Improved electronic transformer current collection method

Abstract

The invention discloses an improved electronic transformer current collection method. The method comprises the following steps of (1) sampling through a digital-to-analog conversion chip, wherein thedigital-to-analog conversion chip adopts a 16-bit digital-to-analog conversion chip; and (2) performing data interpolation operation on sampled data by using a data interpolation algorithm in order toobtain an electric quantity waveform of an electric power system, judging whether a sampling value is valid or not according to the piecewise continuous derivability of the electric quantity waveformof the electric power system, and updating the invalid sampling value by adopting a Newton interpolation method if the sampling value is invalid. According to the method, the sampling precision and the Nyquist cut-off frequency of a collection unit are improved; and the Newton interpolation method is used for carrying out data processing on the sampled signal to filter out the low-frequency noisecaused by spectrum aliasing and the burrs of the system, so that the problems of anti-interference performance, low precision of an integral link and distortion of an electronic transformer collectorare effectively solved, the sampling precision and reliability of the electronic transformer collector are improved, and a guarantee is provided for the normal operation of a rear-end merging unit and a protection device.

Description

technical field [0001] The invention belongs to the technical field of electric power system automation, and in particular relates to an improved electronic transformer current collection method. Background technique [0002] The Rogowski coil is the most commonly used sensing unit in the light-transmitting current transformer. At present, most of the electronic transformers used in China are based on this. It is an air-core inductance coil formed by uniformly winding wires on a non-magnetic skeleton with a circular equal cross-section. Its output voltage is proportional to the differential signal of the primary current with respect to time. Therefore, the integral link is a necessary link based on the current acquisition of the Rogowski coil current transformer. The accuracy of the integral determines the accuracy of the final signal restoration. The quality of the integral link will directly affect the The transient steady-state performance of the electronic transformer, ...

AI Technical Summary

Problems solved by technology

Both of these two solutions have certain technical shortcomings. Because the accuracy and reliability of hardware integration are limited by the electrical parameters of electronic components, there are risks in their accuracy and reliability; the software integration implemented by the merging unit is subject to the collector The sampling bandwidth and transmission rate are limited, and due to the existence of spectral aliasing, low-frequency noise, voltage drift and other phenomena, as well as the limitation of the electrical parameters of the electronic device itself, the accuracy of the integration link cannot be well guaranteed, and even the distortion of high-frequency signals It will lead to an abnormality in the integration link

Therefore, there are certain risks in the accuracy and reliability of the existing acquisition methods, and there is still a large room for improvement in the electronic transformer current acquisition method

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