Transformer three-phase partial discharge simultaneous pressurization test device and test method based on single-phase variable-frequency power source

Abstract

The invention relates to the technical field of electrical equipment high-voltage tests, in particular to a transformer three-phase partial discharge simultaneous pressurization test device and test method based on a single-phase variable-frequency power source. According to the technical scheme, the device comprises a 380V power supply system, a frequency-adjustable single-phase variable-frequency power supply, a digital phase shifter, an exciting transformer, a delta connection parallel controllable reactor group and a tested transformer, wherein the frequency-adjustable single-phase variable-frequency power supply is changed from a three-phase power supply, and the 380V power supply system is connected with the input end of the frequency-adjustable single-phase variable-frequency power supply changed from the three-phase power supply. After the output end of the frequency-adjustable single-phase variable-frequency power supply changed from the three-phase power supply is connected with the input end of the digital phase shifter, the output end of the digital phase shifter is connected with the primary side of the exciting transformer, one end of the secondary side of the exciting transformer is grounded, and the other end of the secondary side of the exciting transformer is connected with the delta connection parallel controllable reactor group. The delta connection parallel controllable reactor group is provided with three leading-out points, and the three leading-out points are respectively connected with the tested transformer through a pressurization line.

Description

technical field [0001] The invention relates to the technical field of high-voltage testing of electrical equipment, in particular to a three-phase partial discharge simultaneous pressurization test device and test method for a transformer based on a single-phase variable frequency power supply. Background technique [0002] Transformer partial discharge test is the most effective handover test for transformers. Through partial discharge tests, problems in transformer manufacturing quality and installation process can be effectively found; previous test standards aimed at three-phase solid transformers, and single-phase variable frequency power supplies can be used to carry out partial discharge tests phase by phase. Therefore , each operation and maintenance unit is equipped with a single-phase variable frequency power supply box and a single-phase excitation transformer in the on-site handover test of the substation. [0003] In recent years, with the promotion of internat...

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Problems solved by technology

[0003] In recent years, with the promotion of international standards, some units have required simultaneous pressurization of the three-phase partial discharge of three-phase body transformers. For transformer manufacturers, generators are installed in the factory, and the power supply capacity is approximately infinite, which can meet the requirements of three-phase partial discharge. Simultaneous pressurization test for partial discharge, but at the handover test site, due to the transportation environment and power capacity, the existing single-phase variable frequency power supply and single-phase transformer cannot meet the simultaneous pressurization test of the partial discharge test of the three-phase body transformer; in addition, the current three The phase-conversion power supply is expensive and bulky, and it is extremely inconvenient to transport and use, which makes it difficult to meet the requirements of the on-site handover test of the substation

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