Electromagnetic transformer error measurement method and system based on digital signal processing

Abstract

The invention discloses a method and system for measuring errors of an electromagnetic type mutual inductor based on digital signal processing. Detected signals are acquired through a first sampling circuit unit, standard signals are acquired through a second sampling circuit unit, and the detected signals and the standard signals are combined through an amplifying circuit unit and an automatic gain control circuit unit to improve a signal-to-noise ratio, and are converted into digital signals through an AD converter unit, sampling analysis is carried out on the digital signals output by the AD converter unit by respectively adopting corresponding algorithms through an FPGA digital signal processing circuit unit, the amplitude value of a fundamental wave is found out, and a ratio error and a phase difference are obtained through the solution of a division formula. The errors of the electromagnetic type mutual inductor are measured. The method and system are high in processing speed, free of an integral windup effect, simple in achievement, stable in operation, light, high in precision, good in linearity and wide in measurement range, overcome the defects that a traditional mutual inductor measuring device is high in signal requirement and slow in response, and have practical significance in the detection and calibration of an existing electromagnetic type mutual inductor.

Description

technical field [0001] The invention belongs to the technical field of transformer measurement, in particular to an electromagnetic transformer error measurement method and system based on digital signal processing. Background technique [0002] Traditional transformer measurement methods mainly use analog circuits to process signals. During the calibration process, there are high environmental requirements, sensitivity to high-order harmonics in the circuit, and slow speed. The measurement output data needs to be processed by the host computer. The dependence is high, and the digital instrument cannot be connected separately and transmitted and shared in the local area network; [0003] In the original analog circuit, in order to obtain the 90° trigger signal, the integrator in the 90° phase-shift circuit needs to use an operational amplifier, but due to the imperfection of the operational amplifier, the input has a bias current, and the integration saturation effect often ...

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Problems solved by technology

[0005] The purpose of the embodiments of the present invention is to provide an electromagnetic transformer error measurement method and system based on digital signal processing, aiming to solve the problem that the traditional measurement method collects data according to the trigger signal because the amount of effective data after collection is small and is vulnerable to testing. Due to the influence of environmental interference, it is not easy to correct the data, and the problem of distortion occurs

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