Interleaved Converters Based on Sliding-Mode Control in a Ring Configuration

The problem of combining interleaved operation of several identical power converters with a hysteretic control is solved in this paper by inducing a sliding regime to all inductor currents in a ring configuration. No external synchronizing signal is required. The sliding-mode approach in a boost converter-based parallel association with a ring configuration for the current control guarantees the desired averaged value of all currents and also provides asymptotic stability. In addition, a detailed analysis to derive the phase displacement of each inductor current and to obtain the value of the resulting switching period in steady state is presented. The analysis takes into account the delay introduced by the filter in the hysteretic control loop of each converter, and the delay caused by the semiconductor turn-on and turn-off. Simulation and experimental results are reported for two and three interleaved converters showing a perfect agreement with theoretical predictions.