Input and output total currents characterization in BCM and CCM Interleaved Power Converters Under Inductance Mismatch

Abstract

• Input and output currents for topologies of BCM-CCM interleaved power converters under inductance mismatch are quantified. • Proposed method is based on the analysis of the geometry of each phase and the selective sum of the phases value in certain key points. • To present a general methodology to obtain the required key points, a waveform that includes the key points of all types of phase currents is presented. • Once the selective sum is performed, it is possible to compute any of total current characteristics. • The characterization method can be used as a tool for a complete analysis, design and optimization of interleaved power converters. This paper presents a complete characterization of input and output currents in interleaved power converters with inductance mismatch, operating in Boundary Conduction Mode ( BCM ) and Continuous Conduction Mode ( CCM ). The proposal allows to compute these currents in several interleaved converter topologies for the entire range of operating points, considering any number of phases and any inductance ratio. Input and output currents are recovered from the values obtained when adding the phase currents in the instants where the slopes change; values that are thus defined as key points. This methodology is based on the coincidences that exist between the instants of the phase current key points and those of total currents. By using the computed key points, ripple amplitude, rms value and harmonic content of input and output total currents for the entire range of operating points can be easily obtained. Simulations are conducted on a 5-phase boost converter and a 5-phase buck converter under different conditions in order to validate the proposal expressions. Experimental tests on a 5-phase buck converter are presented under different operation conditions to verify that the proposed method can be applied in real situation.