3-Phase PFC Circuit

Fuji's experiences of Power Supplies with 3 phase PFC circuit

• (1) 8.5kW AC/DC Power Supply for Disk Storage System
  INPUT: 3-phase 200VAC (LV model) or 400VAC (HV model)
  OUTPUT: 395VDC
• (2) 11.5kW AC/DC Power Supply for Disk Storage System
  Fuji is currently producing this front end power supply since 2004.
  INPUT: 3-phase 200~480VAC (World Wide Range Input)
  OUTPUT: 208VDC, 5VDC, 12VDC
• (3) On going developments
  DSP controlled 3-phase WW PFC

(1) 8.5kW AC/DC Power Supply

3 sets of single-phase PFC

• This model has three identical conventional single phase PFC circuits on each line to line.
  The PFC circuit design is optimized for each 200VAC and 400VAC input. Needs two models to cover world wide markets.
• Three identical DC/DC converters followed by each PFC. Those are synchronized to make power balance.

Circuit diagram

Single-phase PFC + DC/DC x 3

(2) 11.5kW AC/DC Power Supply

3-phase WW (World Wide) PFC + DC/DC

• The PFC circuit is developed by Fuji R&D division.
• It covers all 200V~480VAC input range.One model can cover all world wide markets.
• There are three identical PFC for each arm of three phase AC input.
• Only one DC/DC converter is required.
• Efficiency: PFC = 97%
• High reliability: No failures on PFC circuit in over 20,000 units shipped.

Circuit diagram

3-phase WW PFC + DC/DC

(3) On going developments

3-phase WW PFC with DSP control

• Under development for Printers
  - 6kW model
  - 2kW model
• DSP technology is applied onto the 3-phase WW PFC control circuit
• DSP eliminates number of components on the control circuit