Correlation extension method and system for traceability of Hilbert phase-shifted electronic transformer calibrator

Abstract

The invention relates to a method and a system for tracing the source of a Hilbert phase-shifting electronic transformer calibrator by extending the correlation degree. The standard power source voltage is used to output two identical analog signals and comparison signals, and the analog signals are output to the electronic transformer calibrator. Analog input port; carry out timing weighted correlation waveform matching endpoint extension to the digital sampled signal after the comparison signal is sampled by standard A / D, and add Nuttall window to the extension data, and then perform Hilbert transform phase shift to determine Phase difference; the measurement error of the electronic transformer calibrator is determined based on the differential signal and the indication error of the electronic transformer calibrator. The invention takes the Hilbert transform phase shift as the premise and the characteristics of the signal source as the basis, and proposes a method of combining the time series weighted correlation waveform matching end point extension and Nuttall window function to overcome the end point effect and thereby improve the phase difference. added precision.

Description

technical field [0001] The embodiments of the present invention relate to the technical field of traceability testing of electronic transformer calibrators, and in particular, to a method and system for traceability of a Hilbert phase-shifted electronic transformer calibrator by correlation extension. Background technique [0002] Electronic transformers are a new demand for the development of digital, networked and intelligent power grids. They have superior sensing performance and insulation performance, and are widely used in smart substations. As an important equipment in the measurement assurance system, their traceability system directly Affect operation reliability and measurement accuracy. [0003] At present, the traceability method of electronic transformer calibrator is based on the traditional traceability method of transformer calibrator, both of which use the principle of differential measurement, but the working principles of the two are different. The differ...

AI Technical Summary

Problems solved by technology

The micro-difference method has become mature in the traceability of the traditional transformer calibrator, and has met the requirements through the evaluation of uncertainty. However, there are few studies on the traceability of the electronic transformer calibrator with the micro-difference method. It is proposed to continue to use the traditional transformer calibrator verification device, combined with the 3458A digital multimeter and clock synchronization device, and use the analog differential method to measure the difference to trace the source of the electronic transformer calibrator

However, the hardware of the analog differential method is complex, susceptible to time drift and temperature drift, and its stability is poor, which leads to the problem of large uncertainty introduced by the traceability method and unreliable traceability results

The document "Design of Quantitative Source Traceability Scheme for Electronic Transformer Calibrator Overall Inspection Device" (Lei Ming, Guo Diao, Yan Lieqi, etc. for electronic technology) proposes a method for digital differential source traceability, but does not add any traceability to the differential In-depth research on specific methods and characteristics, and no feasible method to improve the accuracy of differential addition, so the traceability of this method is not perfect enough

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