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Author(s): |
Wu Zhu, Shanghai University of Electric Power shanghai, Shanghai, China, 200090
Shuixiu Guan, Shanghai University of Electric Power shanghai, Shanghai, China, 200090
Xiangcun Tu, Shanghai University of Electric Power shanghai, Shanghai, China, 200090 |
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Abstract: |
In the high-precision measurement of the ac parameters, log and anti-log amplifier was usually used to achieve true RMS AC-DC conversion. The drift of precise resistance and transistor reverse saturation current change with time and temperature and other factors make long-term stability of the system gain is not ideal. To further improve the instrument's long-term stability and accuracy, self-calibration of the instrument must be done. However, the RMS self-calibration is a direct and effective method with high stable standard sinusoidal signal inside the instrument, but this method is very complicated to achieve. This paper presents a novel RMS converter self-calibration method. In order to achieve RMS converter self-calibration, the gain of positive and negative channels is calibrated by DC reference voltage to calibrate, respectively. Experimental results show that the method is feasible.
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