Overvoltage protection method and device of current transformer

Abstract

The invention relates to an overvoltage protection method and an overvoltage protection device of a current transformer. The overvoltage protection method comprises the following steps of: acquiring a current signal on the secondary side of the current transformer; converting the acquired current signal into a voltage signal, comparing the voltage signal with the preset protective value and judging whether the secondary side of the current transformer is an open circuit or not; when the converted voltage signal is more than the preset protective value, short-circuiting the secondary loop of the current transformer; and when the converted voltage signal is not more than the preset protective value, recovering the normal connection state of the current transformer. The overvoltage protection device comprises an acquisition unit, a main control unit, a voltage-limiting protection circuit and an open circuit protection action component, wherein the output terminal of the open circuit protection action component is connected between the output terminals of the current transformer. The method and the device adopt a intelligent mode to control, adopt a mechanical switch to finish open circuit protection and avoid the influence of heating of the electronic device on the whole circuit in the prior art.

Description

technical field [0001] The invention relates to a protection method and device for a current transformer, in particular to a current transformer overvoltage protection method and device for overvoltage protection of secondary circuits of various current transformers. Background technique [0002] When the current transformer is open circuit, in addition to producing a large amount of iron loss to damage the transformer, it also induces dangerous high voltage in the secondary winding, which endangers personal safety. In order to prevent accidents of current transformer open circuit, the existing protection methods are that technicians use analog circuits and electronic components to build various types of current transformer open circuit protection devices. The problem lies in: the method of using analog circuits to realize open circuit protection , it is impossible to achieve intelligent setting for the level of protection voltage and time nodes; the circuit protection actio...

AI Technical Summary

Problems solved by technology

In order to prevent accidents of current transformer open circuit, the existing protection methods are that technicians use analog circuits and electronic components to build various types of current transformer open circuit protection devices. The problem lies in: the method of using analog circuits to realize open circuit protection , it is impossible to achieve intelligent setting for the level of protection voltage and time nodes; the circuit protection action unit built with electronic components is prone to heating when the secondary side circuit current of the transformer is too large, giving the current transformer Unnecessary impact on the stable operation of the

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