Transformer iron core grounding fault diagnosis simulation method and device based on equivalent method

Abstract

The invention discloses a transformer iron core grounding fault diagnosis simulation method and device based on an equivalent method. A transformer three-dimensional finite element model based on an equivalent method thought is established in ANSYS software to simulate a transformer iron core grounding fault, and three-dimensional research analysis is performed on an iron core of a simulation object transformer, windings on the high-/low-voltage sides and a coil for simulating a conduction fault by using a three-dimensional anisotropic conductivity formula and a magnetic conductivity formula.Different fault types are set on an iron core of the simulation device, and the fault current and the relation between the fault current and the fault position are detected and obtained. A short-circuit coil is used for equivalently replacing a complex grounding condition to carry out fault diagnosis. An upper yoke surface is installed at the upper end of a transformer iron core of the device, a high-low voltage simulation winding is installed in a transformer box body, and a fault short-circuit wire is arranged in the high-low voltage simulation winding. The fault short-circuit wire is in short-circuit contact with the short-circuit grounding points of a left iron yoke surface and the upper iron yoke surface to form a simulated transformer fault loop. The method and the device are simple,quick, convenient and accurate in troubleshooting and solving of power transformer faults.

Description

technical field [0001] The invention belongs to the technical field of electric equipment fault diagnosis, and relates to a simulation method and device for transformer iron core grounding fault diagnosis based on an equivalent method. Background technique [0002] When a multi-point ground fault occurs in the transformer iron core, a fault loop is formed between the iron core and the earth, and a fault current is generated. The fault current will cause additional loss in the iron core. The fault current will cause the local temperature of the iron core to be too high, which will cause the transformer oil to decompose and reduce the insulation performance. [0003] There are generally three traditional methods to detect whether the transformer core is grounded at multiple points, namely, the method of measuring the insulation resistance of the iron core, the electrical method of measuring the current of the iron core during operation, and the gas chromatography analysis meth...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art, provide a transformer core grounding fault diagnosis simulation method and device based on the equivalent method, and solve the problems of difficult fault classification, fault location judgment and troubleshooting when the transformer core is multi-point grounded question

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