Method and apparatus for supplying contactless power

• US 6,515,878 B1
• Filed: 08/07/1998
• Issued: 02/04/2003
• Est. Priority Date: 08/08/1997
• Status: Expired due to Term

• Current Assignee: Meins-Sinsley Partnership
• Original Assignee: Meins-Sinsley Partnership
• Inventors: Meins, Jürgen G., Sinsley, John D.
• Primary Examiner(s): Nappi, Robert E.
• Assistant Examiner(s): Laxton, Gary L.
• Application Number:
  US09/131,074
• Time in Patent Office: 1,642 Days
• Field of Search: 363/37, 363/34, 363/123, 307/10.1, 336/118, 336/119, 191/6, 191/10
• US Class Current: 363/37
• CPC Class Codes: B60L 15/005 for control of propulsion for vehicles propelled by linear motors
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 5/005 without mechanical contact between the collector and the power supply line
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: H02M 7/48 using discharge tubes with control electrode or semiconductor devices with control electrode
• CPC Class Codes: H02M 7/4807 having a high frequency intermediate AC stage
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility

Abstract

A method and apparatus for supplying contactless power. Electrical power is transferred from a power source to a load through a primary energy converter that can be connected to the power source, through a primary inductive loop connected to the primary energy converter and a secondary pickup coil magnetically coupled to the primary inductive loop, and then to a secondary energy converter. The power factor for the transfer of electrical energy is one. Multiple loads can receive power from the power source and, where the loads are located in zones, collisions between the loads can be prevented.

Claims

1. A contactless system to magnetically transfer electric power from an input power source to a first secondary load, comprising:

a primary energy converter connected to the input power source and including an output inverter;

a primary inductive loop connected in series to the output inverter through at least one primary capacitor, the loop including at least one turn;

a secondary power pickup unit magnetically coupled to the primary inductive loop, the secondary power pickup unit including a ferromagnetic core and at least two windings which are each distributed on the ferromagnetic core such that they are partly magnetically coupled and partly magnetically not coupled, the two windings each being partly compensated with a parallel capacitor;

compensation circuitry that automatically and passively compensates the two windings to unity power factor and passively supplies in-phase power at a constant voltage to the first secondary load regardless of the magnitude of the first secondary load; and

a secondary energy converter connected to the secondary power pickup unit through at least one secondary capacitor in parallel to the secondary power pickup unit, the secondary energy converter including an input converter and being connected to the first secondary load, the at least one primary capacitor and the at least one secondary capacitor being chosen so that the primary inductive loop and the secondary power pickup unit are tuned to resonance at a desired operating frequency,

whereby the primary inductive loop and the secondary power pickup unit are magnetically coupled at a unity power factor.

2. A contactless inductive system to transfer electric power from a primary system to a first load and at least one additional load, the contactless inductive system having a power factor, comprising:

a first power pickup unit having two segmented windings which are partly magnetically coupled and partly magnetically not coupled, each of the two windings being connected with a resonant capacitor in parallel, so that the first power pickup unit is tuned to a desired operating frequency;

a first inverter which is set at the desired operating frequency, the first inverter feeding the primary system with constant voltage or constant current and maintaining the power factor of the contactless inductive system equal to one, independent of the first load;

a primary inductive loop which is formed as a loop and connected to a first primary inverter through one or more capacitors in series, the primary inductive loop being tuned at the desired operating frequency, the primary inductive loop being separated into at least two power zones, each of the first and additional loads being located in a separate power zone, each of the power zones being independently and automatically switchable from an active mode to an inactive mode, such that each inactive zone is magnetically neutral and is incapable of transferring electric power to any load in that inactive zone, all loads thereby being connected in parallel, seeing the same voltage, and eliminating the multiple series load reflected impedances; and

a constant current power supply feeding the inverter,

wherein the system transfers electric power to at least one load in addition to the first load.

3. The contactless inductive system of claim 2, further including at least one additional inverter and a switching system, the switching system allowing an inverter feeding a power zone to load-share an adjoining power zone in the event one of the inverters fails.

4. The contactless inductive system of claim 2, wherein at least one of the first and additional loads includes a voltage control circuit for maintaining a constant voltage to at least one of the first and additional loads.