System and method for harmonic-based battery charging

Abstract

Aspects of the present disclosure include charging or discharging an electrochemical device, such as a battery. A system generates a waveform, such as a charging signal, for adjusting harmonic attributes of the waveform based on the battery's impedance to one or more harmonics of the waveform. The system may enhance (e.g., add or increase the magnitude) or suppress (e.g., eliminate or reduce the magnitude) the harmonics of the waveform. Such harmonically adjusted waveforms may optimize energy transfer to or from the battery to achieve a variety of possible goals, including enhancing charge rate, battery charge capacity, and / or battery cycle life.

Description

[Technical Field]

[0001] Cross-reference of related applications This Patent Cooperation Treaty (PCT) application relates to and claims priority from U.S. Patent Application No. 63 / 077,331, filed on 11 September 2020, entitled “SYSTEMS AND METHODS FOR HARMONIC-BASED BATTERY CELL CHARGING.” The entire content of that application is incorporated herein by reference for all purposes.

[0002] Embodiments of the present invention generally relate to systems and methods for charging or discharging energy from a battery, and more particularly, for generating an optimal signal to or from a battery through harmonic modulation of the harmonic components of a signal. [Background technology]

[0003] Many electrically powered devices, such as power tools, vacuum cleaners, any number of different portable electronic devices, and all types of electric vehicles, use rechargeable batteries as their power source. Rechargeable batteries are limited by a finite capacity and must be recharged when depleted. Recharging can be inconvenient because powered devices often have to remain stationary for the time required to recharge the battery. In the case of automobiles, recharging can take several hours. Therefore, considerable effort has been invested in developing fast-charging technologies to reduce the time required to recharge batteries. However, fast-charging systems are typically inefficient, while slower-charging systems prolong the recharging process, undermining the fundamental objective of a quick return to service.

[0004] At perhaps its simplest level, as shown in Figure 1A, battery charging involves applying a DC charging current to the battery cell. However, various battery types can only accept a current that does not damage the cell. Figure 1A shows a schematic diagram of a simple circuit 100 for recharging a single-cell battery. Other components of the circuit, such as an ammeter, voltmeter, controller, etc., are not shown. Applying a power signal to the electrodes of the battery cell 104 causes a reverse flow of electrons through the battery, replenishing the stored concentration of charge carriers (such as lithium ions) at the anode. In one particular example, the power supply 102 may be a direct current (DC) voltage source to provide the DC charging current to the battery cell 104. Other types of power supplies, such as current-controlled power supplies, may also be used.

[0005] The various implementations described herein, including charging and discharging, are applicable to electrochemical devices such as batteries. The term “battery” in this art can be used in various ways and may refer to individual cells having anodes and cathodes separated by an electrolyte, and collections of such cells connected in various arrangements. A battery generally comprises repeating units of an ion-conducting barrier, often separated by a liquid or polymer membrane saturated with an electrolyte, and a source of reverse charge and a first electrode layer. These layers are made thin so that numerous units can occupy the volume of the battery, increasing the available power of the battery per stacked unit. While many examples described herein are applied to batteries, cells, or battery cells, it should be understood that the systems and methods described may apply to batteries including many different forms of cells, as well as different possible interconnections of cells, such as parallel, series, and cells coupled in parallel and series. For example, the systems and methods described herein may apply to a battery pack containing numerous cells arranged to provide a predetermined pack voltage, output current, and / or capacity. Furthermore, the implementation configurations described herein, to name a few examples, but not limited to, can be applied to various types of electrochemical devices, including lithium batteries of various different forms, such as lithium metal and lithium-ion batteries, lead-acid batteries, various forms of nickel batteries, and solid-state batteries. The various implementation configurations described herein can also be applied to battery configurations of different structures, such as button or "coin" type batteries, cylindrical cells, pouch cells, and prismatic cells.

[0006] In exploring the effects of charge and discharge signals on batteries, as well as the effects of pulse charging on batteries, sometimes used in so-called fast charging situations, various problems have been discovered. Figure 1B shows a graph 110 of a conventional DC voltage signal 122 produced by a power source 102 and applied to a battery cell 104 to recharge the battery. The graph shows the input voltage 112 versus time 114 of the charge signal 122. Generally, the power source 102 can be controlled to provide repeating pulses 122 to the electrodes of the battery cell 104 to recharge the battery cell. Specifically, the power source 102 can be controlled to provide a repeating square wave (shown as pulse 116, and subsequent pulse 118) signal to the battery cell 104. The peaks of the square wave pulses 116, 118 may be below a voltage threshold 120 corresponding to the operating constraints of the voltage source 102. A typical charge signal used to recharge the battery cell 104 may be applied during the charging period, with some duration of rest periods between the application of the charge signal. The operation of circuit 100 in this manner generates a power recharge signal 122 in the form of a repeating square wave pattern, as shown in Figure 1B.

[0007] However, in some cases, recharging the battery cell 104 by applying a square wave charging signal 122 may degrade the lifespan of the battery cell during recharging or cause inefficiencies in recharging the battery. For example, the rapid application of charging current to the electrodes (usually the anode) of the battery cell 104 (i.e., the sharp forward edge 124 of the square wave pulse 116) may create a large initial impedance across the battery terminals. Specifically, Figure 1C shows a graph of the estimated real impedance value of the battery cell 104 versus the corresponding frequency of the recharging signal applied to the battery cell, according to one embodiment. Specifically, Graph 150 shows a plot of the real impedance value (axis 154) versus the logarithmic frequency axis (axis 152) of the frequency of the input signal to the battery cell 104. Plot 150 shows the real impedance value across the electrodes of the battery cell 104 at various frequencies of the recharging power signal used to recharge the battery. The shape and measurements of plot 150 may vary based on the battery type, battery charge state, battery operating constraints, battery temperature, and similar factors. However, a general understanding of the battery characteristics during charging can be obtained from plot 158. Specifically, the real impedance values ​​experienced at the electrodes of battery cell 104 may vary based on the frequency of the power charging signal supplied to the battery, and at high frequencies, there is a generally sharp increase in the real impedance values ​​328. For example, at frequency f Sq The input power signal to the battery cell 104 at 162 may cause a high real impedance 160 at the electrodes of the battery cell 104, which may reduce the efficiency of the charging process and / or damage parts of the battery cell during charging.

[0008] Returning to the square wave charging signal 122 in Figure 1B, the high frequencies of the signal may be present at the corners of the square wave pulse 116. Specifically, rapid changes in the charging signal to the battery cell 104 (such as the leading edge 124 of pulse 116) can generate noise consisting of high-frequency harmonics, for example, at the leading edge of the square wave pulse, the trailing edge of the square wav pulse, and during the use of conventional inverted pulse schemes. As shown in graph 150 in Figure 1C, such high-order harmonics result in high impedance at the battery electrodes. This high impedance can lead to many inefficiencies, including capacity loss, heat generation, and an imbalance in electrodynamic activity throughout the battery cell, undesirable electrochemical responses at the charging boundary, as well as degradation of materials within the battery cell 104, which can damage the battery and degrade the battery cell's lifespan. Furthermore, cold-starting the battery with high-speed pulses results in limited Faraday activity because capacitive charging and diffusion processes are involved. During this time, the proximal lithium reacts and is rapidly consumed, leaving a period of undesirable side reactions and diffusion-limited conditions that adversely affect the health of the cell and its components. These and other inefficiencies are particularly detrimental during rapid recharging of battery cell 104, which often involves relatively higher currents.

[0009] The various aspects of this disclosure were intended, in particular, with these observations in mind. [Overview of the project]

[0010] In one embodiment, a method for managing the charging or discharging of an electrochemical device includes using a processor to transform a waveform and identify at least one harmonic component of the waveform. The system modifies the harmonic component of the transformed waveform. The method further includes inversely transforming the waveform and generating a harmonic-modified waveform based on the modification of the harmonic component.

[0011] In another embodiment, a method for charging (discharging) an electrochemical device, comprising applying wavelets to a waveform associated with the electrochemical device and identifying harmonic components of the waveform. The method further comprises identifying the effect of the identified harmonic components and modifying the harmonic components of the waveform based on the identified effect.

[0012] In another embodiment, a system for generating waveforms for an electrochemical device comprises a computing element for generating a harmonic-modulated waveform having harmonic attributes of a charge (or discharge) signal, based on the impedance of the battery to the harmonics associated with the harmonic attributes.

[0013] These and other aspects of the disclosure are described in further detail below. [Brief explanation of the drawing]

[0014] [Figure 1A] This is a schematic diagram of a conventional circuit for charging a battery cell. [Figure 1B] This is a signal diagram of a conventional DC voltage or current signal for recharging a battery cell. [Figure 1C] This is a graph of the estimated real impedance value of a battery cell versus the corresponding frequency of the charging signal applied to the battery cell, according to one embodiment. [Figure 2] This is a schematic diagram showing a circuit for charging a battery cell using a charging signal shaping circuit according to one embodiment. [Figure 3] This is a signal diagram of a charging signal for a battery cell and the component harmonics of the charging signal according to one embodiment. [Figure 4] This is a graph of the measured real impedance value of a battery cell versus the corresponding frequency of the charging signal applied to the battery cell, according to one embodiment. [Figure 5] This flowchart shows a method for generating a charging signal for a battery cell based on a frequency corresponding to the minimum impedance value according to one embodiment. [Figure 6A]1 is a signal graph showing an exemplary charging waveform and corresponding frequency conversion of the exemplary charging waveform according to one embodiment. [Figure 6B] It is a diagram showing converted current and voltage waveforms that exhibit the various harmonics revealed by the conversion, and impedance at each of the harmonics. [Figure 6C] It is a different representation of the impedance of each harmonic shown in FIG. 6B. [Figure 7] It is a flowchart of a method for obtaining a harmonic profile of a charging waveform using region conversion with windowing according to one embodiment. [Figure 8] It is a signal graph of an exemplary charging waveform divided into segments for obtaining a harmonic profile of a charging waveform according to one embodiment. [Figure 9A] It is a signal graph of a current charging profile and a voltage charging profile for charging a battery cell according to one embodiment. [Figure 9B] It is a signal graph of a current charging profile and a voltage charging profile for charging a battery cell according to one embodiment. [Figure 10A] It is a graph of a harmonic profile of a current charging signal and a harmonic profile of a voltage charging signal according to one embodiment. [Figure 10B] It is a graph of a harmonic profile of a current charging signal and a harmonic profile of a voltage charging signal according to one embodiment. [Figure 10C] It is a graph of impedance for various harmonics according to one embodiment. [Figure 11] It is a flowchart of a method for performing a wavelet frequency transform function for a charging waveform according to one embodiment. [Figure 12A] It is a diagram showing an exemplary computing environment and system that may be used in implementing embodiments of the present disclosure. [Figure 12B] It is a diagram showing an exemplary computing environment and system that may be used in implementing embodiments of the present disclosure. [Modes for carrying out the invention]

[0015] Systems, circuits, and methods for charging (recharging) or discharging batteries are disclosed herein. The terms charging and recharging are used synonymously herein. Through the systems, circuits, and methods described, the energy required to charge battery cells may be less than that required by previous charging circuits and methods. Aspects of this disclosure may provide several advantages over conventional charging, either individually or in combination. For example, the charging techniques described herein may reduce the rate at which anodes are damaged, reduce the heat generated during charging, which may have several subsequent effects, such as reduced anode and cell damage, reduced risk of fire or short circuit, and so on. In other examples, the charging techniques described herein may allow higher charging rates to be applied to cells, and therefore enable faster charging. The technique may be any optimal charging rate to be used, taking into account other factors such as cycle life and temperature. In one example, the charging rate and parameters may be optimized to result in longer cell life and greater charging energy efficiency. In another example, in what might be considered "fast charging," the systems and methods of the present disclosure result in an improved balance between charging speed and cell life while generating less heat. While previous charging circuits have attempted to address the efficiency of the charging circuit by focusing on the electronic devices of the charging circuit, the systems, circuits, and methods of the present disclosure provide an efficient battery charging signal when applied to charge battery cells.

[0016] Various embodiments described herein can charge or discharge a battery by generating an energy transfer signal corresponding to harmonics (or harmonics) associated with optimal energy transfer based on real and / or imaginary impedance representations of energy transfer to and from the battery. In one example, the charging signal consists of one or more harmonic components selected based on their effective impedances. The system can generate a signal such that the signal contains harmonic components. By focusing on the harmonic components of the signal and their effects on energy transfer to and from the battery, the system can amplify specific harmonic components, filter or suppress harmonic components, shift harmonic components, and otherwise control the composition of the charging signal. Impedance, like resistance, is a measure of interference to and from energy transfer, e.g., current, in the context of charging and discharging a battery. Unlike resistance, impedance also takes into account the effect of frequency on the interference of energy transfer. In some descriptions herein, the system evaluates the impedance effect of the harmonic components of the charging signal on energy transfer to and from the battery. In one example, harmonics may be associated with the minimum impedance value of the battery cell. In other examples, considerations other than reducing impedance may be taken into account. In yet another example, the harmonics of the charging signal correspond to harmonics associated with both the real and imaginary impedance values ​​of the cell. In yet another example, the charging signal may consist of harmonics associated with one or both of the conductance or susceptance of the battery cell's admittance. In various other embodiments, the charging signal for a battery cell may be modified to remove harmonics corresponding to the high impedance of the battery cell, or conversely, to the low admittance. Thus, although impedance is used in the examples above, other measures such as admittance, or its components of susceptance and conductance, may also be used. The term impedance as used herein may include its inverse admittance.

[0017] More specifically, systems and circuits for determining the harmonic profile of a battery charging signal are described. For ease of explanation, the term "charging signal" is used primarily herein, but the concept encompasses "discharge" and, therefore more generally, "energy transfer." The harmonic profile identifies one or more harmonic components of the charging signal and may further identify the impedance effects of any given harmonic. The harmonic profile may be associated with various possible attributes of the battery, such as temperature, charge state, battery type, and so on. Therefore, in some examples, the harmonic profile of the charging signal may change due to the battery's charge state, temperature, and other factors, so the techniques described herein may evaluate or otherwise determine the harmonic profile of the charging signal periodically or otherwise during a charging session. Furthermore, one or more control circuits may shape, modify, or generate a charging signal (e.g., charging current) corresponding to the determined harmonic profile of the charging signal. In one example, the control circuit may augment the portion of the charging signal associated with one or more harmonics corresponding to a minimum impedance value. In other words, the system may generate a charging signal that enhances and otherwise emphasizes harmonic components that more efficiently transfer energy to the battery. In other cases, the control circuit may reduce portions of the charging signal associated with one or more harmonics corresponding to relatively large impedance values, or harmonics corresponding to negative chemical or physical reactions (generally, characteristics) occurring within the battery cell. In other words, the system may generate a charging signal that suppresses and otherwise does not emphasize harmonic components that more significantly hinder energy transfer to the battery, or otherwise are associated with various harmful characteristics and effects. Of course, the system may be configured to provide a charging signal that both enhances some harmonic components and suppresses others. As mentioned above, the charge state and temperature may fluctuate during recharging, and this may cause the harmonic profile of the charging signal to change due to changes in material properties, chemical, and electrochemical processes within the battery.The circuits described herein may, in some cases, perform an iterative process of monitoring or determining the harmonic profile of the battery charging signal and adjusting the charging signal applied to the battery based on the harmonic profile. This iterative process may improve the efficiency of the charging signal used to recharge the battery, thereby providing benefits such as reducing the time required to recharge the battery, extending the battery life (e.g., the number of charge and discharge cycles it can experience), optimizing the amount of current used to charge the battery, managing the battery temperature, and avoiding energy loss due to various inefficiencies.

[0018] To generate a charging signal for a battery with appropriate harmonic components, a battery charging circuit may include one or more charging signal defining circuits and impedance measuring circuits, including both hardware and / or software components, and / or application-specific integrated circuits. In one particular example, hundreds or thousands of measurements of the voltage and current portions of the charging signal may be taken and analyzed via a digital processing system or other similar system to modify the characteristics of the signal that charges the battery cell. In another example, aspects of the charging signal may be analyzed via a domain transformation between time and frequency. The charging signal may be controlled or tuned based on the domain transformation, an understanding of the impedance of one or more harmonic components of the charging signal identified in the domain transformation, and the inverse transformation in the feedback loop control of the charging signal. For example, portions of the charging signal, such as low-amplitude periods between adjacent high-amplitude periods of the signal, including the edge or bulk portion of the dominant harmonic, may be tuned based on the transformation and analysis of the charging signal. In another example, harmonic components identified in the domain transformation may be augmented or suppressed in the inverse transformation based on the impedance of the identified harmonic components.

[0019] In one specific example, charging signals for voltage and current (real or near real-time, or over a single period or multiple averaged periods of a predetermined measurement time frame) may be measured in the time domain. Transformations may be used to convert the measured time-domain data into corresponding data in the frequency domain. In some cases, the type of transformation used may depend on the characteristics of the data, such as stationary / transient or periodic / aperiodic, the format and content of the data, such as the type of noise in the data and the signal-to-noise ratio, or the processor capabilities of the circuit controller or digital processing system. At a high level, transforming charging signal data into the frequency domain can determine the magnitude of individual harmonics in the charging signal and manipulate the resulting charging signal to optimize the analysis of the charging signal in the frequency domain. Specifically, the harmonics obtained from the transformation of the charging signal may be analyzed to determine their respective independent contributions to impedance, power, peak voltage, and / or current in the battery cell during charging by comparing voltage and current. For example, harmonics with relatively high impedance in a battery cell may be eliminated, suppressed (e.g., reduced in magnitude), or shifted, while others may be amplified to create a charging signal composed of an optimized combination of harmonics. In some cases, the optimized charging signal may be defined, at least in part, by the inverse transformation of the harmonic operations from the frequency domain to the original time domain, resulting in an optimized (new) charging signal or its definition, which can be generated by a charging circuit mechanism described herein. The modified harmonic attributes of the optimized charging signal may be associated with a relatively lower impedance, with various associated benefits to the cell, and / or improvements to other battery cell characteristics.

[0020] In some cases, gating may be performed on a time-domain charging signal to independently analyze a window in the charging signal. The system performs domain transformation and harmonic adjustment on the window, then inverse-transforms and recombines the sections to create a complete charging signal in an improved, harmonic-adjusted form. The gating process, which may also be called windowing, may involve analyzing discrete parts of the signal. In other words, the process of gating a transformed charging signal may involve transforming only parts of the time-domain data into the frequency domain for part analysis. For example, the charging signal may be processed by several different bandpass filters, with each band being evaluated independently, or together with the full waveform analysis. This can be useful when the wave segmentation is highly multimodal in magnitude or harmonic content. This can also allow for separate analysis of harmonic content performed in different time orders, or separation of closely spaced harmonics. Gating allows for the analysis of discrete periods without influence from the signal behavior before or after the period of interest in the window. The gating process can enable the analysis of higher frequencies occurring at smaller intervals within the charging signal, which cannot be obtained when the entire charging signal is converted. Depending on the charging signal, the gating process can provide a more discrete signal analysis that can inform the charging signal optimization process described herein, either alone or in combination, and can therefore be useful for analyzing or defining the charging signal to correct oscillating behavior that may occur within the charging signal due to the impedance of the battery cells, heat flux, charge and mass transport phenomena, environmental noise, or the balance of cells within the battery pack.

[0021] Through the systems and methods described herein, a harmonically tuned and formulated transient charging signal may be applied to a battery through the control of a circuit for delivering power to the battery in an optimized amount and timing, which may include adding and / or amplifying some of the harmonic components of the signal, and simultaneously reducing or removing suboptimal harmonics from the signal. Thus, this tuned signal controls the impedance across the contacts in the battery, including the electrodes, during charging or discharging. When the control includes reducing the impedance, energy transfer efficiency may be improved and the charging speed may be improved. As stated above, however, controlling the harmonic content based on impedance is not necessarily based on controlling to the lowest possible impedance, nor is it necessarily based solely on control for charging speed and reduction of interference with energy sufficiency. For example, at certain charging stages, it may be desirable to influence other attributes of the battery through harmonic control and an understanding of how impedance may affect other attributes such as temperature.

[0022] Figure 2 is a schematic diagram showing an exemplary circuit 200 for charging a battery cell 204 using a charge signal shaping circuit 206 and an impedance measurement circuit 208 according to one embodiment. In the description of Figure 2, a cell is referred to, but it should be understood that the description is more generally related to a battery, and the cell is a specific example thereof. Generally, the circuit 200 may include a power source 202, which may be a voltage source or a current source. In one particular embodiment, the power source 202 is a direct current (DC) voltage source, but an alternating current (AC) source is also intended. More specifically, the power supply 202 may include a DC source that provides unidirectional current, an AC source that provides bidirectional current, or a power supply that provides ripple current, such as an AC signal with a DC bias to make the current unidirectional. Generally, the power supply 202 supplies a charging current that can be shaped and used to charge the battery cell 204. In one particular implementation, the circuit 200 in Figure 2 may include a charging signal shaping circuit 206 for shaping one or more aspects of the charging signal for use in charging the battery cell 204. In one example, a circuit controller 210 may provide one or more inputs to the power signal shaping circuit 206 for controlling the shaping of the charging signal. The inputs may be used by the shaping circuit 206 to convert the signal from the power supply 202 into a power charging signal that is more efficient for the battery cell 204. The operation and configuration of the charging signal shaping circuit 206 will be described in more detail below.

[0023] In some cases, the charge signal shaping circuit 206 may modify the energy from the power supply 202 to generate a charge signal that is at least partially based on the impedance effect of the harmonic components of the charge signal on the battery. The charge signal may be modified to amplify and / or suppress harmonics in order to control the impedance of the battery to the charge signal. In some examples, the system may manipulate the harmonic content of the charge signal to reduce and / or minimize the impedance of the battery to the charge signal. It is also possible to characterize the cell such that the impedance is known at any given charge current, voltage level, charge level, number of charge / discharge cycles, and / or temperature, among other factors, so that the impedance is not measured directly but is instead retrieved (or accessed) from memory or similar. In another example, the charge signal may be tailored to various conditions such as battery type, open-circuit voltage, charge state, number of cycles, temperature, and so on, in order to set a charge profile in which one or more harmonic attributes will have some established effect on impedance. The charging profile may be an initial charging profile that is later modified in response to an evaluation of impedance and / or based on other measured attributes other than impedance, which have some pre-established effect on impedance.

[0024] In one example, circuit 200 may include a battery cell measurement circuit 208 connected to battery cell 204 for measuring cell voltage and charging current, as well as other cell attributes such as temperature, and for measuring or calculating the impedance of the cell to a charging signal. In one example, battery cell characteristics may be measured based on an applied charging signal. In another example, battery cell characteristics may be measured as part of a routine that applies signals with various harmonic attributes to generate various battery cell characteristic values ​​associated with different harmonic attributes to characterize the cell, which may be done before charging, during charging, or periodically during charging, and may be used in combination with retrieval techniques and other techniques. The measurement circuit may acquire battery characteristics through previous characterization of the battery, current measurements of the battery, or conditions associated with the battery, or a combination thereof. The characteristics of battery cell 204 may change based on many physical aspects of the cell's chemical characteristics, including the cell's charge state and / or temperature. Therefore, the battery cell measurement circuit 208 can be controlled by the circuit controller 210 to acquire various battery cell characteristic values ​​of the battery cell 204, particularly during the charging of the cell, and to provide these battery cell characteristic values ​​to the circuit controller 210.

[0025] In some cases, the impedance components of the battery cell 204, e.g., real and / or imaginary components, may be provided by the circuit controller to the charge signal regulation circuit 206, thereby defining a charge signal having one or more harmonic components defined based on the effect of harmonics (e.g., harmonics around or near the minimum impedance) on the impedance, or other effects on the battery cell, from the energy from the power supply 202. In another example, the circuit controller 210 may generate one or more control signals based on battery cell characteristic values ​​and provide these control signals to the charge signal regulation circuit 206. The control signals, among other functions, define the charge signal to include harmonic components corresponding to impedance values, increasing the magnitude of the harmonic portion of the charge signal corresponding to relatively low real impedance values, and / or decreasing the magnitude of the harmonic portion of the charge signal corresponding to relatively high impedance values. In some cases, new harmonics may be added, and / or harmonics may be completely eliminated. In other cases, harmonics may be shifted in frequency and / or time, and the new frequencies or times have different impedance responses in the cell. In further examples, and as described above, the charging signal regulating circuit 206 may modify the energy from the power supply 202 to generate a charging signal that at least partially corresponds to the conductance or susceptance component of the admittance of the battery cell 204, or any other aspect related to the impedance in the battery cell. Therefore, although described herein as relating to the real or imaginary component of impedance, systems and methods may similarly measure or consider other attributes of the battery cell, such as the conductance or susceptance component of the admittance of the battery cell. One particular implementation of the charging regulating circuit 106 is described in more detail in U.S. Patent Application No. 17 / 232,975, “Systems and Methods for Battery Charging,” filed April 16, 2021. The entire application is incorporated herein by reference.

[0026] Figure 3 shows an exemplary charging waveform 302 that may be applied to charge a battery cell 204. The composite waveform signal 302 can be understood as consisting of multiple sinusoidal signals or harmonics of different frequencies. While the composite signal 302 in this fairly simple example is in the form of a series of pulses, the charging signals herein may be of any shape when viewed in the time domain, or a series of shaped signals, and otherwise arbitrarily shaped. In the illustrated example, the waveform signal 302 is the sum of a first-frequency sinusoidal signal 304, a second-frequency sinusoidal signal 306, a third-frequency sinusoidal signal 308, and a fourth-frequency sinusoidal signal 310. In any given situation, more or fewer harmonic components are possible, and the example of four is used merely for illustrative purposes. The composite of sinusoidal harmonics 304-310 constitutes the waveform signal 302 in Figure 3. Aspects of the present disclosure include controlling the harmonic content of a charging signal, including the presence or absence of specific harmonics, the magnitude and timing of the harmonics, and using the signal to charge a battery cell. In some cases, various aspects of the waveform, e.g., local rising edges, harmonic content of continuous portions, and / or local falling edges, may be produced through harmonics or a combination of harmonic components. In other cases, the magnitude of various harmonic components of the charging signal may be adjusted based on a harmonic analysis of the charging signal. As described above, the impedance in the battery cell 204 resulting from the application of the charging signal 202 may depend on the harmonics or frequencies contained within the charging signal. Furthermore, uncontrolled potential harmonics in the charging waveform, such as those generated by the power supply, may be associated with a relatively high impedance in the battery cell 204, reducing the efficiency of the waveform for charging the battery cell 204. Therefore, controlling the harmonic content of the charging signal waveform to eliminate or reduce harmonics with high impedance in the battery cell 204 and / or enhance harmonics with low impedance can improve the efficiency of charging the battery, reduce the heat generated during charging, reduce damage to the anode or cathode, shorten the charging time, allow more capacity to be used, and / or increase the battery life.

[0027] To further illustrate this point, Figure 4 is a graph 402 showing a representative relationship between the real impedance value of the battery cell 204 (axis 404) and the corresponding harmonics contained in the charging signal applied to the battery cell (shown as a logarithmic frequency axis (axis 406)). Plot 408 shows exemplary real impedance values ​​across the electrodes of the battery cell 204 at various frequencies of the harmonic components of the charging signal waveform that can be applied to the battery cell 204. As shown in the figure, the real impedance value 408 may vary based on the frequency of the harmonic components of the charging signal, with a relatively lower impedance between an initial higher impedance at lower frequencies and a subsequent relatively rapid increase in the real impedance value at harmonics higher than the frequency at which the lowest impedance is found. Complex impedance may follow a similar plot. Plot 408 of the real impedance value for battery cell 204 is f Min The label indicates the minimum real impedance value 410 corresponding to the attribute of a specific charging signal frequency 412. The attribute may be the frequency of the harmonic components of the charging signal, as well as the discrete rising and / or falling edges of the charging signal, which may rise or fall in proportion to the shape of the rising or falling edges of a sinusoidal signal at a given frequency. The plot of the real impedance value 408 for battery cell 204 may depend on many factors of the cell, such as the battery's chemistry, charge state, temperature, composition of the charging signal, and so on. Therefore, the frequency f corresponding to the minimum real impedance value 410 of battery cell 204 Min 412 may similarly depend on the characteristics of the specific battery cell during charging. Frequency f Min 412 may correspond to other aspects of the battery cell 204, such as the configuration of cells within the pack and the connections between cells within the pack.

[0028] The charging of battery 204 is done at frequency f MinAt or near 412, the circuit controller 210 may utilize the charging signal shaping circuit 206 to define the harmonics and / or other frequency attributes of the charging signal for the battery cell, as this can lead to greater efficiency due to the lower impedance of the battery cell at that frequency. However, as mentioned above, the charging waveform may contain any number of harmonic components. Some harmonic components of the charging waveform have a frequency f Min 412 may be located near or above this harmonic, and the power provided by this component may efficiently charge the battery cell 204. However, other harmonic components may result in inefficient charging of the battery cell 204 and / or impair the chemical or physical properties of the battery cell or cause other undesirable effects such as heat. In particular, to address any or all of these various inefficiencies or effects, the circuit controller 210 may, in some cases, control the charging signal regulation circuit 206 to enhance the charging signal component in the efficient harmonics and / or suppress or eliminate the charging signal component in the inefficient or harmful harmonics.

[0029] Figure 5 shows one method 500 for generating or modifying a charge signal for a battery cell based on harmonic analysis of the charge signal response in a battery cell 204 according to one embodiment. The operation of method 500 can be performed by a circuit controller 210 and, specifically, by providing a control signal to a charge signal shaping circuit 206. The operation of method 500 can be performed through any number of hardware components, software programs, or combinations of hardware and software components.

[0030] Starting from operation 502, the circuit controller 210 may select an initial charge waveform for the charge signal to be used to charge the battery cell 404. In the initial operation, and in some possible implementations, the charge signal may be considered a characterizing signal that may provide some charge but is intended to generate a profile. In one example, the initial charge waveform may be selected by the circuit controller 210 to minimize or reduce the real impedance in the battery cell 204 during the initial charge of the battery. Initially, the impedance of the battery cell 204 is unknown to the circuit controller 210 because no charge signal or other characterizing signal has yet been applied to the battery. Other characteristics, such as charge state, temperature, and similar, may or may not be known. In one particular example, the circuit controller 210 may select the initial charge waveform based on charge state, temperature, historical data of the battery cell 204, historical data of other battery cells of the same form, historical data of the circuit controller 210, or other battery recharge data. In one example, the circuit control may select a charging signal having some known harmonic or frequency attribute based on the type, charge state, cycle count, and / or temperature of the battery cell. The charging signal may be selected from some known set of charging signals and some predetermined knowledge of the effect of those charging signals on the battery. The known set of charging signals may be based on the characterization of battery cells of the same type. For example, some particular harmonic component, or combination of components, may be known to correspond to a relatively low impedance for a typical cell of the same temperature, charge state, charging history, and / or other form. In another example, the initial charging signal may simply contain known harmonic components of a magnitude that does not adversely affect the battery. In yet another example, the circuit controller 210 may analyze previous charging sessions of battery cell 204 or other battery cells. Based on the analysis, the circuit controller 210 selects a frequency f for battery cell 204 where the real or complex impedance of the battery cell is at or near its minimum value. Min We estimate the frequency f MinAn initial charging waveform including large harmonic components at or before and after said frequency can be generated. Similarly, the initial charging waveform can suppress harmonics at other frequencies. In another example, the initial charging waveform has a frequency f corresponding to the minimum real impedance value determined above Min 412 may include a leading edge at or near 412. The initial charging waveform may also comprise a predetermined leading edge, as opposed to a conventional sharp (high-frequency) leading edge, and one or more defined harmonic components based on its impedance effect.

[0031] Regardless of how the initial charging waveform is selected, the circuit controller 210 may provide one or more control signals to the charging signal adjustment circuit 206 to generate the initial charging waveform. However, as described above, the characteristics of the battery cell 204 when charging is initiated and during charging may change, regardless of how the battery is characterized, and due to various changes that may occur during charging. For example, the charge state and temperature of the battery cell 204 may change the harmonic profile of the battery. Therefore, modifying the charging waveform in response to the changing characteristics of the battery cell 204 may be beneficial to the charging of the battery. Thus, starting from operation 506, the circuit controller 210 may generate, or otherwise determine, a harmonic profile that characterizes the impedance effects of various harmonic components of the charging waveform on the battery cell 204. In operation 508, the harmonic profile may generally include the battery cell characteristics for various harmonic frequencies of the charging signal. In one example, the circuit controller 210 may apply one or more characterization signals having various harmonic components, which may also be referred to herein as test signals, to the battery cell 204 as a charging signal, in place of the charging signal, or in addition to the charging signal, to determine the battery cell's response to various harmonics. In one example, the harmonics of the characterization signals may be predetermined by the circuit controller 210 to provide the battery cell 204 with various characterization signals and various associated harmonics, or combinations of harmonics. For each test signal, corresponding battery characteristics, such as impedance values ​​(real, imaginary, and / or complex) corresponding to the harmonic components of a given signal, may be determined and / or stored.

[0032] As will be described in more detail below, the circuit controller 210 may then control the charging signal adjustment circuit 206 in operation 510 to adjust or modify the components of the charging waveform based on the harmonic profile and battery cell characteristics. For example, the circuit controller 210 may adjust the frequency f MinAlternatively, the charging signal regulation circuit 206 can be controlled to increase the magnitude of the charging waveform corresponding to harmonics in or near that frequency, which efficiently increases the transfer of charging energy to the battery cell at harmonics associated with relatively low impedance. Min Adjacent harmonics may be selected based on impedance thresholds or other thresholds, combinations of energy transfer and impedance thresholds, and other criteria. It should also be recognized that even in systems dealing with only a single harmonic, the frequency associated with the minimum impedance is not necessarily selected. Furthermore, in some cases, the minimum frequency may be unknown, or it may be calculated based on other known points. Similarly, the circuit controller 210 may use f to reduce the impedance in the battery cell. Min The charging signal shaping circuit 206 can be controlled to suppress harmonics at frequencies far from the peak. Modifying the harmonic components of the charging signal has further advantages, including controlling or changing the cell temperature, more efficient charging, and / or faster charging. The adjustment of the charging waveform may also be based on other characteristics of the battery cell 204, such as power, peak voltage, peak current, conductance, susceptance, and similar. Furthermore, one or more operations of method 500 may be repeated to continuously monitor the harmonics of the charging waveform and adjust the waveform based on the battery cell characteristics measured in the battery cell 204. Such feedback adjustments may continue for the duration of battery charging or until the battery cell 204 is removed from the charging circuit 200.

[0033] The optimal one or more harmonics of the charging waveform do not necessarily have to be at the absolute lowest impedance. In a characterized system, for example, a battery may not be perfectly characterized for all charge states, life cycles, temperatures, or other conditions, and the characterization may involve reasonable extrapolation and assumptions when selecting harmonic components or frequencies that should define some part of the charging waveform. In other cases, the charging waveform may be defined based on objectives not achieved simply by suppressing harmonics associated with the highest impedance and / or adding or boosting harmonics at correspondingly lower impedances. It is also possible that the control may result in a predetermined charging signal that inaccurately affects harmonics, for example, in which the generated charging signal does not precisely boost or suppress any particular target harmonic. Therefore, the use of “optimal” in the context of impedance, or other values ​​representing the flow of current to or from an electrochemical device, harmonics (frequency), or other measures described herein, does not necessarily mean controlling the harmonics associated with the lowest impedance, nor does it necessarily mean that the correlation between the lowest impedance and harmonics is known or precisely controllable, or that the objective is to control the harmonics at the lowest impedance. Harmonic adjustment may also be based on a charging or discharging objective that can be achieved using some form of harmonic adjustment, the form of adjustment being suboptimal for different charging or discharging objectives. For example, relatively fast charging may be achieved using a different optimal harmonic adjustment compared to adjustment for battery life, using harmonic selection for fast adjustment which may have a negative effect on battery life in some cases, and vice versa. Other measures may also be used, such as power, or admittance, or its components of susceptance and conductance, as described elsewhere herein. In the case of admittance, the optimal value may be associated with harmonics that, during charging or discharging, result in a value of the maximum admittance, or a value within some range of the maximum admittance.

[0034] Furthermore, the charging waveform can be tailored to affect the impedance (or other values) of the electrochemical device in order to optimize its effect on the electrochemical device. For example, the system described herein can operate to balance the charging rate with the battery's cycle life (e.g., the number of charge and / or discharge cycles until the battery capacity drops to some threshold - e.g., 75% (25% loss of capacity)). In some cases, the system may determine harmonics for the highest charging rate, but the applied waveform to achieve that charging rate may not be optimal for the cycle life. Therefore, the system may apply charging at a slower rate than possible, and applying charging at a slower rate can affect the impedance, which can consequently change the harmonic components of the charging waveform. As described above, the charging signal can be continuous or intermittent and can be composed of pulses. In the case of pulses, the leading and trailing edges of the pulse can be controlled to define the shape at certain frequencies, and the content of the pulse body can consist of selected harmonics. The system may apply a harmonically tailored charging waveform having a controlled combination of duty cycle, frequency (e.g., charging pulse), and / or total duration frequency (e.g., charge and pause combination) to balance various possible real-time battery characteristics such as charging speed and / or long-term battery characteristics such as cycle life. For example, relatively higher charging or discharging currents result in lower impedance within the cell, which is generally advantageous for charging or discharging speed, but it is understood that higher charging or discharging speeds will have some impact on cycle life, as with any charging and discharging of a battery, even if optimized for harmonics by the complex impedance feedback described herein. The duty cycle has a strong impact on peak current. On the other hand, for a fixed current RMS, the lowest impedance frequency can benefit cycle life, even at lower charging speeds. Therefore, the system may charge or discharge to optimize the balance between different factors.In other words, aspects of this disclosure may be operable to increase the charge or discharge rate compared to the prior art, and such improvements may also be made while taking into consideration other desirable outcomes, such as the optimization of cycle life under such conditions. In some such cases, the charge or discharge rate may still be improved over the conventional system, but may be operated at some level below the maximum to balance other factors.

[0035] As described above, the circuit controller 210 may determine or acquire the harmonic profile of the charging waveform supplied to the battery cell 204. To acquire the harmonic profile, the circuit controller 210 may apply one or more transformations to the charging waveform. The type of transformation may depend on various attributes of the signal, the system on which the signal operates, the system that generates the signal, the battery, the system that performs the transformation, when the transformation is applied, whether the transformation is applied in real time, versus offline or parallel characterization of the signal with charging, and other factors. In one particular example, the fast Fourier transform (FFT) may be used to transform measured time-domain data of the charging waveform (including voltage and / or current charging waveforms) into corresponding data in the frequency domain. In some cases, and in addition to those described above, the choice of the type of transformation used may depend on the data format, the type of noise in the data and the signal-to-noise ratio, and / or the processor capabilities of the circuit controller or digital processing system. In some cases, a stationary function may be used as a basis for time-frequency transformation. For example, the Bessel function is a single-harmonic sine wave whose amplitude decreases over time. Such transient functions can provide more accurate basis functions for the transformation when applied to transient charging waveforms commonly used to charge battery cells. Therefore, even though the use of FFT-type transformations is described herein, it should be understood that variations of time-frequency transformations, particularly transformations using steady and / or aperiodic basis functions with similar profiles to charging waveforms for battery cells, may be used to achieve lower errors in the transformation.

[0036] Nevertheless, the magnitude of individual harmonics within the charging signal can be determined by converting the charging signal data to the frequency domain. Figure 6A shows various exemplary charging waveforms 602–608 and their corresponding conversions 610–616. For example, waveform 602 is a sine wave shown in the time domain so that the waveform is plotted along the time axis. Since waveform 602 is a simple sine wave with one frequency, conversion 610 of the waveform yields a magnitude 618 on the frequency axis 620 corresponding to the frequency of the sine wave 602. In contrast, waveform 604 contains a sine wave component at a specific frequency, but also includes dormant periods between active periods. This clipping of the lower part of the sine wave component of the waveform, and the dormant periods, produce higher-order harmonics as part of the signal, as can be seen in conversion plot 612 for waveform 604. Waveforms 606 or 608 having a general sine wave pattern but clipped at the top and bottom may yield conversion plots 614 or 616, respectively. Therefore, the transformation plots 610-616 for a given charging waveform 602-808 can graphically represent the various harmonics present in the waveform. Furthermore, the magnitude or height of a frequency in the transformation plots 610-616 indicates how much of the waveform shape corresponds to that particular frequency. For example, waveform 606 has a dominant periodicity at the frequency corresponding to spike 622, while smaller harmonic components at other frequencies 624 indicate harmonics in the waveform at those frequencies, but have a smaller impact on the overall shape of waveform 606. In other words, spikes in the transformation plots 610-616 indicate that the transformed waveforms 602-608 contain harmonics at that frequency, while the magnitude or height of the spike indicates the relative impact of that harmonic component on the overall shape of the waveform.

[0037] Figure 6B shows the current and voltage spectra for the converted current and voltage representations of the charging signal, respectively. As shown in the figure, each spectrum shows harmonics of different scales at various frequencies. On the left side of each spectrum, harmonics with relatively large scales are observed. The figure below shows the impedances of various harmonics. Similarly, Figure 6C is a figure showing the relative impedance magnitudes of various harmonics, with the harmonic associated with the lowest impedance at point 620.

[0038] As described herein, and with reference again to operations 508 and 510 as similar operations described later, it can be seen that suppressing harmonics to the left or right (lower or higher frequency) of the lowest impedance harmonics above a threshold, such as those shown in line 622, can deliver a charging signal with a relatively lower impedance. Furthermore, amplifying the magnitude of harmonics at or near the lowest impedance, such as those below a threshold, can deliver more energy at lower impedances. As will be further described below, in one example, the charging signal may be defined based on the inverse transform of a frequency domain signal, or on various possible representations thereof in which one or more harmonics are amplified and / or suppressed. To achieve a signal with preferably low impedance while delivering sufficient energy for charging in a sufficiently short time, a balance may be required between harmonic suppression for overall charging performance and sufficient energy delivery. In various cases, charging times can be achieved compared to the prior art. Furthermore, it is possible to make additional capacity available without damaging the battery, compared to the prior art, which may sacrifice the use of the total theoretical capacity to avoid damage through overcharging or over-discharging.

[0039] In general, FFT transformations are applied to periodic or stationary waveforms, for example, where the harmonic characteristics of the waveform can be captured by looking at a small time window. For example, even if waveform 602 may persist over a longer period, a single harmonic 618 of waveform 602 may be determined from the transformation of one period or pulse of the waveform. That is, FFT transformations of periodic and stationary waveforms (waveforms whose characteristics do not depend on the time over which the sequence is observed) can yield a profile of frequency content. On the other hand, FFT transformations of non-stationary and / or non-periodic waveforms may have less accurate fidelity and time resolution. For example, a charging signal used to charge a battery cell may be adjusted over time due to battery characteristics such as charge state and temperature, and may contain several components at different levels of fidelity. When observed over the entire charging session, the charging waveform may contain a charging current signal that decreases slowly or stepwise, which may persist over several minutes or hours. At finer fidelity, the charging waveform may contain repeating pulses occurring every few milliseconds or microseconds. At a finer level of fidelity, the charging waveform may contain noise components that occur at the nanosecond level. One or more of these components of the charging waveform may not be captured during the conversion, depending on the chosen time frame for the conversion. For example, a conversion applied to the entire charging waveform over the duration required to fully charge a battery cell will be unable to resolve or accurately represent noise with multiple harmonics of nanosecond-level time constants. Alternatively, limiting the conversion to a smaller period to capture noise harmonics will ignore slower harmonics in the overall charging waveform, potentially missing aspects of the signal behavior. Therefore, traditional time-frequency conversions applied to battery cell charging waveforms may miss multiple harmonics in parts of the charging waveform, leading to errors in waveform analysis.

[0040] To improve the fidelity of the time-frequency analysis of the charging waveform, the circuit controller 210 may perform the method 700 shown in Figure 7, which includes a windowed transformation process. Specifically, the circuit controller 210 may include a digital signal processing system for acquiring data of the charging signal or waveform (such as a charging current waveform, a charging voltage waveform, etc.), perform domain transformation of the charging signal data, and determine harmonic profiles for voltage and current. The operation of the method 700 shown in Figure 7 may be performed using hardware components of the circuit controller 210, one or more software programs, or a combination of both hardware components and software programs.

[0041] Starting from operation 702, the circuit controller 210 may segment the charging waveform into two or more segments and define an analysis window for conversion, and based on the converted data, analysis and manipulation of the charging signal are performed. Generally, the system identifies the period of the signal to be analyzed. For example, Figure 8 shows a signal graph 802 of an example charging waveform 808 which may contain several harmonics. While graph 802 in particular shows a voltage-controlled charging waveform, a current-controlled charging waveform may also be used to charge the battery cell 204. In either case, both voltage and current charging signals may be subjected to analysis unless one or the other is unavailable. If one or the other is unavailable, a single signal may be analyzed, although the degree of information is reduced. The waveform 808 in Figure 8 is shown to be divided into three segments, namely segment 810, segment 812, and segment 814. It should be noted that the system may operate based on analysis of a single segment or without applying a time window to the waveform. Each segment 810-814 of the waveform 808 may correspond to a specific time window or portion of the overall duration of the waveform, defining an analysis window for performing domain transformation. Generally, the waveform 808 can be segmented into any number of analysis windows 810-814, with or without overlap. The number and / or size of the analysis windows may be based on any number of factors, including the processing power of the circuit controller 210, the available storage size for storing acquired waveform data, historical analysis of similar waveforms and / or battery cells 204 during charging, and so on. The definition of the windows may also be based on the characteristics of the signal, such as from filters that acquire statistical information about the signal, such as various frequency attributes of the signal, the magnitude of such frequency attributes, and / or where such frequency attributes occur in time. In one example, the size of the analysis windows 810-814 may be selected to obtain a specific granularity or fidelity of harmonic analysis of the charging waveform 808. Generally, smaller analysis windows 810-814 can yield higher resolution. Therefore, in some cases, the window size may be selected to allow for the conversion analysis of noise components or other fast motion components of the charging waveform 808. Thus, the size of the analysis window may be selected to acquire specific frequencies or harmonics of the charging waveform.For example, the analysis window size may be selected to identify harmonics associated with noise in the charging waveform, typically occurring at very high frequencies. For lower frequencies, a larger analysis window size may be selected to accurately capture longer waveform periods at lower frequencies. Also, the size or boundary of one analysis window 810 may differ from that of another analysis window 812. Furthermore, and as will be described in more detail below, multiple analysis windows may be generated and operated simultaneously, such as an analysis window containing the entire charging waveform and smaller analysis windows set to obtain smaller portions of the charging waveform.

[0042] For the determined analysis window, the circuit controller 210 may, in operation 704, acquire region transformation information for the portion of the charging waveform within the analysis window. Using waveform 808 in Figure 8 as an example, the circuit controller 210 may receive data points of the charging waveform contained within the analysis window 810 and perform transformations on the received data of the charging waveform. The acquired data or information may also be stored in a database or other medium, and some operation may be performed remotely or by a system accessing the stored information. The transformation may provide indication of harmonics within the sample of charging waveform 808 within the analysis window 810.

[0043] In one particular case, in operation 706, a bandpass filter or other type of filter may be applied to the charging waveform data, and in particular to the data within a given window, to reduce artificial harmonics that may arise due to the windowing analysis technique. The upper and / or lower frequencies of the bandpass filter applied for the analysis window 810 may be based on the size of the analysis window, the harmonics intended to be acquired (lower or higher harmonics), the data processing limits of the circuit controller 210, and so on. Additional operations for acquiring frequency and time information from segments of the charging waveform are described in more detail below.

[0044] The circuit controller 210 may determine whether the analysis window is in its final or last position for analysis. As described above, the analysis windows may be applied over some period of time on the charging waveform 808 to isolate and analyze discrete regions of the waveform and identify harmonics within the regions to which those windows are applied, and region transformation analysis may be applied to each segment of the charging waveform 808. In the example in Figure 8, analysis window 814 is the location of the last analysis window as the windows were applied along the charging waveform 808. Note that the window size may vary. The system may apply such windows in different ways. In one example, if the current placement of the window on the charging waveform 808 is not the last position, the system then applies the analysis window to the next set of boundaries in operation 708. For example, after obtaining region transformation information for segment 810 of the charging waveform 808, the circuit controller 210 may determine the boundary for segment 812, return to operation 704, and obtain region transformation information for segment 812. In some cases, obtaining domain transformation information for segment 812 may further include applying a band filter to the frequency boundary of the analysis window to remove or reduce harmonics at the window edges. This iterative process of applying the analysis window along the charging waveform 808 and obtaining domain transformation information as the window is applied along the waveform may continue until the final window location is reached, for example, at the end of a pulse in the charging waveform 808 or at the end of the duration of the charging session.

[0045] For any given window transformation data, the system may, in operation 708, modulate the charging signal associated with the window to its harmonics. In some cases, no modulation will be performed. In some cases, harmonics may be suppressed or amplified, which may include removing harmonics within any given window or adding new harmonics. Harmonic modulation may relate to the impedance effects of any given harmonics, as described herein, and may be based on any charging optimization criteria that can be affected by changing the harmonic content of the charging signal.

[0046] After harmonic adjustment, in operation 708, the system inversely transforms the harmonic-adjusted data back into the original time domain and recombines the windows. The recombined window of time-domain data, having some combination of data in any given window with suppressed or amplified harmonics, defines the charge signal to be applied to the battery. For example, if a harmonic in one window is suppressed by being associated with a relatively higher impedance, the new charge signal will transfer energy to the battery with a lower impedance due to the suppression of the harmonics. Similarly, if a harmonic is amplified by being associated with a relatively lower impedance, the charge signal will transfer more energy in that harmonic. Any harmonic-adjusted content from any window of data may be reconstructed and included in the harmonic-adjusted charge signal. The system applies the harmonic-adjusted charge signal in the time domain, for example, by a charge adjustment circuit. Any filtering used on the windows may be used to appropriately reconstruct the charge signals from the various windows.

[0047] As described above, high impedance in battery cell 204 can occur at high frequencies or harmonics, and therefore, domain transformation analysis of the charging waveform 808 may not accurately identify those harmonics that result in high impedance in battery cell 204. Thus, obtaining the harmonic profile of the entire charging waveform 808 at once may include errors or missed harmonics that could negatively affect the effectiveness of the charging waveform. However, through the transformation and windowing method 700 in Figure 7, a high-resolution harmonic profile that provides both low-frequency and high-frequency harmonics can be obtained. This high-resolution harmonic profile for charging waveform 808 can provide more precise control over the shaping of the charging waveform used to charge battery cell 204.

[0048] Figures 9A and 9B show rolling analysis windows for current charging waveform 908 and voltage charging waveform 928, respectively. As shown, the analysis windows for performing domain transformation analysis can be applied to either type of charging waveform. Specifically, graph 902 shows the current waveform 908 plotted along the measured amperage 904 and the battery's charge state 906, and graph 922 shows the voltage waveform 928 plotted along the measured amperage 924 and the battery's charge state 926. A transformation analysis window 910 similar to that described above can be determined and slid along the charging waveform 908 as the charge state of the battery cell 204 increases. Similarly, an analysis window 930 can be determined and slid along the charging waveform 928 as the charge state of the battery cell 204 increases. In some cases, domain transformation analysis can be performed on both the current portion of the charging waveform 908 and the voltage portion of the charging waveform 928 to obtain harmonic profiles. In another example, the voltage charging waveform 928 may be analyzed as described above, while the current response in the battery cell 204 may be analyzed in a similar manner to determine the harmonic profile of the charging waveform. In general, domain transformation analysis of any component of the charging waveform may be performed as described above.

[0049] As described above, the width of the analysis windows 910, 930 may be based on several factors, including processing resources, the complexity of the dynamic signals, charging waveform control techniques, and similar factors. Furthermore, in some embodiments, the window size (or frequency range defined by the analysis window) may be adjusted or adapted based on the measured characteristics of the charging circuit 200. For example, the window boundaries may be increased or decreased based on the processing speed at which the circuit controller 210 processes the data collected within the window, or based on how rapidly the corresponding charging waveforms 908, 928 are changing within the window. Furthermore, multiple analysis windows may be used simultaneously to acquire different domain transformation information from the charging waveform 908. For example, the circuit controller 210 may sample data of the charging waveform 908 with high resolution within the analysis window 910 to identify higher harmonics in the charging waveform corresponding to the waveform within the analysis window 910. In addition, the circuit controller 210 may downsample the waveform data (or discard previously acquired portions of the waveform data) when the analysis window 910 passes a corresponding portion of the waveform. This downsampled data can be used to perform domain transformation for lower-order harmonics of the charging waveform 908 that would not be visible from the data within the analysis window 910. Therefore, the circuit controller 210 can maintain and transform high-resolution harmonic information for the data within the analysis window 910, as well as lower-resolution harmonic information for the data outside the analysis window 910 (or for portions of the charging waveform 908 that have already occurred). The use of multiple analysis windows at different fidelity levels can further improve the harmonic profile obtained for the charging waveform.

[0050] The circuit controller 210 may adjust the charging waveform applied to the battery cell 204 for charging the battery using the harmonic profiles acquired as described herein. For example, Figure 10A shows a plot of wavelet information or data of a voltage charging waveform. Specifically, plot 1002 shows the acquired harmonic magnitudes 1010 of the voltage charging waveform, having frequency (y-axis 1004) and time (x-axis 1006). The information in plot 1002 may be acquired through a wavelet filtering process as described herein. In a similar manner, plot 1022 shows the acquired magnitudes 1030 of various harmonics of the current charging waveform, having frequency information (y-axis 1024) versus time information (x-axis 1026). Plots 1002 and 1022 provide information about the harmonic content of the charging waveform during a charging session of the battery cell 204. In the examples in Figures 10A and 10B, the corresponding wavelets used to acquire frequency and time information relate to frequencies of at least 1–10 Hz. As will be described in more detail below, wavelets can be used to isolate different parts of a charging waveform to evaluate their harmonic content, or to draw attention to them in other ways.

[0051] Figures 10A and 10B show the magnitudes of various harmonics within the portion of the charging signal corresponding to the applied wavelet. Figure 10C shows the magnitudes of impedance at various harmonics. Higher impedance harmonics 1032 and 1034 are shown at approximately 70 kHz, and at 200 μs–300 μs and 500 μs–600 μs, respectively. The impedance plot in Figure 10C is similar to those in Figures 10A and 10B, but relates to voltage or current plots that are at least from wavelets focusing on the portion of the charging signal between 10 and 100 kHz. Nevertheless, using the impedances obtained for the various harmonics present in the signal, the circuit controller 210 can define the charging waveform by utilizing the harmonic profile of the charging waveform, which can be derived from the voltage and current information of the signal at various identified harmonics, among other things, in the two examples. For example, the circuit controller 210 may be configured to determine battery cell characteristics such as impedance, delivered power, and conductance in the battery cell 204, in or associated with harmonics identified by various transformations described above, including transformations, the windowing technique described above, the wavelet technique described below, and other methods. If the battery cell characteristics indicate an inefficient or damaging charging waveform in one or more specific harmonics, the circuit controller 210 may define or adjust the charging waveform to suppress, for example, remove or reduce, the portion of the waveform corresponding to the inefficient harmonics. Alternatively, or in addition, the circuit controller may enhance (for example, include or amplify) portions of the charging waveform corresponding to one or more particularly efficient harmonics. By these methods, alone or in combination, the charging signal shaping circuit 206 can be controlled using the acquired transformation information of the charging waveform (voltage, current, or both), which, among other advantages, can maximize the efficient transfer of power to the battery cell 204 and reduce harmful or inefficient harmonics in the charging waveform.

[0052] Figure 11 illustrates methods using transformations based on basis functions that represent the steady-state and periodic properties of the charging signal, or methods using wavelets. Some aspects of these methods overlap and are therefore described together. It should be noted that each method can be implemented independently.

[0053] First, in operation 1102, we characterize the charge (or discharge) signal. In particular, depending on the control and battery characteristics, the charge signal can have stationary and periodic characteristics. In many cases, the charge signal can be considered relatively transient and relatively aperiodic. Generally speaking, the stationary nature of a charge signal refers to the statistical features of the signal and whether those statistical attributes change over time (transient) or not (stationary). Such features may refer to some minimum, maximum, representative, average, or other characteristics of the signal. For example, if the magnitude of the maximum current or voltage of the signal changes, these are transient characteristics of the signal. The periodic nature of a charge waveform refers to the repeating behavior of the signal, such as within a given time window. The repeating behavior may extend outside the window. A sine wave whose magnitude does not decay over time or otherwise change is an example of a stationary and periodic signal. Aperiodic characteristics of a signal are non-repeating characteristics. Strictly speaking, the Bessel function is an example of a non-periodic signal that has a strong resemblance to a periodic signal, and can be described as non-stationary due to its apparent sinusoidal pattern of decreasing magnitude. The charging signal can be pre-screened using various filters and other statistical evaluation techniques, or it can be analyzed at various points in time during a charging session. The process can be continuous, periodic, and / or based on changes in the battery (e.g., peak voltage, impedance, etc.), changes in the charge state, changes in temperature, and other factors.

[0054] Based on the stationary and periodic properties of the charging signal, the system may use a variety of different possible basis functions for the transformation to be applied to the signal or a portion thereof in operation 1104. For example, the system may use a transformation that uses a basis function that is in tune with the stationary and periodic properties of the charging signal. Generally speaking, the intention is to use a basis function equivalent to the stationary and periodic properties of the charging signal. In some cases, the basis function may be pre-selected based on the prior characterization of the signal. In other cases, the basis function may be selected by the system, for example, during charging, for some selection of known basis functions having a variety of possible stationary and periodic relationships. In some cases, instead of evaluating the stationary and periodic properties of the signal, the system may use a polynomial or other representation of the signal itself as a basis function. Such a representation encompasses the stationary and periodic properties of the signal through the use of a representation of the signal itself.

[0055] It can be understood that transforms may utilize functions particularly suitable for the accurate analysis of the steady-state and periodic nature of charging signals. For example, for transient signals, the Laplace transform and other types of transforms in which signal attenuation is incorporated into the transform's basis function may be used. Changing the transform's basis function may allow for accurate resolution of harmonics within transient charging signals (either voltage or current, or related information).

[0056] In some cases, the circuit controller 210 may utilize Fourier transform-based techniques (FTs) based on functions other than sinusoidal ones. In some examples, the FT techniques described herein use sinusoidal waves as basis functions to perform a time-frequency transform in which the transform identifies different sinusoidal characteristics in the transformed waveform. However, FTs using sinusoidal functions as basis functions may not be optimal for transient, non-periodic signals. Therefore, in one embodiment, the circuit controller 210 may use transient and non-periodic (aperiodic) functions as basis functions for the transform. An example of such a basis function is a modified Bessel function that includes oscillations similar to the more familiar single-harmonic sine wave, but nevertheless, whose amplitude decreases over time. Such transient functions may provide more accurate FT techniques when applied to transient charging waveforms. However, generally, and as described above, basis functions for FT techniques (or other transforms) that have transient and non-periodic properties similar to the signal being transformed provide the most accurate transforms. In one example, the basis function may include an exemplary charging waveform (or representation thereof) used to charge battery 204, or a similar battery type to the one being charged. For example, the circuit controller 210 may store charging profiles for different types of battery cells that indicate charging waveforms previously used for charging. Such charging profiles may be selected based on the characteristics of battery 204 being charged and used as a basis function for the conversion technique performed above. Since charging profiles can be transient and aperiodic, conversion techniques that use charging profiles as a basis may provide more accurate conversions of similar transient and aperiodic charging waveforms.

[0057] Domain transformations using basis functions based on the steady-state and periodic nature of the charging signal can also be used in conjunction with the aforementioned windowing techniques, which include various aspects of techniques for harmonizing the signal within the window and reconstructing the charging signal.

[0058] Figure 11 shows one specific method 1100 for performing a wavelet transform. The circuit controller 210 may perform one or more operations of method 1100 to obtain transform information from the charging waveform, as described above with respect to operation 506. However, method 1100 in Figure 11 is just one example of such a technique, and other transform techniques may be performed to obtain the harmonic profile of the charging waveform. Starting from operation 1102, the circuit controller 210 may perform one or more time-frequency transforms on the charging waveform, or a portion of the charging waveform. In one specific example, the circuit controller 210 performs one or more wavelet transforms on the charging waveform. As described above, the transforms provide information about the waveform, its harmonic profile, or its spectrum.

[0059] In operation 1104, the circuit controller 210 may obtain a waveform transformation function by performing advanced filtering techniques or other transformations on the frequency domain waveform. Generally, the transformation function is obtained to remove or isolate portions of the charging waveform, such as noise components within the circuit mechanism of the circuit controller 210, which would not be useful in understanding the effect of the charging signal on the battery cell. This transformation function provides a new spectrum of the charging waveform, enabling better distinction of regions within the waveform data. Obtaining the transformation function allows the circuit controller 210 to identify and obtain portions of the waveform corresponding to the most relevant harmonics of the charging waveform in operation 1106. More specifically, the most effective harmonics of the charging waveform can be identified using the purified frequency spectrum obtained via the transformation function. In some cases, high and low thresholds can be identified to create different bands for isolated analysis and frequency boundaries around effective harmonics to define their bandwidths. In one implementation, each band may be isolated using a bandpass filter, such as a bandpass filter, determined by the defined different bands.

[0060] In operation 1106, the system may apply one or more wavelets to the signal. Alternatively, or in addition, the stationary and periodic nature of the charging signal may also be used to select one or more wavelets to apply to the charging signal, or to inform their selection. Wavelet-based techniques may be used instead of the transformation techniques described herein, including the windowing techniques described above. One or more wavelets may be applied to the charging signal to obtain the harmonic content of the signal. A wavelet can be thought of as a special filter applied to a time-charging signal. As shown in Figures 10A and 10B, the application of wavelets may obtain time and frequency domain information about the signal, or a portion of the signal. In some cases, a particular wavelet is applied to a discrete portion of the charging signal. In some cases, the system may select the center frequency of a wavelet based on harmonic frequencies, and the bandwidth of the wavelet may be selected based on evaluating harmonics adjacent to the target harmonic of the center frequency.

[0061] In one example, one or more complex Morlet wavelet transforms with scaling and shifting may be used to identify various harmonics of a charging signal. The Morlet wavelet provides phase and magnitude information of the signal harmonics. In a simple example, the signal may contain a relatively large harmonic at 20 kHz, which indicates that this harmonic is involved in the transfer of a relatively high amount of energy to the battery. The target harmonic may be identified or known through various techniques described herein. Harmonics associated with the 20 kHz harmonic may exist, which do not necessarily have to be sinusoidal in nature, and may be at a frequency where the target harmonic is very audible, e.g., 20.001 kHz. Adjacent harmonics may or may not be in phase with the target wavelet. The Morlet wavelet may be tailored to isolate the 20 kHz harmonic from the charging signal and to capture information about adjacent harmonics. In such an example, the center frequency of the wavelet may be 20 kHz and the bandwidth for capturing adjacent harmonics. The bandwidth, time, and frequency domains may be further scanned to capture features. The bandwidth of a wavelet may be selected so as not to overlap with other relatively large harmonics that may be targeted by other wavelets. Depending on the number of harmonics being targeted, the system may apply different wavelets to determine the presence, time, and magnitude of harmonics at certain frequencies.

[0062] Alternatively, with or without statistical characterization of the signal and with or without windowing, signal transformations can be used to identify signal features, such as harmonics, and then use these to inform the selection of one or more wavelets to be applied to the signal and their attributes. In such cases, any selected wavelets are applied to the time-domain charging signal. In some situations, wavelets can be applied to a signal to identify harmonics of interest and their attributes. In other cases, one or more of signal characterization, domain transformations, and windowing can be used to identify the attributes of the charging signal and inform the selection of wavelets, or wavelet features such as center frequency and bandwidth.

[0063] As described above, one or more wavelets may be applied to the charging signal. The wavelets and their attributes may be predetermined and used at the beginning of any charge or discharge cycle. Such wavelet application may be applied at the start of a charge or discharge and / or repeatedly during it, and harmonic adjustment is performed based on the impedance associated with the harmonics identified by any applied wavelets. In addition to identifying harmonics, the system may also use the magnitude of the harmonics as part of a given harmonic adjustment process. Wavelet selection and wavelet characteristics may be changed during the cycle.

[0064] The application of a given wavelet can be thought of as a channel. The system may use impedance information associated with a specific harmonic identified by the channel (e.g., a 20kHz harmonic identified by a 20kHz Morlet wavelet), or more generally, it may evaluate the impedance of the channel. In any case, as described herein, the system may then modulate the signal to harmonics based on the information from the wavelet and the impedance associated with that information.

[0065] Regardless of the technology, at some point the system identifies the harmonics of the signal and their contribution to the impedance (operation 1108). The system may define or modify the charging signal based on the impedance in the harmonics, as described herein. In the case of a transformed signal that has undergone harmonic manipulation in the frequency domain, the circuit controller 210 may perform an inverse transform of the modified frequency domain signal or the windowed portion thereof. In other words, the frequency domain representation (or representation) of the charging waveform may be modified to suppress or enhance various harmonic attributes, and the modified frequency domain representation may be inverse transformed to define the charging signal. This may be a reconstruction of the current waveform in which each harmonic is suppressed or enhanced. The harmonic adjustment controller generates the signal. As described above, such adjustment of the charging waveform may include amplifying the identified harmonics, as well as suppressing or eliminating the identified harmonics from the charging waveform. Therefore, through method 1100, these individual components may be analyzed to determine the effect each component may have on the charging waveform, and adjustment of the charging waveform may be performed based on such analysis. Furthermore, by limiting the portion of the waveform to be analyzed to an identified region or bandwidth, a reduction in the processing power required to analyze the charging waveform is achieved. In the case of wavelet application, the definition and harmonic adjustment of the charging signal are performed in the time domain.

[0066] The methods described herein may be performed in real time or near real time, in parallel with the charging operation, and / or in the form of a pre-characterization process that defines a harmonic-modulated charging signal to be applied under various circumstances. For example, if a series of windows are to be analyzed, or if a set of wavelets are to be applied, for example, over 10 seconds of the charging signal, or according to 5 or 10 different wavelets, then signal attributes may be obtained from a harmonic-modulation process performed while charging is in progress, and after the process is complete and the harmonic-modulated charging signal has been defined, the definition of the new signal is applied. A selected time, e.g., 10 seconds, may provide a representative sample of data that represents the charging signal over a longer period. As described above, such analysis may be performed prior to charging (or discharging), continuously, on triggers, and / or at different points in time, periodically or otherwise, during the charging (or discharging) process.

[0067] The various methods described herein can be implemented in various different processing environments. For example, referring to Figure 2, the charge signal regulation circuit, circuit controller, and battery cell measurement circuit can be embodied in the form of a processor, ASIC, standalone circuit, or a combination thereof. The computing environment will include various possible forms of computer memory, in which various possible circuit and / or processing configurations may be available to control processes and information related to the battery, their measurement, calculation of impedance, and other information. Various control schemes may be provided in battery-powered devices, in battery packs, in standalone charging for batteries, in remotely connected computing environments, whether mobile or otherwise, and in other possible configurations.

[0068] Figures 12A and 12B illustrate systems that may be used to implement various embodiments of the present disclosure. Appropriate systems will be obvious to those skilled in the art when implementing various embodiments. Similarly, it will be readily apparent to those skilled in the art that other systems are possible. Figure 12A shows an example of a bus computing system 1200 in which system components communicate with each other using a bus 1205. The computing system 1200 may include a processing unit (CPU or processor) 1210, and a system bus 1205 that can connect various system components, including system memory 1215 such as read-only memory (ROM) 1220 and random access memory (RAM) 1225, to the processor 1210. The computing system 1200 may include a high-speed memory cache 1212 directly connected to, or integrated as part of, the processor 1210, or in very close proximity to it. The computing system 1200 can copy data from memory 1215, ROM 1220, RAM 1225, and / or storage device 1230 to cache 1212 for rapid access by processor 1210. In this way, cache 1212 can provide performance improvements by avoiding processor delays while waiting for data. These and other modules can control processor 1210 to perform various actions. Other system memories 1215 may also be available for use. Memory 1215 can contain multiple different types of memory with different performance characteristics. Processor 1210 can include any general-purpose processors and hardware or software modules, as well as dedicated processors with software instructions incorporated into the actual processor design, such as service (SVC) 1 1232, SVC2 1234, and SVC3 1236 stored in storage device 1230, configured to control processor 1210.Processor 1210 can essentially be a completely self-contained computing system encompassing multiple cores or processors, buses, memory controllers, caches, etc. Multicore processors can be symmetrical or asymmetrical.

[0069] To enable user interaction with the computing system 1200, the input device 1245 can represent any number of input mechanisms, such as a microphone for voice, a touch-protected screen for gesture or graphic input, a keyboard, a mouse, motion input, voice, etc. The output device 1235 can also be one or more of a number of output mechanisms known to those skilled in the art. In some cases, the multimodal system can allow the user to provide multiple forms of input for communicating with the computing system 1200. The communication interface 1240 can control and manage user input and system output. There may be no constraints on operation on any particular hardware configuration, and therefore the basic features described herein can be easily replaced with improved hardware or firmware configurations when they are developed.

[0070] The storage device 1230 may be a non-volatile memory, or it may be another type of computer-readable medium capable of storing computer-accessible data, such as a hard disk, magnetic cassette, flash memory card, solid memory device, digital multipurpose disk, cartridge, random access memory, read-only memory, and hybrids thereof.

[0071] As described above, the storage device 1230 may include software SVC 1232, 1234, and 1236 for controlling the processor 1210. Other hardware or software modules are also intended. The storage device 1230 may be connected to the system bus 1205. In some embodiments, a hardware module that performs a particular function may include software components stored in a computer-readable medium related to the hardware components necessary to perform the function, such as the processor 1210, the bus 1205, the output device 1235, etc.

[0072] Figure 12B shows an exemplary architecture for a chipset computing system 1250 that can be used according to one embodiment. The computing system 1250 may include a processor 1255 representing any number of physically and / or logically distinct resources having the ability to run software, firmware, and hardware configured to perform identified computations. The processor 1255 can communicate with a chipset 1260 that can control inputs to and outputs from the processor 1255. In this example, the chipset 1260 can output information to an output device 1265, such as a display, and can read and write information to a storage device 1270, which may include magnetic media, solid media, and other suitable storage media. The chipset 1260 can also read data from and write data to RAM 1275. A bridge 1280 for interfaced with various user interface components 1285 may be provided for interfaced with the chipset 1260. The user interface components 1285 may include a keyboard, microphone, touch detection and processing circuitry, a pointing device such as a mouse, etc. The input to the computing system 1250 can come from any of various sources and may be generated by machine and / or by human.

[0073] The chipset 1260 may also interface with one or more communication interfaces 1290, which may have different physical interfaces. The communication interfaces 1290 may include interfaces for broadband wireless networks, wired and wireless LANs, and personal area networks. Some applications of the methods for generating, displaying, and using the techniques disclosed herein may involve receiving rule datasets through physical interfaces, or may be generated by the machine itself by the processor 1255 analyzing data stored in the storage device 1270 or RAM 1275. Furthermore, the computing system 1250 may accept input from a user via the user interface component 1285 and perform appropriate functions, such as browsing functions, by interpreting and executing these inputs using the processor 1255.

[0074] It will be understood that computing systems 1200 and 1250 may each have more than one processor 1210 and 1255, or may be part of a group or cluster of computing devices networked together to provide greater processing power.

[0075] To clarify the explanation, in some cases, various embodiments may be presented to include individual functional blocks that include functional blocks containing steps or routines in a manner embodied in a device, device components, software, or a combination of hardware and software.

[0076] Claim language that states "at least one of" refers to at least one of the set and indicates that one or more elements of the set satisfy the claim. For example, claim language that states "at least one of A and B" means A, B, or A and B.

[0077] In some embodiments, computer-readable storage devices, media, and memory may include cables or wireless signals that contain bitstreams and similar. However, non-temporary computer-readable storage media, as referred to, explicitly exclude media such as energy, carrier signals, electromagnetic waves, and the signals themselves.

[0078] The methods described in the examples above may be implemented using computer-executable instructions that are stored or otherwise available from a computer-readable medium. Such instructions may include, for example, instructions and data that cause a general-purpose computer, a dedicated computer, or a dedicated processing device to perform a particular function or group of functions, or otherwise configure a general-purpose computer, a dedicated computer, or a dedicated processing device to perform a particular function or group of functions. The portion of the computer resources used may be accessible over a network. Computer-executable instructions may be, for example, binaries, intermediate format instructions such as assembly language, firmware, or source code. Examples of computer-readable media that may be used to store instructions, information used, and / or information generated during the methods described in the examples above include magnetic or optical disks, flash memory, USB devices with non-volatile memory, and networked storage devices.

[0079] Devices implementing the methods described herein may include hardware, firmware, and / or software, and may take any of a variety of form factors. Typical examples of such form factors include laptops, smartphones, small form factor personal computers, personal digital assistants, rack-mount devices, and standalone devices. The functionalities described herein may also be embodied in the form of peripheral devices or add-in cards. Such functionalities may also, as a further example, be implemented on a circuit board, between different chips or different processes running within a single device.

[0080] Instructions, a medium for transmitting such instructions, computing resources for executing them, and other structures for supporting such computing resources are means for providing the functions described in these disclosures.

[0081] Various embodiments of this disclosure are described in detail below. While specific implementations are described, it should be understood that this is for illustrative purposes only. Those skilled in the art will recognize that other components and configurations may be used without departing from the spirit and scope of this disclosure. Therefore, the following descriptions and drawings are illustrative and should not be construed as limiting. Numerous specific details are described to give a full understanding of this disclosure. However, in some cases, well-known or prior art details are omitted to avoid obscuring the description. References to one embodiment or one configuration in this disclosure may refer to the same embodiment or any of the embodiments, and such references mean at least one of the embodiments.

[0082] References to “one embodiment,” “an embodiment,” or similar terms mean that certain features, structures, or characteristics described in relation to an embodiment are included in at least one embodiment of this disclosure. The appearance of the expression “in one embodiment” in various places in this specification does not necessarily refer to the same embodiment, and separate or alternative embodiments do not mutually exclude other embodiments. Furthermore, various features that may be exhibited by some embodiments but not by others are described.

[0083] The terms used herein generally have their common meanings in the art within the context of this disclosure and in the specific context in which each term is used. Alternative words and synonyms may be used for any one or more of the terms described herein, and no special meaning should be given to whether or not a term is detailed or described herein. In some cases, synonyms are provided for specific terms. The inclusion of one or more synonyms does not preclude the use of other synonyms. The use of examples anywhere in this specification, including examples of any term described herein, is illustrative only and is not intended to further limit the scope and meaning of any exemplary term in this disclosure. Similarly, this disclosure is not limited to the various embodiments provided herein.

[0084] Without intending to limit the scope of this disclosure, examples of apparatus, devices, methods, and their associated results according to embodiments of this disclosure are given below. Headings or subheadings may be used in the examples for the convenience of the reader, but it should be noted that these should not in any way limit the scope of this disclosure. Unless otherwise defined, technical and scientific terms used herein have the meanings commonly understood by those skilled in the art to which this disclosure relates. In the event of any conflict, this document, including definitions, shall prevail.

[0085] Further features and advantages of this disclosure will be described below, some of which will be evident from the description or can be known through the practice of the principles disclosed herein. These features and advantages can be realized and obtained using the equipment and combinations specifically indicated in the appended claims. These and other features of this disclosure will be more fully evident from the description below and the appended claims or can be known through the practice of the principles described herein.

Claims

1. A method for generating a charging waveform for an electrochemical device, Using a processor, the waveform is transformed and at least one harmonic component of the waveform is identified. Modifying at least one harmonic component of the converted waveform, The waveform is inversely transformed to generate a harmonic-modulated charging waveform based on the modification of at least one harmonic component, A method that includes this.

2. The method according to claim 1, wherein converting the waveform includes converting from a time-domain representation of the waveform to a frequency-domain representation of the waveform, the frequency-domain representation of the waveform further includes magnitude associated with the at least one harmonic component, and modifying the at least one harmonic component includes modifying the magnitude associated with the at least one harmonic component.

3. The method according to claim 1, further comprising identifying the impedance of the at least one harmonic component in the electrochemical device, wherein the modification of the at least one harmonic component is based on the identified impedance.

4. Establishing a first upper time boundary and a first lower time boundary of a first time boundary that defines a first portion of the waveform, To obtain the converted frequency domain data of the first portion of the waveform, The method according to claim 1, further comprising:

5. Establishing a second upper time boundary and a second lower time boundary of the second portion of the waveform, wherein the second portion of the waveform occurs after the first portion of the waveform. To obtain the converted frequency domain data of the second portion of the waveform, The method according to claim 4, further comprising:

6. The method according to claim 5, further comprising combining the converted frequency domain data of the first portion of the waveform and the converted frequency domain data of the second portion of the waveform on a time period associated with the waveform.

7. The method according to claim 1, wherein modifying the waveform includes suppressing at least one harmonic of the waveform.

8. The method according to claim 1, wherein modifying the waveform includes enhancing at least one harmonic of the waveform.

9. The method according to claim 2, wherein the transformation of the waveform from the time domain to the frequency domain includes utilizing a transformation using basis functions based on the stationary and periodic properties of the waveform.

10. A method for controlling energy transfer in an electrochemical device, Applying a wavelet frequency transform to the waveform associated with the electrochemical device, and transforming the waveform into the frequency domain that includes the harmonic components of the waveform, To identify the impedance effect of the converted waveform on the electrochemical device, Based on the identified impedance effect, the harmonic components of the waveform are modified. Convert the waveform containing the modified harmonic components into the time domain to generate a harmonic-modulated charging waveform containing the modified harmonic components, The harmonic-modulated charging waveform is applied to the electrochemical device to charge the electrochemical device, A method that includes this.

11. The method according to claim 10, wherein the waveform is a charge or discharge signal for energy transfer to or from the electrochemical device.

12. The method according to claim 10, wherein modifying the harmonic components includes enhancing the harmonic components or suppressing the harmonic components.

13. A system for generating waveforms for charging an electrochemical device, wherein the system A system comprising a computing element configured to generate a harmonic-modulated charging waveform by identifying harmonics of a waveform and modifying the waveform in the harmonics based on the impedance response of the harmonics in the electrochemical device.

14. The system according to claim 13, wherein generating the harmonic-modulated charging waveform includes correcting the magnitude of the harmonics.

15. The system according to claim 14, wherein the computing element identifies the magnitude of the harmonics using a domain transformation applied to a time window of the harmonic-modulated charging waveform including the harmonics, or a wavelet applied to the harmonic-modulated charging waveform including the harmonics.

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