Zero sequence current transformer applicable to overhead line

Abstract

The invention discloses a zero sequence current transformer applicable to an overhead line. The current transformer comprises a base tube, a core column, a bolt, a current transformer body and a clamping plate assembly, wherein the base tube comprises a tube pressing part and a plate sealing part; the plate sealing part and the tube pressing part are disposed in a relatively fixed manner; the plate sealing part is equipped with a limiting slide hole and a threading hole; the core column is shaped like a frustum and equipped with a top pressing slide groove and a conical pressing joint face; a center screw hole is formed in the center of the core column along the axial direction of the tube pressing part; the clamping plate assembly comprises at least three line clamping plates; each line clamping plate faces a corresponding pressing joint boss; the bolt comprises a rod body, a fastening part and an outer thread connecting part; the rod body of the bolt passes through the limiting slide hole and is located in the center screw hole of the core column; the current transformer body comprises an annular induction body; each line clamping hole is located in a hole cavity of the annular induction body; the bolt is rotated and the core column is pulled to push and press each line clamping plate, so that the line clamping plates can move outwards along the radial direction of the tube pressing part; the base tube is equipped with an installation screw hole; and a temperature sensing device is firmly disposed in the installation screw hole. The current transformer disclosed by the invention has the advantages of a compact structure and good performance.

Description

technical field [0001] The invention belongs to the technical field of electric power, and particularly relates to a zero-sequence current transformer for overhead lines. Background technique [0002] The basic principle of zero-sequence current protection is based on Kirchhoff's current law: the algebraic sum of the complex currents 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 winding of the zero-sequence current transformer has no signal output, and the actuator does not act. When an electric shock or leakage fault occurs, the vector sum of the currents of each phase is not zero, and the fault current generates 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 the zero-...

AI Technical Summary

Problems solved by technology

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

Images