Improved Method for Identification of Equivalent Circuit Parameters of Transformer Oil-paper Insulation Dielectric Response

Abstract

An improved method for parameter identification of transformer oil-paper insulation dielectric response equivalent circuit, using the recovery voltage method to measure the recovery voltage peak value, peak time and initial slope of the recovery voltage of the transformer oil-paper insulation system on site; using the extended Debye model to simulate the equivalent circuit of the transformer oil-paper insulation system; Establish the recovery voltage peak value, peak time and initial slope characteristic quantity to solve the improved mathematical model of the equivalent circuit parameters of the dielectric response. The equivalent model of n relaxation branches has 2n+2 model parameters to be solved, so it is necessary to pass multiple recovery voltages The test cycle establishes a corresponding scale of nonlinear equations to solve; the solution of nonlinear equations is transformed into an optimization problem to solve the minimum value of the objective function, and the bacterial foraging optimization algorithm of hybrid PSO is used to identify equivalent circuit parameters and calculate the recovery voltage Compared with the recovery voltage measurement curve, it is found that the main time constant of the two is the same, which can accurately judge the insulation state of transformer oil paper.

Description

technical field [0001] The invention relates to a method for identifying parameters of a transformer oil-paper insulation medium response circuit, in particular to an improved method for identifying parameters of a transformer oil-paper insulation medium response equivalent circuit based on a recovery voltage method. Background technique [0002] Power transformers are very important to the normal operation of the power grid. During operation, due to the effects of electrical, thermal and environmental stresses, the state of its oil-paper insulation system changes. The diagnosis of transformer insulation aging status is one of the hot research topics at home and abroad. The life of the transformer mainly depends on the aging state of the oil-paper insulation system. The dielectric properties of the oil-paper insulation will change during operation. At present, the dielectric measurement method has been widely used to evaluate the aging state of the oil-paper insulation of the...

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Problems solved by technology

[0005] In view of the above problems, the purpose of the present invention is to provide an improved method for identifying the equivalent circuit parameters of the transformer oil-paper insulation medium response based on the recovery voltage method, aiming at solving the problem of long measurement time of characteristic quantities and inaccurate initial slope measurement values ​​for parameter identification. The problem that the error and initial slope characteristic value are not ideal when detecting the insulation aging state of small transformers

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