High impedance faults (HIF) are faults which are difficult to detect using standard overcurrent protection relays for earth and phase fault detection.
FIR (Finite Impulse Response) filter banks recognize the distortion of the voltage and current waveforms caused by the arcs usually associated with HIF, by yielding 3 phase voltage and current at a set frequency and inspecting the pattern displayed against a pre set pattern, usually based on an algorithm.
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc