡阳421000

出　　处：《电气技术》2022年第4期18-24,共7页Electrical Engineering

基　　金：省部级重点项目(180SJZ005);国家自然科学基金项目(190KHX009)。

摘　　要：核反应堆电加热工程环境下的高温、大电流、加热损耗导致的单相绝缘故障是IT系统的主要故障形式,本文分析发生单相绝缘故障的两种情形:①故障支路绝缘电阻偏大时导致总注入源回路电流偏小;②故障支路分布电容过大导致支路阻性电流偏小。基于这两种情形产生的误差,本文总结双频法检测绝缘电阻的基本原理,并在利用双相锁相放大技术提取微弱信号的基础上,提出一种变频变压的双频注入绝缘监测方法。通过在Matlab/Simulink中搭建仿真模型,经多次仿真试验表明,绝缘电阻在2~500kΩ、500kΩ~3MΩ时误差分别控制在5%、10%以内,验证了该方法在理论上的可行性。The single-phase insulation fault caused by high temperature,high current and heating loss in the nuclear reactor electric heating engineering environment is the main fault in IT systems.The paper analyzes two scenarios of single-phase insulation faults:①the total injected source loop current is small when the insulation resistance of the faulty branch is large;②the branch resistive current is small when the distributed capacitance of the faulty branch is too large.Based on the errors arising from these two scenarios,the paper summarizes the basic principle of the dual-frequency method to detect insulation resistance,and proposes a dual-frequency injection insulation monitoring method for variable frequency and voltage based on the weak signals extracted by dual-phase locking amplification technology.By building a simulation model in Matlab/Simulink,the data from several simulation tests show that the error of insulation resistance is controlled within 5%and 10%at 2~500kΩand 500kΩ~3MΩ.The theoretical feasibility of the method is verified.

关 键 词：IT系统 锁相放大 变频变压 双频注入法 绝缘监测 

分 类 号：TM44[电气工程—电器] TL364.4[核科学技术—核技术及应用]