I. The Design Background of 3000W PFC Inductor
Input voltage range: 85 – 265 VAC
Full power: 3000W
PFC architecture: The most common type is the three-phase interleaved Boost PFC (approximately 1000 watts per phase)
Operating frequency: 65 – 100 kHz (Si MOSFET) or 130 – 200 kHz (SiC/GaN)
From this, it can be concluded that:
The peak current of each phase inductance can reach over 10-15A. Both core loss and copper loss cannot be ignored, and a balanced approach must be adopted.
The inductive current contains a distinct DC component (high DC biasing capability is crucial)
II. Selection of Core Materials
At the 3000W level, the magnetic core material must possess high DC biasing capability, low loss, and controllable temperature rise. The comparison of several mainstream materials is as follows:
Iron Silicon Aluminum (Sendust)
Saturation magnetic flux density: 0 – 1 T
Advantages: Strong DC bias, low loss, EMI-friendly
Disadvantages: Low magnetic permeability, more turns are required
Applicable: 3000W three-phase interleaved, 65-100kHz per phase
2.High-Flux (Fe-Ni)
Saturation magnetic flux density: 0 – 1.5 T
Advantage: It can withstand a greater current than iron, silicon, and aluminum, and has a smaller volume.
Disadvantage: High cost
Applicable to: High peak current, high power density design