Design of Magnetic Structure for Zero Input Current Ripple in DC-DC Converter with Multi-winding Coupled Inductor

Aiming at application scenarios that require low current ripple, this article proposes a two-phase integrated magnetic core structure to achieve zero current ripple in coupled inductor by controlling the coupling parameters in DC-DC converter. The proposed structure integrates all windings into a pair of magnetic cores so as to improve the utilization rate of the magnetic core. Moreover, the coupling parameter design problem is transformed into a magneto resistive design problem, which is easy to implement in engineering, and the ripple of the two-phase inductor current and input current is attenuated. Then, through the negative coupling characteristics between the phases, the flux in the magnetic core structure is cancelled partially, which reduces the magnetic loss and improves the efficiency of the converter. Finally, the correctness of the theoretical analysis and the feasibility of the proposed topology and magnetic core structure are verified by simulation and experimental results.