Residual current transformer

Abstract

The invention discloses a residual current transformer which comprises a magnetic core component, a coil component and a shielding component. The coil component surrounds the outer surface of the rectangular magnetic core component and comprises a test coil and a measurement coil. The measurement coil is positioned outside the test coil, surrounds the outer surface of the magnetic core component and comprises a left winding coil, a right winding coil, two upper winding coils and two lower winding coils, wherein the left winding coil is wound along a first direction, the right winding coil is wound along a second direction, the two upper winding coils are wound along the first direction and the second direction respectively, and the two lower winding coils are wound along the first direction and the second direction respectively. The left winding coil and the right winding coil are in parallel connection and positioned between the two upper winding coils in parallel connection and the two lower winding coils in parallel connection. By the aid of the residual current transformer, saturation of the shielding component can be restrained, measurement errors are reduced, and reliability of a circuit breaker is improved.

Description

technical field [0001] The invention relates to the field of circuit breakers, in particular to a residual current transformer. Background technique [0002] At present, most common residual current transformers use ring-shaped bobbins and coils with uniform electromagnetic fields. Such residual current transformers are generally used in molded case circuit breakers with relatively small current specifications. For frame circuit breakers, due to the limited internal space, and considering factors such as high temperature rise of the busbar when operating high current, electrical insulation, and easy installation, the residual current transformer for frame circuit breakers is generally installed outside the circuit breaker and has a is a rectangle. The traditional residual current transformer is that the measuring coil is evenly wound on the magnetic core assembly, such as figure 1 shown. In this way, in actual work, due to the generation of false residual current, the cir...

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Problems solved by technology

[0003] (1) The position of the primary current-carrying conductor in the core window is not centered or the distance to each side is not the same, or the secondary winding is unevenly distributed on the core, which may cause the magnetic circuit to be asymmetrical, resulting in partial saturation of the magnetic circuit , generating a false residual current in the secondary winding;

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