Control of a Flyback Converter in Mixed Conduction Mode: Influence on the Converter Design Using Optimization under Constraints

This paper deals with the control of a flyback converter in power factor correction (PFC) mode and the influence of the conduction mode on the converter design when using an optimization under constraints approach. In this context, a mixed control associated with mixed current conduction combining both discontinuous and continuous conduction over the low frequency period is presented, simulated and validated by experiments. This mixed conduction, which allows a compromise between transformer volume and semiconductor current constraints (maximal and RMS current values), is integrated within a flyback design approach using optimization under constraints. The obtained results demonstrate the effectiveness of this optimization approach in determining the balance between discontinuous and continuous conduction durations over the low frequency period. Moreover, the interest to consider the conduction mode as an optimization criterion is established.