Passive component loss minimization for interleaved dc-dc boost converters in electric vehicle applications

This paper presents an inductor loss minimization method for interleaved boost converters in electric vehicle applications. Equivalent circuits are presented to analyze the steady state working conditions of the inductors in interleaving topology with and without coupled inductors. With the proposed equivalent circuits, inductor working conditions can be predicted for both boost inductors and coupled inductors with provided converter steady state working conditions. Based on the predicted inductor working conditions, inductor loss modeling is presented in details considering DC and AC winding loss modeling and core loss prediction with improved generalized Steinmetz equation. Passive component loss minimization method is presented to explore the optimized coupled inductance for total inductor loss minimization. By controlling the inductance of the coupled inductor added to the circuit, the loss distribution can be controlled between boost inductors and coupled inductors, with proper coupled inductance, the total passive component loss can be minimized. Experimental verification is conducted based on a 1 kW interleaved dc-dc boost converter. Inductor loss is measured with different combinations of coupled inductor values and boost inductor values, which verified the effectiveness of the proposed inductor loss minimization method.