Current sensor with adjacent conductor rejection

A fault detection system, comprising:

• a multiport current sensor to measure current in a monitored conductor, the multiport current sensor configured to generate a respective voltage signal at each port in response to the current in the monitored conductor, the multiport current sensor comprising:
• a first port connected to a first Rogowski coil section configured to be positioned on a first side of the monitored conductor in a location that is between the monitored conductor and an adjacent conductor, and
• a second port connected to a second Rogowski coil section configured to be positioned on a second side of the monitored conductor that is opposite the first side of the monitored conductor;
• and
• an analysis circuit to receive a voltage signal from each port of the multiport current sensor, the analysis circuit comprising:
• a combining circuit to phase-align the voltage signals from the first port and the second port to a common phase reference and to add magnitudes of the phase-aligned voltage signals to produce an output signal corresponding to a magnitude of a current in the monitored conductor, and
• an adjacent conductor rejection circuit to compare at least one of (i) magnitudes and (ii) phase angles of the voltage signals from the first and second ports to generate a flag signal indicating the detection of an adjacent-conductor fault.