Methods and systems for rapid wireless charging where the low state of charge (SOC) temperature dependent charging current and low SOC temperature limit are higher than the high SOC temperature dependent charging current and high SOC temperature limit
First Claim
1. A method of adjusting a wireless power control device of a secondary of a wireless charging circuit for one or more cells configured to be charged via a primary side of the wireless charging circuit, the method comprising:
- in a control circuit operable with the one or more cells, determining a state of charge of the one or more cells, a temperature of the one or more cells, and a voltage received from the secondary of the wireless charging circuit;
in response to the state of charge being below a predetermined state of charge threshold;
calculating, in the control circuit, a low state of charge current limit that is determined based upon the state of charge, the temperature of the one or more cells, and the voltage received from the secondary side of the wireless charging circuit;
delivering, to the wireless power control device, a current adjustment input comprising the low state of charge current limit;
monitoring the temperature of the one or more cells to identify if the temperature of the one or more cells is remaining below a predetermined low state of charge cell temperature threshold;
recalculating the low state of charge current limit to reduce the low state of charge current limit as a function of one or more increases in the temperature of the one or more cells;
prior to the temperature of the one or more cells breaching the predetermined low state of charge cell temperature threshold, reducing the low state of charge current limit using the recalculated low state of charge current limit effective to prevent the temperature of the one or more cells from breaching the predetermined low state of charge cell temperature threshold;
transitioning to an operating state associated with a high state of charge; and
responsive to transitioning to the operating state associated with the high state of charge, comparing the temperature of the one or more cells to a predetermined high state of charge cell temperature threshold instead of the predetermined low state of charge cell temperature threshold effective to prevent the temperature of the one or more cells from exceeding the predetermined high state of charge cell temperature threshold; and
in response to the state of charge being above the predetermined state of charge threshold;
calculating, in the control circuit, a high state of charge current limit that is less than the low state of charge current limit, the high state of charge current limit based upon the state of charge, the temperature of the one or more cells, and the voltage received from the secondary side of the wireless charging circuit; and
delivering a current adjustment input comprising the high state of charge current limit to the wireless power control device of the wireless charging circuit effective to;
reduce the voltage received from the secondary side of the wireless charging circuit;
maintain the temperature of the one or more cells below the predetermined high state of charge cell temperature threshold; and
maintain a constant current operating mode in one or more pass elements coupled serially with the one or more cells.
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Accused Products
Abstract
A system and method for wireless charging are provided. A control circuit charges one or more cells in a secondary wireless charging circuit that receives power wirelessly from a primary. The control circuit determines the state of charge and temperature of the cells. The control circuit then calculates a current limit as a function of a combination of the state of charge, input voltage to the control circuit for the wireless controller, FET power dissipation and the temperature and adjusts a wireless power control device in the secondary such that its current limit is set to the state of charge current limit. Different temperature limits can be used for different states of charge such that the cells can be charged at higher temperatures at low states of charge than at higher states of charge.
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Citations
18 Claims
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1. A method of adjusting a wireless power control device of a secondary of a wireless charging circuit for one or more cells configured to be charged via a primary side of the wireless charging circuit, the method comprising:
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in a control circuit operable with the one or more cells, determining a state of charge of the one or more cells, a temperature of the one or more cells, and a voltage received from the secondary of the wireless charging circuit; in response to the state of charge being below a predetermined state of charge threshold; calculating, in the control circuit, a low state of charge current limit that is determined based upon the state of charge, the temperature of the one or more cells, and the voltage received from the secondary side of the wireless charging circuit; delivering, to the wireless power control device, a current adjustment input comprising the low state of charge current limit; monitoring the temperature of the one or more cells to identify if the temperature of the one or more cells is remaining below a predetermined low state of charge cell temperature threshold; recalculating the low state of charge current limit to reduce the low state of charge current limit as a function of one or more increases in the temperature of the one or more cells; prior to the temperature of the one or more cells breaching the predetermined low state of charge cell temperature threshold, reducing the low state of charge current limit using the recalculated low state of charge current limit effective to prevent the temperature of the one or more cells from breaching the predetermined low state of charge cell temperature threshold; transitioning to an operating state associated with a high state of charge; and responsive to transitioning to the operating state associated with the high state of charge, comparing the temperature of the one or more cells to a predetermined high state of charge cell temperature threshold instead of the predetermined low state of charge cell temperature threshold effective to prevent the temperature of the one or more cells from exceeding the predetermined high state of charge cell temperature threshold; and in response to the state of charge being above the predetermined state of charge threshold; calculating, in the control circuit, a high state of charge current limit that is less than the low state of charge current limit, the high state of charge current limit based upon the state of charge, the temperature of the one or more cells, and the voltage received from the secondary side of the wireless charging circuit; and delivering a current adjustment input comprising the high state of charge current limit to the wireless power control device of the wireless charging circuit effective to; reduce the voltage received from the secondary side of the wireless charging circuit;
maintain the temperature of the one or more cells below the predetermined high state of charge cell temperature threshold; andmaintain a constant current operating mode in one or more pass elements coupled serially with the one or more cells. - View Dependent Claims (2, 3, 4, 5)
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6. A system for wireless charging, comprising:
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one or more cells; one or more pass elements coupled serially with the one or more cells; a control circuit operable with the one or more pass elements; a temperature sensor, operable with the control circuit, and configured to sense a temperature of the one or more cells; and a secondary side of a wireless power transfer system configured to deliver power to the one or more cells, the secondary side comprising a wireless power control device, the control circuit further configured to; determine a state of charge of the one or more cells; determine, with the temperature sensor, the temperature of the one or more cells; responsive to determining the state of charge being below a predetermined state of charge threshold; calculate a low state of charge current limit based, at least in part, on a combination of the state of charge and the temperature of the one or more cells; monitor a charging current associated with charging the one or more cells to identify if the charging current is remaining below the low state of charge current limit; monitor the temperature of the one or more cells to identify if the temperature of the one or more cells is remaining below a predetermined low state of charge cell temperature threshold; recalculate the low state of charge current limit to reduce the low state of charge current limit based upon one or more increases in the temperature of the one or more cells; prior to the temperature of the one or more cells breaching the predetermined low state of charge cell temperature threshold, reduce the low state of charge current limit effective to prevent the temperature of the one or more cells from breaching the predetermined low state of charge cell temperature threshold; and transition to an operating state associated with a high state of charge at least by comparing the temperature of the one or more cells to a predetermined high state of charge cell temperature threshold instead of the predetermined low state of charge cell temperature threshold effective to prevent the temperature of the one or more cells from exceeding the predetermined high state of charge cell temperature threshold; and responsive to the state of charge being above the predetermined state of charge threshold; calculate a high state of charge current limit as a function of a combination of the state of charge and the temperature of the one or more cells; monitor the temperature of the one or more cells to identify if the temperature of the one or more cells is remaining below a predetermined high state of charge temperature threshold; and adjust the high state of charge current limit based upon one or more increases in the temperature of the one or more cells. - View Dependent Claims (7, 8, 9, 10, 11)
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12. A method of wirelessly charging one or more cells of a battery, the method comprising:
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at a secondary side of a wireless charging system, in a control circuit operable with the one or more cells, determining a state of charge of the one or more cells and a temperature of the one or more cells; in response to the state of charge being greater than a state of charge threshold, at the control circuit; calculating a high state of charge current limit as a function of the state of charge and the temperature of the one or more cells; and adjusting a current limit of a wireless power control device to the high state of charge current limit; and in response to the state of charge being less than the state of charge threshold; calculating, as a function of the state of charge and the temperature of the one or more cells, a low state of charge current limit that is higher than the high state of charge current limit; adjusting the current limit of the wireless power control device to the low state of charge current limit; monitoring the temperature of the one or more cells to identify if the temperature of the one or more cells is remaining below a predetermined low state of charge cell temperature threshold; recalculating the low state of charge current limit to reduce the low state of charge current limit as a function of one or more increases in the temperature of the one or more cells; prior to the temperature of the one or more cells breaching the predetermined low state of charge cell temperature threshold, reducing the low state of charge current limit effective to prevent the temperature of the one or more cells from breaching the predetermined low state of charge cell temperature threshold; transitioning to an operating state associated with a high state of charge; and responsive to transitioning to the operating state associated with the high state of charge, comparing the temperature of the one or more cells to a predetermined high state of charge cell temperature threshold instead of the predetermined low state of charge cell temperature threshold effective to prevent the temperature of the one or more cells from exceeding the predetermined high state of charge cell temperature threshold. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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Specification