A method for verifying the mixed connection of the secondary circuit of the current transformer

Abstract

The invention provides a hybrid junction verification method for secondary loops of current transformers. The method comprises that n terminal rows are arranged in continuous numbers, and n protectorsare named correspondingly; A phase lines of secondary windings of n current transformers are disconnected with A phase contacts in the corresponding terminal rows, the A phase contact of the terminalrow in the minimal number is shorted from an N phase contact of the maximal number, each of the A phase contacts in other numbers is shorted from an N phase contact in the last number, and each of the N phase contact is shorted from the A phase contact in the next number; and the current loading sequence and loading values of the n terminal rows are determined, and the current values of the n named protectors after each time of current loading are obtained to determine a hybrid junction condition of the secondary windings of the n current transformers. Thus, the hybrid junction phenomenon ofthe secondary loops of the current transformers can be checked rapidly, it is ensured that wiring of the secondary loops of the current transformers is correct, and the protectors are avoided from misoperation.

Description

technical field [0001] The invention relates to the technical field of relay protection detection, in particular to a method for verifying the hybrid connection of a secondary circuit of a current transformer. Background technique [0002] The current transformer uses the principle of electromagnetic induction to convert the large current on the primary side into a small current on the secondary side, and then introduces the secondary side current into the corresponding device through the secondary circuit wiring to provide information and data for various protections based on current principles in the station, thereby realizing Protection of various components in the station. [0003] The current transformer is divided into a primary part and a secondary part, which are respectively connected to the primary and secondary side systems, and then the phase wires are respectively drawn from the three phases A, B, and C of the source of the secondary winding of the current trans...

AI Technical Summary

Problems solved by technology

If the secondary windings of the two current transformers are in normal working condition, the current of each phase is basically the same, and both protection device A and protection device B are in normal operation state; if terminal block D1 is correspondingly connected to the secondary winding of the first current transformer If a single-phase grounding fault occurs on phase A of the terminal block D1, the fault current will flow into the phase B terminal of the protection device B from the A phase contact point of the terminal block D1. Once the fault current meets the protection action conditions of the protection device B, the protection device B will malfunction , on the contrary, if a single-phase ground fault occurs on phase B connected to the secondary winding of the current transformer corresponding to terminal block D2, the fault current will flow from the B-phase contact of terminal block D2 into the A-phase terminal of protection device A, once the fault current meets After the protection action condition of protection device A, it will cause protection device A to malfunction

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