A method of detecting arcing in a DC power system, comprising the steps of: monitoring at least two currents (Ip1, Ip2) by at least two current sensors (802.1, 802.2), respectively, the at least two current sensors having reverse polarities, the at least two currents being provided for monitoring by the respective current sensors over at least two adjacent conductors, respectively, in the DC power system; combining the at least two monitored currents to provide a combined current (ICombined); generating one or more pulses in response to at least one change in the combined current over time (di/dt); processing, by a processor, the respective pulses to determine a presence of arcing in the DC power system; and generating, by the processor, an output indicative of the presence of arcing in the DC power system, characterized in that: the respective pulses have associated durations; and the method further comprises: counting, by the processor, the number of pulses in at least one predetermined time interval to provide a pulse count for the predetermined time interval; measuring, by the processor, a fluctuation in the durations of the respective pulses in the predetermined time interval; calculating, by the processor, a first ratio of the fluctuation in the durations of the respective pulses to the pulse count; and determining, by the processor, the presence of arcing in the DC power system based at least in part on the first ratio. monitoring at least two currents (Ip1, Ip2) by at least two current sensors (802.1, 802.2), respectively, the at least two current sensors having reverse polarities, the at least two currents being provided for monitoring by the respective current sensors over at least two adjacent conductors, respectively, in the DC power system; combining the at least two monitored currents to provide a combined current (ICombined); generating one or more pulses in response to at least one change in the combined current over time (di/dt); processing, by a processor, the respective pulses to determine a presence of arcing in the DC power system; and generating, by the processor, an output indicative of the presence of arcing in the DC power system, characterized in that: the respective pulses have associated durations; and the method further comprises: counting, by the processor, the number of pulses in at least one predetermined time interval to provide a pulse count for the predetermined time interval; measuring, by the processor, a fluctuation in the durations of the respective pulses in the predetermined time interval; calculating, by the processor, a first ratio of the fluctuation in the durations of the respective pulses to the pulse count; and determining, by the processor, the presence of arcing in the DC power system based at least in part on the first ratio. the respective pulses have associated durations; and the method further comprises: counting, by the processor, the number of pulses in at least one predetermined time interval to provide a pulse count for the predetermined time interval; measuring, by the processor, a fluctuation in the durations of the respective pulses in the predetermined time interval; calculating, by the processor, a first ratio of the fluctuation in the durations of the respective pulses to the pulse count; and determining, by the processor, the presence of arcing in the DC power system based at least in part on the first ratio. counting, by the processor, the number of pulses in at least one predetermined time interval to provide a pulse count for the predetermined time interval; measuring, by the processor, a fluctuation in the durations of the respective pulses in the predetermined time interval; calculating, by the processor, a first ratio of the fluctuation in the durations of the respective pulses to the pulse count; and determining, by the processor, the presence of arcing in the DC power system based at least in part on the first ratio.