Battery management system and method for determining an internal state of a battery

Abstract

A system and method for determining an internal state of a battery that synchronizes the overall available charge and discharge power with the present charge and discharge current limits. The system can be operated to determine a current limit for the battery according to an internal state of the battery, a voltage-based current limit, and a merged current limit. The system may also be configured to determine an expected voltage based on the current limit, and to optionally determine an overall available power output based on the current limit and the expected voltage.

Description

[0001] BATTERY MANAGEMENT SYSTEM

[0002] DESCRIPTION

[0003] BACKGROUND

[0004] As more and more devices migrate to using batteries instead of other power sources, it becomes increasingly important for these devices to manage their power consumption to maximize battery performance. This can be particularly important for hybrid or electric vehicles, where the voltage, current, and power involved are large, and where failure to properly manage battery demands can result in reduced battery life or possibly catastrophic battery failure. Therefore, optimizing battery power management is increasingly important.

[0005] DESCRIPTION OF THE INVENTION

[0006] A battery management system and a method for operating the system are disclosed. In one aspect, the disclosed system can be configured to synchronize current and power limits during charging and discharging of a battery, or a collection of batteries operating as a single battery.

[0007] In a general aspect, the method optionally includes determining an internal state of a battery based on the current current draw of the battery. This can be achieved by using an equivalent circuit model implemented in a battery management circuit, such as, for example, a second-order equivalent circuit model. The disclosed equivalent circuit models can be implemented in hardware, software, or any combination thereof, and can optionally be operated in either forward or reverse mode. In forward mode, the equivalent circuit model accepts a current as an input and provides a voltage as an output. In inverse mode, the disclosed equivalent circuit model accepts a voltage as an input and provides a current as an output.

[0008] The disclosed method may also include determining calibration information that can be used by the management system to adjust or fine-tune the disclosed calculations. In one aspect, the calibration information optionally includes maximum and minimum operating temperatures for the battery, and the system may include one or more temperature sensors arranged and configured to detect the current temperature of the battery at any given time. In another embodiment, the calibration information includes an estimate of the state of charge of the battery, and the system may be configured to determine this estimated state of charge, or to obtain it from a device or system independent of the disclosed system.

[0009] Other examples of calibration information include, but are not limited to, a maximum operating battery cell voltage, component current limits specific to individual components electrically connected to the battery such as bus bars, contactors, inverters, converters, and the like, a peak current limit for the battery specifying the maximum instantaneous current that may be drawn from the battery at a given time, or a continuous current limit specifying the maximum current that may be continuously drawn from the battery for an extended period of time. In another aspect, the calibration information may be obtained through experimentation and / or from the battery or cell manufacturer.

[0010] The disclosed method optionally includes determining a current limit that specifies a maximum charge or discharge current that can be provided or obtained from the battery. This may include determining multiple current limits and, optionally, selecting the lowest limit.

[0011] In one aspect, determining the current limit optionally includes determining component current limits, such as by referencing calibration information, or by other means. In another aspect, determining the current limit may include determining a fused current limit that takes into account the peak current limit and the continuous current limit, along with the current load on the battery, either while charging or discharging the battery. In another aspect, determining a current limit may include determining a voltage-based current limit that optionally includes calculating what charge or discharge current, if applied, would cause the battery cell voltage to reach or exceed an operating voltage limit of the battery.In another aspect, this voltage-based current limit can be obtained using a second-order equivalent circuit model running in reverse mode according to the system and method of the present disclosure. In another aspect, the disclosed method optionally includes the action of determining a power limit for the charge or discharge power. In one aspect, determining a power limit can include determining an expected voltage when the battery is operating at the previously determined current limit. A candidate or expected power limit can be determined using the current limit and the expected voltage. The expected voltage is optionally adjusted based on the current and power load to determine an overall available power limit.

[0012] The battery management system of the present disclosure may include a battery management circuit configured to execute actions taken by the disclosed method to obtain current power limits for a battery or for multiple batteries. The battery management circuit of the present disclosure may include control logic including circuit models, control modules, and the like. The control logic may be implemented as hardware, software, or any combination thereof suitable for carrying out the disclosed method.

[0013] Other aspects of the battery management circuit optionally include one or more Proportional and Integral (PI) or Proportional, Integral, and Derivative (PID) controllers, and / or one or more sensors that may be operable to determine battery temperature, current, and / or load power, and the like. In another aspect, the battery management circuit may include a processor that may be arranged and configured to execute control logic and optionally perform other tasks. A memory may be included for storing information about the system while in operation, including configurations, operating profiles, present, past, or predicted values ​​resulting from calculations performed by the processor and / or control logic, and the like.A communication interface may also be included and may be operative to create and / or maintain communication links with other systems or devices such as vehicle control circuit, electric motor controller, transmission controller and the like.

[0014] Additional forms, objects, features, aspects, benefits, advantages and examples of the present invention will become apparent from the detailed description and drawings provided herein.

[0015] BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a component diagram illustrating an example of the components that may be included in the battery management system of the present disclosure.

[0016] FIG. 2 is a circuit diagram illustrating an example of an equivalent circuit model that may be used by the battery management system of the present disclosure.

[0017] FIG. 3 is a flow diagram illustrating an example of actions that may be taken by the battery management system of the present disclosure.

[0018] FIG. 4 is a diagram illustrating an example of actions that the battery management system of the present disclosure may perform to determine calibration information.

[0019] FIG. 5 is a flowchart illustrating an example of actions that the battery management system of the present disclosure may perform to determine a charge or discharge current limit.

[0020] FIG. 6 is a flowchart illustrating an example of actions that the battery management system of the present disclosure may perform to determine a fused current limit.

[0021] FIG. 7 is a flowchart illustrating an example of actions that the battery management system of the present disclosure may perform to determine a voltage-based current limit.

[0022] FIG. 8 is a flowchart illustrating an example of actions that the battery management system of the present disclosure may perform to determine a charge or discharge power limit.

[0023] FIG. 9 is a component diagram illustrating an example of the battery management system of the present disclosure in use in an energy storage system having multiple batteries or battery cells.

[0024] FIG. 10 is a component diagram illustrating another example of the battery management system of the present disclosure in use in an energy storage system having multiple batteries or battery cells.

[0025] FIG. 11 is a component diagram illustrating an example of the battery management system of the present disclosure in use in a vehicle.

[0026] FIG. 12 is a component diagram illustrating an example of a battery management circuit that may be used in a battery management system of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0027] FIG. 1 is a component diagram illustrating at 100 an example of components that may be included in a battery management system of the present disclosure. The battery management system 100 optionally includes a calibration module 104, a current module 105, a power module 106, a sensor module 107, and / or a battery status module 108. Other components may also be included. The illustrated components may be implemented in hardware or software, or any combination thereof. For example, each component may be implemented as code segments, objects, subroutines, functions, packages, or by any other suitable software construct. With respect to software aspects, the software components or portions of components disclosed herein may be executed by a processor, microcontroller, logic circuit, or other hardware.In another example, the components of the present disclosure may be implemented in hardware using logic circuits, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), or other circuits that include analog or digital logic, or any combination thereof.

[0028] In one aspect, the calibration module 104 may be configured to calculate, obtain, access, or otherwise determine calibration information 109. The calibration information 109 optionally includes information about the battery(ies), as well as any other relevant information, that may be useful in taking into account the various factors that may be useful in comparing and manipulating data about the batteries to efficiently and effectively manage the current current and power loads of the battery.

[0029] For example, the battery manufacturer may provide individual values ​​for a portion of the calibration data. These values ​​may be included in the calibration information 109 and stored in a memory of the disclosed system. In another example, the calibration information 109 may be determined through experimentation and stored in memory in a data store that preferably provides rapid access for both reading and updating the data.

[0030] In one aspect, individual battery cells may be uniquely identified and managed separately. Calibration information 109 may be determined for each battery through experimentation, and these battery-specific values ​​may be stored in calibration module 104. The unique calibration values ​​for each cell may be stored independently of other cells so that individual values ​​may be accessed for each battery in a collection of batteries. In another aspect, calibration information 109 may include values ​​that define characteristics of a group of batteries operating as a battery array. In this configuration, the specific characteristics of an individual battery cell are disregarded in favor of operating the entire array as a single unit with multiple cells likely connected together to form a “battery” in the array.Therefore, calibration values ​​can be specific to a battery cell or generalized to include data on multiple individual battery cells, or any combination thereof.

[0031] In one aspect, the calibration information 109 of the calibration module 104 includes maximum and minimum operating temperatures for the battery, an estimated state of charge for the battery, a maximum operating voltage for the battery, a peak current limit specifying a maximum instantaneous current that may be drawn from the battery, and / or a continuous current limit specifying a maximum current that may be continuously drawn from the battery for a specified period of time. This specified time period may be any suitable time, such as less than 10 seconds, less than 1 minute, less than 5 minutes, or 5 minutes or more. Generally, the peak current limit is greater than the continuous current limit.In another aspect, the peak current limit is optionally determined by the system of the present disclosure based on real-time operating factors such as the current battery temperature and / or the current battery state of charge.

[0032] In another aspect, the calibration information 109 of the calibration module 104 optionally includes a state of charge estimate for the battery, and the calibration module 104 is optionally configured to determine an estimated state of charge, or to receive an estimated state of charge from an external device, system, or source. In another aspect, the calibration information 109 retained by the calibration module 104 optionally includes a maximum operating cell voltage.

[0033] In another aspect, the calibration information 109 maintained by a calibration module 104 includes component current limits for individual components electrically connected to the battery such as bus bars, contactors, electronic circuits, inverters, converters, and the like. These components may, for example, be part of a vehicle drive system such as for an electric or hybrid vehicle utilizing one or more electric motors electrically connected to the battery. In this example, the disclosed battery management system may be useful for managing the power and current limits of an electric or hybrid vehicle.

[0034] The sensor module 107 may be operable to obtain information from one or more sensors indicating aspects of the battery that may be useful for determining current and power limits or other aspects of battery management in accordance with the present disclosure. In another aspect, the current current draw of the battery is optionally determined individually for a single battery cell, or for multiple battery cells electrically connected together and operating as a single battery module. The sensors may be configured to detect the disclosed aspects, such as temperature, current, voltage, and the like, individually for a single battery cell or in arrays for multiple battery cells taken together.

[0035] The current current draw of the battery may be determined, for example, using a current sensing circuit that may include, but is not limited to, components such as shunt resistors, Hall Effect sensors, and the like. In one aspect, the sensor module 107 optionally responds to sensors or sensor output obtained from other sensor systems, controllers, control circuits, and the like. In another aspect, the sensor module 107 optionally includes a temperature sensor arranged and configured to detect the current temperature of the battery. In another aspect, the sensor module 107 may obtain sensor input from the battery cells themselves in the case where the batteries are operable to provide such output.

[0036] The battery status module 108 may be arranged and configured to calculate, predict, model, or otherwise determine information about the internal state of the battery(ies). The battery status module 108 optionally includes one or more equivalent circuit models along with other control logic useful for determining specific operating characteristics or behavior of the battery.

[0037] In one aspect, a battery cell under load generally has a voltage that is different from its nominal equilibrium voltage. For example, the voltage may be lower for discharge and higher for charge due to various factors including, but not limited to, the battery's ohmic resistance, its charge transfer resistance, and its diffusion resistance. Ohmic resistance generally refers to the electronic and ionic resistances of cell components, such as the conductivity of the electrolyte, separator, and electrical connections (terminals, current collectors, solder joints, and electrode contacts). Charge transfer resistance generally refers to a resistance generated by electrochemical reactions at the electrodes.In the case of a lithium-ion battery, diffusion resistance generally refers to the localized increase or decrease in the concentration of Li+ in the electrodes and electrolyte. In one aspect, the battery status module 108 optionally includes one or more equivalent circuit models that can be used by the system to calculate specific reactions in the battery cells depending on anticipated changes in voltage and current, in one example, the battery status module 108 includes a second-order equivalent circuit model. A second-order equivalent circuit model may be preferred because it is generally a computationally efficient battery model that characterizes the input / output behavior of the cell independent of its physics.

[0038] FIG. 2 is a circuit diagram illustrating an example of an equivalent circuit model that may be used throughout the system of the present disclosure. A second order equivalent circuit model 200 is illustrated that may be used by the battery health module 108 to determine aspects of the internal state of the battery. A battery 201 defines an ideal open circuit voltage VOC which generally refers to the detectable voltage differential across the positive and negative terminals of an ideal battery. A circuit 202 optionally models ohmic resistance, a circuit 203 optionally models charge transfer resistance, and a circuit 204 optionally models diffusion resistance. In this example of an equivalent circuit model for a battery, circuits 202, 203, and 204 are electrically connected in series between the ideal battery 201 and an output terminal 205.Circuit 202 includes a resistor R0 through which battery current I flows. Circuit 203 includes a charge transfer resistance shown as resistor R1 and a charge transfer capacitance shown as capacitor C1. R1 and C1 are electrically connected in parallel such that a voltage VRC1 represents a charge transfer voltage drop across R1 and C1. In another aspect, circuit 204 includes a diffusion resistance such as resistor R2 and a diffusion capacitance such as capacitor C2. R2 and C2 are electrically connected in parallel such that a voltage VRC2 represents a diffusion voltage drop across R2 and C2. Included in the model is a terminal voltage Vt which represents the actual measured potential difference across the battery that is presented to circuits electrically connected to the positive and negative battery terminals 205 and 206 respectively.

[0039] Using a second-order equivalent circuit model of the battery status module 108, the disclosed system is optionally configured to determine aspects of the battery status according to this model. For example, the battery status module 108 is optionally configured to determine the status of internal battery cells VRC1 and VRC2. These internal battery states VRC1 and VRC2 are optionally calculated using the current current draw of the battery (illustrated in FIG. 2 as I). The current current draw of the battery can be obtained, for example, from the sensor module 107.

[0040] An example of an equation that can be implemented by the battery status module to determine the state of VRC1 is: dVRCl VRC1 1 dt ~ R1C1 ~ C1

[0041] The battery status module 108 may optionally implement the following equation to determine the status of VRC2 as follows: dVRC2 > VRC2 1 dt R2C2 C2

[0042] The battery status module 108 may implement the following equation to determine the battery voltage Vt:

[0043] Vt = VRC1 + VRC2 + Voc — I * R0

[0044] In another aspect, the parameters Voc, R0, R1, C1, R2, C2 are optionally extracted from cell testing in the laboratory by sampling these aspects of the battery when the battery is in different states of charge and at different temperatures using a Hybrid Pulse Power Characterization (HPPC) cycle. The results may then be stored in the battery health module 108 to allow the battery health to be quickly determined in real time.

[0045] In another aspect, the battery status module 108 may be configured with multiple circuit models as shown in FIG. 2. The individual models may be configured differently in the battery status module 108 to determine different aspects of the battery status, or to determine the battery status in different ways.

[0046] In one example, a second-order equivalent circuit model of the present disclosure may include a “forward” mode and optionally an “inverse” mode. In the forward mode, the model may be used to calculate an output voltage based on an input current. In the inverse mode, an input voltage is optionally used to determine an output current. For example, the battery status module 108 may be programmed or otherwise configured to implement a second-order equivalent circuit model operating in an inverse mode to determine a current draw from the battery that would cause the battery voltage to reach or exceed an operating voltage limit for the battery. In another aspect, the battery status module 108 may include a second-order equivalent circuit model configured to operate in the forward mode to determine VRC1 and VRC2 based on the current draw (I).

[0047] Turning now to the remaining modules illustrated in FIG. 1 , the current module 105 may be arranged and configured to calculate, predict, or otherwise determine a charge or discharge current limit 102 for the battery (or batteries in the array). The current module 105 optionally includes a current limit prediction module 120, a current limit correction module 121, a fused current limit module 122, and a current limit prediction module 123.

[0048] The current limit prediction module 120 includes hardware and / or software that is optionally arranged and configured to determine a predicted voltage-based current limit based on a maximum voltage limit for the battery. In one example, the predicted voltage-based current limit is optionally calculated using a second-order equivalent circuit model of the present disclosure configured to operate in the inverse mode where an input voltage is used to determine a predicted output current. In this case, the input voltage is optionally the maximum voltage limit for the battery. In other words, the predicted voltage-based current limit can be determined by calculating what the current would be that causes the battery voltage to comply with the operating voltage limit of the battery and, optionally, without exceeding it.In another aspect, the expected voltage-based current limit may be calculated according to the maximum operating voltage for the battery and / or the internal battery cell states VRC 1 and VRC 2.

[0049] In another aspect, the current limit correction module 121 is an aspect of the system that is configured using hardware, software, or any combination thereof, to determine a correction factor to be applied to the intended voltage-based current limit to obtain the final voltage-based current limit. The correction factor may be useful in accounting for error that may be introduced into calculations made by the circuit models of the present disclosure. Such errors may occur, for example, as the health of the battery degrades over time.

[0050] In one example, the correction factor for the predicted voltage-based current limit is optionally calculated according to the maximum operating voltage of the battery and / or the current battery voltage. The voltage-based current limit may be determined by applying the correction factor to the predicted voltage-based current limit to determine the final voltage-based current limit. In one example, the voltage-based current limit is optionally determined by multiplying the predicted voltage-based current limit by the correction factor. The correction factor may, in that case, be a number greater than zero and less than 2.0.

[0051] In another aspect, the correction factor for the voltage-based current limit may be determined by the current limit correction module 121 using a controller such as a PI or PID controller that is arranged and configured to operate as a closed-loop control to address errors in the intended voltage-based current limit. The controller may be a single piece of hardware included as part of the circuitry of the current limit correction module 121, or in another example, the controller may be implemented in software executed by a processor that is shared by other modules of the battery management circuitry.

[0052] The fused current limit module 122 provides an additional calculation of a current limit based on the battery current draw considered in conjunction with the maximum current draw and the continuous current draw of the battery. The fused current limit module 122 is thus arranged and configured to determine a current limit by merging these aspects. Generally, the resulting fused current limit can be used as an upper limit such that the actual current drawn from the battery is generally less than or equal to the fused current limit.

[0053] In another aspect, the fused current limit module 122 is optionally configured to automatically adjust the fused current limit over time. For example, the fused current limit module 122 may determine a fused current limit that is equal to the peak current limit over a predetermined grace period during which the resulting fused current limit may be greater than the continuous current limit for the battery. In another aspect, the fused current limit module 122 may be configured to automatically decrease the fused current limit over time after the grace period expires. In another aspect, the fused current limit module 122 may be configured to adjust the fused current limit in the direction of the peak current limit after the rest period has expired.In another aspect, the fused current limit module 122 may be configured to automatically decrease the fused current limit when the fused current limit is greater than the continuous current limit. The fused current limit module 122 may be configured to optionally increase the fused current limit to be greater than or equal to the continuous current limit when the actual current drawn by the battery is less than the continuous current limit. In another aspect, the fused current limit module 122 may be configured to maintain the fused current limit at the continuous current limit for a predetermined rest period while the actual current drawn by the battery is less than or equal to both the continuous current limit and the fused current limit.

[0054] The fused current limit module 122 can be configured or programmed to adjust the fused current limit to increase as needed using a linear, geometric, exponential, or other suitable rate of change. The rate of change of the fused current limit is optionally adjusted automatically by the fused current limit module 122.

[0055] The current limit module 123 is optionally arranged and configured to make a final determination of the current limit based on the current limits determined by the current limit prediction module 120, the current limit correction module 121, and the fused current limit module 122. In one aspect, the current limit module 123 may be arranged and configured to compare the current limits of the modules 120, 121, and 122 with component current limits obtained from the calibration information 109. In this example, the current limit for charging or discharging the battery is optionally determined according to the voltage-based current limit, the component current limit, and the fused current limit.In one embodiment, the current limit module 123 may include hardware or software arranged and configured to determine the charge or discharge current limit 102 by selecting the minimum of the voltage-based current limit, the component current limit, and the fused current limit.

[0056] The power module 106 is optionally arranged and configured to calculate or otherwise determine a charge or discharge power limit 103 for the battery (or for multiple batteries operating in conjunction). The power module 106 is optionally configured to determine a power limit 103 for charging and / or discharging that is synchronized with the current limit 102. The power module 106 optionally includes a voltage prediction module 130, a voltage correction module 131, and a power limit module 132.

[0057] In one aspect, the voltage prediction module 130 includes circuitry and / or software that is optionally configured to utilize a second-order equivalent circuit model of the present disclosure operating in a forward mode to determine a predicted battery voltage when the battery provides the charge or discharge current limit. In another aspect, the voltage prediction module 130 may be configured to determine the predicted battery voltage in accordance with the charge or discharge current limit 102 while also considering the current current draw of the battery. The result is optionally the expected battery voltage when the charge or discharge current limit 102 is supplied.

[0058] The voltage correction module 131 may include hardware and / or software that is optionally configured to determine an offset correction to apply to the battery voltage determined by the voltage prediction module 130. This offset correction from the voltage correction module may be used to synchronize power and current limits. In one aspect, the voltage correction module 131 may be arranged and configured to determine the offset in accordance with the charge or discharge current limit, the current current draw of the battery, and the current power output of the battery. In another aspect, the offset correction to apply to the predicted battery voltage may be calculated using a controller such as a PI or PID controller. This controller may be implemented in hardware, software, or any combination thereof.

[0059] The power limit module 132 includes hardware and / or software that can be configured to determine an overall charge or discharge power limit 103 that is optionally synchronized with the charge or discharge current limit 102. In one aspect, the power limit is optionally calculated in accordance with the charge or discharge current limit 102, the predicted battery voltage obtained from the voltage prediction module 130, and optionally corrected in accordance with an offset determined by the voltage correction module 131. The power limit module 132 can be arranged and configured to determine the overall power limit 103, such as by multiplying the charge or discharge current limit 102 with the corrected predicted battery voltage. In another aspect, the charge or discharge power limit 103 can be calculated by determining the power limits for one or more battery cells and combining them together.In another aspect, the charge or discharge power limit 103 may be calculated for a collection of battery cells electrically connected together and therefore appearing to the battery management system of the present disclosure as a single battery.

[0060] An example of actions that may be taken by the battery management system of the present disclosure in estimating voltage, current, and / or power limits for a battery, or a collection of batteries operating together, is illustrated at 300 in FIG. 3. At 301, the system may determine the internal state of the battery. Any suitable aspect or module of the disclosed system may be employed as needed, such as, for example, the battery status module 108 and / or the sensor module 107, and others.

[0061] In another aspect, determining aspects of the battery state at 301 may include utilizing a second order equivalent circuit model such as that illustrated in FIG. 2 and discussed above. Aspects of the battery's internal state that may be determined include, but are not limited to, the open circuit voltage VOC, the battery ohmic resistance R0, the charge transfer resistance R1, the charge transfer capacitance C1, the diffusion resistance R2, the diffusion capacitance C2, the current currently supplied by the battery I, the charge transfer voltage drop VRC1, the diffusion voltage drop VRC2, and the terminal voltage Vt.In another aspect, the second-order equivalent circuit model may be employed in a forward mode to calculate an output voltage based on the input current, or in the inverse mode where an input voltage is provided to determine an output current as disclosed elsewhere herein.

[0062] In another aspect, the internal states VRC1 and VRC2 of the battery may be determined at 301 using the current current draw of the battery as an input. As discussed elsewhere herein, the current current draw of the battery may be determined using a current sensing circuit that includes such aspects as a shunt resistor, a Hall Effect sensor, and any other suitable current sensor. In another aspect, determining the current draw of the battery may include measuring current individually for a battery cell, for each separate battery cell in an array of multiple battery cells electrically connected together, and / or for multiple battery cells in an array electrically connected together and operating in the assembly as a single battery.

[0063] At 302, the system determines calibration information, such as may be obtained using the calibration module 104. A current limit may be determined at 303, such as by using the current limit module 105. Optionally, a power limit is determined at 304, for example, using the power module 106. The resulting charge or discharge current limit 102 and the power limit 103 are the resulting final output. In another aspect, the actions 301-304 may, where possible, be executed in parallel, sequentially, or in any combination thereof suitable to achieve the final result of obtaining the limits 102 and 103.

[0064] An example of actions that the battery management system of the present disclosure may take to determine calibration information is illustrated in FIG. 4 (such as at 302 in FIG. 3 ). These actions, like others shown in the present disclosure, may be performed by any suitable control module, device, circuit, processor, or logic of the disclosed system, whether implemented in hardware or software, or any suitable combination thereof. The system may determine an estimated state of charge for the battery (401), maximum and / or minimum operating temperatures for the battery (402), and / or maximum operating voltage for the battery at 403. A peak current limit for the battery (404), an estimated state of health for the battery (405), and / or a current temperature of the battery may be determined at 406.Current limits for various components coupled to the battery management system or the battery itself may be determined at 407. The continuous current limit for the battery may be determined at 408. The actions illustrated in FIG. 4 may be performed in any suitable sequential order, in parallel, or randomly in no particular order, as needed. As disclosed herein, the system of the present disclosure may access this calibration information thereby performing the disclosed actions as needed.

[0065] Illustrated in FIG. 5 is a flowchart illustrating at a high level an example of actions that the battery management system of the present disclosure may take to determine the charge or discharge current limit 102 (such as at 303 in FIG. 3). At 501, the disclosed system optionally determines component current limits. These component current limits may be obtained in any suitable manner, such as for example, by accessing aspects of the calibration information 109. These component current limits may include limits for components or devices or other aspects of the system that are electrically connected to the battery and thus may be affected by the charge and discharge current or power.For example, component current limits may include limitations imposed by bus bars, contactors, converters, inverters, the electric motor(s), connecting cables, or other aspects of the system or the environment in which the system operates. At 502, the system optionally determines a fused current limit. The fused current limit, as disclosed elsewhere herein, optionally takes into consideration peak and continuous current limits relative to the loads present on the battery in real time. The voltage-based current limit may be completed at 503, and the three separate current limits determined at 501, 502, and 503 may be compared at 504 to determine an overall current limit. In one example, the overall current limit may be the minimum of these three separate current limits.The resulting current limit value can be used as the charge or discharge current limit 102.

[0066] An example of what actions the battery management system of the present disclosure may perform to determine a fused current limit (502) is shown in FIG. 6. In this example, the disclosed battery management system may be operated to determine a current limit that fuses together aspects of the continuous and peak current limits specified by the battery cell manufacturer, thereby allowing the battery to operate above the continuous current limit for a predetermined period of time followed by a predetermined rest period.

[0067] At 601, the battery management system optionally sets an initial working or applied current limit equal to the peak current limit for the battery. At 602, the system optionally determines whether the current current draw is greater than or equal to the continuous current limit. Otherwise, the current limit remains unchanged at 612, and processing optionally continues to monitor whether or not the battery current draw is greater than or equal to the continuous current limit at 602. Thus, as long as the current current draw of the battery is below the continuous current limit, the overall fused current limit optionally remains unchanged at the peak current value.

[0068] If the current current draw of the battery is greater than or equal to the continuous current limit for the battery at 602, the system optionally allows this situation to continue for a predetermined period of time, which may be referred to herein as a “grace period.” This predetermined grace period may be less than one second, less than 10 seconds, less than one minute, less than five minutes, or five minutes or more. Any suitable grace period may be used. During the grace period, i.e., before its expiration, the optionally disclosed system continues to determine whether the current current draw of the battery is greater than or equal to the continuous current limit at 602.If during the grace period the current current draw of the battery falls below the continuous current limit, the grace period can be reset, the current limit can remain unchanged at 612, and the system can continue to monitor whether the current current draw of the battery is below the continuous current limit.

[0069] If the current current draw of the battery remains above the continuous current limit throughout the grace period, then upon expiration of the grace period at 603, the current limit may be reduced at 604, and the system optionally compares the current current draw to the continuous current limit at 605. If so, the system is operable to continue reducing the current limit at 604, and continue comparing the current current draw to the continuous current limit at 605 until the current current draw is less than the continuous current limit.

[0070] This reduction may occur linearly, exponentially, geometrically, or according to any suitable approach. For example, the current limit may be reduced to the continuous current limit immediately (or as quickly as possible) upon expiration of the grace period. In another example, the current limit may be incrementally reduced linearly according to a predetermined reduction over a predetermined period of time, such as a predetermined number of amperes with each run of 604 and 605.

[0071] In another aspect, the rate of change of the derating may be configured in the system's control logic and may automatically adjust over time as conditions change. For example, if the grace period rarely expires while the current current draw is greater than or equal to the continuous current limit, the initial rate of change may be linear and relatively slow (such as only a few milliamps per second). In another example, if the grace period begins to expire more frequently while the current current draw of the battery is greater than or equal to the continuous current limit, then the rate of change for the current limit reduction in 604 may become increasingly rapid over time. In this way, the system optionally automatically adjusts the rate of change of the derating as conditions change.

[0072] When the current draw of the battery is less than the continuous current limit at 605, then the current limit may be increased at 606. As discussed above, this increase may be linear, exponential, geometric, and the like, and the rate of change may be fixed by the system or may be automatically adjusted. When an increase in the current limit is made at 606, the system may compare the current limit to the peak current limit at 607. If they are equal, then the current limit optionally remains unchanged at the peak current limit, and processing continues at 612.

[0073] While the current limit has not yet reached the peak current limit at 607, the system optionally compares the current battery current draw to the continuous current limit to determine if the current current draw is greater at 608. If not, the current limit may be increased at 606, and processing continues at 607 with the comparison to the peak current limit. Thus, at 606, 607, and 608, the system optionally raises the current limit so that it equals the peak current limit while the current battery current draw is less than the continuous current limit.

[0074] In another aspect, if the current battery current draw is greater than the continuous current limit at 608, the system optionally moves again to reduce the current limit at 609 following any suitable protocol process as discussed above, such as linear, exponential, etc. At 610, the system may compare the current battery current draw to the continuous current limit. If the current battery current draw is not equal to the continuous current limit, then the system may be configured to determine if the current current draw is greater than the continuous current limit. If not, the current limit may be increased at 606; if so, the current limit may be decreased at 609. When the current battery current draw equals the continuous current limit at 610, the system optionally enters a rest period at 611.The rest period may be an optional predetermined period of time during which the current limit is maintained at the continuous current limit. This rest period may be provided to give the battery an opportunity to recover from a period of operation in which the current drawn from the battery is above the continuous current limit but below the peak current limit (such as during the grace period discussed above). In this way, the fused current limit may be useful to allow the system to have periods of operation above the continuous current limit followed by rest periods such as those that may be useful to allow the battery cells to cool down.When the rest period has expired at 611 , the current limit may be set equal to the peak current limit at 601 , and processing optionally continues as described above.

[0075] At any point in the process illustrated in FIG. 6, the current limit may be accessed by other aspects of the disclosed battery management system and / or provided as the fused current limit used by the system to determine the overall charge or discharge current limit 102. The process by which the fused current limit is determined may run continuously or run at predetermined repeating intervals. This predetermined interval is optionally a parameter that may be manually adjusted by user input or automatically adjusted by the system over time. For example, determining the fused current limit at 502 may be configured to run less than once per second, every second, more than once per second, more than 10 times per second, more than 10,000 times per second, or more than 1 million times per second, to name a few non-limiting examples.

[0076] In another aspect, FIG. 7 illustrates an example of actions that the battery management system of the present disclosure may take to determine the voltage-based current limit at 503. In one aspect, the system may be operated at 701 to determine a maximum battery voltage. In one example, the maximum battery voltage may be obtained from the calibration information 109. The state of the battery may be determined at 702. This optionally includes any suitable aspect of the battery such as may be determined using an equivalent circuit model such as that illustrated in FIG. 2. Thus, the current state of the battery may include VRC1, VRC2, and / or Vt, or other aspects that may be useful in determining a voltage-based current limit. At 703, an initial current limit is optionally determined based on the expected voltage.For example, the voltage-based current limit can be determined using a second-order equivalent circuit model operating in inverse mode to calculate a current value that would cause the voltage Vt to reach the operating voltage limit for the battery and optionally avoid exceeding it.

[0077] To compensate for errors that may be introduced into the equivalent circuit model calculations, a correction factor for the voltage-based current limit may be calculated starting at 704. The system optionally determines the actual voltage for the battery at 704, such as by employing a voltage sensing circuit or other suitable voltage measurement. If the battery voltage exceeds the maximum voltage, the correction factor is reduced, perhaps to a value less than one, less than zero, or another value that means the predicted voltage-based current limit calculated at 703 should be reduced. The resulting correction factor may then be applied to the voltage-based current limit at 710 to achieve the overall result at 503.

[0078] If the battery voltage does not exceed the maximum voltage at 707, then the system may optionally determine if the current current draw is at the current limit for the battery at 706. Otherwise, processing optionally continues at 704. The current current draw at the battery may be continuously monitored at 705, thereby providing a comparison input at 706. If the current current draw is at the current limit, the correction factor may be increased at 709 to a value greater than zero, greater than one, or some other value indicating that the initial intended voltage-based current limit could be increased. The resulting correction factor is optionally applied at 710 resulting in a voltage-based current limit at 503.

[0079] An example of actions that the battery management system of the present disclosure may take to determine a charge or discharge power limit is illustrated at 800 in FIG. 8. At 801, the system optionally determines an expected voltage when the battery is operating at the charge or discharge current limit 102. A power limit may be determined at 802 using the current limit 102 and the expected voltage of 801. The current limit 102 may be compared to the current current draw from the battery at 803, and the power limit of 802 is optionally compared to the current power output of the battery at 804. The expected battery voltage is optionally adjusted at 805 to synchronize the power limit of 804 and the current limit of 803. An overall available power limit is optionally determined at 806 based on these values.The overall charge or discharge power limit 103 may be determined, for example, by multiplying the available power limit after 805 by the number of battery cells. This may be appropriate in the case where the system estimates the current and power limits by calculating limits for a battery cell that is one of many similar or identical cells in a battery array. In another aspect, determining the overall power limit may not involve any modification in the case where the current and power limits are calculated for a single battery. The result is that the power limit 103 is determined and synchronized with the current limit 102. These current and power limits may then be provided as output to other devices or systems seeking to appropriately regulate their battery draw in accordance with these limit values.

[0080] The battery management system of the present disclosure can be used with any suitable battery and regardless of the operating environment. For example, the disclosed battery management system can be used in small batteries such as power tools, aerial vehicles such as helicopters, drones, or other aircraft, or in other installations such as in a car, truck, tractor, or other vehicle as part of a hybrid or electric drive system. The disclosed system is optionally advantageous for any battery, or group of batteries, particularly where it is preferable to be aware of and respond to battery charge and discharge current power limits, and where it is preferable for the current and power limits to be synchronized.

[0081] An example of the disclosed battery management system installed as part of an energy storage system is illustrated at 900 in FIG. 9. The energy storage system 901 includes multiple individual batteries, or battery cells, 903. In this example, the battery cells are electrically connected together in series, but other configurations, such as a parallel electrical connection, or a combination of series and parallel connections, may also be used.

[0082] In this case, the disclosed battery management system 902 is optionally included separately in each individual battery cell. For example, the battery management system 902 may be implemented in hardware or software and placed within the housing of each of the batteries 903 on a suitable substrate such as a PC board. Individual circuitry of the battery management system 902 within each battery cell 903 may be configured to communicate with a control circuit of the energy storage system 901, or with other control circuitry, such that the batteries 903 can respond to the energy storage system through the disclosed battery management system 902.

[0083] In this configuration, each individual instance of the battery management system 902 is operable to manage the charge and discharge current and power limits as disclosed herein independently for each cell. The energy storage system 901 can access the charge and discharge current and power limits independently for each battery and use that information to manage the flow of power into and out of each cell while the energy storage system 901 is in use.

[0084] In another example, an energy storage system 1001 is illustrated in FIG. 10. In this case, the battery cells 1003 are electrically connected to each other in series (although any suitable electrical connection may be used). In this example, a single instance of the disclosed battery management system is included as part of the energy storage system 1001. For example, the battery management system 1002 may be implemented in hardware or software and mounted on a PC board that is electrically connected to the batteries 1003. The PC board may be mounted in the housing of the energy storage system 1001.In another example, the energy storage system 1001 may include an energy storage system controller or other control circuitry, and the battery management system 1002 may be implemented in hardware, software, or any combination thereof, which is included in the control circuitry of the energy storage system 1001.

[0085] In this configuration, a single battery management system 1002 operates as disclosed herein to manage charge and discharge current limits for the batteries 1003. Calculations and information collected and analyzed by the disclosed battery management system 1002 may optionally be made available to the energy storage system 1001, and possibly to other systems as well. In one aspect, the battery management system 1002 is optionally operable to consider the batteries 1003 as a single battery, and the calculations disclosed herein may be performed for the battery cells 1003 in aggregate rather than individually. In another aspect, the battery management system 1002 may be configured to determine individual operating characteristics and calibration information for each individual cell, such as by polling the cells individually.This information can then be retained and retrieved separately for each battery cell before making an overall determination of the charge and discharge power and current limits for the energy storage system 1001.

[0086] The disclosed battery management system may be included in a vehicle, such as a hybrid or electric vehicle, an example of which is illustrated in FIG. 11 at 1100. Vehicle 1101 includes a battery 1102 that may be electrically connected or otherwise responsive to a battery management system 1103 in accordance with the present disclosure. Battery 1102 may also be electrically connected to an electric motor generator 1105 disposed and configured to transfer power to one or more ground contact elements 1107 and 1108 (such as tires, tracks, wheels, and the like). A transmission 1106 is optionally configured to adjust gear ratios between the electric motor generator 1105 and the ground contact elements 1107 and 1108. Control circuitry 1104 may be included to control operation of vehicle 1101.The battery management system 1103 may exchange information with the control circuit 1104, and the electric motor generator 1105 may similarly send and receive information, instructions, data, and the like with the control circuit 1104. The battery management system 1103 may be implemented in accordance with any of the disclosed examples or aspects to manage current and power limits, or other aspects of the battery 1102.

[0087] The battery management system of the present disclosure may be implemented in a battery management circuit, an example of which is shown at 1200 in FIG. 12. In one example, the battery management circuit 1201 includes control logic 1209. The control logic 1209 may be implemented in hardware including custom ASICs, FPGAs, or any suitable arrangement of logic gates, PI or PID controllers 1204, or other electronic components, operating using digital, analog, or other logic schemes, to implement the disclosed system and method. In another aspect, the control logic 1209 may be implemented in software optionally stored in a memory 1207 and executed by a processor 1206. The control logic 1209 may include any control logic disclosed herein. For example, an equivalent circuit model 1201 may be implemented, as well as control modules 1203.An example of the equivalent circuit model 1201 is illustrated in FIG. 2 and discussed above.

[0088] The control logic 1209 may include multiple individual equivalent circuit models implemented in hardware or software and optionally optimized for particular purposes. For example, one equivalent circuit model may be configured to operate in forward mode, while another may be configured to operate in reverse mode. Inputs disclosed herein may be presented to the forward and inverse models as needed, and outputs may be obtained. In another example, a single equivalent circuit model 1201 may be included in hardware or software and may be configured to operate in forward or inverse mode as needed. In yet another example, multiple equivalent circuit models 1201 may be included, each configured to calculate values ​​as disclosed herein separately and in parallel.In another example, the equivalent circuit models 1201 and control modules 1203 may be implemented in software and may be configured to run in series, parallel, or any combination thereof, to accelerate processing of inputs to determine charge and discharge power and current limits.

[0089] In another aspect, the battery management circuit 1201 may include a communication interface 1205 for establishing and maintaining communication with other systems or resources external to the disclosed battery management system. These may include, but are not limited to, other controllers or control circuitry, which may provide information useful for configuration, maintenance, operation, or other aspects of the disclosed battery management system. Optionally, sensors 1208 may be included in the battery management circuit 1201 to obtain information about batteries useful for the disclosed system and method. In another example, one or more sensors may be included in an external system and not be part of the battery management circuit 1201. These external sensors may be in communication with the battery management circuit 1201, such as via the communication interface 1205.The concepts illustrated and disclosed herein relating to a battery management system may be arranged and configured in accordance with any of the following non-limiting numbered examples:

[0090] Example 1: A power management system for a battery that is configured to estimate battery voltage states and battery current and power limits.

[0091] Example 2: The system of any other example comprising a current module operable to determine the maximum available charge or discharge current of the battery.

[0092] Example 3: The system of any other example comprising a power module operable to determine the maximum charge or discharge power available from the battery.

[0093] Example 4: The system of any other example comprising a battery status module operable to determine the internal state of the battery.

[0094] Example 5: The system of any other example wherein the internal state of the battery includes an open circuit voltage VOC and a battery ohmic resistance R0, a charge transfer resistance R1 , a charge transfer capacitance C1 , a diffusion resistance R2, a diffusion resistance capacitance C2, a current currently supplied by the battery I, a charge transfer voltage drop VRC1 , a diffusion voltage drop VRC2, and a terminal voltage VT representing the potential difference across the battery that is presented to circuits electrically connected to the positive and negative battery terminals.

[0095] Example 6: The system of any other example where the ohmic resistance is the electronic and ionic resistances of the cell components such as the conductivity of the electrolyte, the separator and the electrical connections (terminals, current collectors, soldered joints and contact electrodes).

[0096] Example 7: The system of any other example in which the charge transfer resistance is a resistance generated by the electrical chemical reactions at the electrodes.

[0097] Example 8: The system of any other example in which the diffusion resistance is a resistance caused by the localized increase / decrease of the concentration of L¡+ in the electrode and electrolyte.

[0098] Example 9: The system of any other example in which the battery includes a single battery cell.

[0099] Example 10: The system is any other example in which the battery includes multiple individual battery cells electrically connected to each other and operating as a battery module.

[0100] Example 11: The system of any other example where the voltage state includes the voltage potential across the battery with and without load on the battery.

[0101] Example 12: The system of any other example where the current limits include a peak current limit that represents the maximum possible current that the battery can provide.

[0102] Example 13: The system of any other example where the current limits include a continuous current limit that represents the maximum current that the battery can supply for an extended period of time.

[0103] Example 14: The system of any other example where the system is configured to estimate battery power limits.

[0104] Example 15: The system of any other example where the system is configured to synchronize the current and power limits for the battery.

[0105] Example 16: The system of any other example in which the disclosed power management system is optionally integrated into a PC board electrically connected to the battery.

[0106] Example 17: The system of any other example in which multiple separate instances of the disclosed power management system are optionally integrated into a power distribution system electrically connected to the battery.

[0107] Example 18: The system of any other example in which each individual battery cell is electrically connected to an individual power management circuit of the present disclosure in a battery module that includes multiple cells.

[0108] Example 19: The system of any other example wherein the disclosed power management system is optionally implemented as an electrical circuit that is included in an individual battery cell and is configured to monitor the disclosed aspects only for that particular battery cell.

[0109] Example 20: The system of any other example wherein the disclosed power management system is optionally implemented as an electronic circuit that is included in a battery module having multiple individual battery cells, and the power management system is arranged and configured to monitor the disclosed aspects of each battery cell in the battery module.

[0110] Example 21: The system of any other example wherein the system is included as part of an energy storage system for a hybrid or electric vehicle, and wherein the battery, or batteries, monitored by the disclosed system are electrically connected to an electric motor of the hybrid or electric vehicle.

[0111] Example 22: The system of any other example in which the battery is electrically connected to an electric motor.

[0112] Example 23: The system of any other example in which the system is configured to determine aspects of the battery status based on the current current draw of the battery.

[0113] Example 24: The system of any other example in which the system is configured to determine aspects of the battery state according to a second-order equivalent circuit model.

[0114] Example 25: The system of any other example in which the system is configured to determine the state of the internal battery cells VRC 1 and VRC 2.

[0115] Example 26: The system of any other example in which the internal states of the battery VRC 1 and VRC 2 are calculated using the current current consumption of the battery.

[0116] Example 27: The system of any other example in which the current current consumption of the battery is determined using a current sensor that includes, but is not limited to, a shunt resistor, a Hall Effect sensor and the like.

[0117] Example 28: The system of any other example in which the current current consumption of the battery is determined individually for a battery cell, or for multiple battery cells electrically connected together and operating as a single battery module.

[0118] Example 29: The system of any other example in which the system is configured to use a second-order equivalent circuit model in a direct mode to calculate an output voltage based on the input current.

[0119] Example 30: The system of any other example where the system is configured to use a second-order equivalent circuit model in an inverse mode where an input voltage is used to determine an output current.

[0120] Example 31: The system is any other example in which the system is configured to use a second-order equivalent circuit model to determine a current draw from the battery that would cause the battery voltage to exceed an operating voltage limit for the battery.

[0121] Example 32: The system of any other example where the system includes calibration information about the battery.

[0122] Example 33: The system of any other example where the calibration information includes maximum and minimum operating temperatures for the battery.

[0123] Example 34: The system of any other example in which the system includes a temperature sensor arranged and configured to detect the current temperature of the battery.

[0124] Example 35: The system of any other example in which the calibration information includes an estimate of the state of charge.

[0125] Example 36: The system of any other example in which the system is configured to determine an estimated state of charge of the battery.

[0126] Example 37: The system of any other example in which the system is configured to optionally receive an estimated state of charge from an external source.

[0127] Example 38: The system of any other example where the calibration information includes a maximum operating cell voltage.

[0128] Example 39: The system of any other example in which the calibration information includes specific component current limits of individual components electrically connected to the battery, such as bus bars, contactors, and the like.

[0129] Example 40: The system in any other example where the calibration information includes a peak current limit for the battery that specifies the maximum instantaneous current that can be drawn from the battery at a given time.

[0130] Example 41: The system of any other example where the calibration information includes a continuous current limit that specifies the maximum current that can be continuously drawn from the battery for an extended period of time.

[0131] Example 42: The system of any other example where the peak current limit is greater than the continuous current limit.

[0132] Example 43: The system of any other example in which the peak current limit is determined based on the current battery temperature at the current state of charge of the battery. Example 44: The system of any other example in which the calibration information is obtained through experimentation and / or is provided by the battery manufacturer and is optionally specific to each individual battery cell.

[0133] Example 45: The system of any other example in which the system is configured to determine a fused current limit based on the peak current limit and the continuous current limit.

[0134] Example 46: The system of any other example where the current drawn by the battery is less than or equal to the fused current limit.

[0135] Example 47: The system of any other example where the system is configured to automatically adjust a fused current limit over time.

[0136] Example 48: The system of any other example in which the fused current limit may be equal to the peak current limit for a predetermined grace period during which the fused current limit may be greater than the continuous current limit for the battery.

[0137] Example 49: The system of any other example in which the fused current limit automatically decreases over time after the grace period expires.

[0138] Example 50: The system of any other example in which the fused current limit decreases linearly, geometrically, exponentially or any combination thereof.

[0139] Example 51: The system of any other example where the fused current limit automatically decreases when the fused current limit is greater than the continuous current limit.

[0140] Example 52: The system of any other example wherein the fused current limit is optionally increased to be greater than or equal to the continuous current limit when the actual current drawn by the battery is less than the continuous current limit. Example 53: The system of any other example wherein the fused current limit is optionally maintained at the continuous current limit for a predetermined rest period while the actual current drawn by the battery is less than or equal to the continuous current limit and the current fused current limit.

[0141] Example 54: The system of any other example in which the fused current limit is optionally automatically adjusted towards the peak current limit after the rest period has expired.

[0142] Example 55: The system of any other example in which the system is configured to determine a current limit based on expected voltage based on a maximum voltage limit.

[0143] Example 56: The system of any other example where the expected voltage-based current limit is calculated using a second-order equivalent circuit model in the inverse mode.

[0144] Example 57: The system of any other example where the expected voltage-based current limit is determined by calculating what the current would be that causes the battery voltage to meet or exceed the voltage operating limit for the battery.

[0145] Example 58: The system of any other example in which the expected voltage-based current limit is calculated according to the maximum operating voltage for the battery and / or the internal battery cell states VRC 1 and VRC 2.

[0146] Example 59: The system of any other example in which the system is configured to determine a correction factor to be applied to the intended voltage-based current limit to obtain the voltage-based current limit.

[0147] Example 60: The system of any other example wherein the correction factor for the predicted voltage-based current limit is calculated according to the maximum operating voltage of the battery and / or the current battery voltage. Example 61: The system of any other example wherein the correction factor for the voltage-based current limit is calculated using a PI and / or PID controller using closed-loop control to address errors in the predicted voltage-based current limit.

[0148] Example 62: The system of any other example where the voltage-based current limit is determined using the expected voltage-based current limit and correction factor.

[0149] Example 63: The system of any other example where the voltage-based current limit is determined by multiplying the expected voltage-based current limit by the correction factor.

[0150] Example 64: The system of any other example in which the correction factor is a number greater than zero and less than 2.0.

[0151] Example 65: The system of any other example in which the current limit for charging or discharging the battery is determined according to the voltage-based current limit, the component current limit, and the fused current limit.

[0152] Example 66: The system of any other example where the current limit is the minimum of the voltage-based current limit, the component current limit, and the fused current limit.

[0153] Example 67: The system of any other example in which the system is configured to use a second-order equivalent circuit model in a direct mode to determine an expected battery voltage when the battery provides the current limit.

[0154] Example 68: The system of any other example in which the system is configured to determine the expected battery voltage according to the current limit and the current current draw of the battery.

[0155] Example 69: The system of any other example in which the system is configured to determine an offset correction to apply to the expected battery voltage to adjust the current limits and synchronize the power and current limits.

[0156] Example 70: The system of any other example in which the compensation correction to be applied to the expected battery voltage is calculated according to the current limit, the current current consumption of the battery and the current power output of the battery.

[0157] Example 71: The system of any other example in which the compensation correction to be applied to the expected battery voltage is calculated using a PI and / or PID controller.

[0158] Example 72: The system of any other example in which the system is configured to determine a power limit that is synchronized with the current limit.

[0159] Example 73: The system of any other example in which the power limit is calculated according to the current limit, the expected battery voltage and the expected voltage offset correction.

[0160] Example 74: The system of any other example where the power limit is calculated by multiplying the current limit by the corrected predicted battery voltage.

[0161] Example 75: The system of any other example in which the power limit is calculated by determining the power limits for one or more battery cells and combining them.

[0162] The actions disclosed herein that may be included in a method of operating a battery management system of the present disclosure to determine current and power limits for one or more batteries may include any of the following non-limiting numbered examples:

[0163] Example 1: A method for estimating voltage, current and / or power limits for a battery, or a set of batteries operating together.

[0164] Example 2: The method of any other example comprising using a current module to determine the maximum charge or discharge current available from the battery. Example 3: The method of any other example comprising using a power module to determine the maximum charge or discharge power available from the battery.

[0165] Example 4: The method of any other example comprising using a battery status module to determine the internal status of the battery.

[0166] Example 5: The method of any other example wherein the internal state of the battery includes an open circuit voltage VOC, a battery ohmic resistance R0, a charge transfer resistance R1, a charge transfer capacitance C1, a diffusion resistance R2, a diffusion capacitance C2, a current currently delivered by the battery I, a charge transfer voltage drop VRC1, a diffusion voltage drop VRC2, and a terminal voltage VT representing the potential difference across the battery that is presented to circuits electrically connected to the positive and negative terminals of the battery.

[0167] Example 6: The method of any other example where the ohmic resistance is the electronic and ionic resistances of the cell components such as the conductivity of the electrolyte, the separator and the electrical connections (terminals, current collectors, soldered joints and contact electrodes).

[0168] Example 7: The method of any other example in which the charge transfer resistance is a resistance generated by electrical chemical reactions at the electrodes.

[0169] Example 8: The method of any other example where the diffusion resistance is the resistance caused by the localized increase / decrease in the concentration of L¡+ in the electrode and electrolyte.

[0170] Example 9: The method of any other example where the battery includes a single battery cell.

[0171] Example 10: The method is any other example in which the battery includes multiple individual battery cells electrically connected to each other and functioning as a battery module.

[0172] Example 11: The method of any other example where the voltage state includes the voltage potential across the battery with and without load on the battery.

[0173] Example 12: The method of any other example where the current limits include a maximum current limit that represents the maximum possible current that the battery can provide.

[0174] Example 13: The method of any other example where the current limits include a continuous current limit representing the maximum current that the battery can deliver over an extended period of time.

[0175] Example 14: The method of any other example where the system is configured to estimate battery power limits.

[0176] Example 15: The method of any other example where the system is configured to synchronize the current and power limits for the battery.

[0177] Example 16: The method of any other example comprising determining the internal state of the battery based on the current current draw of the battery.

[0178] Example 17: The method of any other example comprising determining aspects of the battery state according to a second-order equivalent circuit model.

[0179] Example 18: The method of any other example comprising determining the state of the internal battery cells VRC1 and VRC2.

[0180] Example 19: The method of any other example where the internal states of the battery VRC 1 and VRC 2 are calculated using the current current consumption of the battery.

[0181] Example 20: The method of any other example wherein the actual current draw of the battery is determined using a current sensor including, but not limited to, a shunt resistor, a Hall effect sensor, and the like. Example 21: The method of any other example comprising determining the actual current draw in the battery individually for a battery cell, or for multiple battery cells electrically connected together and operating as a single battery module.

[0182] Example 22: The method of any other example comprising using a second-order equivalent circuit model in direct mode to calculate an output voltage based on the input current.

[0183] Example 23: The method of any other example comprising using a second-order equivalent circuit model in an inverse mode where an input voltage is used to determine an output current.

[0184] Example 24: The method of any other example comprising using a second-order equivalent circuit model to determine a current draw from the battery that would cause the battery voltage to exceed an operating voltage limit for the battery.

[0185] Example 25: The method of any other example comprising using calibration information about the battery to determine current and power limits of the battery.

[0186] Example Six: The method of any other example where the calibration information includes maximum and minimum operating temperatures for the battery.

[0187] Example 27: The method of any other example wherein the system includes a temperature sensor arranged and configured to detect the current temperature of the battery.

[0188] Example 28: The method of any other example where the calibration information includes an estimate of the state of charge.

[0189] Example 29: The method of any other example comprising determining an estimated state of charge of the battery. Example 30: The method of any other example comprising determining an estimated state of charge using an external source.

[0190] Example 31: The method of any other example where the calibration information includes a maximum operating voltage of the cell.

[0191] Example 32: The method of any other example where the calibration information includes specific component current limits of individual components electrically connected to the battery, such as bus bars, contactors, and the like.

[0192] Example 33: The method of any other example where the calibration information includes a maximum current limit for the battery that specifies the maximum instantaneous current that can be drawn from the battery at a given time.

[0193] Example 34: The method of any other example where the calibration information includes a continuous current limit that specifies the maximum current that can be continuously drawn from the battery for an extended period of time.

[0194] Example 35: The method of any other example where the peak current limit is greater than the continuous current limit.

[0195] Example 36: The method of any other example comprising determining the peak current limit based on the current temperature of the battery at the current state of charge of the battery.

[0196] Example 37: The method is any other example in which the calibration information is obtained by experimentation and / or is provided by the battery manufacturer and is optionally specific to each individual battery cell.

[0197] Example 38: The method of any other example comprising determining a fused current limit based on the peak current limit and the continuous current limit.

[0198] Example 39: The method of any other example where the current drawn by the battery is less than or equal to the fused current limit.

[0199] Example 40: The method of any other example comprising automatically adjusting a merged current boundary over time.

[0200] Example 41: The method of any other example wherein the fused current limit may be equal to the maximum current limit for a predetermined grace period during which the fused current limit may be greater than the continuous current limit for the battery.

[0201] Example 42: The method of any other example comprising automatically decreasing the current limit merged over time after the grace period expires.

[0202] Example 43: The method of any other example comprising automatically decreasing the fused current limit over time in a linear, geometric, exponential manner, or any combination thereof.

[0203] Example 44: The method of any other example comprising automatically decreasing the fused current limit when the fused current limit is greater than the continuous current limit.

[0204] Example 45: The method of any other example comprising automatically increasing the fused current limit to be greater than or equal to the continuous current limit when the actual current drawn by the battery is less than the continuous current limit.

[0205] Example 46: The method of any other example comprising automatically maintaining the fused current limit at or around the continuous current limit for a predetermined rest time period while the actual current drawn by the battery is less than or equal to the continuous current limit and the fused current limit.

[0206] Example 47: The method of any other example comprising automatically adjusting the fused current limit toward the peak current limit after the rest period has expired.

[0207] Example 48: The method of any other example comprising determining a current limit based on the expected voltage based on a maximum voltage limit.

[0208] Example 49: The method of any other example comprising calculating the voltage-based current limit using a second-order equivalent circuit model in the inverse mode.

[0209] Example 50: The method of any other example comprising determining the current limit based on the expected voltage by calculating what the current would be that causes the battery voltage to reach or exceed the operating voltage limit for the battery.

[0210] Example 51: The method of any other example comprising determining the current limit based on the expected voltage according to the maximum operating voltage for the battery and / or the internal battery cell states VRC 1 and VRC 2.

[0211] Example 52: The method of any other example comprising determining a correction factor to be applied to the intended voltage-based current limit to obtain the voltage-based current limit.

[0212] Example 53: The method of any other example comprising calculating the correction factor for the current limit based on the expected voltage according to the maximum operating voltage for the battery and / or the current voltage of the battery.

[0213] Example 54: The method of any other example comprising determining the correction factor for voltage-based current using a PI and / or PID controller using closed-loop control to address errors in the intended voltage-based current limit.

[0214] Example 55: The method of any other example comprising determining the voltage-based current limit using the predicted voltage-based current limit and the correction factor.

[0215] Example 56: The method of any other example comprising determining the voltage-based current limit by multiplying the predicted voltage-based current limit by the correction factor.

[0216] Example 57: The system of any other example in which the correction factor is a number greater than zero and less than 2.0.

[0217] Example 58: The method of any other example comprising determining the current limit for charging or discharging the battery according to the voltage-based current limit, the component current limit, and the fused current limit.

[0218] Example 59: The method of any other example where the current limit is the minimum of the voltage-based current limit, the component current limit, and the fused current limit.

[0219] Example 60: The method of any other example comprising determining an expected battery voltage for a given current limit.

[0220] Example 61: The method of any other example comprising using a second order equivalent circuit model in a forward mode to determine an expected battery voltage for a given current limit.

[0221] Example 62: The method of any other example comprising determining the expected battery voltage according to the current limit and the current current draw of the battery.

[0222] Example 63: The method of any other example comprising determining an offset correction to apply to the expected battery voltage to adjust current limits and synchronize power and current limits.

[0223] Example 64: The method of any other example comprising determining the compensation correction to be applied to the predicted battery voltage according to the current limit, the current current draw of the battery, and the current power output of the battery. Example 65: The method of any other example wherein the compensation correction to be applied to the predicted battery voltage is calculated using a PI and / or PID controller.

[0224] Example 66: The method of any other example comprising determining a power limit that is synchronized with the current limit.

[0225] Example 67: The method of any other example comprising determining a power limit based on the current limit, the expected battery voltage, and the expected voltage offset correction.

[0226] Example 68: The method of any other example comprising determining a power limit by multiplying the current limit by the corrected predicted battery voltage.

[0227] Example 69: The method of any other example comprising comparing the current limit with a measured current.

[0228] Example 70: The method of any other example comprising comparing the power limit with a measured power.

[0229] Example 71: The method of any other example comprising determining power limits for one or more battery cells and combining them together.

[0230] Glossary of definitions and alternatives

[0231] While the invention is illustrated in the drawings and described herein, this disclosure is to be considered illustrative and not restrictive. This disclosure is exemplary in nature, and all changes, equivalents, and modifications that come within the spirit of the invention are included. The detailed description is included herein to analyze aspects of the examples illustrated in the drawings in order to promote an understanding of the principles of the invention. This is not intended to limit the scope of the invention. Any further alterations and modifications to the examples described, and any further applications of the principles described herein are contemplated as would normally occur to one skilled in the art to which the invention pertains.Some examples are disclosed in detail; however, some features that may not be relevant may have been omitted for the sake of clarity.

[0232] Where references are made to publications, patents, and patent applications cited in this document, they are hereby incorporated by reference as if each individual publication, patent, or patent application were specifically and individually indicated to be incorporated by reference and set forth in its entirety herein.

[0233] The singular forms "a," "an," "the," and similar include plural referents unless expressly indicated otherwise. For illustrative purposes, references to "a device" or "the device" include one or more such devices and their equivalents.

[0234] Directional terms such as "up," "down," "above," "below," "front," "rear," "lateral," "longitudinal," "radial," "circumferential," etc. are used herein solely for the convenience of the reader to help him or her understand the illustrated examples. The use of these directional terms in no way limits the features described, illustrated, and / or claimed to any specific direction and / or orientation.

[0235] Multiple related articles illustrated in the drawings with the same part number that are differentiated by a letter for separate individual instances may generally be referred to by a distinguishable portion of the full name and / or by the number alone. For example, if multiple "laterally extending elements" 90A, 90B, 90C, and 90D are illustrated in the drawings, the disclosure may refer to these as "laterally extending elements 90A-90D", or as "laterally extending elements 90", or by a distinguishable portion of the full name, such as "elements 90".

[0236] The language used in the disclosure is presumed to have only its plain and ordinary meaning, except as explicitly defined below. Words used in the definitions included herein are to have only their plain and ordinary meaning. This plain and ordinary meaning includes all consistent definitions from the most recently published Webster's and Random House dictionaries. As used herein, the following definitions apply to the following terms or common variations thereof (e.g., singular / plural forms, past / present tenses, etc.):

[0237] "Approximately" in reference to numerical values ​​generally refers to plus or minus 10% of the stated value. For example, if the stated value is 4.375, then the term "approximately 4.375" generally means a range between 3.775 and 4.8125.

[0238] "Activate" is usually synonymous with "provide power" or refers to "enabling a specific function" of an already powered circuit or electronic device.

[0239] “AND / OR” generally refers to a grammatical conjunction that indicates that one or more of the cases it connects may occur. For example, it can indicate that one or both of the two listed cases may occur. In general, “and / or” includes any combination from the listed collection. For example, “X, Y, and / or Z” encompasses: any letter individually (e.g., {X}, {Y}, {Z}); any combination of two of the letters (e.g., {X, Y}, {X, Z}, {Y, Z}); and all three letters (e.g., {X, Y, Z}). These combinations may also include other items not listed.

[0240] "Battery" generally refers to an electrical energy storage device or system that includes multiple energy storage devices. A battery may include one or more separate electrochemical cells, each of which converts stored chemical energy into electrical energy by a chemical reaction to generate an electromotive force (or "EMF" measured in volts). An individual battery cell may have a positive terminal (cathode) with a higher electrical potential and a negative terminal (anode) that has a lower electrical potential than the cathode. Any suitable electrochemical cell employing any suitable chemical process may be used, including galvanic cells, electrolytic cells, fuel cells, flow cells, and voltaic piles.When a battery is connected to an external circuit, the electrolytes can move as ions within the battery, allowing chemical reactions to complete at the separated terminals and thus delivering power to the external circuit. A battery may be a "primary" battery that can produce current immediately after assembly. Examples of this type include alkaline, nickel oxyhydroxide, lithium-copper, lithium-manganese, lithium-iron, lithium-carbon, lithium-thionyl chloride, mercuric oxide, magnesium, zinc-air, zinc chloride, or zinc-carbon batteries. These batteries are often referred to as "disposable" in that they are usually not rechargeable and are disposed of or recycled after discharging.

[0241] A battery can also be a "secondary" or "rechargeable" battery that can produce little or no current until charged. Examples of this type include lead-acid batteries, valve-regulated lead-acid batteries, sealed gel cell batteries, and various "dry cell" batteries, such as nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), and lithium-ion (Li-ion) batteries.

[0242] "Capacitor" generally refers to a device that stores electrical energy. A capacitor typically includes one or more pairs of conductors separated by an insulator.

[0243] “Comparison logic” generally refers to software or electronic circuitry configured to compare two or more values ​​and determine an outcome based on one or more rules. The rules may be encoded as software running on a computer processor, or encoded using an arrangement of digital or analog logic gates or circuits. Examples include decision trees, comparisons made based on relationships between sets of values, decision logic implemented in a neural network, fuzzy logic for determining partial truth outcomes, and the like.

[0244] "Communication link" generally refers to a connection between two or more communicating entities for the purpose of transmitting information between the entities. Communication between the communicating entities may be conducted by any suitable means. For example, the connection may be implemented as a physical link, an electrical link, an electromagnetic link, a logical link, or any other suitable link that facilitates communication. In the case of an electromagnetic link, the connection may be implemented by sending or receiving electromagnetic energy at any suitable frequency, thereby allowing communications to pass as electromagnetic waves. These electromagnetic waves may or may not pass through a physical medium such as an optical fiber, or through free space through one or more transmitting and receiving antennas, or any combination thereof.Electromagnetic waves can be transmitted at any suitable frequency, including any frequency in the electromagnetic spectrum.

[0245] A communication link may include any suitable combination of hardware, which may also include software components. Such hardware may include routers, switches, network endpoints, repeaters, signal strength gateways, hubs, and the like.

[0246] "Computer" or "computing device" generally refers to a device configured to calculate a result based on input values ​​or variables. A computer may include a processor to perform calculations to process inputs or outputs. A computer may include memory to store values ​​to be processed by the processor, or to store the results of previous processing.

[0247] A computer can also be configured to accept input and output from a wide range of input and output devices to receive or send values. Such devices include other computers, keyboards, mice, visual displays, printers, industrial equipment, and systems or machinery of all types and sizes. For example, a computer can control a network interface to perform various network communications on demand. The network interface can be part of the computer or characterized as separate and remote from the computer.

[0248] A computer may be a single, physical computing device, such as a desktop or laptop computer, or it may be composed of multiple devices of the same type, such as a group of servers operating as a single device in a networked cluster, or a heterogeneous group, a combination of different computing devices operating as a single computer and linked together by a communications network. The communications network connected to the computer may also be connected to a broader network such as the Internet. Therefore, a computer may include one or more physical processors or other computing devices or circuits, and may also include any suitable type of memory.

[0249] A computer can also be a virtual computing platform that has an unknown or fluctuating number of physical processors and memory or storage devices. Therefore, a computer can be physically located in one geographic location or physically distributed across several widely dispersed locations, with multiple processors connected to each other by a communication network to operate as a single computer.

[0250] The concepts of "computer" and "processor" within a computer or computing device also encompass any processor or computing device used to perform calculations or comparisons as part of the disclosed system. Processing operations related to threshold comparisons, rule comparisons, calculations, and the like that occur on a computer may occur, for example, on separate servers, the same server with separate processors, or in a virtual computing environment having an unknown number of physical processors as described above.

[0251] A computer may optionally be coupled to one or more visual displays and / or may include an integrated visual display. Furthermore, the displays may be of the same type or a heterogeneous combination of different visual devices. A computer may also include one or more operator input devices, such as a keyboard, a mouse, a touchscreen, a laser or infrared pointing device, or a gyroscopic pointing device, to name just a few representative examples. Furthermore, in addition to a display, one or more output devices may be included, such as a printer, a plotter, an industrial manufacturing machine, a 3D printer, and the like. As such, various arrangements of display, input, and output devices are possible.

[0252] Multiple computers or computing devices can be configured to communicate with each other or with other devices via wired or wireless communication links to form a communications network. Network communications may pass through various computers functioning as network devices, such as switches, routers, firewalls, or other network devices or interfaces before passing through other larger computer networks, such as the Internet. Communications may also be transmitted over the communications network as wireless data transmissions carried out via electromagnetic waves over transmission lines or free space. Such communications include the use of Wi-Fi or another wireless local area network (WLAN) or a cellular transmitter / receiver to transfer data. Such signals conform to any of a number of mobile or wireless telecommunications technology standards, such as 802.11a / b / g / n, 3G, 4G, 5G and similar.

[0253] “Computer software” or “software” is an organized collection of bits representing computer instructions and data that tell the computer how to perform a series of actions. This contrasts with the physical hardware that is configured to actually perform the steps specified in the software. Examples include computer programs, libraries, and related non-executable data, such as online documentation or digital media. Software includes specific processor instructions, usually expressed as bits of binary data values, signifying processor instructions that change the state of the computer from its previous state. For example, an instruction may change the value stored in a particular storage location on the computer, an effect that the user cannot directly observe.An instruction can also invoke one of many input or output operations, for example, displaying some text on a computer screen, causing state changes that should be visible to the user. The processor executes instructions in the order they are provided, unless instructed to "jump" to a different instruction or interrupted by the operating system. As of 2015, most personal computers, smartphone devices, and servers have processors with multiple execution units or multiple processors performing calculations together, and computing has become a much more concurrent activity than in the past.

[0254] Most software is written in high-level programming languages. They are easier and more efficient for programmers because they are closer to natural languages ​​than to machine languages. High-level languages ​​are translated into machine language using a compiler, an interpreter, or a combination of both. Software can also be written in a low-level assembly language, which closely matches the computer's machine language instructions and is translated into machine language using an assembler.

[0255] "Contact" generally refers to a condition and / or state in which at least two objects physically touch each other. For example, contact requires at least one location where the objects touch directly or indirectly, with or without any other material member(s) in between.

[0256] "Controller" or "control circuit" generally refers to a mechanical or electronic device configured to control the behavior of another mechanical or electronic device. A controller or control circuit can be configured to provide signals or other electrical impulses that the controlled device can receive and interpret to indicate how it should behave. Controllers or control circuits can control other controllers or control circuits, such as in a master-slave configuration where the master is configured to control a slave based on input from the master.

[0257] "Control logic" generally refers to hardware or software configured to implement an automatic decision-making process by which inputs are considered and corresponding outputs are generated. The output can be used for any suitable purpose, such as providing specific commands to machines or processes that specify specific actions to be performed. Examples of control logic include computer programs executed by a processor to accept commands from a user and generate outputs according to the logic implemented in the program executed by the processor. In another example, control logic can be implemented as a series of logic gates, microcontrollers, and the like, electrically connected together in a predetermined arrangement to accept inputs from other circuits or computers and produce an output according to the rules implemented in the logic circuits.

[0258] "Current" generally refers to the rate of flow of electric charge through a point or region of an electrical circuit. Electric current is said to exist when there is a net flow of electric charge through a region. "Data" generally refers to one or more values ​​of qualitative or quantitative variables that are usually the result of measurements. Data can be considered "atomic" as finite individual units of specific information. Data can also be considered a value or set of values ​​that includes a frame of reference that indicates some meaning associated with the values. For example, the number "2" by itself is a symbol that, in the absence of some context, is meaningless. The number "2" may be considered "data" when it is understood to indicate, for example, the number of floors in a house.

[0259] Data can be organized and represented in a structured format. Examples include a tabular representation using rows and columns, a tree representation with a set of nodes considered to have a parent-child relationship, or a graphical representation as a set of connected nodes, to name a few.

[0260] The term "data" can refer to unprocessed data or "raw data," such as a collection of numbers, characters, or other symbols that represent individual facts or opinions. Data can be collected by sensors in controlled or uncontrolled environments, or generated through observation, recording, or processing of other data. The word "data" can be used in either the plural or singular form. The older plural form "datum" can also be used.

[0261] A "database," also called a "data warehouse," "data repository," or "knowledge base," generally refers to an organized collection of data. The data is usually organized to model aspects of the real world in a way that supports processes that derive information about the world from the data. Access to the data is usually provided by a "database management system" (DBMS), which consists of a single software program or an organized set of software programs that allow a user to interact with one or more databases by providing access to the data stored in the database (although user access restrictions can be set to limit access to a portion of the data). The DBMS provides various functions that allow the input, storage, and retrieval of large amounts of information, as well as ways to manage how that information is organized.A database is generally not portable between different DBMSs, but different DBMSs can interoperate by using standardized protocols and languages ​​such as Structured Query Language (SQL), Open Database Connectivity (ODBC), Java Database Connectivity (JDBC), or Extensible Markup Language (XML) to allow a single application to work with more than one DBMS.

[0262] Databases and their corresponding database management systems are often classified according to the particular database model they support. Examples include a DBMS that relies on the "relational model" to store data, usually referred to as a relational database management system (RDBMS). These systems typically use some variation of SQL to perform functions including querying, formatting, managing, and updating an RDBMS. Other examples of database models include the "object" model, the "object-relational" model, the "file," "indexed file," or "flat file" model, the "hierarchical" model, the "network" model, the "document" model, the "XML" model which uses some variation of XML, the "entity-attribute-value" model, and others.

[0263] Examples of commercially available database management systems include PostgreSQL provided by PostgreSQL Global Development Group; Microsoft SQL Server provided by Microsoft Corporation of Redmond, Washington, USA; MySQL and various versions of Oracle DBMS, often referred to simply as "Oracle", both offered separately by Oracle Corporation of Redwood City, California, USA; the DBMS generally referred to as "SAP" provided by SAP SE of Walldorf, Germany; and the DB2 DBMS provided by International Business Machines Corporation (IBM) of Armonk, New York, USA.

[0264] The database and DBMS software may also be collectively referred to as a "database." Similarly, the term "database" can also collectively refer to the database, the corresponding DBMS software, and a physical computer or set of computers. Therefore, the term "database" can refer to the data, the software for managing the data, and / or a physical computer that includes some or all of the data and / or the software for managing the data.

[0265] "Electric motor" generally refers to an electric machine that converts electrical energy into mechanical energy. Typically, but not always, electric motors operate through the interaction between one or more magnetic fields in the motor and winding currents to generate force in the form of rotation. Electric motors may be powered by direct current (DC) sources, such as batteries, motor vehicles, and / or rectifiers, or by alternating current (AC) sources, such as a power grid, inverters, and / or electric generators. An electric generator may (but is not always) be mechanically identical to an electric motor, but operate in reverse, accepting mechanical energy and converting the mechanical energy back to electrical energy.

[0266] “Electrical Connection” here means a connection between two objects that allows a flow of electrical current and / or electrical signals.

[0267] "Electrically connected" generally refers to a configuration of two objects that allows electricity to flow between or through them. In one example, two conductive materials are physically adjacent to each other and close enough together that electricity can flow between them. In another example, two conductive materials are in physical contact, allowing electricity to flow between them.

[0268] “Power source” generally refers to a device, structure, mechanism, and / or system that provides energy to perform work. The energy supplied by the power source can take many forms, including electrical, chemical, electrochemical, nuclear, hydraulic, pneumatic, gravitational, kinetic, and / or potential energy. The power source, for example, can include ambient energy sources, such as solar panels, external energy sources, such as electric power transmission grids, and / or portable power sources, such as batteries. The power source may include an energy carrier that contains energy that can then be converted to other forms, such as mechanical, thermal, electrical, and / or chemical forms.Energy carriers may include, for example, springs, electric batteries, capacitors, pressurized air, dammed water, hydrogen, oil, coal, wood, and / or natural gas, to name just a few.

[0269] "Interchangeable" generally refers to two or more things that can be put on and / or used in place of one another. In other words, one thing is capable of being substituted and / or exchanged for another. For example, interchangeable parts are typically, but not always, manufactured to have nearly the same structural size and shape within normal manufacturing tolerances and have nearly the same operating characteristics so that one part can be replaced by another interchangeable part. In some cases, interchangeable parts may be manufactured and / or sold by a specific company under the same part or Stock Keeping Unit (SKU) identifier, and in other cases, different companies may manufacture and / or sell the same interchangeable parts.

[0270] “Impedance” generally refers to the opposition to alternating current presented by the combined effect of resistance and reactance in a circuit.

[0271] “Lateral” generally refers to being situated, directed toward or from one side.

[0272] "Longitudinal" generally relates to the length or longitudinal dimension of an object, rather than its width.

[0273] “Means for” in a claim invokes 35 USC 112(f), which literally encompasses the stated function and corresponding structure and their equivalents. Its absence does not, unless sufficient structure for that claim element is not cited. Nothing here or elsewhere restricts the doctrine of equivalents available to the patent owner.

[0274] "Memory" generally refers to any storage system or device configured to retain data or information. Each memory may include one or more types of solid-state electronic memory, magnetic memory, or optical memory, just to name a few. The memory may use any suitable storage technology or combination of storage technologies and may be volatile, non-volatile, or a hybrid combination of volatile and non-volatile varieties. By way of non-limiting example, each memory may include solid-state electronic Random Access Memory (RAM), Sequentially Accessible Memory (SAM) (such as the First-In, First-Out (FIFO) or Last-In (LIFO) variety), first-in, first-out (LIFO), programmable read-only memory (PROM), electronically programmable read-only memory (EPROM), or electrically erasable programmable read-only memory (EEPROM).Memory may refer to dynamic random-access memory (DRAM) or any other variant, including static random-access memory (SRAM), burst SRAM or synchronized burst SRAM (BSRAM), fast page mode DRAM (FPM DRAM), enhanced DRAM (EDRAM), extended data-out RAM (EDO RAM), extended data-out DRAM (EDO DRAM), burst extended data-out DRAM (BEDO DRAM), single data-rate synchronous DRAM (SDR SDRAM), double data-rate SDRAM (DDR SDRAM), direct Rambus DRAM (DRDRAM), or extreme data-rate DRAM (XDR DRAM).

[0275] Memory may also refer to non-volatile storage technologies such as non-volatile read-access memory (NVRAM), flash memory, non-volatile static RAM (nvSRAM), ferroelectric RAM (FeRAM), magnetoresistive RAM (MRAM), phase-change memory (PRAM), conductive bridge RAM (CBRAM), silicon nitride oxide silicon (SONOS) resistive RAM (RRAM), domain wall memory (DWM) or “Racetrack” memory, nano-RAM (NRAM), or millipede memory. Other types of non-volatile memory include optical disc memory (such as a DVD or CD-ROM), a magnetically encoded hard disk or hard disk platter, a floppy disk, a tape, or a cartridge. The concept of “memory” includes the use of any suitable storage technology or any combination of storage technologies.

[0276] "Microcontroller" or "MCU" generally refers to a small computer on a single integrated circuit. It can be similar to, but less sophisticated than, a system-on-a-chip or "SoC"; an SoC may include a microcontroller as one of its components. A microcontroller may contain one or more CPUs (processor cores) along with memory and programmable input / output peripherals. Program memory in the form of ferroelectric RAM, NAND flash, or OTP ROM, as well as a small amount of RAM, may also be included on the chip. Microcontrollers can be designed for embedded applications, unlike the microprocessors used in personal computers or other general-purpose applications, which consist of several discrete chips.

[0277] Microcontrollers can be included in automatically controlled products and devices, such as automotive engine control systems, implantable medical devices, remote controls, office machines, household appliances, power tools, toys, and other embedded systems. An MCU can be configured to handle mixed signals, thus integrating the analog components needed to control non-digital electronic systems.

[0278] Some microcontrollers can use four-bit words and operate at frequencies as low as 4 kHz, for low power consumption (single-digit milliwatts or microwatts). They will typically have the ability to retain functionality while waiting for an event such as a button press or other interrupt; idle power consumption (CPU clock and most peripherals off) can be only nanowatts, making many of them well suited for long-life battery applications. Other microcontrollers can serve in performance roles, where they may need to act more like a digital signal processor (DSP), with higher clock speeds and power consumption. A microcontroller may include any suitable combination of circuitry such as:

[0279] 1. a central processing unit: ranging from small, simple processors with registers as small as 4 bits or a list, to complex processors with registers of 32, 64 or more bits

[0280] 2. volatile memory (RAM) for data storage

[0281] 3. ROM, EPROM, EEPROM or Flash memory for storing programs and operating parameters

[0282] 4. Discrete input and output bits, allowing control or detection of the logic state of an individual package pin

[0283] 5. Serial input / output as serial ports (UART)

[0284] 6. other serial communications interfaces such as l 2 C, Serial Peripheral Interface and Controller Area Network for system interconnection

[0285] Seven, peripherals such as timers, event counters, PWM generators and monitoring devices.

[0286] 8. Clock generator: often an oscillator for a quartz timing crystal, a resonator, or an RC circuit.

[0287] 9. Many include analog-to-digital converters, some include digital-to-analog converters

[0288] 10. In-circuit programming and in-circuit debugging support. "Module" or "Engine" generally refers to a collection of computational or logical circuits implemented in hardware, or to a series of logical or computational instructions expressed in executable, object, or source code, or any combination thereof, configured to perform tasks or implement processes. A module may be implemented in software maintained in a computer's volatile memory and executed by a processor or other circuitry. A module may be implemented as software stored in erasable / programmable non-volatile memory and executed by a processor or processors. A module may be implemented as software encoded in an application-specific integrated circuit (ASIC). A module may be a collection of digital or analog circuitry configured to control a machine and / or generate a desired output.

[0289] Modules can run on a single computer with one or more processors, or on multiple computers with multiple processors connected by a network. Separate aspects, calculations, or functionalities performed by a module can be executed by separate processors on separate computers, by the same processor on the same computer, or by different computers at different times.

[0290] "Motor" generally refers to a machine that supplies motive power to a device with moving parts. A motor may include rotor-type and linear-type motors. A motor may be powered in a variety of ways, such as through electricity, internal combustion, pneumatic, and / or hydraulic power sources. By way of non-limiting examples, a motor may include a servo motor, an air motor, a hydraulic motor, a steam engine, a pneumatic piston, a hydraulic piston, and / or an internal combustion engine.

[0291] "Multiple" as used herein is synonymous with the term "plurality" and refers to more than one, or by extension, two or more.

[0292] "Network" or "computer network" generally refers to a telecommunications network that allows computers to exchange data. Computers can transmit data to each other through data connections, transforming the data into a collection of datagrams or packets. Connections between computers and the network can be established through cables, optical fibers, or through electromagnetic transmissions, such as those of wireless network devices.

[0293] Computers attached to a network can be called "nodes" or "hosts" and can originate, transmit, route, or accept data from the network. Nodes can include any computing device, such as personal computers, telephones, and servers, as well as specialized computers that function to maintain the flow of data across the network, called "network devices." Two nodes can be considered "networked" when one device can exchange information with another device, whether or not they have a direct connection.

[0294] Examples of wired network connections may include digital subscriber lines (DSL), coaxial cable lines, or fiber optic lines. Wireless connections may include BLUETOOTH®, Worldwide Interoperability for Microwave Access (WiMAX), infrared channel or satellite band, or any wireless local area network (Wi-Fi) such as those implemented using the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (e.g., 802.11(a), 802.11(b), 802.11(g), or 802.11(n), to name a few). Wireless links may also include or use any cellular network standard used to communicate between mobile devices, including 1G, 2G, 3G, or 4G. Network standards may qualify as 1G, 2G, etc. by conforming to a specification or standards such as those maintained by the International Telecommunication Union (ITU).For example, a network may be called a “3G network” if it meets the criteria of the International Mobile Telecommunications-2000 (IMT-2000) specification, regardless of its other designations. A network may be called a “4G network” if it meets the requirements of the International Mobile Telecommunications-Advanced (IMTAdvanced) specification. Examples of cellular networks or other wireless standards include AMPS, GSM, GPRS, UMTS, LTE, LTE Advanced, Mobile WiMAX, and WiMAX-Advanced.

[0295] Cellular network standards can use various channel access methods, such as FDMA, TDMA, CDMA, or SDMA. Different types of data can be transmitted across different links and standards, or the same types of data can be transmitted across different links and standards.

[0296] The geographic reach of the network can vary widely. Examples include a body area network (BAN), a personal area network (PAN), a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), or the Internet.

[0297] A network can have any suitable network topology that defines the number and use of network connections. The network topology can take any suitable form and may include point-to-point, bus, star, ring, mesh, or tree. A network can be an overlay network, which is virtual and configured as one or more layers that utilize or "lay on top" of other networks.

[0298] A network can use different communication protocols or messaging techniques, including protocol layers or stacks. Examples include the Ethernet protocol, the Internet Protocol Suite (TCP / IP), ATM (Asynchronous Transfer Mode), SONET (Synchronous Optical Network), or SDE1 (Synchronous Digital Equation). The TCP / IP Internet Protocol Suite may include the application layer, the transport layer, the Internet layer (including, for example, IPv6), or the link layer.

[0299] “Of the present disclosure” generally refers to any example of a concept that shares the same or a similar name that is included in the chain of priority of the present application, or that is included by reference, if such inclusion is permitted and applicable. For example, a “system of the present disclosure” refers to any example, or combination or permutation of features, of a system presented herein.

[0300] “Optionally” means discretionary; not required; possible, but not mandatory; left to personal choice.

[0301] "Portion" means a part of a whole, whether separate from it or integrated into it.

[0302] “Positive clutch” generally refers to a type of clutch that is designed to transmit torque without slippage, such as through a mechanical interference-type connection. Some examples of positive clutches include jaw clutches (e.g., square or spiral jaw clutches) and dog clutches. “Powertrain” generally refers to devices and / or systems used to transform stored energy into kinetic energy for propulsion purposes. The powertrain may include multiple energy sources and may be used in non-wheeled vehicles. By way of non-limiting examples, stored energy sources may include chemical, solar, nuclear, electrical, electrochemical, kinetic, and / or other potential energy sources. For example, the powertrain of a motor vehicle includes the devices that generate energy and deliver it to the road surface, water, and / or air.These devices in the powertrain include engines, transmissions, driveshafts, differentials and / or final drive components (e.g., drive wheels, continuous tracks, propellers, propellers, etc.).

[0303] "Predominantly" as used in this document is synonymous with more than 50%.

[0304] "Processor" generally refers to one or more electronic components configured to operate as a single unit configured or programmed to process inputs to generate an output. Alternatively, when in multi-component form, a processor may have one or more components remotely located with respect to one another. One or more components of each processor may be of the electronic variety that define digital circuits, analog circuits, or both. In one example, each processor is a conventional integrated circuit microprocessor arrangement, such as one or more PENTIUM, i3, i5, or i7 processors supplied by INTEL Corporation of 2200 Mission College Boulevard, Santa Clara, California 95052, USA.In another example, the processor uses a Reduced Instruction Set Computing (RISC) architecture, such as an Advanced RISC Machine (ARM) type processor developed and licensed by ARM Holdings of Cambridge, U.K. In still other examples, the processor may include a Central Processing Unit (CPU) and / or an Accelerated Processing Unit (APU), such as those using the K8, K10, Bulldozer, Bobcat, Jaguar, and Zen series architectures supplied by Advanced Micro Devices, Inc. (AMD) of Santa Clara, California.

[0305] Another example of a processor is an application-specific integrated circuit (ASIC). An ASIC is an integrated circuit (IC) customized to perform a specific set of logical operations to control the computer to perform specific tasks or functions. An ASIC is an example of a processor for a special-purpose computer, rather than a processor configured for general-purpose use. An application-specific integrated circuit is generally not reprogrammable to perform other functions and can be programmed once during manufacture.

[0306] In another example, a processor may be of the "field-programmable" type. Such processors can be programmed multiple times "in the field" to perform various specialized or general-purpose functions after manufacture. A field-programmable processor may include a field-programmable gate array (FPGA) on an integrated circuit within the processor. The FPGA can be programmed to perform a specific set of instructions, which can be stored in non-volatile memory cells within the FPGA. The FPGA can be configured by a customer or designer using a hardware description language (HDL). An FPGA can be reprogrammed using another computer to reconfigure the FPGA to implement a new set of commands or operating instructions. Such an operation can be performed by any suitable means, such as by updating the processor circuit firmware.

[0307] Just as the concept of a computer is not limited to a single physical device in a single location, the concept of a "processor" is not limited to a single logical physical circuit or circuit package, but rather includes one or more such circuits or circuit packages, possibly contained within or between multiple computers in numerous physical locations. In a virtual computing environment, an unknown number of physical processors may be actively processing data, and that unknown number may also change automatically over time.

[0308] The term "processor" includes a device configured or programmed to perform threshold comparisons, rule comparisons, calculations, or perform logical operations by applying a rule to data that produces a logical result (e.g., "true" or "false"). Processing activities may occur on multiple single processors on separate servers, on multiple processors on a single server with separate processors, or on multiple processors physically remote from each other on separate computing devices.

[0309] "Reactance" generally refers to the opposition presented to current by inductance and / or capacitance. For example, a higher reactance results in a lower current value for the same applied voltage.

[0310] "Resistance" generally refers to a measure of the opposition to current flow in an electrical circuit. Resistance is usually expressed in ohms.

[0311] "Resistor" means a device that has a resistance to the passage of electric current.

[0312] "Resistor-capacitor circuit" generally refers to a circuit with one or more resistors and one or more capacitors.

[0313] "Rule" usually refers to a conditional statement with at least two outcomes. A rule can be compared against available data, which can produce a positive result (all aspects of the rule's conditional statement are satisfied by the data) or a negative result (at least one aspect of the rule's conditional statement is not satisfied by the data). The following is an example of a rule as pseudocode for an "if / then / else" statement that can be coded in a programming language and executed by a processor in a computer: if (clouds. areGrey() and (clouds. numberOfClouds > 100) ) then { prepare for rain;

[0314] } else {

[0315] Prepare for sunshine;

[0316] }

[0317] "Sensor" generally refers to a transducer configured to detect or sense a characteristic of the environment local to the sensor. For example, sensors can be constructed to detect events or changes in sensed quantities or parameters by providing a corresponding output, usually as an electrical or electromagnetic signal. The sensitivity of a sensor indicates how much the sensor's output changes when the input quantity being measured changes.

[0318] "Sensing parameter" generally refers to a property of the environment detectable by a sensor. As used herein, "sensing parameter" may be synonymous with an operating condition, environmental factor, sensor parameter, or environmental condition. Sensory parameters may include temperature, air pressure, velocity, acceleration, the presence or intensity of sound or light or other electromagnetic phenomena, the strength and / or orientation of a magnetic or electric field, and the like.

[0319] "Series" means an electrical connection of two or more components where the current passes through the first component to the second component, and where the current passing through the two components is the same.

[0320] “State” generally refers to the particular condition in which someone or something is at a specific time.

[0321] “Substantially” generally refers to the degree to which a quantitative representation can deviate from an established reference without resulting in a fundamental change in the basic function of the subject matter. The term “substantially” is used in this document to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, and / or other representation.

[0322] "Transmission" generally refers to a power system that provides a controlled application of mechanical energy. A transmission uses gears and / or gear trains to provide speed, direction, and / or torque conversions from a rotating power source to another device.

[0323] "Transversal" generally refers to things, axes, straight lines, planes, or geometric shapes that extend non-parallel and / or transversely to each other. For example, when in a transverse arrangement, lines may extend at right or perpendicular angles to each other, but lines may extend at other non-right angles, such as acute, obtuse, or reflex angles. For example, transversal lines may also form angles greater than zero (0) degrees, such that the lines are not parallel. When extending transversely, lines or other things do not necessarily have to intersect each other, but they may.

[0324] “Triggering a rule” generally refers to a result that occurs when all elements of a conditional statement expressed in a rule are met. In this context, a conditional statement can result in either a positive outcome (the data satisfy all of the rule’s conditions) or a negative outcome (the data does not satisfy at least one of the rule’s conditions) when compared to the available data. The conditions expressed in the rule are triggered if all conditions are met, causing program execution to proceed along a different path than if the rule is not triggered.

[0325] “Vehicle” generally refers to a machine that transports people and / or cargo. Common vehicle types may include land vehicles, amphibious vehicles, watercraft, aircraft, and spacecraft. By way of non-limiting examples, land vehicles may include wagons, carts, scooters, bicycles, motorcycles, automobiles, buses, trucks, semi-trailers, trains, trolleys, and trams. Amphibious vehicles may include, for example, hovercraft and duck boats, and watercraft may include ships, boats, and submarines, to name just a few examples. Common forms of aircraft include airplanes, helicopters, autogyros, and balloons, and spacecraft, for example, may include rockets and rocket-powered aircraft. The vehicle may have numerous types of power sources. For example, the vehicle may be powered by human propulsion, electrical propulsion, chemical combustion, nuclear propulsion, and / or solar propulsion.The vehicle's steering, speed, and operation can be controlled by humans, autonomously, and / or semi-autonomously. Examples of autonomously or semi-autonomously controlled vehicles include automated guided vehicles (AGVs) and drones.

Claims

CLAIMS 1. A method comprising: determining an internal state of a battery based on a current draw of the battery according to a first stage equivalent circuit model implemented in a battery management circuit; determining a predicted voltage-based current limit based on a maximum voltage limit for the battery according to a second stage equivalent circuit model implemented in the battery management circuit; determining a current limit correction factor to be applied to the predicted voltage-based current limit using the battery management circuit; determining a voltage-based current limit by combining the predicted voltage-based current limit and the correction factor using the battery management circuit;determining a current limit for charging or discharging the battery according to the voltage-based current limit, a peak current limit, and a continuous current limit using the battery management circuit; determining an expected voltage based on the current limit using the battery management circuit; and determining an available power output based on the current limit and the expected voltage using the battery management circuit.

2. The method of claim 1, wherein determining an expected voltage comprises: determining an expected battery voltage based on the current limit and the internal state of the battery according to a third-stage equivalent circuit model implemented in the battery management circuit; and combining the predicted battery voltage and an offset correction to determine the expected voltage using the battery management circuit.

3. The method of claim 1, wherein determining an available power output comprises: calculating a power limit by multiplying the battery current limit and the expected voltage using the battery management circuit.

4. The method of claim 1, comprising: determining calibration information about the battery using the battery monitoring circuit.

5. The method of claim 4, wherein determining the calibration information comprises any combination of: determining an estimated state of charge of the battery; determining maximum and minimum operating temperatures for the battery; and determining a maximum operating voltage for the battery.

6. The method of claim 4, wherein determining the calibration information comprises any combination of: determining a peak current limit specifying a maximum instantaneous current that can be drawn from the battery; and determining a continuous current limit specifying a maximum current that can be continuously drawn from the battery for a specified period of time.

7. The method of claim 1, wherein determining the current limit for charging or discharging the battery comprises: determining a fused current limit based on the peak current limit and the continuous current limit using the battery monitoring circuit, wherein the battery monitoring circuit automatically adjusts the fused current limit according to the current current consumption of the battery.

8. The method of claim 7, wherein the fused current limit may be equal to the peak current limit for a predetermined grace period during which the fused current limit may be greater than the continuous current limit of the battery.

9. The method of claim 8, comprising: decreasing the fused current limit over time after the grace period expires using the battery management circuit.

10. The method of claim 8, comprising: maintaining the fused current limit within one percent of the current limit. continuous for a predetermined rest time period while the actual current drawn by the battery is less than or equal to the continuous current limit and the fused current limit.

11. The method of claim 10, comprising: adjusting the fused current limit toward the peak current limit after the predetermined rest period expires using the battery monitoring circuit.

12. The method of claim 1, wherein the first stage equivalent circuit model includes a second order equivalent circuit model operating in a forward mode and accepting the current draw of the battery as an input, and wherein the internal state of the battery is provided as an output and includes an open circuit voltage Voc, an ohmic resistance of the battery R0, a charge transfer resistance R1, a charge transfer capacitance C1, a diffusion resistance R2, a diffusion capacitance C2, a current currently supplied by the battery I, a charge transfer voltage drop VRC1, a diffusion voltage drop VRC2, and a terminal voltage Vt representing a potential difference of the battery.

13. The method of claim 1, wherein the second stage equivalent circuit model includes a second order equivalent circuit model operating in an inverse mode that accepts as input a maximum operating voltage of the battery, and the internal state of the battery as inputs, and that provides the intended voltage-based current limit as an output.

14. The method of claim 1, wherein the first and second stage circuit models are the same second order equivalent circuit model implemented in the battery management circuit.

15. The method of claim 1, wherein determining a current limit correction factor comprises: applying a maximum battery voltage and a current terminal voltage of the battery as inputs to a PI or PID controller circuit of the battery management circuit, wherein the PI controller circuit is configured to determine the correction factor.

16. The method of claim 1, comprising: sending the available power output to a vehicle drive system that includes at least one electric motor arranged and configured to operate as a prime mover for a vehicle, wherein the drive system includes a drive system control circuit configured to except the available power output as input, and wherein the drive system control circuit is operable to reduce the power consumed by the electric motor such that the power drawn from the battery is less than or equal to the available power output.

17. A method comprising: determining an internal state of a battery using a battery management circuit configured to determine at least one aspect of the internal state of the battery; determining a current limit for charging or discharging a battery according to a second stage equivalent circuit model implemented in the battery management circuit; comparing the current limit to a measured current using the battery management circuit; determining a predicted battery voltage based on the current limit and the internal state of the battery according to a third stage equivalent circuit model implemented in the battery management circuit; determining an offset correction using as inputs the current limit, a current current draw in the battery, and a current power output of the battery using the battery management circuit;and calculate a power limit by multiplying the battery current limit and the expected battery voltage using the battery management circuit.; 18. The method of claim 17, wherein the internal state of the battery is determined using a current draw in the battery as input to a first stage equivalent circuit model.

19. The method of claim 17, wherein determining the current limit comprises: determining a predicted voltage-based current limit according to the second stage circuit model, which accepts as inputs a maximum voltage limit for battery and maximum component current limits, wherein the second-stage circuit model is a second-order equivalent circuit model operating in inverse mode; determining a current limit correction factor to be applied to the predicted voltage-based current limit using the battery management circuit; determining a voltage-based current limit by combining the predicted voltage-based current limit and the correction factor using the battery management circuit; and determining the current limit using the voltage-based current limit, a peak current limit, and a continuous current limit.

20. The method of claim 17, wherein determining an offset correction using the battery management circuit comprises: receiving the current current draw of the battery; receiving the current power output of the battery circuit; and comparing the power limit to a current power output of the battery.

21. The method of claim 20, wherein the battery management circuit includes a PI or PID controller circuit that is configured to accept the current current draw, the current power output, and the power limit as input, and to provide the offset correction as output.

22. The method of claim 17, wherein the second and third stage circuit models are the same second order equivalent circuit model implemented in the battery management circuit.

23. The method of claim 17, comprising: determining the current limit and the power limit for multiple individual battery cells in a battery array, wherein the battery is one of multiple individual battery cells in the battery array; and determining an available power output by summing the power limit of the multiple individual battery cells in the battery array.

24. The method of claim 17, comprising: multiplying the power limit by a number of battery cells in a battery array. batteries to determine an available power output, where the battery is one of the battery cells in the battery array.

25. The method of claim 17, comprising: outputting the power limit to a vehicle drive system including at least one electric motor arranged and configured to operate as a prime mover for a vehicle, wherein the drive system includes a drive system control circuit configured to except the power limit as input, and wherein the drive system control circuit is operable to reduce power consumed by the electric motor such that power drawn from the battery is less than or equal to the power limit.

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