同步采样技术在金属氧化物避雷器特性检测中的应用

介绍金属氧化物避雷器(MOA)阻性电流基波测量的基本原理,分析了测量阻性电流基波时同步采样的必要性,采用同步采样AD转换器MAX1310,可保证电压电流信号同时采样,避免了投影角的测量误差;采用锁相环技术可实现特定周期内整数点采样。实验证明采用同步采样技术的实验装置,测量精度(特别是夹角测量精度)有了较大的提高。同步采样技术减小了非整周期采样所带来的栅栏泄漏效应,使普通FFT谐波分析可以应用到MOA阻性电流基波的测量中,减小了采样不同步所造成基波电压和基波电流之间的夹角误差。同步采样技术对于精确测量两个信号基波夹角具有普遍的意义。

Appling of Simultaneous Sampling in MOA Performance Inspection

The fundamentals of measurement of cardinal wave of resistive current was described and the necessity for simultaneous sampling at measuring cardinal wave of resistive current was analyzed.Application of AD converter MAX1310 can ensure simultaneous sampling of voltage and current signals avoiding measurement error of projection angle.Application of locked phase loop technology may realize sampling at integer points of given period.Practice shows considerable rise of measurement precision(esc in case of angle measurement) with usage of simultaneous sampling which reduces the grid leakage effect occurred at sampling at non-integer period,making possibility of applying FFT harmony analysis to measurement of cardinal current wave and reducing the angle measurement error between cardinal voltage and current.The simultaneous sampling technique has an universal significance in accurate measurement of angle between two cardinal wave signals.