A capacitor voltage measuring circuit device applied to 10kv distribution network

Abstract

The invention discloses a voltage measurement circuit device applied to a 10-kV power distribution network by applying capacitance, which comprises a capacitor conversion device, a current transformer and a post-stage conditioning circuit, wherein the capacitor conversion device comprises an insulating sleeve, a copper net, a conductor and an electric conduction screw, the electric conduction screw is connected with a primary side of the current transformer in series by a guide line, a secondary side of the current transformer is connected with the post-stage conditioning circuit, the post-stage conditioning circuit is an integrated operation amplification circuit provided with a negative feedback resistor R, and the phase of voltage obtained through measurement is beyond the phase of voltage of the 10-kV power distribution network by 90 degrees. The voltage measurement circuit device has small volume and light weight, and is low in cost and low in energy consumption; moreover, the capacitance in the insulating sleeve is fully utilized to measure voltage, and system ferromagnetic resonance caused by adopting an electromagnetic voltage transformer can be effectively prevented.

Description

technical field [0001] The invention relates to a capacitor voltage measuring circuit device applied to a 10kV distribution network, belonging to the technical field of voltage sensing. Background technique [0002] At present, in the power system, the traditional electromagnetic voltage transformer is mainly used for high voltage measurement. This kind of transformer is large in size, relatively heavy, requires high insulation strength, and is prone to ferromagnetic resonance, causing large excitation. current, causing damage to the electromagnetic voltage transformer. There is also a capacitive voltage transformer commonly used with concentric circle capacitance screen type or one to multiple bushing type coupling capacitors. Whether it is a concentric circle capacitance screen or a sleeve type coupling capacitor, it is bulky and costly, and is not suitable for 10kV power grids. Applications are limited to ultra-high voltage power grids. Contents of the invention [00...

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Problems solved by technology

[0002] At present, in the power system, the traditional electromagnetic voltage transformer is mainly used for high voltage measurement. This kind of transformer is large in size, relatively heavy, requires high insulation strength, and is prone to ferromagnetic resonance, causing large excitation. current, causing damage to the electromagnetic voltage transformer

There is also a capacitive voltage transformer commonly used concentric circle capacitive screen type or one or more bushing type coupling capacitors. Whether it is a concentric circle capacitive screen or a bushing type coupling capacitor, it is bulky and costly, and is not suitable for 10kV power grids. application, limited to EHV grid

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