FLOAT CURRENT MEASURING PROBE AND METHOD

摘要

A float current probe measuring a float current flowing in a conductor comprises a core adapted to be magnetically coupled to the conductor. Excitation and field cancellation windings are magnetically coupled to the core. A detector detects when energy in the excitation winding reaches a predetermined threshold corresponding to a saturated core condition. A timer measures first and second delays needed to saturate the core as a result of the excitation winding being energized through a switch circuit in the forward and reverse polarity successively. A computing unit determines a magnetic field induced by the conductor based on the first and second measured delays. The field cancellation winding is energized by a current source with a current level and direction as a function of the computed magnetic field, to cancel the magnetic field induced by the conductor. The current level is representative of the float current in the conductor.