Difference current detection system - uses annular core with two opposing gaps each with magnetic field sensor enclosing symmetrical current leads

摘要

The detection system uses a sum current transducer with an annular core (2) enclosing a pair of current leads (10,20) with two diametrically opposing gaps (4,5) each containing a magnetic field sensor (6,7). The current centres (S10,S20) of the current leads are symmetrical to a common symmetry axis (8) for both gaps, along a perpendicular axis (9), both passing through the centre (m) of the core. Pref. both current leads are enclosed by a common screening (12) for reducing eddy current losses. ADVANTAGE - Uses symmetry of magnetic field lines for compensation of magnetic field in each gap.