The pfc line is to make the AC current follow the AC voltage change, one is the phase factor, the other is the waveform distortion factor, and the PFC line can improve the power factor through the coil.
PFC itself has a power loss,PFC only raises the power factor rather than the power, so that the current voltage is in phase, but also reduces the harmonic component of the current. It is mainly to reduce the current overshoot of the power grid and electrical equipment, and at the same time, the proportion of active power is improved (although the apparent power is reduced), so that the utilization of electric energy can be improved, and the efficiency can be said to be improved.