一种新型介质损耗tanδ测量系统研究  

Measuring system for dielectric loss tan δ

作　　者：李怀龙[1] 孟志强[1] 王同业[1] 陈燕东[1] 

机构地区：[1]湖南大学电气与信息工程学院,湖南长沙410082

出　　处：《电力自动化设备》2006年第11期55-57,共3页Electric Power Automation Equipment

摘　　要：为了提高测量介质损耗和准确度,对介质损耗测量中存在的误差进行了研究,介绍过零点时差法测量介质损耗的原理。详细讨论了过零点测量时失调与温飘误差和电网波动误差的形成机理,针对过零点时差法测量tanδ时存在的主要误差——过零比较器的失调与温飘误差和电网波动产生的误差,设计了一种基于AT89C51单片机、采用双向过零平均鉴相技术和锁相技术的介质损耗tanδ测量系统,给出该测量系统的详细工作过程,得出了样机对试品的测量结果,对试品测量结果分析后证明该系统可有效消除过零点失调与温飘误差和电网波动误差的影响。To improve the accuracy of dielectric loss measueement,measurement errors of the dielectric loss are studied,and the measuring principle of crossing-zero time difference method is introduced. The generating mechnism of malajustment and temperature excursion errors of crossing -zero measurement and power network undulation is discussed. To avoid main errors in measuring the dielectric loss tan δ,caused by maladjustment and temperature excursion errors of crossing-zero comparator and power network undulation,a new measuring system based on AT 89C 51 microcontroller is presented ,which uses bidirectional crossing- zero mean phase demodulation and phase -locked technology to eliminate the maladjustment and excursion errors and frequency tracking to reduce error induced from the power network undulation. The operating process is described in detail and measurements of a prototype achieved. The analysis shows its effectiveness.

关 键 词：介质损耗 平均鉴相 单片机 双向过零 失调 

分 类 号：TM934[电气工程—电力电子与电力传动]