Alternating current transformer

Abstract

The invention relates to an alternating current transformer. The alternating current transformer comprises a magnetic core, a primary winding, a first secondary winding, a second secondary winding, a gain amplification unit, a load element and an auxiliary direct current exciting circuit, wherein the primary winding, the first secondary winding and the second secondary winding are respectively arranged on the magnetic core; the primary winding is connected with a tested circuit; after being serially connected with the gain amplification unit, the first secondary winding is serially connected with the second secondary winding; the second secondary winding is also serially connected with the load element; the auxiliary direct current exciting circuit is used for providing direct current exciting current; and the direct current exciting current is used for generating a magnetic field, so that working magnetic induction intensity of the magnetic core is between one fifth and four fifths of saturation induction intensity of the magnetic core. By the alternating current transformer, the magnetic conductivity of the magnetic core is increased, the conversion errors of the alternating current transformer are reduced, and the precision of the alternating current transformer is improved.

Description

technical field [0001] The invention relates to the technical field of transformers, in particular to an alternating current transformer. Background technique [0002] The AC current transformer is one of the key components in the electrical measuring instrument, and its accuracy directly affects the overall technical indicators of the instrument. Therefore, the AC current transformer is required to have the characteristics of high stability and small error. The traditional electronic compensation zero-flux current transformer, its principle block diagram is as follows figure 1 shown. The electronically compensated zero-flux current transformer includes a multi-winding transformer 1 , a high-gain electronic circuit amplifying unit 2 and a load resistor 3 . The multi-winding transformer 1 includes a primary winding N1, a first secondary winding N3 and a second secondary winding N2. where L S is the equivalent excitation inductance of the primary winding N1. The amplifica...

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Problems solved by technology

Moreover, for the consideration of the stability of the electronic circuit and the signal-to-noise ratio of the sampling signal, the improvement of the gain amplification factor A and the load resistance R L The reduction is very limited, so the traditional zero-flux current transformer based on electronic compensation still has a large conversion error and low precision, which limits the application of this type of current transformer in the field of higher precision electrical measurement

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