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US 11,387,680 B2Granted
Coreless power transformer
AssigneeMassachusetts Institute of Technology
InventorsChathan M. Cooke, Angel J. Carvajal
Life of this patent
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Abstract
A transformer system is provided that includes four magnetically coupled coils having fixed spacing geometry. The four magnetically coupled coils include a drive coil that produces magnetic fields and a load coil. All coils are coupled in the transformer system, but the first resonant coil is highly coupled with the drive coil so that the resonant coil can receive energy from the drive coil and the second resonant coil is highly coupled to the load coil so that the load coil can extract energy efficiently from the second resonant coil.
Claims14
A transformer system comprising:
- four magnetically coupled coils have a fixed spacing geometry comprising
- a drive coil;
- a load coil;
- a first resonant coil of a length X2;
- and
- a second resonant coil of the length X2,
- wherein a following six magnetic couplings exist between the four magnetically coupled coils:
- a first magnetic coupling between the drive coil and the first resonant coil, a second magnetic coupling between the first resonant coil and the second resonant coil, a third magnetic coupling between the second resonant coil and the load coil, a fourth magnetic coupling between the drive coil and the second resonant coil, a fifth magnetic coupling between the first resonant coil and the load coil, and a sixth magnetic coupling between the drive coil and the load coil;
- wherein the drive coil producing magnetic fields and the first resonant coil being magnetically coupled to the drive coil producing energy that is stored by the first resonant coil and the second resonant coil being magnetically coupled to the first resonant coil to propagate the energy stored in the first resonant coil to the second resonant coil without using a magnetic core, wherein the second resonant coil is then magnetically coupled to the load coil where the energy is transferred to the load coil, and
- wherein a first scaling parameter f1 is used to characterize a first variation position where the drive coil is wrapped around the first resonant coil, and a second scaling parameter f2 is used to characterize a second variation position where the load coil is wrapped around the second resonant coil, and the first scaling parameter f1 and the second scaling parameter f2 are defined as:
- f1=d1/X2 and f2=d2/X2, where d1 represents a first distance between a first center position of the drive coil and a first edge of the first resonant coil and d2 represents a second distance between a second center position of the load coil and a second edge of the first resonant coil,
- wherein any of, or a combination of, a group of parameters are picked to achieve a pre-defined transmission coefficient, and the group of parameters are the first center position, the second center position, a separation distance between the first resonant coil and the second resonant coil, a number of turns in the first resonant coil, a number of turns in the second resonant coil, a number of turns in the drive coil, and a number of turns in the load coil,
- wherein the first magnetic coupling between the drive coil and the first resonant coil is higher than the fourth magnetic coupling between the drive coil and the second resonant coil and the sixth magnetic coupling between the drive coil and the load coil;
- and
- wherein the third magnetic coupling between the second resonant coil and the load coil is higher than the fifth magnetic coupling between the load coil and the first resonant coil and the sixth magnetic coupling between the load coil and the drive coil.
12 more elements
A method comprising:
- providing four magnetically coupled coils have a fixed spacing geometry comprising a drive coil, a load coil, a first resonant coil of a length X2, and a second resonant coil of the length X2, wherein a following six magnetic couplings exist between the four magnetically coupled coils:
- a first magnetic coupling between the drive coil and the first resonant coil, a second magnetic coupling between the first resonant coil and the second resonant coil, a third magnetic coupling between the second resonant coil and the load coil, a fourth magnetic coupling between the drive coil and the second resonant coil, a fifth magnetic coupling between the first resonant coil and the load coil, and a sixth magnetic coupling between the drive coil and the load coil;
- producing magnetic fields using the drive coil;
- magnetically coupling the first resonant coil to the drive coil producing energy that is stored by the first resonant coil;
- magnetically coupling the second resonant coil to the first resonant coil to propagate the energy stored in the first resonant coil to the second resonant coil without using a magnetic core, wherein the second resonant coil is then magnetically coupled to the load coil where the energy is transferred to the load coil, and wherein a first scaling parameter f1 is used to characterize a first variation position where the drive coil is wrapped around the first resonant coil, and a second scaling parameter f2 is used to characterize a second variation position where the load coil is wrapped around the second resonant coil, and the first scaling parameter f1 and the second scaling parameter f2 are defined as:
- f1=d1/X2 and f2=d2/X2, where d1 represents a first distance between a first center position of the drive coil and a first edge of the first resonant coil and d2 represents a second distance between a second center position of the load coil and a second edge of the first resonant coil,
- wherein any of, or a combination of, a group of parameters are picked to achieve a pre-defined transmission coefficient, and the group of parameters are the first center position, the second center position, a separation distance between the first resonant coil and the second resonant coil, a number of turns in the first resonant coil, a number of turns in the second resonant coil, a number of turns in the drive coil, and a number of turns in the load coil,
- wherein the first magnetic coupling between the drive coil and the first resonant coil is higher than the fourth magnetic coupling between the drive coil and the second resonant coil and the sixth magnetic coupling between the drive coil and the load coil;
- and
- wherein the third magnetic coupling between the second resonant coil and the load coil is higher than the fifth magnetic coupling between the load coil and the first resonant coil and the sixth magnetic coupling between the load coil and the drive coil.
7 more elements
Dependencies are inferred from the claim text.