Excitation characteristic testing device of voltage transformer

Abstract

The invention discloses an excitation characteristic testing device of a voltage transformer. The excitation characteristic testing device comprises a data processing unit, an excitation characteristic testing circuit and a programmable power supply, wherein the excitation characteristic test circuit comprises multiple paths of AD sampling circuits, a plurality of program control amplification circuits, a plurality of testing branches and a voltage sampling mutual inductor; each path of AD sampling circuit is used for collecting the output voltage of one programmable amplification circuit andobtaining a plurality of sampling voltage values, the input end of one programmable amplification circuit is used for being connected with the output end of a voltage sampling mutual inductor, and theinput ends of the other programmable amplification circuits are used for being connected with the output end of one testing branch; the testing branch is used for connecting a tested voltage transformer; the data processing unit is used for obtaining a plurality of sampling voltage values and calculating excitation characteristic data of the tested voltage transformer according to the basic parameters of the tested voltage transformer and the sampling voltage values. Through the scheme, the workload is reduced, and the testing efficiency is improved.

Description

technical field [0001] The present application relates to the technical field of instruments, and more specifically, relates to an excitation characteristic testing device of a voltage transformer. Background technique [0002] In my country's 6kV ~ 35kV power distribution system, the neutral point of the system is not effectively grounded, and the system busbar is connected with an electromagnetic voltage transformer (PT) insulated from the ground. When the busbar switch is closed and the circuit occurs When the single-phase arc grounding disappears automatically or the system load changes drastically, the transient impact process will excite the ferromagnetic resonance phenomenon between the PT and the capacitance of the three-phase wires to the ground. Ferromagnetic resonance will produce a relatively common internal overvoltage phenomenon in power systems. This voltage lasts for a long time and can even be self-maintained for a long time. It is one of the main reasons for...

AI Technical Summary

Problems solved by technology

[0005] At present, the excitation test of electromagnetic voltage transformer is mainly carried out manually by using a power frequency voltage regulator and measuring voltmeter and ammeter. The test signal is a power frequency sine wave voltage. Record the display data on the voltmeter and ammeter, resulting in a large workload and low efficiency

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