A High Precision Digital Output Electronic Current Transformer

Abstract

A high-precision-digital-quantity-output electronic current transformer comprises a high-voltage-side sensing unit, a lower-voltage-side acquiring and transmitting unit and a high-voltage shell, and the high-voltage-side sensing unit comprises two hollow coil sensors which are positioned in a grounded screening case and connected with the lower-voltage-side acquiring and transmitting unit in a base via a shielding cable. The high-precision-digital-quantity-output electronic current transformer has the advantages that the two hollow coil sensors are adopted to measure current in a wire once by the high-voltage-side sensing unit, and synthesized output of two coils is adopted as final output of the transformer, so that common-mode interference is decreased beneficially, and accuracy in measurement of the transformer is increased; difference between outputs of the two hollow coil sensors is adopted to judge running status of the transformer, so that self-diagnosis on accuracy of the transformer is achieved, and the level of intelligentization is improved.

Description

technical field [0001] The invention is an electronic current transformer with high-precision digital quantity output, which is used for real-time and accurate measurement of current signals in transmission lines of intelligent substations. Background technique [0002] The accuracy and reliability of electronic current transformers are the guarantee for the safe and stable operation of power systems. At present, there are many types of electronic current transformers, such as an electronic current transformer disclosed in Chinese patent CN101707129A, which uses an optical element as a sensor. Chinese patent CN203838218U discloses an electronic current transformer powered by CT on the high voltage side, using a Rogowski coil as a measuring unit. Chinese patent CN103646768A provides an active electronic transformer, the high-voltage side uses an iron core with an air gap as an energy-taking coil. However, in these transformers, the optical components are susceptible to fact...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problems of low accuracy and inconvenient energy supply in current electronic current transformers, this invention proposes a high-precision digital output electronic current transformer. The high-voltage side sensing unit uses two air-core coil sensors to measure once The current in the wire uses the comprehensive output of the two coils as the final output of the transformer, which is conducive to reducing common-mode interference and improving the accuracy of transformer measurement

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