Three-phase power zero-sequence current transformer

Abstract

The invention discloses a three-phase power zero-sequence current transformer. The current transformer comprises a core tube, a current transformer, a planar nut, two sets of pressing claw assemblies and six crimping parts, wherein six radial limiting sliding holes are formed in the tube wall of the core tube; each crimping part is equipped with a plate pressing part and an anti-loosening connecting part; the crimping parts are detachably arranged on the core tube through the anti-loosening connecting parts; each set of pressing claw assembly comprises three pressing claws; each pressing claw comprises a top plate part, a guiding sliding block part and a driving thread part; the guiding sliding block part is inserted in the corresponding radial limiting sliding hole; the driving thread part extends to the tube cavity of the core tube; the planar nut is rotationally arranged in the tube cavity of the core tube; a planar thread part is arranged at each of the two side ends, along the axial direction of the core tube, of the planar nut separately; each planar thread part is meshed and adapted with the driving thread part of each pressing claw in one corresponding set of pressing claw assembly; the current transformer also comprises an annular base body; the annular base body is positioned on the outer side of the crimping part; the planar nut synchronously drives the pressing claws in the two sets of pressing claw assemblies to move towards the center of the core tube in a manner of being close to each other or far away from each other. The three-phase power zero-sequence current transformer has an excellent ant-loosening effect.

Description

technical field [0001] The invention belongs to the technical field of electric power, and in particular relates to a three-phase electric zero-sequence current transformer. Background technique [0002] The basic principle of zero-sequence current protection is based on Kirchhoff's current law: the algebraic sum of the complex current flowing into any node in the circuit is equal to zero. When the line and electrical equipment are normal, the vector sum of the currents of each phase is equal to zero. Therefore, the secondary side winding of the zero-sequence current transformer has no signal output, and the actuator does not operate. When an electric shock or leakage fault occurs, the vector sum of the currents of each phase is not zero, and the fault current causes magnetic flux in the iron core of the zero-sequence current transformer, and the current generated by the zero-sequence current transformer is the zero-sequence current. When the protection mechanism receives t...

AI Technical Summary

Problems solved by technology

[0003] Most of the existing zero-sequence current transformers are installed by means of flange installation or bonding. The installation location generally needs to be reserved, so its application and promotion are more restricted.

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