Large-scale generator stator winding major insulation aging state test method based on frequency domain spectroscopy

Abstract

The invention discloses a large-scale generator stator winding major insulation aging state test method based on frequency domain spectroscopy. The method includes the steps: making a generator stop running and be reliably disconnected from a circuit, and cooling the generator to an ambient temperature; testing wiring: connecting a stator winding of the generator with a high-voltage end of a test cable of a dielectric spectrum tester, and connecting a grounding end of a housing of a generator with a grounding end of the test cable of the dielectric spectrum tester; setting a parameter and starting a test; testing a frequency characteristic curve [epsilon]-f of a major insulation complex dielectric constant of the stator winding of the generator, and obtaining the dielectric loss factor increment [delta]tan[delta]N of the current major insulation through calculation by a formula; and evaluating the aging state of the major insulation of the stator winding of the generator according to the obtained dielectric loss factor increment [delta]tan[delta]N. The method is a non-destructive test method, has simple test principles, enables convenient wiring, can accurately determine the dielectric loss factor increment [delta]tan[delta]N of the stator winding of the generator, and thus can effectively evaluate the aging state of the generator.

Description

technical field [0001] The invention belongs to the technical field of main insulation state evaluation and life prediction of generator stator windings, and specifically refers to a large-scale generator stator winding main insulation aging state evaluation method based on frequency domain dielectric spectrum method. Background technique [0002] Large-scale generators are one of the most important and critical equipment in the power system, and their safety and reliability are directly related to the safety and stability of the power system. During the operation of the motor, the main insulation of the generator winding is subject to the combined effects of multi-factor stresses such as electricity, heat, machinery and various environmental factors, and gradually ages. With the growth of time, the aging of insulation not only reduces the mechanical strength and electrical strength of the generator, but also causes insulation breakdown and causes the motor to fail. Therefo...

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Problems solved by technology

There are problems in the actual measurement: first, some tests need to apply high voltage, which is easy to cause new damage to the insulation and reduce the service life of the generator; second, these detection methods are limited to a single information, providing little insulation information, and all There is a lot of interference information, and the test results are very scattered, so it is difficult to fully and accurately judge the insulation status of the generator

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