Arc Fault Detection

Discussion in 'The Projects Forum' started by alfdan, Feb 26, 2014.

  1. alfdan

    Thread Starter New Member

    Feb 26, 2014
    I am developing an Arc Fault Detector for PV modules (DC) and have run into some problems. Let me give you a run down first on what we are trying to detect with an arc fault. Arcs generate high frequency noise concentrated between 25-45kHz however, it also generates wide band noise up to MHz. The general idea how this device works is that it senses noise at those specific frequencies and will flag or turn off the PV module if the noise exists.

    I have attempted using a hall effect current sensor to sense the frequency and transform that into a voltage to input it into a micro controller, but the current is too low to sense. The reason I used a hall effect sensor is so I can sense the current without interrupting the PV module line its self.
    I have also attempted using a differential amplifier to sense the frequency through voltage. The problem with this design is that it taps directly off the lines, which is not part of the design. Also, with voltages being around 1kV and using a voltage divider to step down the voltage, it is inefficient and the current is too low to even pass through the resistors.

    The next idea is to create a simple radio receiver by designing an oscillator with a trim-cap and a coil connected to a diode (much similar to an AM receiver). Once the signal is obtained through the receiver it then goes through an amplifier and bandpass filter to be input into the micro controller.

    Would this idea work? Or are there easier or more efficient ways of obtaining the frequency noise that is desired?