| 摘要 |
Methods, systems, and devices for sensitive and selective identification of ground faults in a three phase power distribution system are described. The three phase conductors of the three phase power distribution system may be surrounded by a sensor comprising a magnetic ring with a thin opening, and a sensitive magnetometer that operates on magnetoresistance may be disposed in the opening of the ring. The output voltage of the magnetometer is proportional to the magnetic field in the opening of the magnetic ring and is proportional to ground current that transits the magnetic ring and returns outside the ring on the ground system. Comparison of the quantity and/or phase angle between the sensed circuit current and the current in the neutral can determine whether the current is inherent capacitive current or a ground fault. |
