Wire break alarm detector of current transformer

Abstract

The present invention relates to a wire break alarm detector of a current transformer. The wire break alarm detector of the current transformer comprises a current transformer, a work inductor, a rectification amplification circuit, a filtering circuit and an output relay. A wiring output end of a secondary side of the current transformer is connected with an input end of the work inductor, the output end of the work inductor is connected with an input end of the rectification amplification circuit, an output end of the rectification amplification circuit is connected with an input end of thefiltering circuit, an output end of the filtering circuit is connected with an input end of the output relay, and an output end of the output relay outputs alarm signals. The alarm detector is simplein electrical structure, wherein the rectification amplification circuit and the relay are employed to achieve an open circuit alarm function of a current transformer with no need for extra power supply, and the alarm detector is very convenient in field usage.

Description

technical field [0001] The invention relates to an alarm detector, in particular to an alarm detector for disconnection of a current transformer, and belongs to the technical field of power systems. Background technique [0002] The measurement and control device in the power system needs to use a current transformer (CT) when collecting the high-voltage transmission equipment of the power grid. The current transformer converts the large current in the high-voltage power grid into a safe small current that can be used by the measurement and control device. However, when the secondary side of the current transformer is open due to various reasons, a high voltage will be induced on the secondary side, which may burn the equipment or cause electric injury to people. [0003] At present, in the prior art, the CPU processor is generally used to detect whether there is an open circuit voltage, and the CPU unit controls the thyristor module to protect the current transformer. The d...

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Problems solved by technology

[0004] 1) If the CPU processor uses the voltage or current of the secondary side of the CT to supply power for it, due to the complex harmonics and large fluctuations of the secondary side of the CT, it is easy to affect the stable operation of the CPU processor;

[0005] 2) If an external voltage is used to power the CPU processor through a switching power supply, the complexity and cost of the detector will be increased

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