A digital differential traceability system and method for an electronic transformer calibrator

Abstract

The invention relates to a digital differential traceability system and method for an electronic transformer calibrator. The traceability system includes: a power source, a multi-channel signal conversion module, a digital differential input module and an optimal message selection module; a multi-channel signal conversion module The module includes a signal conversion module with n channels; an ordinary power source is used as the voltage output source, which reduces the requirements for hardware and increases the requirements for digital differential algorithms; a digital differential algorithm based on Hilbert-Huang transform is proposed , realizing the high-precision addition of digital differential, reducing the performance requirements for the power source; for the system random error caused by the digital differential algorithm, using multiple channels to select the optimal standard signal output, reducing the system random error and improving the traceability Reliability: The error of the electronic transformer calibrator is expressed according to the difference between the superimposed standard differential and the indication error of the electronic transformer calibrator, so as to realize its traceability.

Description

technical field [0001] The invention relates to the field of traceability testing of electronic transformer calibrators, in particular to a digital differential traceability system and method of an electronic transformer calibrator. Background technique [0002] Electronic transformers meet the needs of digital, networked and intelligent power grid construction. They have excellent sensing performance and insulation performance. They are widely used in smart substations. As an important device in the measurement assurance system, their traceability system directly affects the operation. Reliability and Metrological Accuracy. [0003] At present, the traditional electromagnetic transformer has a complete traceability system, and the traceability method of the electronic transformer calibrator is based on the traceability method of the traditional transformer calibrator. , but the two work differently. The differential method has become mature in the traceability of traditio...

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. Research on the method of traceability of unit tester value" (Wu Dalei, Sun Yansong, Lin Jun, etc., Electronic Technology, 2018, 044(008): 122-125) It is proposed to continue to use the traditional transformer calibrator verification device, combined with 3458A digital multimeter and clock Synchronization device, using analog differential method to measure the difference, trace the source of the electronic transformer calibrator

However, there are two problems in the traceability process: first, there is a lack of perfect theoretical analysis; second, the stability of the simulated differential source is poor, and the uncertainty is not evaluated to verify whether it can meet the reliability requirements

Literature "Key Technologies Affecting the Design Accuracy of Electronic Transformer Calibration System" (Zhang Mingzhu, Li Kaicheng, Li Zhenxing. Electric Measurement and Instrumentation, 2012,49(12):5.), "Error Analysis of Electronic Transformer Calibration System Method" (Lin Guoying, Zhou Shangli, Electrical Measurement and Instrumentation, 2010, 47(006): 28-31) Aiming at the problem of large phase error introduced when the signal source frequency shifts or contains harmonics, a window error correction is proposed Algorithm and quasi-synchronous DFT algorithm can reduce the phase error, but when the signal is in a non-stationary state, it still has limitations

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