UHV (Ultra High Voltage) transformer field variable frequency partial discharge test device

Abstract

The invention introduces a UHV (Ultra High Voltage) transformer field variable frequency partial discharge test device. A No.1 frequency conversion cabinet (2) and a No.2 frequency conversion cabinet (3) are connected in parallel between a control cabinet (1) and an exciting transformer (4) of the UHV transformer field variable frequency partial discharge test device; the high voltage output end of the exciting transformer (4) is connected in parallel with a capacitive voltage divider (5), a compensation reactor (6) and a 1,000kV AC (Alternate Current) UHV transformer (7); and the 1,000kV AC UHV transformer (7) is connected in parallel with a partial discharge tester (8) by end screens of high voltage, intermediate voltage and low voltage sleeves of the 1,000kV AC UHV transformer (7). The device has the advantages that 1, adaptability is strong; 2, the device has a small volume and a light weight and is convenient to transport and assemble; 3, reliability is high and the voltage and the frequency can be continuously regulated; 4, direct contact between people and live equipment is avoided and safety is high; and 5, the device has a wide output frequency range and also can be used as a withstand voltage test variable frequency power supply of equipment such as a UHV GIS (Gas Insulated Switchgear), a mutual inductor and the like.

Description

technical field [0001] The invention belongs to the technical field of electrical engineering, and relates to a field frequency conversion partial discharge test device for an ultra-high voltage transformer. The device is suitable for field frequency conversion partial discharge test of 1000kV AC UHV transformer. Background technique [0002] In recent years, the State Grid Corporation of China has vigorously developed UHV AC power transmission and transformation projects. The 1000kV AC UHV transformer is one of the main equipment of the project, and the partial discharge test is one of the important routine tests on the equipment site. This test item can Detect the insulation status of UHV transformers, including 1000kV AC UHV transformers, after long-distance transportation and on-site installation. [0003] Since the UHV transformer, especially the 1000kV AC UHV transformer, is a split structure with complex structure, high voltage level and large capacity, there are man...

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Problems solved by technology

During the partial discharge test, the capacitive reactance needs to be compensated by compensating reactance, and the output of the generator-type partial discharge device is a fixed frequency. Compensating the capacitive reactance of the AC UHV transformer can only be realized by adjusting the size of the compensating reactor. The body compensating reactor has a large weight and a large volume, and it is difficult to adjust during the field test. It often occurs that the reactance value of the compensating reactor cannot match the capacitive reactance value of the UHV transformer, resulting in a large amount of power supply required for the field test. The on-site partial discharge test of high-voltage transformers is more difficult. Therefore, it is urgent to develop an improved frequency conversion partial discharge test device, which can adjust the test frequency and reduce the reactance of the compensation reactor during the on-site partial discharge test of 1000kV AC UHV transformers. It is difficult to match the capacitance value with the capacitive reactance value of UHV transformer, thereby reducing the difficulty of on-site partial discharge test of 1000kV AC UHV transformer

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