Ripple current reduction for wireless electric vehicle charging
First Claim
1. An apparatus for wireless power transmission comprising:
- a power input node configured to receive direct-current (DC) power;
an inverter circuit having an input coupled to the power input node;
a resonant circuit coupled to outputs of the inverter circuit, the resonant circuit including a tuning portion and a coil portion;
a current sensor coupled to the resonant circuit; and
a controller coupled to the inverter circuit and the current sensor, the controller configured to;
apply, to the inverter circuit, a periodic control signal for use by the inverter circuit to invert the DC power to alternating current;
receive, from the current sensor, an indication of a peak-to-peak amplitude of the alternating current that flows to the coil portion of the resonant circuit; and
alter, based on the indication, the periodic control signal to adjust the peak-to-peak amplitude of the alternating current that flows between the tuning portion and the coil portion of the resonant circuit.
2 Assignments
0 Petitions
Accused Products
Abstract
The present disclosure describes aspects of ripple current reduction for wireless electric vehicle charging. In some aspects, an apparatus for wireless power transmission includes an inverter circuit to provide alternating current and a resonant circuit having a tuning portion and a coil portion to transmit power based on the alternating current. The apparatus also includes a current sensor to provide an indication of peak-to-peak amplitude (e.g., ripple current) of the alternating current that flows to the coil portion of the resonant circuit. Based on this indication, a control signal of the inverter is altered to adjust the peak-to-peak amplitude of the alternating current, such as to reduce ripple current in the coil portion. By so doing, ripple current can be reduced in power-transmitting or power-receiving devices, which may improve power transmission efficiency, enable use of smaller decoupling capacitors, or reduce stress on elements of respective resonant circuits.
7 Citations
30 Claims
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1. An apparatus for wireless power transmission comprising:
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a power input node configured to receive direct-current (DC) power; an inverter circuit having an input coupled to the power input node; a resonant circuit coupled to outputs of the inverter circuit, the resonant circuit including a tuning portion and a coil portion; a current sensor coupled to the resonant circuit; and a controller coupled to the inverter circuit and the current sensor, the controller configured to; apply, to the inverter circuit, a periodic control signal for use by the inverter circuit to invert the DC power to alternating current; receive, from the current sensor, an indication of a peak-to-peak amplitude of the alternating current that flows to the coil portion of the resonant circuit; and alter, based on the indication, the periodic control signal to adjust the peak-to-peak amplitude of the alternating current that flows between the tuning portion and the coil portion of the resonant circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for wirelessly transmitting power comprising:
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a direct-current (DC) power source configured to convert alternating-current (AC) power of a first frequency to DC power; an inverter circuit coupled to the DC power source, the inverter circuit configured to invert, based on a pulse-width modulation (PWM) control signal, the DC power to alternating current of a second frequency that is different from the first frequency; a resonant circuit coupled to the inverter circuit, the resonant circuit including a tuning portion and a coil configured to wirelessly transmit, based on the alternating current, power to another resonant circuit of a power-receiving device; a current sensor coupled to the resonant circuit; and a controller configured to; receive, from the current sensor, an indication of the alternating current flowing to the coil of the resonant circuit; determine, based on the indication, an amount of the alternating current flowing to the coil at a third frequency, the third frequency being less than one half of the second frequency; and alter, based on the determined amplitude, the PWM signal of the inverter circuit to reduce the amount of the alternating current flowing to the coil at the third frequency. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method for wireless power transmission comprising:
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receiving direct-current (DC) power; applying, to an inverter circuit, a periodic control signal used by the inverter circuit to invert the DC power to provide alternating current; applying the alternating current provided by the inverter circuit to a resonant circuit that includes a tuning portion and a coil portion; receiving, from a current sensor, an indication of peak-to-peak amplitude of the alternating current flowing to the coil portion of the resonant circuit; and altering, based on the indication, the periodic control signal to adjust the peak-to-peak amplitude of the alternating current flowing to the coil portion of the resonant circuit. - View Dependent Claims (22, 23, 24, 25, 26)
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27. An apparatus for wireless power transmission comprising:
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a power input node configured to receive direct-current (DC) power; an inverter circuit having an input coupled to the power input node; a resonant circuit coupled to outputs of the inverter circuit, the resonant circuit including a tuning portion and a coil portion; means for applying, to the inverter circuit, a periodic control signal for use by the inverter circuit to invert the DC power to alternating current; means for sensing the alternating current that flows to the coil portion of the resonant circuit; means for determining, based on the sensed alternating current, a peak-to-peak amplitude of the alternating current that flows to the coil portion of the resonant circuit; and means for altering, based on the peak-to-peak amplitude of the alternating current, the periodic control signal to adjust the peak-to-peak amplitude of the alternating current that flows to the coil portion of the resonant circuit. - View Dependent Claims (28, 29, 30)
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Specification