Converter transformer symmetrical pressurization partial discharge test circuit

Abstract

The invention discloses a converter transformer symmetrical pressurization partial discharge test circuit. The circuit comprises a frequency conversion power source, an excitation transformer T1 and an excitation transformer T2 which are of the same structure, a first voltage divider, a second voltage divider, a first compensation reactor branch and a second compensation reactor branch. The high-voltage tail ends of the high-voltage windings of the excitation transformer T1 and the excitation transformer T2, after respectively passing through an ammeter A1 and an ammeter A2, are grounded, and the high-voltage winding output end of the excitation transformer T1 and the high-voltage winding output end of the excitation transformer T2 are respectively connected with the two ends of a valve side winding of a converter transformer; and the first compensation reactor branch comprises a fixed compensation reactor L1 and an adjustable reactor L3 which are connected in series, and the second compensation reactor branch comprises a fixed compensation reactor L2 and an adjustable reactor L4 which are connected in series. According to the invention, through the adjustable reactors, it is ensured that the imbalance of the voltage at the two ends of the valve side winding of the converter transformer and the circulation phenomenon generated when reactive power at the two ends are not consistent when the converter transformer is subjected to a symmetrical pressurization partial discharge test are prevented.

Description

technical field [0001] The invention relates to the technical field of converter transformers, in particular to a test circuit for long-duration induced voltage band partial discharge measurement tests during on-site handover tests of converter transformers. Background technique [0002] At present, due to the restriction of the voltage level of the excitation transformer in the field partial discharge test of the converter transformer, the pressure is generally applied from the end with a lower voltage level, that is, the valve side. Due to the relatively small transformer ratio of the delta-connected converter, in order to ensure that the voltage level of the test device is reasonable and the valve side does not exceed the AC withstand value, the field test adopts a symmetrical pressurization method on the valve side. Please refer to figure 1 As shown, it includes a partial discharge test circuit for symmetrical pressurization of a converter transformer, which includes a ...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the problem that the existing symmetrical pressurization cannot solve the problem of double-terminal voltage and reactive power imbalance, the present invention provides a test method, which can not only solve the problem of capacity rise effect that may occur, but also solve the problem that the two-terminal cannot be simultaneously Circulation problems when fully compensated

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