Inrush Current Simulation Method and Device for UHV Transformer No-Load Closing

Abstract

The invention provides an excitation inrush current simulation method and device for an ultra-high voltage transformer under a condition of no-load closing. The excitation inrush current simulation method comprises the following steps: on the basis of the transitional area between the linear area and the non-linear area of the non-hysteresis curve, non-hysteresis magnetization intensity indicated by Langvin function is corrected; the corrected non-hysteresis magnetization intensity is utilized to establish a J-A magnetic hysteresis model; the parameters of the J-A magnetic hysteresis model are recognized; an analysis is conducted on the ultra-high voltage transformer and the differential magnetic susceptibility equation is determined; through the J-A magnetic hysteresis model and the differential magnetic susceptibility equation, the excitation inrush current of the ultra-high voltage transformer under the empty charging condition is determined. The excitation inrush current simulation method and device for the ultra-high voltage transformer under the condition of non-load losing correct the non-hysteresis magnetization intensity, enable the transitional area between the linear area and saturation area of the non-hysteresis curve to be closer to a true value and accurately simulate the magnetization characteristics of the transformer; moreover, the special construction of the ultra-high voltage transformer is considered and the excitation inrush current of the ultra-high voltage transformer under the condition of empty charging is simulated. Errors in the simulation are reduced.

Description

Technical field [0001] The invention relates to the technical field of electric power systems, and in particular to a simulation method and device for an excitation inrush current of an UHV transformer under no-load closing conditions. Background technique [0002] With the expansion of the power system, UHV power transmission is a brand-new business in the field of world power grid development. More and more large-capacity transformers are put into the power grid. As one of the core equipment, UHV transformers have increasingly higher parameters and operation requirements. . [0003] The magnetic circuit of the transformer is mainly composed of ferromagnetic materials, called iron core. When alternating magnetic flux circulates in the iron core, hysteresis and eddy current loss will occur, making the change of magnetic induction intensity lag behind the magnetic field intensity, and the hysteresis loop is obtained after repeated magnetization for many cycles. Due to the non-line...

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Problems solved by technology

[0006] In view of this, the present invention provides an excitation inrush current simulation method and device in the case of UHV transformer no-load closing, to solve the problem that the simulation method in the prior art cannot truly reflect the characteristics of ferromagnetic materials, thus inevitably The ground causes the simulation error of the excitation current, and the technical solution is as follows:

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