Electronic type voltage transformer

Abstract

The invention provides an electronic type voltage transformer, which is characterized in that a voltage divider formed by connecting a voltage divider high voltage arm, a signal electrode and a voltage divider low voltage arm in sequence is fixed in an inner cavity of a core insulator and is located above the axle wire of the core insulator; a high voltage wire is connected with a high voltage electrode of the voltage divider high voltage arm through a high voltage wire outlet hole; a signal output wire is connected with the signal electrode through a signal output wire outlet hole; an earth lead is connected with an earth electrode of the voltage divider low voltage arm through an earth lead outlet hole; one end of an earth terminal shielding connecting wire is connected with an earth terminal shielding layer, and the other end of the earth terminal shielding connecting wire is connected with the earth lead; one end of a signal output terminal shielding connecting wire is connected with a signal output shielding layer, and the other end of the signal output terminal shielding connecting wire is connected with the signal output wire; a pouring body with a skirt is poured outside a shielding cavity formed by the core insulator and a seal end cover sealing the mouth of the core insulator; the high voltage wire is led outside the pouring body at the top of the pouring body; and the signal output wire and the earth lead are led outside the pouring body at the bottom of the pouring body.

Description

technical field [0001] The invention belongs to the field of electrical instruments and high-voltage equipment, and relates to an electronic voltage transformer used for voltage measurement of a voltage level of 6kV to 35kV in a power system. technical background [0002] Existing voltage transformers mainly include electromagnetic voltage transformers and capacitive voltage transformers. In recent years, optical voltage transformers (OVT), electronic voltage transformers with resistive or capacitive voltage division have also appeared at home and abroad. [0003] Electromagnetic voltage transformers have complex insulation structures, large volume, medium quality, high cost, and are prone to ferromagnetic resonance and magnetic saturation. Capacitive voltage transformers have poor transient response and are prone to ferromagnetic resonance due to intermediate transformers and compensating reactors. [0004] The basic principle of optical voltage transformer is to use the ...

AI Technical Summary

Problems solved by technology

However, optical materials are greatly affected by factors such as temperature and mechanical vibration, and the cost is high

[0005] Existing electronic voltage transformers with resistance or capacitance division are usually difficult to ensure the consistency of the temperature coefficient of resistance (or capacitance) that forms the high and low voltage arms, and its measurement accuracy is seriously affected by temperature. Or electronic components to compensate the secondary output value

Although CN200910143450 discloses a kind of integrated voltage divider resistance made on the same ceramic tube with the high voltage arm and the low voltage arm to improve the consistency of the temperature coefficient of the high and low voltage arms, but because the voltage divider resistance is affected by casting (filling) materials, etc., Its measurement accuracy still depends on the compensation and adjustment of the thermistor and phase-shifting capacitor, its linearity is not ideal, and the manufacturing process is complicated

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