Improved transformer oil-paper insulation medium response equivalent circuit parameter identification method

Abstract

An improved transformer oil-paper insulation medium response equivalent circuit parameter identification method comprises the steps that a return voltage method is adopted to measure return voltage peak, peak time and return voltage initial slope of a transformer oil-paper insulation system in a field; an extension Debye model is adopted to simulate an equivalent circuit of the transformer oil-paper insulation system; characteristic quantities of the return voltage peak, peak time and return voltage initial slope are established to solve improved mathematical models of a medium response equivalent circuit parameters, wherein the equivalent models of n relaxed branch circuits have 2n+2 model parameters to be solved, and accordingly a corresponding number of nonlinear equation systems are needed to be established through multiple return voltage testing cycles for solution; the solution of the nonlinear equation systems is converted into solution of the optimization problem of an objective function minimum value, a PSO mixed bacteria foraging optimization algorithm is adopted to identify the equivalent circuit parameters and calculate a return voltage curve, the return voltage curve is compared with a return voltage measurement curve to find that the main time constants of the two curves are identical, and the oil-paper insulation state of a transformer can be accurately judged.

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 proble

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