CE mark and EN 61000-3-2 normalisation ask a minimum 50Hz harmonic re-injection on the power line, and requires a form factor at least equal to 98%, this figure is made by a PFC (Power Factor Corrector) device.
Power supplies with PFC and current generation for halogen lamp
Triphase PFC filter 2KW
Power supplies with PFC and multiples switching with 17 independent outputs