SYSTEM AND INSTALLATION FOR TRANSFERRING ELECTRICAL ENERGY WITHOUT CONTACT

• US 20120025625A1
• Filed: 02/20/2009
• Published: 02/02/2012
• Est. Priority Date: 02/20/2009
• Status: Abandoned Application

• Current Assignee: Numexia SA
• Original Assignee: Numexia SA
• Inventors: Jufer, Marcel
• Application Number:
  US13/148,411
• Publication Number:
  US 20120025625A1
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: B60L 2220/44 Wheel Hub motors, i.e. integrated in the wheel hub
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• CPC Class Codes: H01F 27/346 Preventing or reducing leakage fields using magnetic shields H01F27/36; using auxiliary windings H01F27/38
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A contact-free inductive power transfer system for minimizing the radiating magnetic field in the vicinity of the transmission zone. The system includes a primary coil (9) of n₁ turns and a secondary coil (10) of n₂ turns. In operation, the same volume of current is circulated in the primary and in the secondary coil during transfer and the number of turns n₁ in the primary coil multiplied by the current circulating in the primary coil is equal to the number of turns n₂ in the secondary coil multiplied by the current circulating in the secondary coil, the currents circulating in the primary and secondary coil being in phase opposition so as to minimize the radiating magnetic field generated by the coils. An installation for energizing a movable vehicle (14) through an intermediate loading station (6) is also described.

Claims

1. A contact-free inductive power transfer system for minimizing the radiating magnetic field in the vicinity of the transmission zone of two coaxial coils (9,10) comprising a primary coil (9) of n₁ turns and a secondary coil (10) of n₂ turns characterized in that the same volume of current is circulated in the primary and in the secondary coil during transfer and in that the number of turns n₁ in the primary coil (9) multiplied by the current circulating in the primary coil is equal to the number of turns n₂ in the secondary coil (10) multiplied by the current circulating in the secondary coil, the currents circulating in the primary and secondary coil being in phase opposition.

2. A contact-free inductive power transfer system according to claim 1 characterized in that it comprises means connected to the primary coil (9) and to the secondary coil (10) for modifying the mutual inductance between the primary and the secondary coil.

3. A system according to claim 1 characterized in that the means for adapting the mutual inductance between the primary coil and the secondary coil are constituted of a serial capacitor C1s connected to the primary coil and a serial capacitor C2s connected to the secondary coil.

4. A system according to claim 1 characterized in that the primary tension U₁ alimenting the primary coil (9) is inferior to a value U_1lim given by the following formula U_{1 lim}=√

{square root over (2π

fn₁²Λ

₁₂P_u)} where

n₁=number of turns of the primary coil

Λ

₁₂=mutual permeance between the primary and the secondary

f=frequency

P_u=useful power at the secondary

5. A system according to claim 1 characterized in that the primary coil (9) is installed on or in the ground and in that the secondary coil (10) is located under a vehicle.

6. A system according to claim 1 characterized in that it is used to transfer useful power in the range of 10 kW to 500 kW at a frequency comprised between 1 and 200 kHz.

7. An installation for powering an electrical vehicle (14) thanks to a power transfer system according to claim 1 characterized in that it further comprises an intermediate loading station (6) having a bank of super capacitors (7) as well as a high frequency generator (8) for alimenting a primary coil (9) located in or above the ground and in that the secondary coil (10) is located under the floor of the vehicle (14) which also comprises at least one bank of super capacitors (12).