Large-scale transformer differential protective system test method

Abstract

The invention relates to a large transformer, in particular to a test method for large transformers. A large transformer differential protection system test method comprises a different protection relay of a transformer, a phase meter and an ammeter and comprises the steps of: 1, selecting the ranges of the phase meter according to the test current for the check of a phase angle; switching the display picture of the differential synthetic protection relay to a differential current display unit; 2, connecting a power supply, utilizing the ammeter and the differential synthetic protection relay to check the current passing the transformer; 3, utilizing the phase meter at the current input of the differential protection relay to check and record the phase difference of the cophase currents at two sides; 4, simulating the fault state of the transformer, measuring the phase angle and the detection differential current on the relay, confirming the reliable operation of the differential protection relay under the default state; 4, ending the test, turning off the power supply and recovering former wires.

Description

technical field [0001] The invention relates to large transformers, in particular to a testing method for large transformers. Background technique [0002] The differential protection of large-scale transformers is to alarm in time to trip the upper-level circuit breaker and cut off the power supply in case of a fault in the protection area to protect the transformer. [0003] The differential protection is mainly composed of a differential protection relay and two sets of current transformers (3 in each group) on the high and low voltage sides of the transformer. During the test, in order to verify whether the protection relay can operate reliably, in addition to the single test of the differential protection relay In addition, it is also necessary to conduct a system comprehensive test on the system composed of relays and transformers. [0004] In the case of using electromechanical or electromagnetic differential protection relays in the past, due to the limitation of te...

AI Technical Summary

Problems solved by technology

[0005] The invention aims to solve the defects of the existing detection means, and provides a test method for a large-scale transformer differential protection system

The invention can not only solve the problem that in the comprehensive test of the differential protection system of a large transformer, a relatively large test current is required to complete the test due to the limitation of the test detection means, and a little carelessness may cause damage to the substrate, and the problem of high risk can be solved, and it also solves the problem that the differential protection system of the large transformer The comprehensive test of dynamic protection system has high cost, high energy consumption, and long test preparation time, etc.