A switching power converter includes an integrated transformer and coupled inductor, first and second primary switching circuits, and a master controller. The integrated transformer and coupled inductor includes (a) first and second primary windings electrically coupled in series and (b) first and second secondary windings. The first and second primary switching circuits are electrically coupled to an end of the first primary winding and an end of the second primary winding, respectively. The master controller is configured to determine a magnitude of magnetizing current of the integrated transformer and coupled inductor from a difference between magnitude of current flowing through the first secondary winding and magnitude of current flowing through the second secondary winding, when the first and second primary switching circuits are in their respective off-states.