Optimal Design of Integrated Magnetics for Differential Rectifiers and Inverters

In this paper, a type of low-frequency integrated ac inductor without inductance coupling is proposed for differential rectifiers/inverters. The objective is to increase the power density of these converters by replacing their two bulky and low-frequency ac inductors with the proposed integrated ac inductor, which is much more compact. The principles of the proposed magnetic integration approach and the optimization procedures are explained in detail. An integrated inductor with 34.9% reduction in volume as compared to its discrete-inductor counterpart is designed and tested via simulations using the software Maxwell. Three integrated inductor prototypes with a core volume reduction of up to 30.9% are constructed in the laboratory and are applied to a buck differential rectifier for experimental verification. Their performance in terms of coupling effect, thermal temperature, power efficiency, and system switching frequency is examined.