Patent ID: 8314674
Filing Date: 2012-11-20
Classification: H01F

Abstract:
1. An electrical transformer with unidirectional flux compensation, comprising: a transformer including a soft-magnetic core on which a primary winding arrangement, a secondary winding arrangement, and a compensation winding arrangement are arranged; a magnetic field measuring device measuring a magnetic field in the soft-magnetic core of the transformer or a stray magnetic field that closes outside the core via an air path and provides a control signal; a current control device connected via a current path which contains a reactance dipole to the compensation winding arrangement, the current control device feeds a compensation current into the compensation winding arrangement using the control signal in such a way that the effect of the compensation current in the core is in a direction opposite to a magnetic unidirectional flux, wherein the control signal is fed to the current control device, wherein the magnetic field measuring device includes a signal processing unit that is connected in a signal-conducting manner to at least two magnetic field detectors, wherein each magnetic field detector is arranged outside the core and register a stray flux of the transformer, wherein each magnetic field detector is embodied as an induction probe, wherein each induction probe is an air-cored coil, wherein the core includes three limbs, wherein at least two of the three limbs are fitted with a compensation winding, and wherein each air-cored coil is arranged in a gap, the gap formed from an outer circumferential surface and an enclosing compensation winding or the secondary winding, approximately at center limb height.