Wide-range current transformer and error compensation method thereof

Abstract

The invention discloses a wide-range current transformer and an error compensation method thereof, the wide-range current transformer comprises a main mutual inductance unit and a compensation unit, and the main mutual inductance unit comprises a first winding, a second winding, a main insulating layer and a main iron core; the compensation unit comprises a first compensation winding, a second compensation winding and a compensation iron core; the first winding is serially connected with the first compensation winding. The second winding is parallelly connected with the second compensation winding. The compensation unit injects a compensation magnetic flux on the second winding of the main mutual inductance unit to compensate the excitation magnetic flux of the main mutual inductance unit. According to the invention, the compensation unit is arranged to form the compensation magnetic flux to offset the excitation magnetic flux of the main mutual inductance unit, so that the error compensation of the main mutual inductor under 0.1-1% In and 120-200% In is realized, the metering deviation is reduced, the wide-range current transformer with the accurate metering range of 0.1-200% In is realized, the accuracy of power grid operation metering is ensured, and the working efficiency is improved. And meanwhile, a plurality of technical problems caused by realizing a wide-range current transformer in the prior art are also solved.

Description

technical field [0001] The invention belongs to the technical field of power equipment, and more particularly, relates to a wide-range current transformer and an error compensation method thereof. Background technique [0002] At present, some loads in the power system vary widely, and the line current often exceeds the normal operating current range. When the current is too high or too small, the measurement deviation is large, which affects the accuracy of the measurement. According to JJG1021 "Power Transformer" verification regulations, the accurate measurement range of S-class current transformer is rated primary current I n 1% to 120%, the current transformers put into operation generally meet the measurement accuracy within this range. In actual operation, the measurement range of the current transformer often exceeds 120%I n or below 1%I n At this time, it may cause measurement deviation, and it is difficult to ensure the accuracy of grid operation measurement. ...

AI Technical Summary

Problems solved by technology

The accurate measurement range of the original current transformer is 1~120%I n , and the accurate measurement range required by the wide range is 0.1~200%I n , the latter is nearly 17 times larger than the former; only by increasing the cross-sectional area of ​​the iron core and sacrificing the utilization rate of the iron core, the economy is insufficient, and the transformer is large in size and heavy in weight, and it is not easy to hang the grid.

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