Two SMPS with front end PFC connected to same AC voltage source/grid 50Hz.. PFC(digital control) is operating at 24kHz in both SMPS. I am observing a 0.2Hz envelop on PFC current which is changing if the difference in switching frequency is increased. The low frequency ripple in current is high at lower voltages (high current). Instantaneous currents are in opposite magnitude at switching frequency level. There is a CM (pi) filter at front end. Voltage sense for PFC is after EMI filter. 0.2Hz envelop is also seen in voltage after EMI filter. How to avoid this?
SMPS with front end PFC in parallel
Thanks for ur time.