Inductive charger field shaping using nonmagnetic metallic conductors

• US 5,594,317 A
• Filed: 12/02/1994
• Issued: 01/14/1997
• Est. Priority Date: 12/02/1994
• Status: Expired due to Fees

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: Delco Electronics Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Ramos, Sergio, Yeow, Eddie Y., Woody, George R., Radys, Ray G.
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US08/348,667
• Time in Patent Office: 774 Days
• Field of Search: 320/2, 320/5, 336/DIG. 2, 336/55, 336/60, 336/61
• US Class Current: 320/108
• 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: Y10S 336/02 Separable

Abstract

An inductive battery charging system that uses heat conducting heat exchangers that shape electromagnetic fields produced by the windings of the charging system. The field shaping provided by the heat exchangers of the present invention improves the power handling capacity of the system. The charging system includes a charge probe that includes a primary winding of a transformer and a charge port that includes secondary windings of the transformer. The heat exchangers are heat sinks that are inserted between or are disposed adjacent turns of the windings and are used to remove heat from windings. In the present invention, the heat exchangers are also used to shape the leakage flux near the edges of the windings in such a manner that AC losses in the windings are considerably reduced. The present invention may be used to increase the inductive charging capacity of an electric vehicle battery pack to on the order of 120 KW and beyond. The present invention eliminates overheating in the at the interface between the transformer windings at a 50 KW level or higher. The present invention may be used with almost any magnetic device, such as a transformer or inductor that uses foil windings or solid wire conductors.

Claims

1. An inductive charging system for use in charging batteries of an electric vehicle, wherein said inductive charging system comprises a power source, a charge station coupled to the power source, a charge paddle that comprises a primary core and a primary winding of a transformer coupled to the charge cable by means of an extendable charging cord, a charge port disposed in the electric vehicle that comprises a secondary core and secondary windings of the transformer, and a charge controller coupled between the charge port and the batteries of the electric vehicle, wherein the improvement comprises:

a charge paddle that comprises a primary heat exchanger having a width that overlaps the primary winding, and wherein the primary heat exchanger shapes leakage flux at edges of the primary winding to reduce AC losses therein by reducing two-dimensional losses; and

a charge port that comprises secondary heat exchangers each having a width that overlaps the secondary windings, and wherein the secondary heat exchangers shape leakage flux at edges of the secondary windings to reduce AC losses therein by reducing two-dimensional losses.

2. The system of claim 1 wherein the primary heat exchanger is disposed between predetermined ones of the turns of primary winding, and wherein the secondary heat exchangers are disposed adjacent predetermined ones of the secondary winding.

3. The system of claim 1 wherein the primary winding is comprised of an even number of turns and is disposed around the primary core, and wherein the primary heat exchanger is disposed between the even number of turns, and wherein the secondary core comprises an E-core having a plurality of windings disposed between inner edges thereof, and wherein the secondary heat exchangers are disposed between respective the secondary winding and inner surfaces of the E-core.

4. The system of claim 1 wherein the transformer comprises a primary winding having an even number of turns wherein the heat exchanger is centrally disposed between the even number of turns, and a plurality of secondary windings that have heat exchangers disposed at distal surfaces of the secondary windings.

5. The system of claim 1 wherein the heat exchangers comprise nonmagnetic metallic electrically conductive heat exchangers.