Combined voltage and frequency tuning for efficiency optimization
Methods and devices for increasing power delivery efficiency of wireless power transfer systems are disclosed. A wireless power transfer system may include a power transmitter system and a power receiver system. The power transmitter system may comprise a power amplifier, a power transmitter, a controller, and a sensing circuit. The power amplifier may be configured to receive an input power. The power transmitter system may include a transmitter-side coil configured to wirelessly couple to a receiver-side coil of the power receiver system. The controller may be configured to set a voltage and a frequency of the power transmitter system based on output power information of the power receiver system to increase wireless power delivery efficiency of the wireless power transfer system. The sensing circuit may be configured to determine the output power information of the power receiver system.
1. A wireless power transmitter system, comprising:
a DC/DC converter configured to receive an input power;
a controller coupled to the DC/DC converter and having a storage medium;
a power amplifier coupled to the DC/DC converter, and coupled to the controller;
a power transmitter coupled to the power amplifier, the power transmitter including a transmitter-side coil configured to wirelessly couple to a receiver-side coil of a power receiver system; and
a sensing circuit coupled to the controller, the sensing circuit configured to determine output power information of the power receiver system,
wherein the controller is configured to set a set voltage and a set frequency of the wireless power transmitter system corresponding to the power receiver system by conducting a voltage-frequency tuning process based on the output power information of the power receiver system to reach desired wireless power delivery efficiency of a wireless power transfer system that includes the wireless power transmitter system and the power receiver system, wherein the output power information includes an amount of power received by a load of the power receiver system, wherein the voltage-frequency tuning process includes:
determining whether the load of the power receiver system is the same as a previously-powered load;
setting, in response to the load of the power receiver system being the same as the previously-powered load, a previously-saved voltage and a previously-saved frequency corresponding to the previously-saved load as the set voltage and the set frequency, respectively; and
conducting, in response to the load of the power receiver not being the same as the previously-powered load, operations comprising:
sensing, by the power transmitter system and based on a coupling coefficient between the transmitter-side coil and the receiver-side coil, a position of the receiver-side coil;
setting, based on the position of the receiver-side coil and a correspondence between a sensed position of the receiver-side coil and an amount of voltage, the set voltage;
consecutively setting, by the controller, one or more frequencies of the wireless power transmitter system until the desired wireless power delivery efficiency is achieved, so as to obtain the set frequency; and
storing, by the controller, the load of the power receiver system, and the set voltage and the set frequency corresponding to the load of the power receiver system, wherein the set voltage and the set frequency are reused when the load is again powered by the wireless power transmitter system.
2. The wireless power transmitter system of claim 1 , wherein the output power information of the power receiver system includes amounts of a voltage and a current of the power receiver system.
3. The wireless power transmitter system of claim 1 , wherein the output power information of the power receiver system is determined based on load modulation.
4. The wireless power transmitter system of claim 1 , wherein the output power information of the power receiver system is determined based on communication with the power receiver system.
5. The wireless power transmitter system of claim 1 , wherein the sensing circuit includes a load de-modulator, the load de-modulator configured to de-modulate signals modulated by a load modulator of the power receiver system, the signals including the output power information of the power receiver system.
6. The wireless power transmitter system of claim 1 , wherein the sensing circuit includes a first radio, the first radio configured to receive the output power information of the power receiver system from a second radio of the power receiver system.
7. A method for wirelessly providing power to devices, the method comprising:
wirelessly coupling a transmitter-side coil of a power transmitter system to a receiver-side coil of a power receiver system, the transmitter-side coil included in a power transmitter coupled to a power amplifier, the power amplifier coupled to a DC/DC converter and a controller, the DC/DC converter configured to receive an input power and coupled to the controller;
determining output power information of the power receiver system;
setting a set voltage and a set frequency of the power transmitter system by conducting a voltage-frequency tuning process based on the output power information of the power receiver system to reach desired wireless power delivery efficiency of a power transfer system that includes the power transmitter system and the power receiver system, wherein the output power information includes an amount of power received by a load of the power receiver system, wherein the voltage-frequency tuning process includes:
determining whether the load of the power receiver system is the same as a previously-powered load;
setting, in response to the load of the power receiver system being the same as the previously-powered load, a previously-saved voltage and a previously-saved frequency corresponding to the previously-saved load as the set voltage and the set frequency, respectively; and
conducting, in response to the load of the power receiver not being the same as the previously-powered load, operations comprising:
sensing, by the power transmitter system and based on a coupling coefficient between the transmitter-side coil and the receiver-side coil, a position of the receiver-side coil;
setting, based on the position of the receiver-side coil and a correspondence between a sensed position of the receiver-side coil and an amount of voltage, the set voltage;
consecutively setting, by the controller, one or more frequencies of the power transmitter system until the desired wireless power delivery efficiency is achieved, so as to obtain the set frequency; and
storing, by the controller, the load of the power receiver system, and the set voltage and the set frequency corresponding to the load of the power receiver system, wherein the set voltage and the set frequency are reused when the load is again powered by the power transmitter system.
8. The method of claim 7 , wherein the output power information of the power receiver system includes amounts of a voltage and a current of the power receiver system.
9. The method of claim 7 , wherein the output power information of the power receiver system is determined based on load modulation.
10. The method of claim 7 , wherein the output power information of the power receiver system is determined based on communication with the power receiver system.