Wireless power for variable load

Abstract

The present disclosure provides systems, methods, and devices for wireless power transmission and reception. A wireless power transmission device (102) may include a primary coil (104) that transmits power to a corresponding secondary coil (120) in a wireless power receiving device (118). The wireless power transmission device (102) may configure characteristics of the wireless power transmission based on a load setting of the wireless power receiving device (118). The wireless power transmission device (102) may take into account a coupling coefficient and power transmission characteristics of the wireless power transmission device (102) when determining a configuration for wireless power transmission from the wireless power receiving device (118) to the wireless power receiving device (118). In some implementations, a change in wireless power transmission may be made based on a corresponding change in load (130). For example, the change in wireless power transmission and the corresponding change in load (130) may occur in connection with a synchronization event.

Description

Technical Field

[0001] This disclosure generally relates to wireless power. More specifically, this application relates to a wireless power transmission device and a wireless power reception device.

Background Art

[0002] Some wireless power systems utilize wireless power technology to wirelessly supply power to cordless devices such as some types of blenders, kettles, mixers, etc. In these wireless power systems, the wireless power transmission device may be installed on a countertop or other flat surface, and the wireless power reception device may be included in the cordless device. The wireless power transmission device may include a primary coil that generates an electromagnetic field capable of inducing a voltage in the secondary coil of the wireless power reception device when the secondary coil is disposed close to the primary coil. In this configuration, the electromagnetic field can wirelessly transmit power to the secondary coil. The power can be transmitted using inductive coupling or resonant coupling between the primary coil and the secondary coil. The wireless power reception device can supply the received power to operate the cordless device.

Summary of the Invention

[0003] The systems, methods, and devices of this disclosure each have several innovative aspects, and only one of which alone is not involved in the desirable attributes disclosed herein.

[0004] One innovative aspect of the subject matter described in this disclosure may be implemented as a method for wireless power transmission. In some implementations, the method may include a step of receiving information in a first time indicating at least a load setting associated with a variable load of a wireless power receiver. The method may also include a step of determining operational control parameters for a wireless power transmission device based at least in part on the load setting. The method may also include a step of changing the amount of wireless power transmitted by the wireless power transmission device in a second time, based at least in part on the operational control parameters, the second time being for a synchronization event after the first time.

[0005] In some implementations, information indicating at least the load setting is received by the communication coil of the wireless power transmission device.

[0006] In some implementations, the method may further include the step of transmitting radio power from at least a first primary coil of a radio power transmission device to at least a first secondary coil of a radio power receiving device in a third time.

[0007] In some implementations, the third time period precedes the first time period.

[0008] In some implementations, the step of determining the operational control parameters may further include the step of determining estimated operational control parameters based at least in part on information indicating at least the load setting associated with the variable load of the radio power receiver. The step of determining the operational control parameters may further include the step of modifying the estimated control parameters based at least in part on the difference between a reference voltage indicating the voltage required by the variable load of the radio power receiver and a load voltage indicating the voltage available to the variable load, wherein the modified estimated control parameters are the operational control parameters.

[0009] In some implementations, the operating control parameters indicate the estimated frequency of the radio power.

[0010] In some implementations, the operational control parameter indicates the duty cycle at the operating frequency in radio power.

[0011] In some implementations, the synchronization event occurs in relation to the time when the alternating current (AC) voltage supplied to the wireless power transmission device is equal to 0 volts.

[0012] In some implementations, the method may further include receiving information from the radio power receiver indicating one or more reference control parameters associated with one or more reference coupling coefficients between the radio power receiver and a reference radio power transmission device at one or more load powers and one or more load voltages of the radio power receiver. The method may further include receiving a reference voltage from the radio power receiver indicating a voltage required by the load associated with the radio power receiver, and the step of determining the operating control parameters is at least in part based on the information and the reference voltage.

[0013] In several implementations, the information was determined by experimental testing with reference radio power transmission equipment.

[0014] In some implementations, the method may further include the step of applying a voltage to the primary coil of a wireless power transmission device to induce a received voltage in the secondary coil of a wireless power receiver, wherein the magnitude of the received voltage is smaller than the magnitude of the load voltage of the wireless power receiver. The method may further include the step of receiving a received voltage value from the wireless power receiver indicating the received voltage induced in the first secondary coil of the wireless power receiver. The method may further include the step of determining a transmission voltage value indicating the amount of transmission voltage supplied to the first primary coil of the wireless power transmission device. The method may further include the step of determining an operating coupling coefficient between the wireless power transmission device and the wireless power receiver, at least in part on the ratio of the received voltage value to the transmission voltage value, and the step of determining operating control parameters is at least further on the operating coupling coefficient.

[0015] In some implementations, the load setting indicates power consumption under a variable load.

[0016] In some implementations, the operational control parameters may further be based on information indicating one or more reference control parameters associated with one or more reference coupling coefficients between the radio power receiver and a reference radio power receiver at one or more load powers and one or more load voltages of the radio power receiver. The operational control parameters may further be based on the operational coupling coefficient of the secondary coil of the radio power receiver to the first primary coil of the radio power transmission device. The operational control parameters may further be based on a power estimate indicating the amount of energy required by the variable load and a reference voltage indicating the amount of voltage required by the variable load.

[0017] In some implementations, the step of determining the operating control parameters may include interpolating and extrapolating the information, using operating coupling coefficients, power estimates, and reference voltages, to indicate one or more reference control parameters associated with one or more reference coupling coefficients at one or more load powers and one or more load voltages of a wireless power receiver.

[0018] In some implementations, the first time is after a communication delay related to information indicating at least the load setting associated with the variable load of the wireless power receiver.

[0019] Other innovative aspects of the subject matter described in this disclosure may be implemented as a method for controlling a radio power receiving device comprising at least one secondary coil. The method may also include the step of receiving radio power from at least one corresponding primary coil of a radio power transmission device by the secondary coil. The method may also include the step of transmitting information indicating a load setting associated with a variable load of the radio power receiving device. The method may also include the step of changing the amount of radio power consumed by the variable load based at least in part on the load setting in response to a synchronization event.

[0020] In some implementations, the method may further include transmitting information to a wireless power receiver indicating one or more reference control parameters associated with one or more reference coupling coefficients of the wireless power receiver to a reference wireless power transmission device at one or more load powers and one or more load voltages of the wireless power receiver. The method may also include transmitting a reference voltage to the wireless power transmission device indicating a voltage required by a load associated with the wireless power receiver. The method may also include transmitting a measured load voltage to the wireless power transmission device indicating a voltage available to the load.

[0021] In some implementations, the synchronization event occurs in relation to the time when the alternating current (AC) voltage supplied to the wireless power transmission device is equal to 0 volts.

[0022] In some implementations, the method may also include the step of transmitting a received voltage value to a wireless power transmission device, which represents a received voltage induced in at least one secondary coil of a wireless power receiver.

[0023] In some implementations, the received voltage induced in the secondary coil of a wireless power receiver corresponds to the voltage applied to the primary coil of a wireless power transmission device, and the magnitude of the received voltage is smaller than the magnitude of the load voltage of the wireless power receiver.

[0024] Another innovative aspect of the subject matter described in this disclosure may be implemented as a method for controlling a wireless power transmission device. The method may include the step of a power controller controlling the transmission of wireless power from one or more primary coils of the wireless power transmission device to one or more secondary coils of a wireless power receiver. The method may also include the step of receiving information from the wireless power receiver indicating one or more reference control parameters of the wireless power receiver, associated with one or more reference coupling coefficients between the wireless power receiver and a reference wireless power transmission device, at one or more load powers and one or more load voltages of the wireless power receiver. The method may also include the step of receiving second information from the wireless power receiver indicating one or more peak voltages induced in the secondary coils of the wireless power receiver. The method may also include the step of the power controller determining an operating coupling coefficient for the wireless power receiver based at least in part on the second information. The method may also include the step of the power controller determining an estimated load power in a load setting associated with the wireless power receiver. The method may also include the step of receiving a reference voltage from the wireless power receiver indicating a voltage required by the load. The method may also include the step of a power controller determining operating control parameters based at least in part on information received from a wireless power receiver, operating coupling coefficients, estimated load power, and reference voltage. The method may also include the step of a power controller changing wireless power in response to a synchronization event based at least in part on control information.

[0025] In some implementations, the method may also include the step of receiving a measurement load voltage from a wireless power receiver that indicates the voltage available to the load. The method may also include the step of determining a voltage error based on the difference between a reference voltage and the measurement load voltage, and the step of modifying control information based at least in part on the voltage error.

[0026] Other innovative aspects of the subject matter described in this disclosure can be implemented as a computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform any one of the aforementioned functions.

[0027] Other innovative aspects of the subject matter described in this disclosure can be implemented as a system having means for implementing any one of the aforementioned functions.

[0028] Other innovative aspects of the subject matter described in this disclosure can be implemented as an apparatus having one or more processors configured to perform one or more operations from any one of the aforementioned methods.

[0029] One or more embodiments of the subject matter described in this disclosure are described in the accompanying drawings and the following description. Other features, aspects, and advantages may become apparent from the description, drawings, and claims. Note that the relative dimensions of the following figures may not be drawn to scale. **Brief Description of the Drawings**

[0030] [Figure 1] A block diagram showing an example of a wireless power system including an example of a wireless power transmission device and an example of a wireless power reception device is shown. [Figure 2A] A perspective view of an example of a countertop mount wireless power transmission device is shown. [Figure 2B] A perspective view of an example of a countertop mount wireless transmission device and an example of a cordless device is shown. [Figure 3] A block diagram conceptually showing an example of a wireless power transmission device is shown. [Figure 4] A block diagram conceptually showing the components of an example of a power controller is shown. [Figure 5] An example of a voltage curve showing that the power controller of a wireless power transmission device can be synchronized with the load controller of a wireless power reception device is shown. [Figure 6] A block diagram conceptually showing an example of a wireless power reception device is shown. [Figure 7] An example of a voltage graph associated with a wireless power system implementing conventional feedback control technology is shown. [Figure 8] Examples of voltage graphs associated with wireless power systems that implement power control according to some embodiments of this disclosure are shown. [Figure 9] This flowchart shows an example of the process for supplying wireless power to a wireless power receiving device. [Figure 10] This flowchart shows an example of the process for receiving wireless power in a wireless power receiving device. [Figure 11] This flowchart shows an example of the process for transmitting wireless power to a wireless power receiving device. [Figure 12] A block diagram of an example of equipment for use in a wireless power system is shown. Please note that the relative dimensions in the drawing may not be proportional to the actual size. [Modes for carrying out the invention]

[0031] The following description relates to specific implementations for the purpose of illustrating innovative aspects of this disclosure. However, as will be readily apparent to those skilled in the art, the teachings herein can be applied in numerous different ways. The embodiments described may be implemented in any means, apparatus, system, or method for transmitting or receiving wireless power.

[0032] Conventional cordless kitchen systems may include wireless power transmission devices integrated into or otherwise positioned on a flat surface. They may also include cordless equipment, including wireless power receivers. A wireless power transmission device may include a primary coil that transmits wireless energy (as a wireless power signal) to a corresponding secondary coil within the wireless power receiver. A primary coil refers to the source of wireless energy (such as inductive or magnetic resonance energy) in the wireless power transmission device. The secondary coil, positioned within the wireless power receiver, receives the wireless energy and can use it to charge or power cordless equipment. For example, a cordless blender may be positioned near the primary coil of the wireless power transmission device. For example, the wireless power transmission device may include a countertop-mounted primary coil or primary coil embedded in or manufactured on a surface on which a cordless blender can be installed. The cordless blender can receive power wirelessly from the primary coil and supply that power to its motor.

[0033] Wireless power transmission is more efficient when the primary and secondary coils are positioned close together. Conversely, if the primary and secondary coils are misaligned, efficiency may decrease (or charging may stop). When properly aligned, the primary and secondary coils can transmit up to the amount of wireless energy predetermined by the wireless standard. For example, with proper alignment, the primary coil can transmit power ranging from 30 watts (W) to 2.2 kilowatts (KW). Since alignment affects the amount of power transmitted, wireless power transmission equipment can change the amount of wireless power based on its alignment with wireless power receiving equipment.

[0034] Different cordless devices have different load types, load settings, and power requirements. For example, a cordless blender may include a variable motor load with multiple user-selectable load settings for controlling motor speed. Depending on the load setting, a cordless blender may require 100W to 600W. In contrast, a cordless kettle may include a resistive load with three load settings for controlling temperature. Depending on the load setting, a cordless kettle may require up to 1.5KW. Furthermore, depending on their load type, load setting, and alignment (also called coupling coefficient) with the wireless power transmission device, cordless devices may exhibit different levels of voltage gain from the primary coil to the receiving coil at different primary coil excitation frequencies (such as wireless power transmission frequencies). Voltage gain can be measured in terms of the ratio of the voltage received by the secondary coil to the voltage applied to the primary coil. For example, to achieve a desired load voltage, a cordless blender may operate best at a first operating frequency for a first load setting, such as a low motor speed setting. However, when the load setting changes, the cordless blender may not achieve the same load voltage when operating at a first operating frequency. For example, the first operating frequency may promote a first voltage gain when the cordless blender is set to a first load setting (such as a low-speed setting), but the first operating frequency may give a lower voltage gain when the cordless blender is set to a second setting (such as a high-speed setting). Furthermore, the cordless blender may exhibit different voltage gains at different operating frequencies with different coupling coefficients. To maintain the load voltage, the wireless power transmission device may change the frequency (or other characteristics) of the wireless power based on the load setting, operating coupling coefficient, or other conditions. Because load types, load settings, and power requirements vary considerably among cordless devices, the wireless power transmission device may change the voltage output (e.g., by changing the frequency, duty cycle, or voltage) to achieve the desired load voltage.

[0035] As described herein, some cordless devices have user-selectable load settings. The user can select a first load setting to start the cordless device. While the cordless device is operating with the first load setting, the user can select a second load setting that requires more or less power. Without the technology in this disclosure, a wireless power receiver could immediately begin consuming different amounts of power in response to a change in load setting. However, there may be some delay before the wireless power transmission device can supply the amount of power required by the wireless power receiver. These delays may result in undervoltage conditions, overvoltage conditions, hardware damage or failure, and other malfunctions of the cordless device.

[0036] This disclosure provides systems, methods, and apparatus for wireless power transmission and reception. Various embodiments generally relate to wireless power transmission devices that include a primary coil for transmitting power to a corresponding secondary coil in a wireless power receiver. In some embodiments, the wireless power transmission device may configure the characteristics of wireless power transmission based on the load setting of the wireless power receiver. The wireless power transmission device may also take into account coupling coefficients, power transmission characteristics of the wireless power receiver, load changes, or any combination thereof when determining the configuration of wireless power transmission from the wireless power transmission device to the wireless power receiver. In some embodiments, changes in wireless power transmission may occur based on a corresponding change in the load. In some embodiments, changes in wireless power transmission and corresponding load changes may occur in connection with a synchronization event.

[0037] In some implementations, a power controller within a wireless power transmission device can configure the characteristics of the wireless power based on information received from a wireless power receiver. In some implementations, the information represents one or more reference control parameters, such as operating frequency, load voltage, and load power, at different reference coupling coefficients of the wireless power receiver. For example, the reference coupling coefficients may be based on experimentally obtained data when the wireless power receiver is powered by the reference wireless power receiver under one or more reference coupling coefficients (based on the alignment between the wireless receiver and the reference wireless power transmission device) at one or more load powers and one or more load voltages of the wireless power receiver. The operating coupling coefficient refers to a coupling coefficient based on the actual alignment between the wireless power receiver and the wireless power transmission device (different from the reference wireless power transmission device) currently supplying wireless power. The reference coupling coefficients can represent data points under various reference operating conditions, and even if the operating coupling coefficients are not exactly the same as the reference coupling coefficients, they can be interpolated or extrapolated. Thus, the power controller can use this information to determine one or more operating control parameters used to supply wireless power with specific characteristics, such as a particular frequency, duty cycle, and voltage. A power controller can also supply radio power that enables relatively efficient operation of a radio power receiver by using information to determine the characteristics of the radio power transmitted to the radio power receiver. For example, a power controller can configure the radio power so that the radio power receiver operates at peak efficiency for a specific load setting, load voltage, and operating coupling coefficient.

[0038] In some implementations, a power controller can respond to load setting changes by synchronizing power changes with a wireless power receiver. Load settings may indicate that a user has selected a different speed setting for a motor load, a different temperature setting for a resistive load, or otherwise changed the user-selectable load setting of a cordless device. If the load setting of a variable load associated with a wireless power receiver changes, the power controller may need to change the wireless power to accommodate the new load setting. The power controller may change the frequency, duty cycle, voltage, or any other appropriate characteristic of the wireless power. The power controller may synchronize with the wireless power receiver so that the wireless power receiver begins consuming the changed wireless power substantially simultaneously with the power controller beginning to transmit the changed wireless power. Such synchronous coordination can avoid delays in meeting the power requirements of the wireless power receiver. By avoiding these delays, the power controller can enable the wireless power receiver to respond quickly to load setting changes and avoid fault conditions that could burden the cordless device and degrade the user experience.

[0039] In some implementations, a power controller may modify one or more operational control parameters used to supply radio power based on information received from a radio power receiver. This information may include load settings, estimated power required by the variable load, voltage information for determining the operating coupling coefficient, and a reference voltage indicating the voltage required by the variable load. The power controller may use some or all of this information to determine the operational control parameters for modifying the radio power. In some implementations, the power controller may initiate transmission of the modified radio power in response to any appropriate synchronization event, such as when the alternating current (AC) supplied to the power controller crosses zero volts.

[0040] Furthermore, various embodiments generally relate to a radio power receiver that includes a secondary coil that receives power from a corresponding primary coil of the radio power transmission device. In some implementations, the load controller of the radio power receiver can synchronize and coordinate power changes with the radio power transmission device. As previously mentioned, the load setting can be changed with respect to a variable load associated with the radio power receiver. In response to a load setting change, the load controller may notify the radio power transmission device of the load setting. Instead of immediately drawing the changed power from the radio power transmission device, the load controller may wait for a synchronization event before drawing the changed power from the radio power transmission device. By waiting for a synchronization event, the load controller can coordinate with the radio power transmission device to draw the changed power substantially simultaneously with the radio power transmission device transmitting the changed power.

[0041] The technology of this disclosure enables a wireless power transmission device to estimate operational control parameters faster than a wireless power transmission device that does not implement the disclosed technology. For example, conventional feedback techniques designed to change power after detecting a load change. Therefore, conventional feedback techniques can introduce a delay between the time the load setting is changed and the time when wireless power can be supplied to accommodate the new load setting. This wireless power delay can strain cordless devices and cause fault conditions that degrade the user experience. Using the technology of this disclosure, a wireless power transmission device can estimate operational control parameters for a specific load setting of a wireless power receiver before the load is actually changed. The wireless power transmission device and the wireless power receiver can then adjust wireless power transmission and load changes, respectively, so that power is available when the load setting requires power to be supplied to the load.

[0042] Certain implementations of the subject matter described in this disclosure may be implemented to achieve one or more of the following potential benefits. In some implementations, the described techniques can be used to configure a wireless power transmission device and supply wireless power having characteristics (e.g., specific frequency, duty cycle, voltage, etc.) that allow a wireless power receiver to operate at relative efficiency at appropriate times. In some implementations, the described techniques can be used to achieve synchronous coordination between a wireless power transmission device and a wireless power receiver when responding to changes in load settings. These techniques can avoid delays associated with conventional feedback mechanisms designed to facilitate power changes. These techniques can also improve the user experience by increasing responsiveness to user-selected load settings.

[0043] The examples in this disclosure are based on wireless power used in kitchen systems, but the technology is applicable to other types of systems. For example, the technology can be used with wireless power systems related to household appliances, electronic devices, fans, space heaters, speaker systems, air compressors, gardening equipment, or components of electric vehicles, among other examples.

[0044] Figure 1 shows a block diagram of an example of a wireless power system, including an example of a wireless power transmission device and an example of a wireless power receiving device. In Figure 1, dashed lines represent communication lines to distinguish them from solid lines, which represent electrical circuit lines.

[0045] The wireless power system 100 comprises a wireless power transmission device 102 and a wireless power receiving device 118. The wireless power transmission device includes a primary coil 104. The primary coil 104 may be associated with a power signal generator 106. The primary coil 104 may be a wire coil that transmits wireless power (sometimes called wireless energy). The primary coil 104 can transmit wireless energy using induction or a magnetic resonance field. The power signal generator 106 may include components (not shown) for preparing wireless power. For example, the power signal generator 106 may include one or more switches, drivers, series capacitors, rectifiers, or other components.

[0046] In some implementations, the power signal generator 106, the power controller 108, and other components (not shown) may be collectively referred to as the power transmission circuit 110. Some or all of the power transmission circuit 110 may be embodied as an integrated circuit (IC) that implements features of the present disclosure for controlling and transmitting radio power to one or more radio power receiving devices. The power controller 108 may be implemented as a microcontroller, a dedicated processor, an integrated circuit, an application-specific integrated circuit (ASIC), or any other suitable electronic device.

[0047] The power supply 112 can supply power to the power transmission circuit 110 in the wireless power transmission device 102. The power supply 112 can convert alternating current (AC) power to direct current (DC) power. For example, the power supply 112 may include a converter that receives AC power from an external power source and converts that AC power into DC power used by the power signal generator 106.

[0048] A communication controller 122 is connected to the first communication interface 114. The first communication interface 114 is connected to the first communication coil 116. The communication controller 122 may include logic for controlling one or more switches and other components that cause the transmission and reception of radio signals via the first communication coil 116. In some embodiments, the communication controller 122, the first communication interface 114, and the first communication coil 116 may be collectively referred to as the first communication unit 124. In some embodiments, the first communication unit 124 may support Near Field Communication (NFC), a technology that performs data transfer at a carrier frequency of 13.56 megahertz (MHz). The first communication unit 124 may also support any suitable communication protocol.

[0049] The wireless power receiver 118 may include a secondary coil 120, a rectifier 126, a receiver controller 128, a second communication interface 132, a load controller 136, a load 130, and memory (indicated as RX datastore 138). Although shown as different components, some components may be packaged or implemented in the same hardware. For example, in some implementations, the receiver controller 128 and the load controller 136 may be implemented as a single controller. The receiver controller 128, the load controller 136, or any combination thereof may be implemented as a microcontroller, a dedicated processor, an integrated circuit, an application-specific integrated circuit (ASIC), or any other suitable electronic device.

[0050] The power controller 108 may detect the presence or proximity of the wireless power receiver 118. This detection may occur during the periodic pinning process of the first communication interface 114 in the wireless power transmission device 102. The first communication interface 114 may also supply power to the second communication interface 132 (via the first communication coil 116) (via the second communication coil 134) when the wireless power receiver 118 is in proximity. The second communication interface 132 may "wake up" and power up the receiver controller 128 and send a reply signal back to the first communication interface 114. A handshake process may take place before power transmission, during which the power controller 108 may receive data relating to the receiver's power rating, size, and dimensions.

[0051] During the handshake process, the power controller 108 may also receive information indicating one or more reference control parameters, such as the operating frequency of the radio power receiver 118 at different reference coupling coefficients, the load voltage of the radio power receiver 118 when operating on a reference radio power transmission device, and the load power. In some implementations, the information may include data (e.g., interpolation points, vector values, etc.) that allows the power controller 108 to adapt locally stored information to various conditions and settings, so that the power controller 108 can supply power that allows the radio power receiver 118 to operate relatively efficiently. In some implementations, the radio power receiver 118 may provide empirical formulas for calculating one or more reference control parameters as functions of the reference coupling coefficient, load voltage, and load power.

[0052] The format of the information provided by the wireless power receiver 118 may differ in different embodiments. For example, information indicating one or more reference control parameters, such as operating frequencies associated with one or more reference coupling coefficients between the wireless power receiver and the reference wireless power transmission device, at one or more load powers and one or more load voltages of the wireless power receiver, may be formatted as a data structure included in the communication from the wireless power receiver 118 to the wireless power transmission device 102. An example of a data structure is: RX DATA { Array( Reference control parameters, Reference coupling coefficient, Load voltage, (Received power) } Here, the information (RX DATA) includes values ​​for reference control parameters (e.g., operating frequency, duty cycle at a given frequency, or both), reference coupling coefficient, load voltage, and received power obtained during testing of the radio power receiver 118 with a reference radio power transmission device. The load voltage and received power indicate the power transmission achieved by the radio power receiver 118 during testing with the reference radio power transmission device, when the reference control parameters are used as reference coupling coefficients between the radio power transmission device 102 and the reference radio power receiver. This information may be stored in the memory of the radio power receiver 118 (indicated as the RX data store 138). The second communication interface 132 may retrieve the information from the RX data store 138 and communicate it to the first communication unit 124 of the radio power transmission device 102. In some implementations, the number of data points in the array may vary to provide either fine resolution (more data) or coarse resolution (less data). In some implementations, the RX DATA may be compressed to reduce the size of the communication. For example, RX DATA may include vectors, adjustment values, or other data points that can be used by the radio power transmission device 102 to reconstruct information indicating one or more reference control parameters (such as one or more operating frequencies) associated with one or more reference coupling coefficients between the radio power receiver and the reference radio power transmission device at one or more load powers and one or more load voltages of the radio power receiver. For example, RX DATA may include coefficient values, vector values, or other types of compressed data that, when applied to an equation, enable the radio power transmission device 102 to determine reference control parameters such as operating frequencies associated with different reference coupling coefficients, load voltages, and powers.

[0053] Furthermore, the power controller 108 can also determine the operating coupling coefficient associated with the wireless power receiver 118. The power controller 108 can determine the operating coupling coefficient based on one or more voltages induced in the secondary coil 120 of the wireless power receiver 118 with respect to one or more voltages applied to the primary coil 104 under the condition that there is no current in the secondary coil 120. The wireless power receiver 118 may provide information indicating one or more voltages induced in the secondary coil 120 via the first communication unit 124.

[0054] The power controller 108 may control the characteristics of the radio power supplied to the radio power receiver 118. The power controller 108 may receive information from the radio power receiver 118 after detecting it. For example, the power controller 108 may receive such information during a handshake process with the radio power receiver 118. This information may indicate reference control parameters such as the operating frequency of the radio power receiver 118, the load voltage, and the load power of the radio power receiver 118 at different reference coupling coefficients. The power controller 108 can use this information to determine at least one operating control parameter (e.g., frequency, duty cycle, voltage) for the radio power supplied to the radio power receiver 118. Thus, the power controller 108 can supply radio power that enables relatively efficient operation of the radio power receiver 118. For example, the power controller can configure the radio power so that the radio power receiver operates at peak efficiency for a particular load setting, load voltage, and operating coupling coefficient.

[0055] The power controller 108 may respond to changes in load settings by synchronously coordinating power changes with the wireless power receiver 118. Load settings may indicate that the user has selected a different speed setting for a motor load, a different temperature setting for a resistive load, or otherwise changed any other appropriate user-selectable setting on the cordless device. If the load setting of a variable load associated with the wireless power receiver changes, the power controller 108 may need to change the wireless power to accommodate that change. The power controller 108 may change the frequency, duty cycle, voltage, or any other appropriate characteristic of the wireless power. The power controller 108 may coordinate synchronously with the wireless power receiver 118 so that the power controller 108 begins transmitting the changed wireless power substantially simultaneously with the wireless power receiver 118 beginning to consume the changed wireless power. Such synchronous coordination can avoid delays in meeting the power requirements of the wireless power receiver 118. By avoiding these delays, the power controller 108 may be able to avoid failure conditions in which the wireless power receiver could overload the cordless device or degrade the user experience. In some embodiments, the power controller 108 can modify the radio power based on information received from the radio power receiver. This information may include load settings, estimated power required by the variable load, voltage information for determining the operating coupling coefficient, and a reference voltage indicating the voltage required by the variable load. The power controller 108 can use some or all of this information to determine operating control parameters for modifying the radio power. In some embodiments, the power controller 108 can initiate the transmission of the modified radio power in response to any appropriate synchronization event, such as when the AC power supplying the radio power transmission device 102 crosses zero volts.

[0056] In some implementations, the wireless power receiver 118 may be included in cordless appliances such as cordless blenders, cordless kettles, and cordless juicers. The wireless power receiver 118 may include a secondary coil 120, a rectifier 126, and a receiver controller 128. When the secondary coil 120 is aligned with the primary coil 104, the secondary coil 120 can generate an induced voltage based on the wireless power signal received from the primary coil 104. A capacitor may be connected in series between the secondary coil 120 and the rectifier 126. The rectifier 126 can rectify the induced voltage and supply it to a load 130. The load 130 may be any suitable load, such as a variable motor load, a variable resistance load, or a variable induction heating load.

[0057] The receiver controller 128 may be connected to a rectifier 126 and a second communication interface 132. The second communication interface 132 may include a modulation / demodulation circuit for wireless communication via a second communication coil 134. Thus, the receiver controller 128 can wirelessly communicate with the communication controller 122 via the second communication interface 123 to the first communication interface 114 using NFC communication. Alternatively or in addition, the receiver controller 128 may use load modulation to communicate via an in-band communication link (not shown) including a secondary coil 120.

[0058] The load controller 136 may be connected to the load 130 and the second communication interface 132. The load controller 136 can detect changes in load settings. For example, the load controller 136 can detect changes in user-selectable load settings such as a temperature selector and a motor speed selector. The load controller 136 can also determine a load voltage reference and a power estimate based on the load settings. The load controller 136 can also provide the load settings, power estimate, load voltage reference, and any other appropriate information to the receiver controller 128 or the second communication interface 132 for communication with the wireless power transmission device 102. The receiver controller 128 can further determine and provide load voltage feedback indicating the voltage available to the load 130, and coil voltage information related to determining the operating coupling coefficient. Although the receiver controller 128 and the load controller 136 are shown separately, they may be included in the same component of the wireless power receiver 118.

[0059] In some implementations, the load controller 136 can synchronize changes to wireless power with the wireless power transmission device 102. For some motor loads, the load controller 136 can also control additional hardware associated with the load (not shown in Figure 1), such as switches and drivers. In some implementations, these additional switches can be turned on or off to enable load changes in synchronization with changes to wireless power transmission. As previously stated, the load settings can be changed with respect to load 130. In response to load setting changes, the load controller 136 may notify the wireless power transmission device 102 of the load setting changes. Instead of immediately drawing the amount of power corresponding to the load settings, the load controller 136 may wait for a synchronization event before configuring load 130 to draw the changed amount of wireless power. By waiting for a synchronization event, the load controller 136 can coordinate with the wireless power transmission device 102 to begin consuming the changed wireless power substantially simultaneously with the wireless power transmission device beginning to generate the changed power. The synchronization event may be any suitable event, such as when the average DC voltage after the rectifier 126 (based on the line frequency of the AC mains supplying power to the wireless power transmission device) is close to a minimum value (such as 0 volts). In another example, the synchronization event may correspond to the time when the AC mains voltage supplying power to the wireless power transmission device crosses 0 volts.

[0060] In some implementations, techniques for determining the operational control parameters of the wireless power may be performed from the start of wireless power transmission to the wireless power receiver 118, such as during the initialization phase of wireless power transmission. In some implementations, these techniques may be used to determine new operational control parameters in response to changes in the user-selected load setting of the wireless power receiver.

[0061] Figure 2A shows a perspective view 200 of an example of a countertop-mounted wireless power transmission device. In some embodiments, the wireless power transmission device may be coupled to or integrated with the countertop 202. For example, the primary coil 204 of the wireless power transmission device may be flush-mounted within the countertop 202. For brevity, only the primary coil 204 of the wireless power transmission device is shown in Figure 2A. However, other components of the wireless power transmission device, such as those described with reference to Figure 1, may be incorporated into or mounted on the countertop 202.

[0062] Figure 2B shows a perspective view 200 of an example of a countertop-mounted wireless transmission device and an example of a cordless device. The cordless device (shown as a blender 206) can be mounted on the primary coil 204. The cordless device may include a user-selectable load setting 208. The cordless device may include a wireless power receiver (not shown in Figure 2B). The wireless power transmission device and the wireless power receiver may include any of the components and functions described herein.

[0063] Figure 3 shows a conceptual block diagram of an example of a wireless power transmission device. In Figure 3, the wireless power transmission device 300 may include a power supply 302, which is shown as an AC power supply. However, the power supply 302 may be a DC power supply or any other suitable power supply. The power supply 302 may be connected to a rectifier 304, which may be connected to a capacitor 306. The power supply 302 may also be connected to a synchronization unit 308. The synchronization unit 308 may generate a synchronization signal based on the AC power from the power supply 302. The synchronization unit 308 can provide the synchronization signal to the power controller 108 and the communication controller 324.

[0064] The rectifier 304 may supply DC power to the first switch 316 and the second switch 318. The first switch 316 and the second switch 318 may, in particular, be metal-oxide-semiconductor field-effect transistors (MOSFETs) or insulated-gate bipolar transistors (IGBTs), among several examples. The first switch 316 may be connected to a first pulse-width modulation (PWM) driver 312, and the second switch 318 may be connected to a second PWM driver 314. The power controller 108 may be connected to the first PWM driver 312 and the second PWM driver 314.

[0065] The power controller 108 can exchange communications with a wireless power receiver via a communication controller 324 which may be connected to the communication interface 326. The communication interface 326 may include a communication coil 328. In some implementations, the communication interface 326 and the communication coil 328 are configured to communicate using the NFC communication protocol.

[0066] The wireless power transmission device 300 may supply wireless power to the wireless power receiver. The power controller 108 can detect the wireless power receiver adjacent to the primary coil 322 and perform a handshake process during which the power controller 108 receives information from the wireless power receiver. The power controller 108 may receive this information via the communication interface 326 and the communication controller 324. The information may include one or more reference control parameters, such as the operating frequency of the wireless power receiver at different reference coupling coefficients, the load voltage of the wireless power receiver, and the load power of the wireless power receiver. This information may also indicate the load type and load setting of a variable load associated with the wireless power receiver. The power controller 108 can use this information to supply wireless power that has characteristics that allow the wireless power receiver to operate at relative efficiency from the start. For example, the power controller 108 may select reference control parameters such as the frequency of the wireless power based on the load type and load setting information received from the wireless power receiver. The power controller 108 may supply wireless power by determining operation control parameters and controlling the first and second PWM drivers (312 and 314, respectively) based on the operation control parameters. The PWM drivers (312 and 314, respectively) may operate the first switch 316 and the second switch 318. The first switch 316 and the second switch 318 may energize the primary coil 322 to transmit wireless power to the secondary coil of the wireless power receiver according to the operation control parameters.

[0067] After supplying power, the wireless power transmission device 300 can change the wireless power based on one or more change conditions, such as a change in load settings related to the load connected to the wireless power receiver. The power controller 108 and the wireless power receiver may change their respective configurations in response to the change in conditions. For example, the power controller 108 may determine one or more new operational control parameters (such as the frequency of the wireless power) to accommodate a change in load settings. The power controller 108 and the wireless power receiver may implement their respective configuration changes in response to a synchronization event. In some implementations, the power controller 108 begins supplying the changed wireless power substantially simultaneously with the wireless power receiver beginning to consume the changed wireless power.

[0068] Figure 4 shows a block diagram conceptually illustrating the components of an example power controller. The power controller 108 may reside within a wireless power transmission device, such as either of the wireless power transmission devices 102 and 300 described with reference to Figures 1 and 3, respectively. In Figure 4, the power controller 108 may include a parameter determination unit 412. The parameter determination unit 412 can receive information from an RX data receiving unit 402, a coupling coefficient unit 404, a power estimator 406, and a load voltage reference unit 408. The RX data receiving unit 402 may include a memory for storing information received from the wireless power receiving device (such as reference control parameters). In some embodiments, the wireless power transmission device can operate from a nominal input voltage (such as an AC main voltage), and the nominal value does not change substantially. In some embodiments, the parameter determination unit 412 can also receive information regarding the input voltage (such as an AC main voltage) and parameters, the coil inductance of the reference wireless power transmission device, or any combination thereof. For example, the parameter determination unit 412 may adjust or scale the calculation of control parameters based on changes in the input voltage or changes in parameters related to the reference radio power transmission device, such as the coil inductance of the reference radio power transmission device.

[0069] As described herein, a wireless power transmission device can supply power having characteristics (such as a selected frequency) that allow a wireless power receiver to operate with relative efficiency. During or after the handshake process, the power controller 108 can receive information from the wireless power receiver. The information may include one or more reference control parameters, such as the operating frequency of the wireless power receiver at different reference coupling coefficients, the load voltage of the wireless power receiver, and the load power. In Figure 4, the power controller 108 may receive information (shown as RX data) in the RX data receiving unit 402. The power controller 108 may also receive coupling coefficient information in the coupling coefficient unit 404, indicating the received voltage in the secondary coil. The power controller 108 may also receive power estimates in the power estimator 406, indicating the estimated power required by the load (also called estimated load power) and load settings associated with the load. The power controller 108 may also receive a load voltage reference in the load voltage reference unit 408, indicating the voltage required by the load.

[0070] As part of the process of supplying power to the wireless power receiver, the RX data receiving unit 402 may supply RX data to the parameter determination unit 412. Before supplying power, the coupling coefficient unit 404 may determine the operating coupling coefficient based on coupling coefficient information fed back from the wireless power receiver and provide the operating coupling coefficient to the parameter determination unit 412. For example, the coupling coefficient unit 404 may determine the operating coupling coefficient between the wireless power transmission device and the wireless power receiver (such as a zero current state in the secondary coil) based on the ratio of the received voltage value in the coupling coefficient information to the transmitted voltage value measured by the wireless power transmission device. The received voltage value and the transmitted voltage value may be measured by the wireless power receiver and the wireless power transmission device, respectively, over a consistent time, such as a measurement slot associated with a synchronization event. The coupling coefficient unit 404 can transmit the operating coupling coefficient to the parameter determination unit 412. The power estimator 406 may also provide the parameter determination unit 412 with an estimate of the power required by the load and load settings. The load voltage reference unit 408 may also provide the parameter determination unit 412 with a load voltage reference.

[0071] The parameter determination unit 412 can determine estimated control parameters based on RX data, operating coupling coefficients, power estimates, and load voltage references. In some implementations, the RX data may include one or more reference coupling coefficients, one or more load powers, and one or more reference control parameters (such as operating frequencies) when operating with a reference wireless power transmission device at a reference wireless power transmission device. In some implementations, the parameter determination unit 412 can determine estimated control parameters by interpolating and extrapolating the RX data using the operating coupling coefficients, power estimates, and load voltage references. The parameter determination unit 412 can provide the estimated control parameters to the logic unit 418. If the logic unit 418 does not receive feedback parameters from the feedback controller 414, the estimated control parameters become operating control parameters. The operating control parameters can be used to initiate or modify power transmission in synchronous events. In some cases (e.g., in response to a changed load setting), the power controller 108 can determine new estimated control parameters and modify the new estimated control parameters based on information communicated from the wireless power receiver. In some implementations, the power controller 108 can coordinate with the radio power receiver to synchronize changes to estimated control parameters (such as power increases) in order to cause synchronized transmission and consumption of radio power. The explanation in Figure 5 illustrates further details regarding such synchronization.

[0072] The power controller 108 may utilize information fed back from the wireless power receiver after supplying power to the wireless power receiver. Using such information, the power controller 108 can account for errors in power estimates, errors in operating coupling coefficients, and differences in parameters between the operating wireless power receiver and the reference wireless power receiver. In response to a changed load setting, the power controller 108 can determine new estimated control parameters as described. The power controller 108 may also determine feedback parameters based on information fed back from the wireless power receiver. To determine the feedback parameters, the load voltage reference unit 408 can provide a load voltage reference to the comparator 420. Alternatively, the voltage feedback unit 410 can supply a load feedback voltage to the comparator 420. The reference voltage may indicate the voltage required by the load, while the load feedback voltage may indicate the measurable voltage available to the load. The comparator 420 can determine the load voltage error based on the load voltage reference and the load feedback voltage. The load voltage error may be the difference between the load reference voltage and the load feedback voltage. The comparator 420 can provide the voltage error to the feedback controller 414. The feedback controller 414 may determine feedback parameters based on the voltage error. The feedback parameters may be values ​​used to adjust estimated control parameters (provided by the parameter determination unit 412) based on information fed back from the radio power receiver. The feedback parameters may relate to frequency, duty cycle, voltage, or any other suitable characteristic of radio power. The feedback controller 414 can provide the feedback parameters to the logic unit 418. In some implementations, estimated control parameters have a greater impact on operational control parameters than feedback parameters.

[0073] The logic unit 418 may include one or more comparators, adders, subtractors, lookup tables, and any other suitable logic for determining operational control parameters. The logic unit 418 may receive operational control parameters and feedback parameters. The logic unit 418 may determine operational control parameters based on estimated control parameters and feedback parameters. The operational control parameters may represent one or more of the frequency, duty cycle, voltage, energy, or other suitable characteristics of the radio power supplied to the radio power receiver. The logic unit 418 may provide the operational control parameters to the PWM controller 416. Based on the operational control parameters, the PWM controller 416 may control a switch driver (not shown in Figure 4) to supply radio power having one or more characteristics (such as a selected frequency) that allow the radio power receiver to operate at relative efficiency. In some implementations, the power controller 108 may work with the radio power receiver to synchronize the transmission and consumption of radio power. The description in Figure 5 illustrates further details regarding such synchronization.

[0074] Figure 5 shows an example of voltage curves that the power controller of a wireless power transmission device can synchronize with the load controller of a wireless power receiver. In Figure 5, AC voltage graph 500 shows AC voltage curve 502. AC voltage curve 502 can represent the AC voltage from the main terminal (referred to herein as the "AC trunk") that supplies power to the wireless power transmission device. For illustrative purposes, the AC trunk frequency may be 50 Hz. In Figure 5, DC voltage graph 504 shows DC voltage curve 506. DC voltage curve 506 can represent the rectified voltage available after the rectifier in the wireless power transmission device. DC voltage curve 506 can also represent the output of a smaller rectifier connected to a voltage sensor and / or bias power supply unit that supplies power to the AC trunk and powers the electronics in the wireless power transmission device. Line 508 indicates the point where AC voltage curve 502 and DC voltage curve 506 simultaneously have a voltage of 0V (also called zero voltage).

[0075] The wireless power transmission device may include a synchronization unit that can supply a signal representing an AC voltage curve 502 or a rectified DC voltage curve 506 to the power controller 108. The power controller 108 may disable the PWM driver and enable NFC-based data communication between the wireless power transmission device and the wireless power receiver near each point where the AC power supply voltage is zero (also known as a zero crossing), or perform a foreign object detection (FOD) operation to suspend power transmission for a short period (e.g., about 300 microseconds, about 1 millisecond, or any other appropriate period). Figure 5 shows the time intervals over which data communication instances occur via line 508, which indicates every other zero crossing of the AC power supply voltage. In some implementations, the wireless power transmission device may perform an FOD operation for each zero crossing not marked by one of the lines 508. In some implementations, the absence of power transmission to the wireless power transmission device in these cases can function as a clock to the wireless power receiver to synchronize its operation with the wireless power transmission device. Thus, the wireless power transmission device can cooperate synchronously with the wireless power receiver. More specifically, the power controller 108 and the load controller 136 can cooperate to synchronize their respective power operations. For example, when the power controller 108 is supplying power to a wireless power receiver, it may wait for a synchronization event before initiating power transmission. The synchronization event may be the next time point in the AC voltage curve 502 has zero voltage. In response to the synchronization event (such as the next instance of zero voltage), the power controller 108 may initiate wireless power transmission based on its operational control parameters (as described with reference to Figure 4). Similarly, the load controller 136 may also wait for a synchronization event before configuring a load change to consume the modified power. In some cases, the power controller 108 may initiate wireless power transmission substantially simultaneously with the load controller 136 configuring the load to begin consuming wireless power.

[0076] Figure 5 includes a temporal marker 510 indicating events in a wireless power system. More specifically, the temporal marker 510 indicates events that occur when the load setting changes. At time T0, the load controller 136 can detect the change to the load setting. For example, a load setting change can be initiated by a user changing a knob or other setting in the equipment. In some embodiments, communication may occur synchronously at every other zero voltage. At time T1, if the power controller 108 is unable to transmit power, the load controller 136 may communicate the changed load setting to the power controller 108. Instead of immediately configuring the load to correspond to the load setting, the load controller 136 may wait for a synchronization event before configuring the load.

[0077] Furthermore, at time T1 (or effectively time T1), the power controller 108 can receive load settings from the load controller 136.

[0078] During the duration between time T1 and time T2, the power controller 108 may determine new operating control parameters (as described, for example, with respect to Figure 4). Instead of immediately starting wireless power transmission based on the new operating control parameters, the power controller 108 may wait for a synchronization event.

[0079] At T2, the AC voltage curve 502 and DC voltage curve 506 have zero voltage, during which time power transfer is disabled by the power controller 108. The synchronization event is detected in both the wireless power transmission device (such as the power controller 108) and the wireless power receiving device (such as the receiver controller 128 or load controller 136). In response to the synchronization event, the power controller 108 starts supplying wireless power according to the new operating control parameters, and the load controller 136 configures the load to the modified load setting. Once switching is resumed by the power controller 108, power transfer to the modified load setting may resume according to the new operating control parameters (e.g., frequency duty cycle, voltage, etc.).

[0080] Figure 6 shows a conceptual block diagram of an example of such a wireless power receiving device. In Figure 6, the wireless power receiving device 600 includes a secondary coil 602. The secondary coil 602 may be connected to a series capacitor 603 and a rectifier 604 which may be connected to a load 608. The wireless power receiving device 600 may also include a communication interface 626 which may include a second communication coil 628. The communication interface 606 may be connected to a receiver controller 624.

[0081] Furthermore, the receiver controller 624 may receive various information via the communication interface 626 and transmit that information to the wireless power transmission device. The receiver controller 624 can receive wireless power receiver data from the wireless power receiver data store 616 (indicated as RX data store 616). The wireless power receiver data may include, in particular, reference control parameters such as the operating frequency of the wireless power receiver at different reference coupling coefficients, and the load voltage and load power of the wireless power receiver obtained when the wireless power receiver was tested with a reference wireless power transmission device. The receiver controller 624 may also receive information from the load controller 136 indicating load settings and power estimates. The receiver controller 624 may also receive first voltage information from a first voltage sensor 618 connected to the secondary coil 602. The first voltage information may indicate the peak or root mean square (RMS) voltage of the secondary coil 602. The receiver controller 624 may also receive second voltage information from a second voltage sensor 614 connected to the rectifier 604. The second voltage information may indicate the voltage available to the load 608. The receiver controller 624 can also receive current information from the current sensor 612 connected to the rectifier 604. The current and voltage information can indicate the amount of energy available to the load 608.

[0082] The receiver controller 624 may transmit to the radio power receiver the aforementioned radio power receiver data, first voltage information, second voltage information, and current information, which indicates load settings and power estimates for the load. In some cases, the receiver controller 624 may transmit some or all of the radio power receiver data to the power controller during the handshake process, as described herein. In some cases, the receiver controller 624 may transmit one or more of the load settings, load power estimates, first voltage information, second voltage information, and current information to the power controller 108 as part of a feedback mechanism that allows the power controller 108 to change the radio power being transmitted to the radio power receiver 600.

[0083] The synchronization unit 630 may be associated with the first voltage sensor 618. The synchronization unit 630 can determine a synchronization event and provide a synchronization signal that allows components to synchronize their operation. For example, the synchronization unit 630 may determine a synchronization event based on the time when the coil detection voltage (in the first voltage sensor 618) is zero, indicating no switching in the wireless power transmission device. The synchronization event detected by the synchronization unit 630 may occur substantially simultaneously with the corresponding synchronization event determined by a synchronization unit (not shown) of the wireless power transmission device.

[0084] As described herein, the load controller 136 can synchronize its operation with the power controller 108. For example, the load controller 136 can wait for a synchronization event (such as zero voltage) before configuring the load 608 according to the changed load settings. For motor-type loads, this may involve switching a relay / switch (not shown in the figure) within the load 608 on or off. The load controller 136 can synchronize with the power controller 108 before power transmission when receiving power or during operation after the load settings have been changed.

[0085] Figure 7 shows an example of a voltage graph 700 related to a wireless power system implementing conventional feedback control techniques. The first graph includes a reference load voltage curve 702 representing a desired load voltage at the wireless power receiver. The second graph includes an actual load voltage curve 704 representing the average value of the load voltage sensed at the load of the wireless power receiver. These graphs represent voltages in conventional wireless kitchen systems (such as heating appliances) that are not of interest to this disclosure. Conventional wireless kitchen systems may use conventional feedback control techniques that control changes in wireless power transmission by feedback messages from the wireless power receiver to the wireless power transmission device after a change in the load setting of the wireless power receiver. The actual load voltage curve 704 shows the delayed response of power supplied to the load. At a first time (shown as T0), power flows through the wireless power receiver at a first load voltage (V1). At a second time (shown as T1), the power setting of the device is increased. Based on the new power setting, the reference load voltage curve 702 changes from V1 to a second load voltage (V2). Conventional feedback control techniques may include a feedback message indicating that the reference load voltage has changed to V2. However, even if the wireless power transmission device has not yet determined new operating control parameters based on the new reference load voltage, the load can immediately begin drawing power for the second load voltage. Therefore, after the reference load voltage 702 increases from V1 to V2 at T1, the actual load voltage curve 704 may take a considerable amount of time to reach the new steady-state value of V2. As shown in Graph 700, the actual load voltage curve 704 shows a sloped curve with a delayed response after T1. At a third time (shown as T2), the power setting is reduced to indicate the decrease in the reference load voltage setting from V2 to V1. Similar to the delayed response to the increase in reference load voltage, after the reference load voltage is reduced from V2 to V1 at T2, the average load voltage (represented by the actual load voltage curve 704) may take a considerable amount of time to reach the new steady-state value.

[0086] Figure 8 shows an example of a graph 800 relating to a wireless power receiving system implementing power control according to several embodiments of the present disclosure. The first graph includes a reference load voltage curve 802 representing a desired load voltage in the wireless power receiving device. The changes in load voltage at T1 and T2, and the corresponding reference load voltage curve 802 in Figure 8, are the same as the reference load voltage curve 802 described with reference to Figure 7. The second graph includes an actual load voltage curve 804 representing the average value of the load voltage detected at the load of the wireless power receiving device. In contrast to Figure 7, the average value of the load voltage represented by the actual load voltage curve 804 in Figure 8 shows how the load voltage may be affected by the operation of the load controller 136 and power controller 108 described herein. When the power is increased (at T1) by changing the reference load voltage from V1 to V2, the average value of the load voltage (represented by the actual load voltage curve 804) shows settling to the load setpoint of V2 in a relatively short time. Similarly, at T2, when the load setting decreases due to a drop in the reference voltage from V2 to V1, the average load voltage settles to V1 relatively quickly. The power controller 108 can determine new operating control parameters based on the change in load setting voltage, resulting in faster transient behavior. As shown in the figures, the functions and components described herein can improve responsiveness to power changes and enhance the user experience.

[0087] Figure 9 shows a flowchart illustrating an example of the operation of a process for supplying wireless power to a wireless power receiving device. For simplicity, the operation is described as being performed by the device. The operation of process 900 can be carried out by the wireless power transmission devices described herein. For example, process 900 can be carried out by the wireless power transmission device 102 and power controller 108 described with reference to Figure 1, the wireless power transmission device 300 and power controller 108 described with reference to Figure 3, the power controller 108 described with reference to Figure 4, or the device 1200 described with reference to Figure 12.

[0088] In block 902, the device first receives information indicating at least the load setting associated with the variable load of the wireless power receiver.

[0089] In block 904, the device determines the device's operational control parameters based at least in part on the load setting.

[0090] In block 906, the device modifies the amount of radio power transmitted by the device at least in part based on operational control parameters, the second time being for a synchronization event following the first time.

[0091] Figure 10 shows a flowchart illustrating an example of the operation of a process for receiving wireless power in a wireless power receiver. For simplicity, the operation is described as being performed by the device. The operation of process 900 may be performed by wireless power receivers described herein. For example, process 1000 may be performed by the wireless power receiver 118 and load controller 136 described with reference to Figure 1, and the wireless power receiver 600 described with reference to Figure 6.

[0092] In block 1002, the device receives radio power from one or more primary coils of a corresponding radio power transmission device through one or more secondary coils.

[0093] In block 1004, the device transmits information indicating the load setting associated with the device's variable load.

[0094] In block 1006, the device changes the amount of radio power consumed by the variable load based at least in part on the load setting in response to a synchronization event.

[0095] Figure 11 shows a flowchart illustrating an example of the operation of a process for transmitting wireless power to a wireless power receiving device. For simplicity, the operation is described as being performed by the device. The operation of process 1100 can be carried out by the wireless power transmission devices described herein. For example, process 1100 can be carried out by the wireless power transmission device 102 and power controller 108 described with reference to Figure 1, the wireless power transmission device 300 and power controller 108 described with reference to Figure 3, the wireless power transmission device 400 and power controller 108 described with reference to Figure 4, or the device 1200 described with reference to Figure 12.

[0096] In block 1102, the device controls the transmission of radio power from one or more primary coils to one or more secondary coils of a radio power receiver.

[0097] In block 1104, the device receives information from the radio power receiver indicating one or more reference control parameters of the radio power receiver, associated with one or more reference coupling coefficients between the radio power receiver and the reference radio power transmission device, for one or more load powers and one or more load voltages of the radio power receiver.

[0098] In block 1106, the device receives second information from the radio power receiver indicating one or more peak voltages induced in the secondary coil of the radio power receiver.

[0099] In block 1108, the apparatus determines the operating coupling coefficient of the radio power receiver based at least in part on the second information.

[0100] In block 1110, the device determines the estimated load power in the load setting associated with the wireless power receiver.

[0101] In block 1112, the device receives a reference voltage from the wireless power receiver that indicates the voltage required by the load.

[0102] In block 1114, the device determines operating control parameters based at least partially on information received from the wireless power receiver, operating coupling coefficients, estimated load power, and reference voltage, using a power controller.

[0103] In block 1116, the device modifies the radio power at the synchronization point based at least partially on control information.

[0104] Figure 12 shows a block diagram of an example of equipment for use in a wireless power system. In some embodiments, equipment 1200 may be a wireless power transmission device as described herein (e.g., wireless power transmission device 102). In some embodiments, equipment 1200 may be an example of the power controller 108 described with reference to Figure 1, or the wireless power transmission device 300 described with reference to Figure 3. Equipment 1200 may include a processor 1202 (which may include multiple processors, multiple cores, multiple nodes, or multithreading, etc.). Equipment 1200 may also include memory 1206. Memory 1206 may be system memory or one or more possible implementations of computer-readable media as described herein. Equipment 1200 may also include a bus 1211 (e.g., PCI, ISA, PCI-Express, HyperTransport®, InfiniBand®, NuBus, AHB®, AXI, etc.).

[0105] The device 1200 may include one or more controllers 1262 configured to manage a plurality of primary or secondary coils (such as a coil array 1264). In some implementations, the controllers 1262 may be distributed within the processor 1202, memory 1206, and bus 1211. The controllers 1262 may perform some or all of the operations described herein. For example, the controller 1262 may be a power controller such as the power controller 108 described with reference to Figure 1 or the power controller 108 described with reference to Figure 3.

[0106] Memory 1206 may contain computer instructions that can be executed by processor 1202 to implement the functions of the embodiments described with reference to Figures 1 to 11. Any of these functions may be partially (or entirely) implemented in hardware or on processor 1202. For example, the functions may be implemented in an application-specific integrated circuit, logic implemented on processor 1202, a peripheral device, or a coprocessor on a card. Furthermore, the implementation may include fewer or additional components not shown in Figure 12. Processor 1202, memory 1206, and controller 1262 can be coupled to bus 1211. Although shown coupled to bus 1211, memory 1206 may be coupled to processor 1202.

[0107] Figures 1 to 12 and the operations described herein are examples intended to aid in understanding exemplary implementations and should not be used to limit potential implementations or the scope of the claims. Some implementations may perform additional operations, fewer operations, operations in parallel or in different sequences, and several different operations.

[0108] The figures, operations, and components described herein are examples intended to aid in understanding exemplary implementations and should not be used to limit potential implementations or the scope of the claims. Some implementations may perform additional operations, fewer operations, operations in parallel or in different sequences, and several different operations.

[0109] As used herein, the phrases “at least one of” or “one or more of” the list of items refer to any combination of those items, including a single component. For example, “at least one of a, b, or c” is intended to cover the possibilities of a only, b only, c only, a and b combination, a and c combination, b and c combination, and a, b, and c combination.

[0110] The various exemplary components, logic, logic blocks, modules, circuits, operations, and algorithmic processes described in relation to the embodiments disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware, or software, including the structures disclosed herein and their structural equivalents. Hardware, firmware, and software compatibility is generally described with respect to functionality and is shown in the various exemplary components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware, firmware, or software depends on the specific application and the design constraints imposed on the overall system.

[0111] Hardware and data processing devices used to implement the various exemplary components, logic, logic blocks, modules, and circuits described in relation to the embodiments disclosed herein may be implemented or run using general-purpose single-chip or multi-chip processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices (PLDs), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration. In some embodiments, specific processes, operations, and methods may be performed by circuits specific to a given function.

[0112] As stated above, some aspects of the subject matter described herein can be implemented as software. For example, various functions of the components disclosed herein, or various blocks or steps of the methods, operations, processes, or algorithms disclosed herein, can be implemented as one or more modules of one or more computer programs. Such computer programs may include non-temporary processor-executable instructions or computer-executable instructions encoded on one or more tangible processor-readable or computer-readable storage media to be executed by or control the operation of a data processing device including the components of the devices described herein. Such storage media may include, but are not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, magnetic disk storage devices or other magnetic storage devices, or any other media that can be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media.

[0113] Various modifications to the embodiments described herein may be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the scope of this disclosure. Accordingly, the claims are not intended to be limited to the embodiments shown herein, but should be given the broadest scope consistent with the disclosure, principles, and novel features disclosed herein.

[0114] Furthermore, various features described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately or in any suitable subcombination in multiple embodiments. Thus, features may be described and initially claimed as acting in a particular combination, but one or more features from a claimed combination may, in some cases, be removed from that combination, and the claimed combination may cover a partial combination or a variation of a partial combination.

[0115] Similarly, while actions are shown in a specific order in the diagrams, this should not be understood as requiring that such actions be performed in a specific order or sequentially, or that all shown actions be performed, in order to achieve the desired result. Furthermore, diagrams may schematically illustrate one or more exemplary processes in the form of flowcharts or flow diagrams. However, other actions not illustrated can be incorporated into the schematicly illustrated exemplary processes. For example, one or more additional actions can be performed before, after, simultaneously with, or in between any of the illustrated actions. In some situations, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the aforementioned implementation forms should not be understood as requiring such separation in all implementation forms, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged in multiple software products.

Claims

1. A method for wireless power transmission using a wireless power transmission device, The steps include receiving first information from a wireless power receiving device that indicates one or more reference control parameters relating to one or more load settings associated with the variable load of the wireless power receiving device, The steps include receiving a message indicating at least one of the aforementioned load settings at a first time, A step of estimating an operating control parameter for the wireless power transmission device based at least partially on the load setting and one or more reference control parameters relating to the load setting, A step of changing the amount of radio power transmitted by the radio power transmission device at a second time, based at least in part on the operation control parameters, wherein the second time is a time relative to a synchronization event occurring after the first time. A method that includes this.

2. The method according to claim 1, wherein the message indicating at least the load setting is received by the communication coil of the wireless power transmission device.

3. The method according to claim 1, further comprising the step of transmitting the radio power from at least a first primary coil of the radio power transmission device to at least a first secondary coil of the radio power receiving device in a third time.

4. The method according to claim 3, wherein the third time is before the first time.

5. The step of determining the operation control parameters is: The steps include determining estimated control parameters based at least in part on the message indicating the load setting associated with the variable load of the wireless power receiver, A step of changing the estimated control parameter based at least partially on the difference between a reference voltage indicating the voltage required by the variable load of the wireless power receiving device and a load voltage indicating the voltage available to the variable load, wherein the changed estimated control parameter is the operation control parameter. The method according to claim 1, including the method described in claim 1.

6. The method according to claim 1, wherein the operation control parameter indicates the operating frequency in the wireless power.

7. The method according to claim 1, wherein the operation control parameter indicates the duty cycle at the operating frequency in the wireless power.

8. The method according to claim 1, wherein the synchronization event occurs in relation to the time when the alternating current (AC) voltage supplied to the wireless power transmission device is equal to 0 volts.

9. The steps of receiving information from the wireless power receiver indicating one or more reference control parameters associated with one or more reference coupling coefficients between the wireless power receiver and a reference wireless power transmission device for one or more load powers and one or more load voltages of the wireless power receiver, The steps include receiving a reference voltage from the wireless power receiving device that indicates the voltage required by the load associated with the wireless power receiving device, It further includes, The method according to claim 1, wherein the step of determining the operation control parameters is at least in part based on the information and the reference voltage.

10. The method according to claim 9, wherein the information is determined by experimental testing of the reference wireless power transmission device.

11. A step of applying a voltage to the primary coil of the wireless power transmission device to induce a received voltage in the secondary coil of the wireless power receiving device, wherein the magnitude of the received voltage is smaller than the magnitude of the load voltage of the wireless power receiving device. The steps include receiving a received voltage value from the wireless power receiving device that indicates the received voltage induced in the first secondary coil of the wireless power receiving device, The steps include determining a transmission voltage value that indicates the amount of transmission voltage supplied to the first primary coil of the wireless power transmission device, A step of determining the operating coupling coefficient between the wireless power transmission device and the wireless power receiving device based at least in part on the ratio of the received voltage value and the transmitted voltage value, It further includes, The method according to claim 9, wherein the step of determining the motion control parameters is at least partially based on the motion coupling coefficient.

12. The method according to claim 1, wherein the load setting indicates the power consumption due to the variable load.

13. The aforementioned operation control parameters are: Information indicating one or more reference control parameters associated with one or more reference coupling coefficients between the wireless power receiver and the reference wireless power transmission device at one or more load powers and one or more load voltages of the wireless power receiver, The operating coupling coefficient of the secondary coil of the wireless power receiving device with respect to the first primary coil of the wireless power transmission device, A power estimate indicating the amount of power required by the variable load, The method according to claim 1, further comprising a reference voltage indicating the amount of voltage required by the variable load, and further based on the above.

14. The method according to claim 13, wherein the step of determining the operation control parameters comprises interpolating and extrapolating the information that indicates one or more reference control parameters associated with one or more reference coupling coefficients at one or more load powers and one or more load voltages of the wireless power receiver, using the operation coupling coefficients, the power estimates, and the reference voltages.

15. The method according to claim 1, wherein the first time is after a communication delay associated with the message indicating a load setting associated with the variable load of the wireless power receiver.

16. A primary coil configured to transmit radio power to at least one secondary coil of a radio power receiving device, It is a power controller, The wireless power receiving device receives first information indicating one or more reference control parameters relating to one or more load settings associated with the variable load of the wireless power receiving device. A message indicating at least one of the aforementioned load settings is received at a first time, The operation control parameters are estimated based at least partially on the load setting and one or more reference control parameters related to the load setting. The power controller is configured to change the amount of radio power at a second time, at least in part, based on the aforementioned operation control parameters, wherein the second time is a time relative to a synchronization event occurring after the first time. A wireless power transmission device equipped with the following features.

17. The wireless power transmission device according to claim 16, wherein the message indicating the load setting is received by the communication coil of the wireless power transmission device.

18. The wireless power transmission device according to claim 16, wherein the power controller is further configured to control the transmission of wireless power from at least a first primary coil of the wireless power transmission device to at least a first secondary coil of the wireless power receiving device at a third time.

19. The wireless power transmission device according to claim 18, wherein the third time is before the first time.

20. The power controller determines estimated control parameters at least in part based on the message indicating the load setting associated with the variable load of the wireless power receiver, The wireless power transmission device according to claim 16, further configured to change the estimated control parameter at least partially based on the difference between a reference voltage indicating the voltage required by the variable load of the wireless power receiving device and a load voltage indicating the voltage available to the variable load, wherein the changed estimated control parameter becomes the operation control parameter.

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