INPUT PARASITIC METAL DETECTION
First Claim
1. A method of controlling inductive power transfer in an inductive power transfer system, the system including a primary unit, having a tank circuit and switching circuit, operable to generate an electromagnetic field and at least one secondary device, separate from the primary unit, and adapted to couple with the field when the secondary device is in proximity to the primary unit so that power is received inductively by the secondary device from the primary unit without direct electrical conductive contacts therebetween, the method comprising:
- measuring a characteristic of input power in the primary unit;
measuring a characteristic of power in the tank circuit of the primary unit;
receiving, in the primary unit, information from the at least one secondary device;
estimating power consumption in the inductive power transfer system as a function of at least the measured characteristic of power in the tank circuit of the primary unit;
comparing the measured characteristic of input power in the primary unit, the information from the at least one secondary device, and the estimated power consumption to determine there is an unacceptable amount of parasitic metal present in proximity to the primary unit; and
restricting or stopping the inductive power transfer from the primary unit in response to a determination that the unacceptable amount of parasitic metal is present in proximity to the primary unit.
3 Assignments
0 Petitions
Accused Products
Abstract
A system and method of controlling inductive power transfer in an inductive power transfer system and a method for designing an inductive power transfer system with power accounting. The method of controlling inductive power transfer including measuring a characteristic of input power, a characteristic of power in the tank circuit, and receiving information from a secondary device. Estimating power consumption based on the measured characteristic of tank circuit power and received information and comparing the measured characteristic of input power, the information from the secondary device, and the estimated power consumption to determine there is an unacceptable power loss. The method for designing an inductive power transfer system with power accounting including changing the distance between a primary side and a secondary side and changing a load of the secondary side. For each distance between the primary side and the secondary side and for each load, measuring a circuit parameter on the primary side in the tank circuit and a circuit parameter on the secondary side during the transfer of contactless energy. The method further including selecting a formula to describe power consumption in the system during the transfer of contactless energy based on coefficients and the circuit parameters, and determining the coefficients using the measured circuit parameters.
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Citations
45 Claims
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1. A method of controlling inductive power transfer in an inductive power transfer system, the system including a primary unit, having a tank circuit and switching circuit, operable to generate an electromagnetic field and at least one secondary device, separate from the primary unit, and adapted to couple with the field when the secondary device is in proximity to the primary unit so that power is received inductively by the secondary device from the primary unit without direct electrical conductive contacts therebetween, the method comprising:
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measuring a characteristic of input power in the primary unit; measuring a characteristic of power in the tank circuit of the primary unit; receiving, in the primary unit, information from the at least one secondary device; estimating power consumption in the inductive power transfer system as a function of at least the measured characteristic of power in the tank circuit of the primary unit; comparing the measured characteristic of input power in the primary unit, the information from the at least one secondary device, and the estimated power consumption to determine there is an unacceptable amount of parasitic metal present in proximity to the primary unit; and restricting or stopping the inductive power transfer from the primary unit in response to a determination that the unacceptable amount of parasitic metal is present in proximity to the primary unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method for designing an inductive power transfer system with power accounting comprising:
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providing a primary side with a tank circuit for transferring contactless energy; providing a secondary side including a secondary coil for receiving the contactless energy and a load in electrical communication with a load; changing the distance between the primary side and the secondary side; changing the load of the secondary side; for a plurality of distances between the primary side and the secondary side and for a plurality of loads, measuring at least one circuit parameter on the primary side in the tank circuit during the transfer of contactless energy; for a plurality of distances between the primary unit and the secondary device and for a plurality of loads of the secondary device, measuring at least one circuit parameter on the secondary side during the transfer of contactless energy; selecting a formula to describe power consumption in the system during the transfer of contactless energy based on a plurality of coefficients, the at least one circuit parameter on the primary side in the tank circuit, and the at least one circuit parameter on the secondary side; and determining the coefficients using the measured circuit parameters on the secondary side and the measured circuit parameters on the primary side. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A primary unit, having a tank circuit and switching circuit, operable to generate an electromagnetic field for transferring power to at least one secondary device, separate from the primary unit, and adapted to couple with the field when the secondary device is in proximity to the primary unit so that power is received inductively by the secondary device from the primary unit without direct electrical conductive contacts therebetween, the primary unit comprising:
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a sensor for measuring a characteristic of input power in the primary unit; a sensor for measuring a characteristic of power in the tank circuit of the primary unit; a receiver for receiving information from the at least one secondary device; a controller programmed for; estimating power consumption in the inductive power transfer system as a function of at least the measured characteristic of power in the tank circuit of the primary unit; comparing the measured characteristic of input power in the primary unit, the information from the at least one secondary device, and the estimated power consumption to determine there is an unacceptable amount of parasitic metal present in proximity to the primary unit; and restricting or stopping the inductive power transfer from the primary unit in response to a determination that the unacceptable amount of parasitic metal is present in proximity to the primary unit. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45)
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Specification