数字检相式互感器校验仪误差分析

Error Analysis of C. T. Calibrator with Digital Phase Detectors

对数字检相式互感器校验仪进行了误差分析，包括取差电阻自身阻值误差和对取差互感器反作用误差、９０°移相误差、异或门检相误差、ＣＬＫ频率误差、平衡彻底世误差、Ｄ／Ａ转换误差、传输系数误差、关门误差及噪声等。通过分析，认为起主要作用的是ＣＬＫ频率和异或门检相带来的误差，在最佳ＣＬＫ频率，两项之和近达±１％ＦＳ。最后，整机误差综合后误差略超±１％ＦＳ，与实测结果相符。

This paper analyse error source of the C. T. calibrator with digital phase detectors,including differential transformor,differential resistance alld its reaction to differential resistance, shifting 90-degree phase, XOR gate phase detecting, CLK frequency, D/A transformation, transmission coefficient,colnparing and noise. The main errors above are CLK frequency and XOR gate phase detection. At the best frequency, the sum of the two errors is nearly ±1% FS. Finally,by synthesizing the error as a whole,it is a little bit over ±1% Fs.