A Capacitive Impedance Epoxy Resin Casting Insulated Electromagnetic Voltage Transformer

Abstract

The invention provides an electromagnetic voltage transformer with an insulation function through capacitive impedance epoxy resin casting. The electromagnetic voltage transformer is characterized in that layer insulations with high dielectric constants are adopted, epoxy resin mixtures with high dielectric constants are adopted, the area of a high-low voltage electrostatic screen is increased, the distributed capacitance of the high-low voltage electrostatic screen can be 300-500 pF, and the transformer is still capacitive with perceptual load. The electromagnetic voltage transformer comprises an iron core, a wire wrapping framework, a secondary winding, an inner electrostatic screen, the layer insulation, an outer electrostatic screen and a primary winding. The wire wrapping framework is arranged in the middle of an iron core window, the secondary winding and the primary winding are sequentially wound on the wire wrapping framework from inside to outside, the inner electrostatic screen is arranged on the inner side of the primary winding, the outer electrostatic screen is arranged on the outer side of the primary winding, the layer insulation is arranged between layers of the primary winding, and the iron core, the wire wrapping framework, the secondary winding, the inner electrostatic screen, the layer insulation, the outer electrostatic screen and the primary winding all are arranged in an epoxy resin mixed-casting material layer. The electromagnetic voltage transformer can normally operate under 2.5 times the rated voltage, core saturation is basically avoided, and a ferromagnetic resonance area is avoided.

Description

technical field [0001] The invention relates to a capacitive impedance epoxy resin casting insulated electromagnetic voltage transformer. Background technique [0002] In the current transmission and distribution power system, since the voltage transformer is a nonlinear inductive load, its inductance L changes with the change of the external electrical parameters. When excitation conditions occur, LC resonance will be formed with the busbar-to-ground capacitance C in the system, including parallel resonance and series resonance, collectively referred to as ferromagnetic resonance. Ferroresonance often causes fuses to blow or voltage transformers to burn out. [0003] If the voltage transformer is a capacitive load, it will not generate LC resonance with the ground capacitance in the system, which can better suppress the occurrence of ferromagnetic resonance. Contents of the invention [0004] The purpose of the present invention is to provide a capacitive impedance epox...

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Problems solved by technology

Ferromagnetic resonance often causes fuses to blow or voltage transformers to burn out

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