Alternating current series arc fault detection method

摘要

A method of detecting and indicating a presence of alternating current (AC) series arc fault events in current supplied by an AC electrical power source (4) to an electrical load (6) for the power source comprises the steps of: measuring (14) positive and negative current through the load over a first sample cycle of the AC power to establish first measured positive and first measured negative current levels; determining (10) the absolute value of the first measured positive and first measured negative current levels to establish a first absolute positive current level and a first absolute negative current level; adding the first absolute positive current level and the first absolute negative current level to establish a first sum current level; measuring positive and negative current through the load over a second sample cycle staggered from the first sample cycle to establish second measured positive and second measured negative current levels; determining the absolute value of the second measured positive and second measured negative current levels to establish a second absolute positive current level and a second absolute negative current level; adding the second absolute positive current level and the second absolute negative current level to establish a second sum current level; subtracting the second sum current level from the first sum current level to establish a current difference level; and indicating (20) a series arc fault event if the current difference level exceeds a predetermined threshold level.