Parameter Estimation for Wireless Charging

Abstract

The present disclosure relates to a system and method for estimating one or more parameters associated with a converter to configure a wireless charging setting for a wireless charging system. In some embodiments, the method includes perturbing a first coil inductively coupled with a second coil, estimating one or more circuit parameters of a converter including the first coil and the second coil based on the perturbing step, and configuring one or more wireless charging settings of the wireless charging system based on the one or more circuit parameters, wherein the wireless charging system is configured to charge a battery pack of a vehicle based on wireless transfer of power between the first coil and the second coil.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to U.S. Provisional Patent Application No. 63 / 487,564, filed February 28, 2023, entitled "ACTIVE VEHICLE ADJUSTMENT FOR WIRELESS CHARGING," the technical disclosure of which is incorporated herein by reference in its entirety for all purposes.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates to systems and methods for wireless charging. More particularly, embodiments of the present disclosure relate to wireless charging systems and mechanisms for charging a vehicle battery pack. [Background technology]

[0003] A wireless charging device can be used to wirelessly charge a vehicle, such as an electric vehicle, with a battery pack. The wireless charging device can receive power from an external source, such as a grid, a solar cell, or the like, and wirelessly transfer it to the electric vehicle (e.g., via induction). The wireless charging device can be placed under the electric vehicle to charge it.

[0004] The self-inductance of transformer coils used in wireless charging applications can have large variations caused by environmental factors such as the placement of the charging pad (e.g., with respect to the vehicle) and / or nearby ferrous objects. The result of this variation poses technical challenges for fixed power converters in wireless charging systems, where the transformer inductance and impedance of the resonant tank are generally constant. Summary of the Invention [Problem to be solved by the invention]

[0005] The systems, methods, and devices of the present disclosure each have several innovative embodiments, no single one of which is solely responsible for all of the desirable attributes disclosed herein. Details of one or more implementations of the subject matter described herein are set forth in the accompanying drawings and the description below. [Means for solving the problem]

[0006] In some aspects, the technology described herein relates to a first coil and a charging configuration determination module configured to perform a charging configuration determination procedure, the charging configuration determination procedure including: perturbing the first coil, where the first coil is inductively coupled with a second coil; estimating one or more circuit parameters of a converter including the first coil and the second coil based on the perturbing step; and configuring one or more wireless charging settings of a wireless charging system based on the one or more circuit parameters, wherein the wireless charging system is configured to charge a battery pack of a vehicle based on wireless transfer of power between the first coil and the second coil.

[0007] In some aspects, the technology described herein relates to a wireless charging system, where a first coil is located on a ground pad and a second coil is located on a vehicle pad attached to a vehicle.

[0008] In some aspects, the technology described herein relates to a wireless charging system, wherein perturbing a first coil includes: shorting a second coil; applying a plurality of signal waveforms to the first coil in a time-sequential manner, each of the plurality of signal waveforms being generated based on a frequency of a plurality of frequencies; measuring a peak current through the first coil when each of the plurality of signal waveforms is applied to the first coil; and selecting one of the plurality of frequencies corresponding to a minimum peak current through the first coil as a self-resonant frequency of the second coil.

[0009] In some aspects, the technology described herein relates to a wireless charging system, wherein perturbing the first coil includes applying a signal waveform to the first coil that is generated based on a self-resonant frequency of the second coil, and measuring a peak current through the second coil to obtain a peak steady-state current when the signal waveform is applied to the first coil.

[0010] In some aspects, the technology described herein relates to a wireless charging system, wherein estimating the one or more circuit parameters is further based on a peak steady-state current.

[0011] In some aspects, the technology described herein relates to a wireless charging system, wherein the charging configuration determination procedure further includes perturbing a second coil.

[0012] In some aspects, the technology described herein relates to a wireless charging system, wherein the steps of perturbing a first coil and perturbing a second coil are performed in a non-overlapping manner.

[0013] In some aspects, the technology described herein relates to a wireless charging system, wherein the one or more circuit parameters include one or more of a self-inductance of a first coil, a self-inductance of a second coil, a reactance associated with the first coil, a coupling coefficient associated with the first coil and the second coil, or a turns ratio associated with a converter.

[0014] In some aspects, the technology described herein relates to a wireless charging system, wherein the one or more circuit parameters include a self-inductance of a first coil and a self-inductance of a second coil.

[0015] In some aspects, the technology described herein relates to a wireless charging system, wherein the one or more circuit parameters include a coupling coefficient associated with a first coil and a second coil.

[0016] In some aspects, the technology described herein relates to a wireless charging system, wherein the one or more wireless charging settings include one or more of an operating frequency of a converter, a power limit of the wireless charging system, or a DC voltage level applied to a ground pad of the wireless charging system.

[0017] In some aspects, the technology described herein relates to a wireless charging system, wherein a charging configuration determination procedure is performed at the beginning of a wireless charging sequence.

[0018] In some aspects, the technology described herein relates to a wireless charging system, wherein the charging configuration determination procedure further includes charging a battery pack of the vehicle according to one or more wireless charging settings.

[0019] In some aspects, the technology described herein relates to a wireless charging system, wherein the charging configuration determination procedure further includes causing an air suspension system of the vehicle to lower a body of the vehicle.

[0020] In some aspects, the technology described herein relates to a method for wireless charging, the method including: perturbing a first coil, wherein the first coil is inductively coupled with a second coil; estimating one or more circuit parameters of a converter including the first coil and the second coil based on the perturbing step; and configuring one or more wireless charging settings of a wireless charging system based on the one or more circuit parameters, wherein the wireless charging system is configured to charge a battery pack of a vehicle based on the wireless transfer of power between the first coil and the second coil.

[0021] In some aspects, the technology described herein relates to a method further including wirelessly charging a battery pack of a vehicle according to one or more wireless charging configurations.

[0022] In some aspects, the technology described herein relates to a method for wireless charging, the method including perturbing a first coil of a converter of a wireless charging system; estimating a self-resonant frequency of a second coil of the converter of the wireless charging system based on the perturbing the first coil; estimating the self-resonant frequency of the first coil based on the perturbed second coil; calculating one or more parameters associated with the converter based at least on the self-resonant frequency of the first coil and the self-resonant frequency of the second coil; and setting one or more wireless charging settings for the wireless charging system based at least on the one or more parameters associated with the converter.

[0023] In some aspects, the techniques described herein relate to a method, wherein perturbing a first coil to estimate a self-resonant frequency of a second coil includes: shorting the second coil; applying a plurality of signal waveforms to the first coil in a time-sequential manner, each of the plurality of signal waveforms being generated based on a frequency from a plurality of frequencies; measuring a peak current passing through the first coil when each of the plurality of signal waveforms is applied to the first coil; and selecting one of the plurality of frequencies corresponding to a minimum peak current passing through the first coil as the self-resonant frequency of the second coil.

[0024] In some aspects, the techniques described herein relate to a method, wherein perturbing a first coil to estimate a self-resonant frequency of a second coil includes applying a signal waveform to the first coil that is generated based on the self-resonant frequency of the second coil, and measuring a peak current through the second coil to obtain a peak steady-state current when the signal waveform is applied to the first coil.

[0025] In some aspects, the technology described herein relates to a method, wherein calculating the one or more parameters is further based on a peak steady state current.

[0026] In some aspects, the technology described herein relates to a method, wherein the step of perturbing a first coil occurs before or after a second coil is perturbed.

[0027] In some aspects, the technology described herein relates to a method, further including charging a battery pack of a vehicle using one or more wireless charging configurations. [Brief explanation of the drawings]

[0028] Throughout the drawings, reference numbers are reused to indicate correspondence between referenced elements. The drawings are provided to illustrate examples of the subject matter described herein, but not to limit its scope.

[0029] Embodiments of the present disclosure will be described with reference to the accompanying drawings, in which like reference numerals refer to like elements.

[0030] [Figure 1A] FIG. 1 illustrates an exemplary wireless charging environment in which embodiments of the present disclosure may be implemented.

[0031] [Figure 1B] FIG. 1B is a block diagram illustrating the example wireless charging environment of FIG. 1A, according to an embodiment of the present disclosure.

[0032] [Figure 2] FIG. 1 is a block diagram illustrating at least a portion of a wireless charging system, according to an embodiment of the present disclosure.

[0033] [Figure 3A] FIG. 1 is an exemplary block diagram of a wireless charging system according to an embodiment of the present disclosure.

[0034] [Figure 3B] FIG. 3B illustrates an exemplary circuit model that models at least a portion of a converter of the wireless charging system of FIG. 3A, according to an embodiment of the present disclosure.

[0035] [Figure 3C] FIG. 3B illustrates an exemplary circuit model that models at least a portion of a converter of the wireless charging system of FIG. 3A, according to an embodiment of the present disclosure.

[0036] [Figure 4] FIG. 4 illustrates an example process for estimating and / or calculating parameters associated with the example circuit model of FIGS. 3B and 3C.

[0037] [Figure 5A] FIG. 3B illustrates an exemplary circuit topology of a converter, such as the converter of FIG. 3A, in accordance with an embodiment of the present disclosure.

[0038] [Figure 5B] FIG. 5B illustrates an example circuit model of the example circuit topology of FIG. 5A.

[0039] [Figure 6] FIG. 5C illustrates an example process for estimating and / or calculating parameters associated with the example circuit model of FIG. 5B. DETAILED DESCRIPTION OF THE INVENTION

[0040] The following detailed description of certain embodiments presents various descriptions of specific embodiments. However, the innovations described herein can be embodied in many different ways, for example, as defined and encompassed by the claims. This description refers to the drawings, in which like reference numbers and / or terminology can indicate identical or functionally similar elements. It will be understood that the elements depicted in the drawings are not necessarily drawn to scale. It will also be understood that certain embodiments can include more elements and / or a subset of the elements depicted in the drawings. Furthermore, some embodiments can incorporate any suitable combination of features from two or more drawings. Headings are provided for convenience only and do not affect the scope or meaning of the claims.

[0041] Generally described, one or more aspects of the present disclosure relate to systems and methods that adapt to variations associated with the environment and / or components utilized in wireless charging. More specifically, some embodiments of the present disclosure disclose an estimation flow for estimating and / or calculating parameters associated with a resonant converter or transformer. These parameters can be used to adjust settings of a wireless charging system accordingly to address technical challenges associated with inductance variations caused by the wireless charger's surrounding environment. Advantageously, the estimation flow enables the wireless charging system to operate more efficiently and / or safely in the presence of inductance variations.

[0042] The wireless charging device can be enabled to wirelessly charge a vehicle, such as an electric vehicle with a battery pack. The wireless charging device can wirelessly transfer power (e.g., via induction) from an external source, such as a grid, a solar cell, etc., to the electric vehicle. The wireless charging device can also wirelessly transfer power (e.g., via induction) from the electric vehicle to the grid. In some embodiments, the wireless charging device can be located under the vehicle. For example, the vehicle can run over the wireless charging device.

[0043] The self-inductance of transformer coils used in wireless charging applications can have relatively large variations caused by environmental factors such as the placement of the charging pad (e.g., with respect to the vehicle) and / or nearby ferrous objects. The consequences of this variation pose new technical challenges from the perspective of traditional fixed direct current to direct current (DC / DC) resonant converters in wireless charging systems, where the transformer inductance is constant and therefore the impedance of the resonant tank is constant. Due to the relatively large variations in resonant tank inductance, it can be advantageous for the wireless charging system to adapt (e.g., through firmware control) to the varying inductance to achieve the desired operation and power output of the wireless charging system.

[0044] To address at least some of the above-identified technical problems, some aspects of the disclosed technology perform or otherwise enable a parameter estimation sequence to estimate and calculate variables and / or parameters of an equivalent circuit model associated with a resonant converter employed by a wireless charging system. Using an electrical signal source, the coupling coefficient estimation sequence can perturb the converter's coils using various signal waveforms to estimate each coil's self-resonant frequency and / or one or more other variables associated with the equivalent circuit model, and calculate each coil's self-inductance based on the estimated variables (e.g., each coil's self-resonant frequency). Based on each coil's self-inductance and / or one or more other calculated parameters (e.g., one or more of the turns ratio, coupling coefficient, etc.), the wireless charging system can adjust settings and / or configurations for wireless charging (e.g., the converter's operating frequency, the wireless charging system's power limit, or the direct current (DC) voltage level applied to the wireless charging system's ground pad). The one or more parameters can be determined before each wireless charging session in a particular application.

[0045] In some embodiments, the disclosed wireless charging system may include a converter and a charging configuration determination module. The converter may include a ground pad coil and a vehicle pad coil. The ground pad coil may be deployed on a ground pad of the wireless charging system. The vehicle pad coil may be deployed on a vehicle pad attached to or otherwise integrated with the vehicle to be charged. The charging configuration determination module may execute a charging configuration determination procedure including a coupling coefficient estimation sequence to at least calculate the self-inductance of the ground pad coil and the vehicle pad coil. Based on the calculated self-inductance and / or one or more other parameters associated with the converter (e.g., turns ratio, coupling coefficient, series reactance, etc.), the charging configuration determination procedure may further update or adjust the charging settings or configuration of the wireless charging system.

[0046] In some embodiments, the charging configuration determination procedure may include perturbing the ground pad coil to estimate a self-resonant frequency of the vehicle pad coil; perturbing the vehicle pad coil to estimate the self-resonant frequency of the ground pad coil; calculating a set of parameters associated with a circuit model that models the converter based on at least the self-resonant frequency of the ground pad coil and / or the self-resonant frequency of the vehicle pad coil; and configuring one or more wireless charging settings for the wireless charging system based at least on the set of parameters associated with the circuit model.

[0047] In some embodiments, perturbing the ground pad coil to estimate the self-resonant frequency of the vehicle pad coil may include shorting the vehicle pad coil and performing a signal frequency sweep (e.g., injecting various electrical signals having various signal frequencies) across a frequency range on the ground pad coil. More specifically, multiple signal waveforms may be applied to the ground pad coil sequentially and non-overlappingly in time while the vehicle pad coil is shorted throughout the application of the multiple signal waveforms. Each of the multiple signal waveforms may correspond to a distinct signal frequency. During application of each of the multiple signal waveforms, a peak current through the ground pad coil may be measured. The signal waveform with the lowest peak current may be identified. The signal frequency of the signal waveform may be selected as the self-resonant frequency of the vehicle pad coil.

[0048] For example, assume that N (e.g., a positive integer greater than or equal to two) signal waveforms are applied to the ground pad coil while the vehicle pad coil is shorted. A first signal waveform (e.g., a square wave, a triangular waveform, or any other suitable type of signal waveform having a specific voltage amplitude) may have a first signal frequency (e.g., 50 kilohertz (kHz)), a second signal waveform may have a second signal frequency (e.g., 55 kHz), and an Nth signal waveform may have an Nth signal frequency. The first signal waveform may be applied to the ground pad coil for a specific time period (e.g., 3 milliseconds (ms)). During the specific time period that the first signal waveform is applied, the wireless charging system may measure a first peak current through the ground pad coil. After a waiting period (e.g., 1 ms), a second signal waveform may be applied to the ground pad coil for a specific time period. During the specific time period that the second signal waveform is applied, the wireless charging system may measure a second peak current through the ground pad coil. The above waveform application and peak current measurement process may continue until an Nth signal waveform is applied to the ground pad coil and an Nth peak current through the ground pad coil is measured. The wireless charging system may select the signal frequency of the signal waveform that results in the smallest peak current as the self-resonant frequency of the vehicle pad coil. For example, if a second peak current measured during application of the second signal waveform is smaller than all other peak currents, the second signal frequency may be selected as the self-resonant frequency of the vehicle pad coil.

[0049] In some embodiments, the step of perturbing the vehicle pad coil to estimate the self-resonant frequency of the ground pad coil may be performed similarly to the step of perturbing the ground pad coil to estimate the self-resonant frequency of the vehicle pad coil according to any suitable principles and advantages described above, except that the ground pad coil is shorted and a signal waveform is applied to the vehicle pad coil. Perturbing the vehicle pad coil may estimate the self-resonant frequency of the ground pad. In some embodiments, the step of perturbing the ground pad coil may be performed sequentially, with the vehicle pad coil perturbed (e.g., before or after). The step of perturbing the ground pad coil may not overlap in time with the step of perturbing the vehicle pad coil.

[0050] Based on at least the self-resonant frequency of the ground pad coil and the self-resonant frequency of the vehicle pad coil, the wireless charging system (e.g., a charging configuration determination module) may calculate a set of parameters associated with a circuit model that models the converter (e.g., the self-inductance of the ground pad coil, the self-inductance of the vehicle pad coil, a turns ratio, a coupling coefficient, a series reactance, etc.) associated with the converter. Based on at least the set of parameters associated with the circuit model, the wireless charging system may configure or set one or more wireless charging settings (e.g., the operating frequency of the converter, the power limit of the wireless charging system, or the DC voltage level applied to the ground pad of the wireless charging system) to achieve a desired operation for charging. For example, if the self-inductance of the ground pad coil deviates upward due to fluctuations caused by environmental conditions (e.g., due to a nearby ferrous object), the wireless charging system may reduce the DC voltage level applied to the ground pad for charging. The one or more wireless charging settings may be set by any suitable circuitry and / or processor of the wireless charging system. For example, the one or more processors may instruct the system to operate in any of the wireless charging settings disclosed herein.

[0051] In some embodiments, to adjust or strengthen the inductive coupling between the ground pad coil and the vehicle pad coil, the wireless charging system may generate a control signal to lower the vehicle body closer to the ground pad. For example, the wireless charging system may generate a control signal to the vehicle's air suspension system to reduce the distance between the vehicle and the wireless charger so that the vehicle pad coil can be closer to the ground pad coil. Reducing the distance can increase the coupling coefficient for wireless charging. The air suspension can bring the vehicle pad and the ground pad as close to each other as possible in certain applications. The air suspension can bring the vehicle pad coil closer to the ground pad coil before wireless charging.

[0052] While various aspects are described according to exemplary embodiments and feature combinations, those skilled in the art will understand that the examples and feature combinations are exemplary in nature and should not be construed as necessarily limiting. More specifically, aspects of the present application may be applicable to various types of wireless charging systems and devices under different circumstances. Still further, while specific architectures of circuit block diagrams or flows for estimating coupling coefficients and parameters associated with converters are described, such exemplary circuit block diagrams or state machines or architectures should not be construed as necessarily limiting. Thus, those skilled in the relevant art will understand that aspects of the present application are not necessarily limited to application to a particular type of converter or wireless charging infrastructure.

[0053] Wireless Charging Overview Inductive charging, commonly referred to as wireless charging, is a type of wireless power transfer. Inductive charging uses electromagnetic induction to generate or otherwise provide electricity to a device without the need for a physical electrical connection. Specifically, various devices can be placed near a charging station or induction pad without the need for precise alignment, electrical contact, physical dock, electrical plug, etc. Such devices include, but are not limited to, vehicles, manufacturing equipment, consumer electronics, medical devices, etc.

[0054] According to aspects of the present application, an inductive charging system is configured to transfer energy through inductive coupling between components. One exemplary charging system includes a transfer component, which may be configured as a charging station or charging pad. Alternating current (e.g., input current) from a power source passes through an induction coil of the charging station or pad. Based on the input current, charge moving through the induction coil (e.g., transmitting coil) generates (or draws) a magnetic field. Illustratively, the strength of the magnetic field may vary at least in part with changes or fluctuations in the amplitude of the input current. The changing magnetic field generates an alternating current in the induction coil on a receiving device (e.g., receiving coil). The induced alternating current at the receiving device can then pass through a rectifier to convert the induced alternating current to direct current. Finally, the receiving vehicle may include additional charging components and / or systems that utilize the converted direct current to charge a battery system, provide operating power, or a combination thereof.

[0055] When an exemplary inductive charging system uses resonant inductive coupling components / techniques, a greater distance can be achieved between the transmitting coil and the receiving coil. More specifically, in some embodiments, a capacitor can be connected to each inductive coil to create two LC circuits with specific resonant frequencies. The frequency of the AC current is matched to the resonant frequencies. In addition, the matched frequency can be further selected depending on the distance between the transmitting and receiving devices, taking peak efficiency into consideration. Furthermore, the use of other materials for the receiver coil, such as silver-plated copper or possibly aluminum to minimize weight and reduce resistance, can be utilized for energy transfer efficiency purposes.

[0056] FIG. 1A illustrates an environment 100 for implementing an inductive-based wireless charging system in accordance with various aspects of the present application. The environment 100 can illustratively correspond to a commercial implementation, such as a parking lot, parking stall, or charging booth. The environment 100 can also correspond to a private or other non-commercial implementation, such as a private home. As an illustrative example, an implementation of an inductive-based wireless charging system in a non-commercial implementation can include a transmitting component 102 configured to generate a variable magnetic field according to an inductive charging methodology. As also shown in FIG. 1A , the transmitting component 102, which may also be referred to as a transmission component, can correspond to a standalone component that may be operable to be mounted or positioned on a floor 104 or other flat surface. In other embodiments, the transmitting component 102 can be integrated with or combined with other devices or components.

[0057] The transmitting component 102 may be connected to one or more power sources, such as an input from a utility company, a real-time power source (e.g., a solar or wind energy source), a stored energy cell, or a combination thereof. The power source is configured to provide input alternating current as described herein. The transmitting component 102 may be connected to the power source via a direct electrical connection 106, such as through a junction box 108 located on a wall surface 118.

[0058] As shown in FIG. 1A , in one embodiment, the transmitting component 102 corresponds to a form factor that allows it to be positioned on the floor 104 for wireless charging with a vehicle having a receiving coil. The transmitting component 102 may have a form factor such that a vehicle can be placed directly above the top surface of the transmitting component. Illustratively, the dimensions of the transmitting component 102 (e.g., the height and width of the transmitting component 102) may be configured so that the distance between the top surface of the transmitting component 102 and the bottom surface of the vehicle meets certain criteria, such as a minimum distance between the transmitting coil and the receiving coil, a maximum distance between the transmitting coil and the receiving coil, etc. In some embodiments, the vehicle or the transmitting component 102 (or a combination) may be configured with additional components to dynamically adjust such distance or otherwise change the relative orientation between the transmitting component 102 and the vehicle. In some embodiments, the transmitting component 102 may be configured to charge a vehicle's battery pack, which may have a nominal voltage greater than 200 volts (e.g., a nominal voltage of approximately 350 volts or 355 volts) and a maximum voltage of 400 volts. In some embodiments, the transmitting component 102 can be configured to provide 800 volts of DC power. In some embodiments, the transmitting component 102 can provide a voltage in the range of approximately 200 volts to 800 volts.

[0059] 1B shows a block diagram of an environment 100 including a wireless charging device 111 (e.g., transmitting component 102) that wirelessly communicates with a vehicle 112, such as via an induction-based magnetic field. The wireless charging device 111 is further connected to one or more energy sources 110. While the wireless charging device 111 is shown with a direct connection to the energy sources 110, at least a portion of the currently alternating input may also be provided via wireless transmission methods. Additionally, in embodiments involving multiple power sources, the environment may also include various switching components for selecting energy from individual energy sources 110 or combinations of energy sources 110.

[0060] 2 shows a block diagram of a transmitting component 102 that can function as a wireless charging device 111 (shown in FIG. 1B). The transmitting component 102 can include at least a transmitting coil component 202 for generating a magnetic field from an input current provided from an energy source 110. As shown in FIG. 2, the input current can be provided by a direct electrical connection 106.

[0061] In some embodiments, the transmitting component 102 may also include various sensor components 204 related to the charging process. By way of example, the sensor components 204A, 204B, 204C, and 204A may be configured for various functions such as detecting the vehicle 112, detecting objects, measuring distance to the vehicle, environmental sensors (e.g., temperature sensors, moisture sensors), pressure sensors, etc. In one embodiment, the sensor components 204 may include radar sensors. The sensor components 204 may include logic and processing components related to the charging process, including operational measurements, operational control, safety measurements, communication components, etc.

[0062] (Exemplary Wireless Charging System) 3A illustrates an exemplary wireless charging system 300 operable to estimate and calculate parameters associated with a resonant converter and / or a transformer. The wireless charging system 300 can be adjusted to respond to inductance variations caused by the environment. The environments described in FIGS. 1A, 1B, and 2 can be implemented according to any suitable principles and advantages of the wireless charging system 300 and may utilize the same or similar architecture as that described in FIG. 3A.

[0063] As shown in FIG. 3A , the wireless charging system 300 includes the energy source 110, a converter 310 (e.g., a DC / DC converter) including a grounding pad 302 and a vehicle pad 304, and a charging configuration determination module 306. The grounding pad 302 may be part of the transmitting component 102. The vehicle pad 304 may be attached to or part of the vehicle 112. The wireless charging system 300 is represented in a simplified logical form and one or more additional components that may be implemented for wireless charging functionality. Furthermore, some of the components shown separately therein may be physically integrated. For example, some of the components (e.g., a portion of the converter 310, such as the grounding pad 302 including the grounding pad coil) may be deployed external to the vehicle (e.g., on the ground), and some of the components (e.g., another portion of the converter 310, such as the vehicle pad 304 including the vehicle pad coil) may be deployed within the vehicle. Thus, in some embodiments, the ground pad 302 may be integrated as part of the transmitting component 102 of FIG. 1A, and the vehicle pad 304 may be integrated as part of the vehicle 112 of FIG. 1B.

[0064] In some embodiments, the wireless charging system 300 of Figure 3A is used to charge a battery pack (which may be installed in the vehicle 112 of Figure 1B) through the operation of a converter 310 that converts power from the energy source 110 to a voltage level suitable for charging the battery. In some embodiments, the ground pad 302 is wired and powered by the energy source 110.

[0065] In some embodiments, the charging configuration determination module 306 may perform a charging configuration determination procedure to estimate and calculate the self-inductance of at least the ground pad coil of the ground pad 302 and the vehicle pad coil of the vehicle pad 304. Based on the calculated self-inductance and / or other parameters associated with the converter 310 (e.g., turns ratio, coupling coefficient, series reactance, etc.), the charging configuration determination procedure may further update or adjust the charging settings or configuration of the wireless charging system 300 to achieve safe and power-efficient wireless charging operation. The charging configuration determination module 306 may cause the wireless charging system 300 to perform operations related to measurements and / or calculations to determine one or more parameters of the converter 310. The charging configuration determination module 306 may be implemented by any suitable circuitry, such as dedicated circuitry, circuitry configured to execute specific instructions, or any suitable combination thereof. One or more processors executing specific instructions may implement some or all of the charging configuration determination module 306.

[0066] (Example circuit model) 3B illustrates an exemplary circuit model 300B that models at least a portion of a converter, such as converter 310, according to some embodiments of the present disclosure. As shown in FIG. 3B, circuit model 300B represents an LLC converter topology and, therefore, may be represented by exemplary parameters that may be related to impedances Za, Zb, and Zc, as an example. In some embodiments, reactances Xa, Xb, and Xc (not shown in FIG. 3B) associated with Za, Zb, and Zc may be determined using the estimation process illustrated with reference to FIG. 4.

[0067] As described above, the estimation process may include applying perturbations (e.g., variable electrical signal waveforms generated by the charging configuration determination module 306) to the converter and measuring the response to calculate parameters (e.g., Xa, Xb, and Xc) associated with the circuit model 300B.

[0068] 3C illustrates an exemplary circuit model 300C that models at least a portion of a converter, such as converter 310, according to some embodiments of the present disclosure. As shown in FIG. 3C, circuit model 300C includes a ground pad coil 312 and a vehicle pad coil 314. Ground pad coil 312 is deployed on ground pad 302, and vehicle pad coil 314 is deployed on vehicle pad 304. Ground pad coil 312 has a self-inductance L1, and vehicle pad coil 314 has a self-inductance L2. As described above, self-inductance L1 and self-inductance L2 may change due to various environmental conditions, such as, for example, the positioning of ground pad 302 (e.g., relative to vehicle pad 304) and / or nearby ferrous objects. Additionally, turns ratio n and / or other parameters (not shown in FIG. 3C) associated with circuit model 300C may also change due to environmental conditions.

[0069] As described above, in some embodiments, the charging configuration determination module 306 may perform a charging configuration determination procedure to determine at least one or more of the self-inductance L1, the self-inductance L2, the turns ratio n, or one or more other parameters associated with the circuit model 300C.

[0070] In some embodiments, one exemplary sequence for estimating parameters associated with circuit model 300B and / or circuit model 300C based on the equations described below includes determining the self-inductance L2 of the vehicle pad 304 (e.g., the vehicle's charging coil) followed by the self-inductance L1 of the ground pad coil 312. These self-inductances L2 and L1 may then be used to determine the turns ratio n. The series reactance (e.g., Xa) may then be determined based on the turns ratio n. The coupling coefficient k and / or other parameters (e.g., Xb and Xc) may also be determined. Circuit Parameter Estimation Process

[0071] FIG. 4 illustrates an exemplary process 400 for estimating and / or calculating parameters and / or variables associated with an exemplary circuit model of converter 310. Process 400 may include a parameter estimation sequence that may be part of a charging configuration determination procedure. The parameter estimation sequence may be performed at the beginning of each charging session. In some embodiments, exemplary process 400 may be performed and / or directed by charging configuration determination module 306 to determine parameters and / or variables associated with a circuit model that models converter 310. As shown in FIG. 4, process 400 may include two stages, including stage 402 and stage 404. While stage 402 is shown as being performed before stage 404, in other embodiments, stage 404 may be performed before stage 402. It should also be noted that the time durations illustrated in FIG. 4 (e.g., 3 ms, 1 ms, 100 ms, 500 ms, etc.) are exemplary in nature, and any other suitable time durations may alternatively or additionally be used. In some embodiments, the exemplary process 400 can be performed and completed by the wireless charging system 300 within approximately 660 ms.

[0072] In some embodiments, during stage 402, the charging configuration determination module 306 may cause the wireless charging system 300 to perturb the ground pad coil 312 to estimate the self-resonant frequency of the vehicle pad coil 314. More specifically, during the first portion 406 of stage 402, the charging configuration determination module 306 may short-circuit the vehicle pad coil 314 (e.g., by closing an electrical switch to form a short circuit) and perform a signal frequency sweep (e.g., injecting various electrical signals having various signal frequencies into the ground pad coil 312) across a frequency range on the ground pad coil 312. For example, the charging configuration determination module 306 may apply multiple signal waveforms to the ground pad coil 312 sequentially and non-overlappingly in time while shorting the vehicle pad coil 314. Each of the multiple signal waveforms may correspond to a distinct signal frequency. During application of each of the multiple signal waveforms, the peak current through the ground pad coil 312 may be measured. The signal waveform that results in the lowest peak current through the ground pad coil 312 may be identified by the charging configuration determination module 306. The signal frequency of the signal waveform may be selected as the self-resonant frequency of the vehicle pad coil 314 .

[0073] For example, as shown in a first portion 406 of stage 402, N (e.g., a positive integer greater than or equal to two) signal waveforms are applied to the ground pad coil 312 while the vehicle pad coil 314 is shorted. The first signal waveform 402-1 (e.g., a square waveform, a triangular waveform, or any other suitable type of signal waveform) may have a first signal frequency (e.g., 50 kHz), the second signal waveform 402-2 may have a second signal frequency (e.g., 55 kHz), and the Nth signal waveform 402-N may have an Nth signal frequency. The first signal waveform 402-1 may be applied to the ground pad coil 312 for a specific time period (e.g., 3 milliseconds). During the specific time period that the first signal waveform 402-1 is applied, the charging configuration determination module 306 may measure a first peak current through the ground pad coil 312. After a waiting period (e.g., 1 millisecond), the second signal waveform 402-2 may be applied to the ground pad coil 312 for a specific time period. During the specific time period that the second signal waveform 402-2 is applied, the charging configuration determination module 306 may measure a second peak current through the ground pad coil 312. The above waveform application and peak current measurement process may continue until an Nth signal waveform 402-N is applied to the ground pad coil 312 and an Nth peak current through the ground pad coil 312 is measured. The charging configuration determination module 306 may select the signal frequency of one of the signal waveforms 402-1, 402-2 through 402-N that results in the smallest peak current as the self-resonant frequency of the vehicle pad coil 314. For example, if the second peak current is smaller than all the other peak currents, the charging configuration determination module 306 may select the second signal frequency of the second signal waveform 402-2 as the self-resonant frequency of the vehicle pad coil 314. In some embodiments, the first portion 406 of the stage 402 may last approximately 100 milliseconds.

[0074] During the second portion 408 of the phase 402, the charging configuration determination module 306 operates the converter 310 at the self-resonant frequency of the vehicle pad coil 314 obtained during the first portion 406 of the phase 402 to determine the peak steady-state current (e.g., i 2p) may be measured. For example, the charging configuration determination module 306 may cause the wireless charging system 300 to apply or inject a signal waveform generated using the self-resonant frequency of the vehicle pad coil 314 to the ground pad coil 312 and measure the peak current through the vehicle pad coil 314 to obtain a peak steady-state current through the vehicle pad coil 314 associated with the signal waveform being applied to the ground pad coil 312. In some embodiments, the second portion 408 may be completed within approximately 500 ms.

[0075] Based on the self-resonant frequency of the vehicle pad coil 314 and / or the peak steady-state current measured during the second portion 408 of stage 402, the self-inductance L2 of the vehicle pad coil 314 and other parameters may be obtained in operation 410. The self-inductance L2 of the vehicle pad coil 314 may be determined after determining the self-resonant frequency of the vehicle pad coil 314. For example, the self-inductance L2 of the vehicle pad coil 314 may be calculated through use of equation (1), where f sw1 is the self-resonant frequency of the vehicle pad coil 314, and C vp is the coupling capacitance of the vehicle pad coil 314.

[0076] L2=1 / ((2πf swl ) 2 C vp ) (1)

[0077] During stage 404, the charging configuration determination module 306 may cause the wireless charging system 300 to perturb the vehicle pad coil 314 to estimate the self-resonant frequency of the ground pad coil 312. More specifically, during stage 404, the charging configuration determination module 306 may cause the wireless charging system 300 to short-circuit the ground pad coil 312 and perform a signal frequency sweep (e.g., injecting various electrical signals having various signal frequencies into the vehicle pad coil 314) across a frequency range on the vehicle pad coil 314. For example, the charging configuration determination module 306 may cause the wireless charging system 300 to apply multiple signal waveforms to the vehicle pad coil 314 in a time-sequential and non-overlapping manner while shorting the ground pad coil 312. Each of the multiple signal waveforms may correspond to a distinct signal frequency. During application of each of the multiple signal waveforms, the peak current through the vehicle pad coil 314 may be measured. The signal waveform that results in the lowest peak current through the vehicle pad coil 314 may be identified. The signal frequency of the signal waveform can be selected as the self-resonant frequency of the ground pad coil 312 .

[0078] As shown in step 404, M (e.g., a positive integer greater than or equal to 2) signal waveforms are applied to the vehicle pad coil 314 while the ground pad coil 312 is shorted. The first signal waveform 404-1 (e.g., a square waveform, a triangular waveform, or another type of signal waveform) may have a first signal frequency (e.g., 50 kHz), the second signal waveform 404-2 may have a second signal frequency (e.g., 55 kHz), and the Mth signal waveform 404-M may have an Mth signal frequency. The first signal waveform 404-1 may be applied to the vehicle pad coil 314 for a specific time period (e.g., 3 milliseconds). During the specific time period that the first signal waveform 404-1 is applied, the charging configuration determination module 306 may measure a first peak current through the vehicle pad coil 314. After a waiting period (e.g., 1 millisecond), the second signal waveform 404-2 may be applied to the vehicle pad coil 314 for a specific time period. During the particular time period that the second signal waveform 404-2 is applied, the charging configuration determination module 306 may measure a second peak current through the vehicle pad coil 314. The above waveform application and peak current measurement process may continue until an Mth signal waveform 404-M has been applied to the vehicle pad coil 314 and an Mth peak current through the vehicle pad coil 314 has been measured. The charging configuration determination module 306 may select the signal frequency of one of the signal waveforms 404-1, 404-2 through 404-M that results in the smallest peak current as the self-resonant frequency of the ground pad coil 312. For example, if the first peak current is smaller than all the other peak currents, the charging configuration determination module 306 may select the first signal frequency of the first signal waveform 404-1 as the self-resonant frequency of the ground pad coil 312.

[0079] Based on the self-resonant frequency of the ground pad coil 312 estimated and / or calculated during step 404, the self-inductance L1 of the ground pad coil 312 may be obtained in operation 412. The self-inductance L1 of the ground pad coil 312 may be determined after determining the self-resonant frequency of the ground pad coil 312. For example, the self-inductance L1 of the ground pad coil 312 may be calculated using equation (2), where f sw2is the self-resonant frequency of the ground pad coil 312, and C gp is the coupling capacitance of the ground pad coil 312. As another example, the turns ratio n can be determined based on the self-inductance L1 of the ground pad coil 312 and the self-inductance L2 of the vehicle pad coil 314. More specifically, the turns ratio n can be calculated using equation (3) by taking the square root of the self-inductance L1 of the ground pad coil 312 divided by the self-inductance L2 of the vehicle pad coil 314. As yet another example, the reactance Xa can be calculated based on the coupling capacitance C of the vehicle pad coil 314. vp , turns ratio n, and the induced current i through the vehicle pad coil 314 2p More specifically, through the use of equation (4), the coupling capacitance C vp The product of and the turns ratio n is the induced current i 2p As yet another example, the coupling coefficient k can be determined using equation (5) based on the reactance Xa, the self-inductance L1 of the ground pad coil 312, and the self-resonant frequency f of the ground pad coil 312: sw2 The determination can be made based on the following:

[0080] L1=1 / ((2πf sw2 ) 2 C gp ) (2)

[0081] n=sqrt(L1 / L2) (3)

[0082] Xa=(nC vp ) / i 2p (4)

[0083] k=Xa / ((2πf sw2 ) 2 L1) (5)

[0084] Utilizing the exemplary process 400, the charging configuration determination module 306 may update one or more wireless charging settings for the wireless charging system 300. More specifically, based on at least a set of parameters associated with the circuit model (e.g., self-inductance L1, self-inductance L2, turns ratio n, etc.), the charging configuration determination module 306 may update or adjust one or more wireless charging settings (e.g., the operating frequency of the converter 310, the power limit of the wireless charging system 300, or the DC voltage level applied to the grounding pad 302 of the wireless charging system 300) to achieve efficient and safe operation of wireless charging. For example, if the self-inductance L1 of the grounding pad coil 312 deviates upward due to fluctuations caused by environmental conditions (e.g., due to a nearby ferrous object), the charging configuration determination module 306 may reduce the DC voltage level applied to the grounding pad 302 for charging.

[0085] In this manner, the wireless charging system 300 may charge the vehicle 112 more efficiently than if it did not estimate any of the wireless charging parameters. The wireless charging system 300 may include one or more processors that use firmware to perform the example process 400 described herein.

[0086] (More examples of circuit models and parameter estimation processes) FIG. 5A illustrates an exemplary circuit topology 500A of the converter 310 according to some embodiments of the present disclosure. The circuit topology 500A represents a bidirectional CLLC resonant dual active bridge (DAC) converter including two H-bridge circuits. More specifically, transistors 502, 504, 506, and 508 form a first H-bridge circuit on the ground pad, and transistors 522, 524, 526, and 528 form a second H-bridge circuit on the vehicle pad. As shown in FIG. 5A, a ground pad coil 512 and a compensation capacitor 516 are connected in series on the ground pad. One end of the ground pad coil 512 is connected to node 544 of the first H-bridge circuit including transistors 502, 504, 506, and 508, and one end of the compensation capacitor 516 is connected to node 542 of the first H-bridge circuit. A vehicle pad coil 514 and a compensation capacitor 518 are connected in series on the vehicle pad. One end of the vehicle pad coil 514 is connected to a node 546 of a second H-bridge circuit including transistors 522, 524, 526, and 528, and one end of the compensation capacitor 518 is connected to a node 548 of the second H-bridge circuit.

[0087] 5A, a ground pad voltage (denoted as V_GP+ and V_GP−) can be applied and / or measured across terminals 552 and 554 of a first H-bridge circuit including transistors 502, 504, 506, and 508. A capacitor 572 can be shunted across terminals 552 and 554 on the ground pad. A vehicle pad voltage (denoted as V_VP+ and V_VP−) can be applied and / or measured across terminals 558 and 556 of a second H-bridge circuit including transistors 522, 524, 526, and 528. A capacitor 574 can be shunted across terminals 558 and 556 of the vehicle pad.

[0088] In wireless power transfer, the coil equivalent self-inductance may vary from its nominal value due to misalignment. Therefore, for better control and performance of wireless charging, it may be desirable to estimate the coil equivalent self-inductance before and / or at the beginning of a charging cycle. As shown in FIG. 5A , the ground pad coil 512 has a self-inductance L1, and the vehicle pad coil 514 has a self-inductance L2. The compensation capacitor 516 has a capacitance of C1, and the compensation capacitor 518 has a capacitance of C2. A current i1(t) (also referred to as i1) flows through the resonant tank formed by the ground pad coil 512 and the compensation capacitor 516, and a current i2(t) (also referred to as i2) flows through the resonant tank formed by the vehicle pad coil 514 and the compensation capacitor 518. Furthermore, the ground pad coil 512 and the vehicle pad coil 514 have a coupling coefficient k. In some embodiments, the resonant tank including the ground pad coil 512 and the compensation capacitor 516 and the resonant tank including the vehicle pad coil 514 and the compensation capacitor 518 are designed so that the self-resonant frequency of the vehicle pad coil 514 and the self-resonant frequency of the ground pad coil 512 are close to each other. In some embodiments, the coupling coefficient k may be between 0.1 and 0.3.

[0089] FIG. 5B illustrates an exemplary circuit model 500B that models circuit topology 500A according to some embodiments of the present disclosure. As shown in FIG. 5B, the ground pad bus voltage (shown as V_GP+ and V_GP− in FIG. 5A) is modeled as V1(t) (also referred to as V1), and the vehicle pad bus voltage (shown as V_VP+ and V_VP− in FIG. 5B) is modeled as V2(t) (also referred to as V2). Additionally, a first H-bridge circuit including transistors 502, 504, 506, and 508 is modeled by a transfer function S1(t) (also referred to as S1), and a second H-bridge circuit including transistors 522, 524, 526, and 528 is modeled by a transfer function S2(t) (also referred to as S2). As shown in FIG. 5B, n represents the effective turns ratio from ground pad coil 512 to vehicle pad coil 514.

[0090] FIG. 6 illustrates an example process 600 for estimating and / or calculating parameters and / or variables associated with circuit model 500B. Process 600 may include a parameter estimation sequence that may be part of a charging configuration determination procedure. The parameter estimation sequence may be performed at the beginning of each charging session. In some embodiments, example process 600 may be performed and / or directed by charging configuration determination module 306 to determine parameters and / or variables associated with circuit model 500B. As shown in FIG. 6 , process 600 may include a ground pad stage 602 and a vehicle pad stage 604. While ground pad stage 602 is shown as being performed before vehicle pad stage 604, in other embodiments, vehicle pad stage 604 may be performed before ground pad stage 602. In some embodiments, ground pad coil 512 and vehicle pad coil 514 may be shorted between portions 602-3, 602-4, 604-2, and 604-3.

[0091] During the ground pad phase 602, the charging configuration determination module 306 may cause the wireless charging system 300 to perturb the ground pad coil 512 to estimate the self-resonant frequency of the vehicle pad coil 514. More specifically, during the first portion 602-1 of the ground pad phase 602, the charging configuration determination module 306 may perform operations to short the vehicle pad coil 514 (e.g., through closing an electrical switch to form a short circuit) and perform a frequency sweep of a signal across a frequency range on the ground pad coil 512 (e.g., perturbing the ground pad coil 512 by injecting various electrical signals having various signal frequencies into the ground pad coil 512). The charging configuration determination module 306 may increase and / or decrease the frequency of the signal input to the ground pad coil 512 while measuring the current i1 flowing through the ground pad coil 512. The frequency at which the current i1 reaches a minimum value (e.g., 0) is the self-resonant frequency of the vehicle pad coil 514. During the second portion 602-2 of the ground pad phase 602, the charging configuration determination module 306 may measure the current i2 flowing through the vehicle pad coil 514 when operating the converter 310 below the self-resonant frequency of the vehicle pad coil 514 obtained during the first portion 602-1 of the ground pad phase 602. During the portion 604-1 of the vehicle pad phase 604, the self-resonant frequency of the ground pad coil 512 may be obtained similarly to the first portion 602-1 of the ground pad phase 602, except that the ground pad coil 512 is shorted and a frequency sweep is performed on the vehicle pad coil 514.

[0092] For example, the self-resonant frequency f of the vehicle pad coil 514 sw1 can be obtained based on measuring the current i1 and using equations (6) to (8), where Z in is the input impedance looking from terminals 552 and 554 into the resonant tank including ground pad coil 512 and compensation capacitor 516, and by definition ω s is 2πf sw1 is equal to.

number

number

[0093] More specifically, when equation (8) is established, i1 and Z in Based on the relationship with Z in approaches infinity, which causes i1 to approach 0. Thus, by sweeping to a frequency that leads to i1 closest to or equal to 0, the frequency is adjusted to the self-resonant frequency f of the vehicle pad coil 514. sw1 The self-resonant frequency f sw1 Based on this, the self-inductance L2 of the vehicle pad coil 514 can be obtained using equation (9). In addition, the self-inductance L1 of the ground pad coil 512 can be similarly obtained based on other equations that reflect equations (6) to (9).

number

[0094] As another example, the coupling coefficient k can be determined based on equation (10), where i2 is the coupling coefficient k when the resonant tank including the vehicle pad coil 514 is at the self-resonant frequency f of the vehicle pad coil 514. sw1 , the current flowing through the vehicle pad coil 514 when the vehicle pad coil 514 is operating below its self-resonant frequency f sw1 When operating at , i2 can be expressed using equation (11).

number

number

[0095] The foregoing disclosure is not intended to limit the disclosure to the precise form or particular field of use disclosed. Accordingly, various alternative embodiments and / or modifications to the disclosure, whether expressly described or implied herein, are contemplated as possible in light of the present disclosure. While embodiments of the present disclosure have been described in this manner, those skilled in the art will recognize that changes can be made in form and detail without departing from the scope of the present disclosure. Accordingly, the present disclosure is limited only by the scope of the claims.

[0096] conclusion The foregoing disclosure is not intended to limit the disclosure to the precise form or particular field of use disclosed. Accordingly, various alternative embodiments and / or modifications to the disclosure, whether expressly described or implied herein, are contemplated as possible in light of the present disclosure. While embodiments of the present disclosure have been described in this manner, those skilled in the art will recognize that changes can be made in form and detail without departing from the scope of the present disclosure. Accordingly, the present disclosure is limited only by the scope of the claims.

[0097] It should be understood that not necessarily all objectives or advantages may be achieved in accordance with any particular example described herein. Thus, for example, those skilled in the art will recognize that some examples may be operated to achieve or optimize one advantage or advantages as taught herein without necessarily achieving other objectives or advantages as may be taught or suggested herein.

[0098] All of the processes described herein may be embodied in and fully automated via software code modules executed by a computing system including a computer or processor. The code modules may be stored on any type of non-transitory computer-readable medium or other computer storage device. Some or all of the methods may be implemented in dedicated computer hardware.

[0099] Many other variations beyond those described herein will be apparent from this disclosure. For example, depending on the example, some actions, events, or functions of any of the algorithms described herein may be performed in a different order, added, merged, or omitted entirely (e.g., not all actions or events described may be necessary to implement an algorithm). Furthermore, in some examples, actions or events may be performed simultaneously rather than sequentially, for example, through multithreading, interrupt processing, or multiple processors or processor cores, or on other parallel architectures. Additionally, different tasks or processes may be performed by different machines and / or computing systems that can function together.

[0100] The various illustrative logic blocks and modules described in connection with the examples disclosed herein may be implemented or executed by a machine, such as a processing unit or processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. A processor may be a microprocessor, but alternatively, a processor may be a controller, microcontroller, or state machine, combinations thereof, or the like. A processor may include electrical circuitry for processing computer-executable instructions. In some examples, a processor includes an FPGA or other programmable device that performs logical operations without processing computer-executable instructions. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, a microprocessor in combination with a DSP core, or any other such configuration. While described herein primarily with reference to digital technology, a processor may also include primarily analog components. The computing environment may include any type of computer system, including, but not limited to, a computer system based on a computational engine within a microprocessor, mainframe computer, digital signal processor, portable computing device, device controller, or appliance, to name a few.

[0101] Elements of the methods, processes, routines, or algorithms described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor device, or in a combination of the two. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of non-transitory computer-readable storage medium. An exemplary storage medium may be coupled to the processor device such that the processor device can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integral to the processor device. The processor device and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. Alternatively, the processor device and the storage medium may reside as discrete components of a user terminal.

[0102] The processes described herein or illustrated in the figures of this disclosure may be initiated in response to an event, such as a predetermined or dynamically determined schedule, on demand when initiated by a user or system administrator, or in response to some other event. When such processes are initiated, a set of executable program instructions stored on one or more non-transitory computer-readable media (e.g., hard drives, flash memory, removable media, etc.) may be loaded into memory (e.g., RAM) of a server or other computing device. The executable instructions may then be executed by a hardware-based computer processor of the computing device. In some embodiments, such processes, or portions thereof, may be implemented in multiple computing devices and / or multiple processors, serially or in parallel.

[0103] In particular, conditional language such as "can," "could," "might," or "may," unless otherwise specified, is understood within the context in which it is generally used to convey that some examples include certain features, elements, and / or steps, while other examples do not. Thus, such conditional language is generally not intended to imply that the features, elements, and / or steps are somehow methodical to the examples, or that the examples necessarily include logic for determining whether those features, elements, and / or steps should be included in or performed in any particular example, with or without user input or prompting.

[0104] Disjunctive language, such as the phrase "at least one of X, Y, or Z," is generally understood in its context of usage to express that an item, term, etc. can be either X, Y, or Z, or any combination thereof (e.g., X, Y, and / or Z), unless otherwise indicated. Thus, such disjunctive language is generally not intended to, and should not, imply that some instances require at least one of X, at least one of Y, or at least one of Z, respectively, to exist.

[0105] Any process descriptions, elements, or blocks in the flow diagrams described herein and / or shown in the accompanying drawings should be understood as potentially representing modules, segments, or portions of code containing executable instructions for implementing specific logical functions or elements in the process. As will be appreciated by those skilled in the art, alternative examples are included within the scope of the examples described herein in which elements or functions may be omitted, performed, or described in a different order than that shown or described, including substantially simultaneously or in reverse order, depending on the functionality involved.

[0106] It should be emphasized that many variations and modifications may be made to the above examples, and that the elements thereof are to be understood as being among the other acceptable examples, and all such modifications and variations are intended to be included within the scope of this disclosure.

[0107] Any process descriptions, elements, or blocks in the flow diagrams described herein and / or shown in the accompanying drawings should be understood as potentially representing modules, segments, or portions of code containing executable instructions for implementing specific logical functions or elements in the process. As will be appreciated by those skilled in the art, alternative implementations in which elements or functions may be omitted, performed, or described in a different order than that shown or described, including substantially simultaneously or in reverse order, depending on the functionality involved, are included within the scope of the examples described herein.

[0108] Unless otherwise specified, articles such as "a" or "an" should generally be construed to include one or more listed items. Thus, a phrase such as "an apparatus configured to" is intended to include one or more listed apparatuses. Such one or more listed apparatuses may also be collectively configured to perform the stated enumeration. For example, "a processor configured to perform enumerations A, B, and C" may include a first processor configured to perform enumeration A working in combination with a second processor configured to perform enumerations B and C.

Claims

1. A wireless charging system, a first coil; 1. A charging configuration determination module comprising: circuitry configured to cause a charging configuration determination procedure to be performed, the charging configuration determination procedure comprising: perturbing the first coil, the first coil being inductively coupled with a second coil; estimating one or more circuit parameters of a converter including the first coil and the second coil based on the perturbing step; and configuring one or more wireless charging settings of the wireless charging system based on the one or more circuit parameters; The wireless charging system is configured to charge a battery pack of a vehicle based on wireless transmission of power between the first coil and the second coil.

2. 10. The wireless charging system of claim 1, wherein the first coil is in a ground pad and the second coil is in a vehicle pad attached to the vehicle.

3. The step of perturbing the first coil comprises: shorting the second coil; applying a plurality of signal waveforms to the first coil in a time-sequential manner, each of the plurality of signal waveforms being generated based on a frequency of a plurality of frequencies; measuring a peak current through the first coil when each of the plurality of signal waveforms is applied to the first coil; and selecting one of the plurality of frequencies corresponding to a minimum peak current through the first coil as a self-resonant frequency of the second coil.

4. The step of perturbing the first coil comprises: applying a signal waveform generated based on a self-resonant frequency of the second coil to the first coil; and measuring a peak current through the second coil to obtain a peak steady-state current when the signal waveform is applied to the first coil.

5. 5. The wireless charging system of claim 4, wherein the estimating one or more circuit parameters is further based on the peak steady state current.

6. 10. The wireless charging system of claim 1, wherein the charging configuration determination procedure further comprises perturbing the second coil.

7. 7. The wireless charging system of claim 6, wherein the steps of perturbing the first coil and perturbing the second coil are performed non-overlapping in time.

8. 2. The wireless charging system of claim 1, wherein the one or more circuit parameters include one or more of a self-inductance of the first coil, a self-inductance of the second coil, a reactance associated with the first coil, a coupling coefficient associated with the first coil and the second coil, or a turns ratio associated with the converter.

9. The wireless charging system of claim 1 , wherein the one or more circuit parameters include a self-inductance of the first coil and a self-inductance of the second coil.

10. 2. The wireless charging system of claim 1, wherein the one or more circuit parameters include a coupling coefficient associated with the first coil and the second coil.

11. 2. The wireless charging system of claim 1, wherein the one or more wireless charging settings include one or more of an operating frequency of the converter, a power limit of the wireless charging system, or a DC voltage level applied to a ground pad of the wireless charging system.

12. The wireless charging system of claim 1 , wherein the charging configuration determination procedure is performed at the beginning of a wireless charging sequence.

13. The wireless charging system of claim 1 , wherein the charging configuration determination procedure further comprises charging a battery pack of the vehicle according to the one or more wireless charging settings.

14. The wireless charging system of claim 1 , wherein the charging configuration determination procedure further comprises lowering a body of the vehicle using an air suspension system of the vehicle.

15. 1. A method of wireless charging, comprising: perturbing a first coil, the first coil being inductively coupled with a second coil; estimating one or more circuit parameters of a converter including the first coil and the second coil based on the perturbing step; configuring one or more wireless charging settings of a wireless charging system based on the one or more circuit parameters; The method, wherein the wireless charging system is configured to charge a vehicle battery pack based on wireless transfer of power between the first coil and the second coil.

16. The method of claim 15 , further comprising wirelessly charging a battery pack of the vehicle in accordance with the one or more wireless charging configurations.

17. 1. A method of wireless charging, comprising: perturbing a first coil of a converter of a wireless charging system; estimating a self-resonant frequency of a second coil of the converter of the wireless charging system based on the step of perturbing the first coil; estimating a self-resonant frequency of the first coil based on the second coil being perturbed; calculating one or more parameters associated with the converter based on at least a self-resonant frequency of the first coil and a self-resonant frequency of the second coil; setting one or more wireless charging settings for the wireless charging system based at least on the one or more parameters associated with the converter; A method comprising:

18. perturbing the first coil to estimate a self-resonant frequency of the second coil; shorting the second coil; applying a plurality of signal waveforms to the first coil in a time-sequential manner, each of the plurality of signal waveforms being generated based on a frequency of a plurality of frequencies; measuring a peak current through the first coil when each of the plurality of signal waveforms is applied to the first coil; and selecting one of the plurality of frequencies corresponding to a minimum peak current through the first coil as a self-resonant frequency of the second coil.

19. perturbing the first coil to estimate a self-resonant frequency of the second coil; applying a signal waveform generated based on a self-resonant frequency of the second coil to the first coil; and measuring a peak current through the second coil to obtain a peak steady-state current when the signal waveform is applied to the first coil.

20. 20. The method of claim 19, wherein calculating the one or more parameters is further based on the peak steady state current.

21. 18. The method of claim 17, wherein the step of perturbing the first coil occurs before or after the second coil is perturbed.

22. 20. The method of claim 17, further comprising charging a vehicle battery pack using the one or more wireless charging settings.

23. 20. A computer readable storage device having instructions stored thereon that, when executed by circuitry of a wireless charging system, cause the device to perform the method of claim 17.

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