Test device for excitation characteristic of voltage transformer

Abstract

The invention discloses a test device for excitation characteristic of a voltage transformer, and aims to provide the test device, capable of improving test accuracy, for the excitation characteristicof the voltage transformer. The test device comprises a power frequency voltage source and a DC current source, wherein the power frequency voltage source comprises a power frequency voltage source front-stage switch, a power frequency voltage source voltage regulator, a power frequency voltage source post-stage switch, a power frequency transformer, an AC loop capacitor, an AC loop resistor, a protection device, a power frequency voltage divider high-voltage arm capacitor, a power frequency voltage divider low-voltage arm capacitor, a power input voltmeter, a power frequency transformer primary voltmeter, a power frequency voltage divider voltmeter and a transformer primary ammeter, the power frequency voltage source front-stage switch is arranged at a primary side of the power frequencyvoltage source voltage regulator, the power frequency voltage source post-stage switch is arranged at a secondary side of the power frequency voltage source voltage regulator, a primary side of the power frequency transformer is connected with the secondary side of the power frequency voltage source voltage regulator, and one end of the power frequency voltage divider high-voltage arm capacitor is connected with an A terminal of a secondary side of the power frequency transformer.

Description

Technical field [0001] The invention relates to the technical field of power supplies, in particular to a test device for testing the excitation characteristics of a voltage transformer. Background technique [0002] In the operation of 10kV and 35kV power grids, the primary side fuse of the voltage transformer (PT) often blows frequently. In severe cases, it may even cause the PT to burn and explode. Preliminary research and analysis are mainly due to the fact that the direct current component flows through the primary winding of the PT during the restoration of the ground fault, causing the PT core to be magnetically saturated, and the ground capacitance and the PT have ferromagnetic resonance, which ultimately leads to the destruction of the PT. [0003] At present, the test method for PT volt-ampere characteristics in the industry is mainly to add standard AC voltage to the PT secondary winding to test the PT terminal voltage and no-load current, but this test method does not c...

AI Technical Summary

Problems solved by technology

But it is not as good as directly applying DC current from the primary side to reflect the state of the grid more realistically

Therefore, although the conventional PT volt-ampere characteristic test equipment can test the PT's volt-ampere characteristic, there is no equipment that simultaneously applies power frequency voltage and DC current to the primary side of the PT from the high-voltage side of the PT, so as to truly simulate the DC current. Effect on PT Saturation Characteristics

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