Low-voltage series fault arc detection system

Abstract

The invention discloses a low-voltage series fault arc detection system. The system comprises a voltage detection circuit, a signal conditioning circuit and an operational amplifier transmitting circuit, the voltage detection circuit collects low-voltage series fault arc voltage; the signal conditioning circuit uses an operational amplifier AR1, a diode D1 and a diode D2 to form a mean value circuit to screen out mean value signals. Meanwhile, a triode Q2 and a triode Q3 are used for forming a push-pull circuit to prevent signal crossover distortion; an input operational amplifier AR3 is arranged in the in-phase input end; an absolute value circuit is formed by an operational amplifier AR2, a diode D3, a diode D4 and an operational amplifier AR5; after being detected by a detection circuitconsisting of a silicon controlled rectifier VTL1 and a voltage stabilizing tube D5, the signal is input into an inverting input end of an operational amplifier AR3; and finally, an operational amplifier transmitting circuit uses an operational amplifier AR4 to amplify the signal in the same phase, the signal is transmitted to the arc detection system control terminal through a signal transmitterE1, and the signal is converted into series fault arc state detection through voltage change and directly transmitted to the arc detection system control terminal.

Description

technical field [0001] The invention relates to the field of circuit technology, in particular to a low-voltage series fault arc detection system. Background technique [0002] At present, the hidden dangers of series arc faults may be distributed in the entire low-voltage power distribution system. There are many causes of series arc faults, such as: wire insulation aging, internal conductors being squeezed and broken, or poor contact of wires. The detection of series arc faults in low-voltage power distribution systems faces the following difficulties: First, the load combinations of low-voltage power distribution systems are various. During normal operation, the loop current waveform may mainly show linear characteristics (no harmonics), or may It mainly shows nonlinear characteristics (with harmonics or interharmonics). The load current waveform with nonlinear characteristics may be very similar to the current waveform when there is a series arc fault in the circuit, whi...

AI Technical Summary

Problems solved by technology

The detection of series arc faults in low-voltage power distribution systems faces the following difficulties: First, the load combinations of low-voltage power distribution systems are various. During normal operation, the loop current waveform may mainly show linear characteristics (no harmonics), or may It mainly shows nonlinear characteristics (with harmonics or interharmonics). The load current waveform with nonlinear characteristics may be very similar to the current waveform when there is a series arc fault in the circuit, which will interfere with the arc fault detection; secondly, the influence of the arc There are many factors. The series fault arc has the characteristics of unstable arc burning, and the arc is time-varying. Therefore, it is necessary to detect the series fault arc in real time and ensure the accuracy of the signal.

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