A method for tracing the source of analog input merging unit calibrator based on digital differential method

Abstract

The invention discloses a method for tracing the source of an analog input merging unit calibrator based on the digital differential method. Construct a 0.02-level standard merging unit with superimposed differential function, and realize the traceability method based on digital differential. This method includes a phase differential algorithm based on Hilbert transform. Under the comprehensive influence of reference conditions, it has better than 10 ‑10 The phase-shifting accuracy of 0.05 and below can be obtained by using the digital differential method, which can provide traceability for merging unit calibrators with an accuracy level of 0.05 and below. , good stability, not easy to be affected by the environment, high algorithm precision, and has good engineering application value.

Description

technical field [0001] The invention belongs to the technical field of calibration of digital electric energy meters, and in particular relates to a method for tracing the source of an analog input merging unit calibrator based on a digital differential method. Background technique [0002] At present, the principle of its analog input merging unit calibrator is: [0003] The analog input merging unit calibrator is mainly composed of a standard power source, a synchronous clock source, a standard signal converter, a synchronous A / D sampler and a computing unit. Its structure is as follows: figure 2 As shown, the standard power source outputs two identical analog signals at different test points, one is sent to the merging unit under test, and the other is sent to the merging unit calibrator. The calibrator of the merged unit under test and the standard A / D sampler simultaneously receive the synchronous pulse second signal (PPS) for synchronous sampling. After the input sign...

AI Technical Summary

Problems solved by technology

However, there are great differences between the merging unit calibrator and the traditional transformer calibrator in terms of signal input and calibration principle

The measured input channel of the merging unit calibrator is a data frame conforming to IEC61850, which adopts the direct measurement method under polar coordinates. If the traditional Cartesian coordinate system difference measurement method is still used for the overall verification device, a large theoretical error will be introduced to a certain extent

[0008] In addition, the key part of the power amplifier in the analog differential source will inevitably produce a large power dissipation when it is working, which will affect the performance of itself and surrounding devices, resulting in instability of the output voltage and current, affected by temperature drift and time drift. Affected, the device parameters will change, resulting in changes in performance, and the accuracy of the differential output is difficult to guarantee

At the same time, the cost of using high-precision analog devices will be greatly increased

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