Current transducer for measuring an electrical current

摘要

The present invention concerns current transducers for measuring a current flowing through a cable. The current transducers have a ferromagnetic core providing a substantially ring-shaped portion and at least two legs. The ring-shaped portion has one air gap or two air gaps. A magnetic field sensor is placed in or at each of the air gap(s). The ring-shaped portion forms a magnetic circuit that encloses the cable and guides the magnetic field generated by current to the air gap(s). Each leg extends from the center of the associated magnetic field sensor in a direction that runs perpendicularly to the longitudinal axis of the cable and has a certain length. The length of the legs is designed so long that at least two magnetic paths are formed which guide a component of an external magnetic field which extends in the direction of the legs around the magnetic field sensor(s).

主权项

1. Current transducer for measuring a current flowing through a cable, the current transducer comprising:
a ferromagnetic core with an air gap, and a magnetic field sensor placed in or at the air gap, wherein the ferromagnetic core comprises a ring-shaped portion, a first leg and a second leg, the ring-shaped portion encloses the cable and forms a magnetic circuit for guiding the magnetic field generated by the current flowing through the cable to the air gap, the first leg is coupled to a first end of the ring-shaped portion near the air gap and extends in a predetermined direction that runs perpendicularly to a longitudinal axis of the cable, the second leg is coupled to a second end of the ring-shaped portion near the air gap and extends in a direction opposite to the predetermined direction, and a length of the first and second leg is designed so long that at least two magnetic paths are formed which guide a component of an external magnetic field which extends in the predetermined direction around the magnetic field sensor.