High-accuracy electronic compensated current transformer

Abstract

The invention relates to a high-accuracy electronic compensated current transformer, and belongs to the field of current measuring. The compensated current transformer is composed of an iron core, a winding and an auxiliary circuit used for compensating a magnetizing current. The iron core is a nested structure composed of a detecting iron core and a shielding iron core, the detecting iron core detects the zero magnetic flux state of the iron core through the winding wound on the detecting iron core and then controls the auxiliary circuit to provide the excitation current necessary for the current transformer, so that the error source of the current transformer is eliminated, and accuracy of the current transformer is greatly improved. A 0.001-level high-accuracy current transformer which is insensitive to secondary loads and an open type current transformer with the accuracy degree superior to 0.01level can be developed by using the high-accuracy electronic compensated current transformer.

Description

technical field [0001] The invention relates to a high-accuracy electronic compensation type current transformer, which belongs to the field of current measurement. Background technique [0002] The development of traditional electromagnetic current transformers is very mature. Through some compensation measures, the accuracy can reach 0.01 level. The accuracy of the double-stage current transformer used as a current standard in the laboratory can reach 0.001 level, but its load capacity is poor, and it is generally only used as a standard. The current comparator with higher accuracy does not belong to the type of current transformer, and generally can only be used for laboratory calibration and verification. [0003] In recent years, people pay more and more attention to the online measurement of current, phase and power. To achieve this purpose, it is often necessary to disconnect the primary circuit to access a high-accuracy current transformer. This work is time-consu...

AI Technical Summary

Problems solved by technology

Its essence is a zero-flux self-balancing current transformer. Due to the limitation of system stability, the amplification factor of the feedback circuit is limited, so its error is still relatively high.

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