A DC Flux Cancellation Design Method for Inverse-Coupled Inductors Used in Interleaved Boost Converters

This paper proposed a DC flux cancellation magnetic design method for inverse-coupled inductors used in interleaved boost converters (IBCs). Compared with the discrete inductor, the coupled inductor with the proposed magnetic design method has a much lower saturation degree since the DC flux can be almost completely canceled out by the closely inverse-coupled configuration. Therefore, the core is fully used and the power density and efficiency of the IBC are improved. Besides, it is found that the leakage inductance of the coupled inductor is the factor that affects the input current ripple. The proposed magnetic design method makes the input current ripple level of IBC with coupled inductors greatly decrease by increasing leakage inductance. Finally, a 10kW-rated prototype is made and experimental results are presented to verify the previous conclusions. Under the same level of input current ripple, the power density of the proposed coupled inductor is 90% higher than that of discrete inductors. The maximum efficiency of the IBC with the proposed coupled inductor is 98.6%.