Dear Members! In a near-aircraft fixed ground application i have to run a special, multi output SMPS which has a L6561 based PFC front end. So far this SMPS was run off regular 230V 50Hz mains, but due to the re-structuring of the whole application this supply will not be available anymore. The only power which will be available is 3x208V 400hz AC. Don't really want to try running this SMPS on 1-phase of the 208V 400Hz supply due to increased leakage currents in the EMI filter and not really shure about how the PFC circuit would handle and work with the internal 800Hz rectified half-sine waves. As there is no requirement regarding the power factor i was thinking to rectify+filter the 3x208V mains and power the SMPS with the filtered DC voltage of around 280V. Browsing the datasheet of the L6561 reveals that during normal AC operation it samples the rectified half-sine waves (pin3 - muiltiplier input) and also looks for the zero crossings sampled from the boost coil (pin5 - ZCD input). In case of DC operation how this PFC circuit would react? Basically there will be no zero crossings available for the PFC controller, so my assumption that this will run the boost coil with simple average current and the whole unit will act as a simple boost converter? Do you see any risk of this operation? Thanks a lot!
