An Integrated Approach for Current Balancing and Open-Circuit Fault Diagnosis for Interleaved Boost Converter

Interleaved boost converters (IBCs) are widely used in many applications such as automotive and renewable energy systems due to their high efficiency, reduced input and output ripple currents, and enhanced voltage regulation. Equalizing the current handled by each phase and embedding an open-circuit switch fault detection module will improve the reliability of the converter. This article addresses these challenges by proposing one diode current sensor at the output, thereby avoiding the need for individual current sensors for each phase. The total diode current and input current of the IBC are sensed, from which the individual phase current is reconstructed. The reconstruction strategy involves selecting the proper sampling instant of the diode current and input current depending on the operating duty cycle. The proposed approach is applicable for both the continuous conduction mode and the discontinuous conduction mode of operation of the converter. Using the reconstructed phase current, both the balancing of the phase current and fault detection are performed. A perturbation-based approach is proposed for the balancing of phase current. The faulty phase can be easily detected from the reconstructed phase current. The proposed method is validated on a prototype of a three-phase IBC showing its robustness and effectiveness.