Multiphase coupled and integrated inductors with printed circuit board (PBC) windings for power factor correction (PFC) converters
A power factor correction (PFC) power converter, particularly of a multiphase totem-pole or other topology presenting a switching bridge that can potentially provide bi-directional power transfer control, reduces a nominal switching frequency and achieves zero voltage switching over an increased portion of a half line cycle by providing positive or inverse coupling of inductors in an inductor structure that can be formed of a multi-layer printed circuit board such that at least three different inductances are presented during each half line cycle period; allowing increased switching frequency and simplifying EMI filtering arrangements. Parasitic capacitances can be balanced with additional coupled windings to reduce differential mode and common mode noise. The PFC power converter is particularly applicable to provide bi-directional power control from an on-board battery charger in an electrically powered vehicle.
1. A power converter including a plurality of switches wherein said switches are controlled in a manner to provide a switching cycle, and an inductor structure including at least two inductors wherein said at least two inductors are magnetically coupled with each other to present one or more equivalent inductance values which vary during different portions of a switching cycle and differing from an inductance value of respective ones of said at least two inductors, said at least two inductors being connected in series with said plurality of switches during said switching cycle and wherein respective windings of each of said at least two inductors are placed on outer legs of a core, said at least two inductors being formed of printed circuit board layers, said printed circuit board layers being interleaved to provide at least one layer of each winding between said printed circuit board layers of another winding of said at least two inductors, wherein a board layer configuration of one leg is opposite that of another leg.
2. The power converter as recited in claim 1 , wherein said power converter has a multiphase totem-pole topology.
3. The power converter as recited in claim 2 , wherein said power converter is a two-phase power converter.
4. The power converter as recited in claim 1 , wherein at least one said winding of at least one said printed circuit board layer is split to form at least two turns of said winding.
5. The power converter as recited in claim 1 , wherein at least one said layer of said at least one printed circuit board layer forms a single turn of at least one said winding, said winding being spaced from a core by a distance greater than a spacing of a winding that is split to form at least two turns.
6. The power converter as recited in claim 1 , wherein at least two of said layers of said at least one inductor form a single turn of at least two said windings, said two windings being separate windings and spaced from a core by a distance greater than a spacing of a winding that is split to form at least two turns.
7. The power converter as recited in claim 1 wherein said at least two inductors are formed on an EI-shaped core.
8. The power converter as recited in claim 1 , wherein said at least two said inductors are positively coupled.
9. The power converter as recited in claim 1 , wherein said at least two inductors are inversely coupled.
10. The power converter as recited in claim 1 , wherein said switches are operated for power factor correction at a nominal switching frequency of at least 1 MHZ at a mid-point of a half line cycle.
11. The power converter as recited in claim 1 , wherein said at least two inductors include at least two additional inductors coupled to said at least two inductors for balancing parasitic capacitances of said inductor structure.
12. An inductor structure including at least two inductors wherein said at least two inductors are magnetically coupled with each other to present one or more equivalent inductance values which vary during different portions of a switching cycle and are different from a value of either of said at least two inductors and wherein respective windings of each of said at least two inductors are placed on outer legs of a core, said at least two inductors being formed of printed circuit board layers, said printed circuit board layers being interleaved to provide at least one layer of each winding between said printed circuit board layers of another of said at least two windings inductors, wherein a board layer configuration of one leg is opposite that of another leg.
13. The inductor structure as recited in claim 12 , wherein at least one said winding of at least one said printed circuit board layer is split to form at least two turns of at least one said winding.
14. The inductor structure as recited in claim 12 , wherein at least one said layer of said at least one printed circuit board layer forms a single turn of at least one said winding, said single turn being spaced from a core by a distance greater than a spacing of a winding that is split to form at least two turns.
15. The inductor structure as recited in claim 12 , wherein at least two of said layers of said at least one printed circuit board layer forms a single turn of at least two said windings, said two windings being separate windings and spaced from a core by a distance greater than a spacing of a winding that is split to form at least two turns.
16. The inductor structure as recited in claim 12 , wherein said at least two inductors are formed on a UI-shaped core.
17. The inductor structure as recited in claim 12 , wherein said at least two inductors are formed on an EI-shaped core.
18. The inductor structure as recited in claim 12 , wherein said at least two inductors are positively coupled.
19. The inductor structure as recited in claim 12 , wherein said at least two inductors are inversely coupled.
20. The inductor structure as recited in claim 12 , wherein said at least two inductors include at least two additional inductors coupled to said at least two inductors for balancing parasitic capacitances of said inductor structure.