Improving the design of integrated magnetics for power electronics systems

This paper presents a systematic improving methodology for integrated magnetics solutions. Magnetic integration for power converters was firstly proposed several years ago. It is applied in order to reduce the number of ferromagnetic cores needed in a power electronic system, and it allows increasing the overall efficiency of the system. The magnetic integration for power converters can be achieved using a core sharing approach (core integration) or/and a winding sharing approach (winding integration). Solutions based on a winding sharing approach allow not only core saving but also copper saving. However, the design complexity increases, since the discrete integrated components that share its windings are defined by the same number of winding turns. This paper is organized in the following way: Initially, solutions based on core sharing and on both core sharing and winding sharing are analyzed, pointing out their advantages and drawbacks. Later on, models of equivalent electric circuits for integrated magnetics solutions are discussed. Finally, a systematic methodology to allow overcoming the interrelation effects in winding sharing approach is presented. The proposed method is illustrated over a simple example: transformer-inductor integration. Experimental results validate the expected electric behavior of the improved developed topologies.