AC trace source DC correcting method

Abstract

The invention discloses a tracing to the source direct current correcting method for a Delta-typed direct current. By externally adding a stable AC voltage source, AC voltage output forms a voltage channel by a voltage divider, low conversion voltage value of a voltage loop is obtained from the voltage channel; the AC voltage output of the stable AC voltage source is connected with a current transformer by a high precision resistance, thus forming a current channel; and the measured voltage value representing current is obtained from the current channel by impedance conversion; precise stable voltage direct current reference voltage and the measured conversion voltage value of the voltage loop are connected into an AC / DC voltage comparator with self correction, so as to obtain a sine voltage output by the voltage source steadily; composite ratio and angular difference of the current transformer and an equivalent impedance of a secondary load are obtained in a way that the measured voltage value obtained in the AC / DC voltage comparator is combined and connected based on the obtained sine voltage, error compensation parameters are stored for error compensation of impedance conversion measured by the following current. The invention has few error sources, simple electrical structure and high precision.

Description

technical field [0001] The invention relates to a correction technology, in particular to a correction method for a delta-type alternating current traceable direct current. Background technique [0002] In the process of power frequency AC measurement, it is difficult to guarantee the high precision and long-term stability of voltage, current and power measurement due to frequency changes, distribution parameters, device AC parameters and temperature characteristics. Especially when low impedance measurement is performed on a small current, it will bring a very large error. [0003] The AC→DC traceability methods adopted by existing laboratories are as follows: figure 1 As shown in the figure, the working principle of the power comparator is based on the current comparator technology and the DC voltage traceability technology. The DC voltage traceability technology traces the system’s working voltage AC 100V to the DC voltage standard U through the AC and DC voltage compar...

AI Technical Summary

Problems solved by technology

[0006] This method has as many as eight links and many error sources, that is, instruments of various grades of accuracy complete the standard transfer through the first-level comparison method. If there is a problem in one link, there will be a large error; the calibration process is easy. error, very troublesome

The equipment is huge, complicated to operate, cannot be moved, and is not suitable as a benchmark for daily work

[0007] In addition, because the instrument for measuring alternating current often needs to measure from mA to hundreds of amperes, K I The uncertainty in the measurement range is often 1-2 orders of magnitude larger than other types of error sources, and the current transformer with wide range limit error and small error is large in size and cannot realize the portability of the instrument at all.

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