A Fault-Tolerant Control Method for Interleaved Boost Converters

Interleaved DC-DC converters have garnered significant interest due to their benefits, including reduced input current ripple, increased equivalent frequency and redundancy. However, open circuit faults (OCFs) in semiconductor switching devices will increase input current ripple and decrease the equivalent frequency, thereby disrupting the 'interleaving' benefits. In multiphase interleaved DC-DC converter, OCFs of a single phase will lead to an imbalance in the remaining healthy phase currents, a results of asymmetric conduction after OCF. This paper presents quantitative analysis of phase current imbalance after OCF. Additionally, for a three-phase boost interleaved converter, a fault-tolerant control method is proposed in this paper. This method reconfigures control signals based on phase shift frequency adjustment and constant on-time control utilizing useful information from the fault diagnosis module. Notably, the proposed method requires only a single current sensor. Both simulation and hardware experiment results verify the effectiveness of the proposed method.