Implementation and Experimental Evaluation of an Efficiency-Improved Modulation Technique for IBCI DC-DC Converters

This paper presents an efficiency-improved modulation and control approach referring to the interleaved boost with coupled inductors (IBCI) dc-dc converter topology. Pulse-width modulation approaches for this converter allow various degrees of freedom, which should be exploited in order to minimize conduction and switching losses. On the basis of a detailed analysis of the topology, favorable switching sequences are identified for all the feasible converter's operating points, deriving a modulation scheme that allows significant efficiency improvements as compared to classical modulation approaches. Actually, considering an experimental prototype rated 1.5 kW, it is shown that the achieved efficiency performance is close to the optimal one found by a brute force characterization of the prototype. Finally, the obtained modulation scheme is integrated into a closed-loop control of the converter's power flow, achieving low power losses also during non steady-state conditions and tracking of given references. Three different implementation techniques are discussed, based on a look-up table, a neural network, and a piecewise linear approximation approach, and compared in terms of accuracy, computational complexity, and memory utilization when deployed in a digital controller.