Electrified powertrain employing a method of determining battery limits based on cell factors

Abstract

A method for adjusting a usage level of a battery pack includes measuring, using a cell sensing circuit, cell sense data for each respective battery cell, the cell sense data including cell voltage, current, and temperature. The method includes processing, by a plurality of battery state functions of a controller, the cell sense data for each respective battery cell to generate a numerical cell degradation value (CDV). The battery state functions are calibrated relationships of the cell sense data to predetermined battery failure conditions. Thereafter, the method includes automatically adjusting, via the controller, the usage level of the battery pack based on the numerical CDV during operation of the battery pack. An electric powertrain system includes a battery pack, a cell sensing circuit, a rotary electric machine, and a controller configured to perform the above-described method.

Description

[0001] introduction. Background Technology

[0002] Rotary electric motors are used to generate or receive torque during different operating modes of many mobile and stationary electromechanical systems. For example, the electrified powertrain of battery electric vehicles and hybrid electric vehicles includes at least one electric propulsion motor whose output shaft is coupled to a drive shaft. Several electric propulsion motors can be used in other configurations to individually power different drive shafts and / or wheels. During regenerative mode, the motor can operate as a generator to capture kinetic energy and convert it into charging current, for example, to recharge the high-voltage propulsion battery pack. In addition to being able to charge in this way, in some configurations, the propulsion battery pack can also be charged via off-board chargers, using on-board solar panels / solar cells, or other possible charging technologies.

[0003] To power an electric propulsion motor in a typical automotive application, the aforementioned battery pack can be used as an onboard DC power supply connected to a DC voltage bus. When the electric propulsion motor is a single-phase or multi-phase / AC device, the DC side of the power inverter module is connected to the DC voltage bus, and the AC side is connected to the electric propulsion motor. High-speed switching control of the power inverter module generates an AC output voltage suitable for the excitation phase windings. During regenerative mode, the AC input voltage is fed into the power inverter module, where internal switching operations provide the DC output voltage to the battery pack.

[0004] A typical propulsion battery pack consists of a suitable number of electrochemical cell units, within which charged electrode foils are immersed in an electrolyte material. The exposed terminal pieces of the cell units are electrically connected in series or parallel with varying configurations to provide the desired DC output voltage. However, at some point in the battery pack's operational life, a given cell may exhibit intermittent or persistent internal short-circuit conditions or other faults. Such fault conditions may not be easily distinguished from the electrical behavior of an otherwise healthy, aging battery, and therefore, reaction control strategies may be less than ideal in terms of drive performance and operational life. Summary of the Invention

[0005] This document discloses a system, associated control logic, and methods for controlling the charging or discharging operation of high-voltage propulsion battery packs in motor vehicles or other mobile platforms with electrified powertrains. As understood in the art, detecting electrical short circuits or other fault conditions (even transient ones) in high-voltage propulsion battery packs often leads to suppression of charging or discharging modes as reactive control actions. The vehicle may become inoperable, or practically inoperable, until the fault is repaired. However, older vehicles may not be worth repairing, significantly reducing their residual value. Therefore, this strategy enables operators to potentially extend the lifespan of the battery pack / vehicle by automatically distinguishing and characterizing electrical short circuit conditions and subsequently determining the corresponding charging or discharging battery limits based on this characterization.

[0006] In particular, this disclosure envisions an implementation of a computer-executable method that, when executed in a motor vehicle, automatically adjusts battery usage limits to extend battery availability and lifespan. For example, lowering the charge termination limit may reduce the total stored energy, as well as the voltage potential across the degraded cells. Therefore, lowering the charge termination limit could be a long-term method of delayed repair, at least until the internal resistance decreases to a point where continued operation is impossible or unacceptable.

[0007] Enabling strategies, partly based on the estimated state of the constituent battery cells of the battery pack, aim to improve vehicle availability as the battery pack ages and / or begins to fail, but has not yet actually reached its final end-of-life. The disclosed method closely monitors battery cell behavior to determine indications of individual cell health and then determines available thresholds for maintaining battery life and sustaining battery pack operation. This method can be used alone or as part of an overall battery charging / battery control arbitration strategy that also includes other factors to ensure desired battery life extension and energy utilization.

[0008] In a non-limiting exemplary embodiment, this document describes a method for adjusting the usage level of a battery pack having multiple battery cells. The method in this embodiment includes measuring cell sensing data for each corresponding battery cell using cell sensing circuitry. The cell sensing data includes cell voltage, current, and temperature. The method also includes processing the cell sensing data for each corresponding battery cell through multiple battery state functions of a controller. In this way, the controller generates multiple numerical battery degradation values ​​(CDVs), as described in detail herein. The battery state functions are calibration relationships between the cell sensing data and predetermined battery failure conditions. As part of this method, the controller subsequently automatically adjusts the usage level of the battery pack during battery pack operation based on the numerical CDVs.

[0009] The predetermined battery failure conditions may vary depending on the intended end use / application. In a possible embodiment, battery failure conditions include intermittent or persistent electrical short-circuit conditions within the respective battery cell. In such an embodiment, the battery state function may include an electrical short-circuit function indicating intermittent or persistent electrical short-circuit conditions.

[0010] Alternatively or simultaneously, predetermined battery failure conditions may include the active material coating of the corresponding battery cell, wherein the battery state function may include a coating function indicating the level of the active material coating. Other battery failure conditions may include a reduced energy retention capacity of the corresponding battery cell, in which case the battery state function may include a capacity function indicating the reduced energy retention capacity. In addition to responding to capacity reduction, this method may also modify control limits where possible to protect capacity, for example, by using navigation / route planning information as input when determining the limits.

[0011] The rising or falling temperatures of individual battery cells can also be used; the battery state function may include a temperature function indicating the rising or falling temperatures. Other predetermined battery failure conditions may include the electrolyte leakage condition of the corresponding battery cell; the battery state function may include an electrolyte leakage function indicating the electrolyte leakage condition.

[0012] In some embodiments of this method, automatically adjusting the usage level of the battery pack may include modifying the calibrated charging limits and / or thermal limits of the battery pack during charging operations, and / or modifying the calibrated discharging limits and / or thermal limits of the battery pack during discharging operations.

[0013] For example, the controller can automatically adjust the battery pack's usage level by automatically modifying the charging behavior of off-board charging stations and / or on-board solar panels.

[0014] The battery state function processing unit sensed data may optionally include the processing unit sensed data via the controller's arbitration logic block and at least one additional powertrain control factor of the aforementioned motor vehicle. In this configuration, automatically adjusting the battery pack usage level may include assigning relative weights to each corresponding one of the plurality of battery state functions and the additional powertrain control factor via the arbitration logic block.

[0015] As an example, additional powertrain control factors may include the life modeling limits of the electric powertrain, the energy / regenerative optimization limits, and / or limits based on navigation / route planning.

[0016] This document also discloses an electrified powertrain system. In an exemplary embodiment, the powertrain system includes a battery pack having multiple battery cells and cell sensing circuitry configured to measure cell sensing data for each battery cell. Additionally, the powertrain system in this embodiment includes a rotating motor electrically connected to the battery pack. The battery pack is configured to supply electrical energy to the rotating motor in a discharge mode and receive electrical energy in a charging mode, such as from an off-board charging station, an on-board solar panel / system, or the motor. As part of the powertrain system, a controller communicates with the cell sensing circuitry and the rotating motor, and the controller is configured to perform the exemplary methods described above.

[0017] This invention provides the following technical solutions:

[0018] 1. A method for adjusting the usage level of a battery pack having multiple battery cells, the method comprising:

[0019] The cell sensing circuit measures cell sensing data for each corresponding cell in the battery cell, the cell sensing data including cell voltage, cell current and cell temperature;

[0020] Cell sensing data for each of the plurality of battery cells is processed by multiple battery state functions of the controller to generate multiple numerical cell degradation values ​​(CDVs), wherein the multiple battery state functions are a calibration relationship between the cell sensing data and a predetermined battery failure condition; and

[0021] During battery pack operation, the battery pack usage level is automatically adjusted via the controller based on the numerical CDV.

[0022] According to the method of technical solution 1, the predetermined battery fault condition includes an intermittent or continuous electrical short circuit condition in the corresponding battery cell, and the plurality of battery state functions include an electrical short circuit function indicating the intermittent or continuous electrical short circuit condition.

[0023] According to the method of technical solution 1, the predetermined battery fault condition includes the active material coating of the corresponding battery cell, and the plurality of battery state functions include a coating function indicating the level of the active material coating.

[0024] According to the method of technical solution 1, the predetermined battery failure condition includes a reduced energy retention capacity of the corresponding battery cell, and the plurality of battery state functions include a capacity function indicating the reduced energy retention capacity.

[0025] According to the method of technical solution 1, the predetermined battery fault condition includes the temperature rise or fall of the corresponding battery cell, and the plurality of battery state functions include a temperature function indicating the temperature rise or fall.

[0026] According to the method of technical solution 1, the predetermined battery fault condition includes the electrolyte leakage condition of the corresponding battery cell, and the plurality of battery state functions include an electrolyte leakage function indicating the electrolyte leakage condition.

[0027] According to the method described in technical solution 1, automatically adjusting the usage level of the battery pack includes modifying the calibrated charging limit, charging rate, and / or thermal limit of the battery pack during charging operations.

[0028] According to the method described in technical solution 1, automatically adjusting the usage level of the battery pack includes modifying the calibrated discharge limit and / or thermal limit of the battery pack during discharge operation.

[0029] According to the method described in technical solution 1, automatically adjusting the usage level of the battery pack during its operation includes modifying the charging behavior of off-board charging stations and / or on-board solar panels during the charging operation of the battery pack.

[0030] According to the method of technical solution 9, processing the cell sensing data through the plurality of battery state functions includes processing the cell sensing data and at least one additional powertrain control factor of the motor vehicle through an arbitration logic block of the controller, and wherein automatically adjusting the usage level of the battery pack includes assigning relative weights to each corresponding one of the plurality of battery state functions and the additional powertrain control factor via the arbitration logic block.

[0031] According to the method described in technical solution 10, the additional power system control factor includes the life modeling limit of the motor vehicle, the energy / regeneration optimization limit, or the limit based on navigation / route planning.

[0032] An electric powertrain system, comprising:

[0033] A battery pack having multiple battery cells and a cell sensing circuit configured to measure cell sensing data for each corresponding one of the battery cells;

[0034] A rotating motor electrically connected to the battery pack, wherein the battery pack is configured to supply electrical energy to the rotating motor in a discharge mode and receive electrical energy from the rotating motor, an off-board charging station, and / or solar panels in a charging mode; and

[0035] A controller that communicates with the unit sensing circuit and the rotating motor, wherein the controller is configured to:

[0036] The cell sensing circuit receives cell sensing data from each corresponding cell in the battery cell, the cell sensing data including cell voltage, cell current and cell temperature;

[0037] Cell sensing data for each of the plurality of battery cells is processed by multiple battery state functions to generate multiple numerical cell degradation values ​​(CDVs), wherein the plurality of battery state functions are calibration relationships between the cell sensing data and predetermined battery failure conditions; and

[0038] The battery pack's usage level is automatically adjusted based on numerical CDV during battery pack operation.

[0039] According to the electric powertrain system of technical solution 12, the predetermined battery fault condition includes an intermittent or continuous electrical short circuit condition in the corresponding battery cell, and the plurality of battery state functions include an electrical short circuit function indicating the intermittent or continuous electrical short circuit condition.

[0040] According to the electric power system of technical solution 12, the predetermined battery fault condition includes the active material coating condition and / or electrolyte leakage condition of the corresponding battery cell, and the plurality of battery state functions include a coating function indicating the level of the active material coating condition and / or an electrolyte leakage function indicating the electrolyte leakage condition.

[0041] According to the electric powertrain system of technical solution 12, the predetermined battery fault condition includes a reduced energy retention capacity of the corresponding battery cell, and the plurality of battery state functions include a capacity function indicating the reduced energy retention capacity.

[0042] According to the electric powertrain system of technical solution 12, the automatic adjustment of the battery pack usage level includes modifying the calibrated charging limit, charging rate and / or thermal limit of the battery pack using off-board charging stations and / or on-board solar panels during the charging cycle of the battery pack.

[0043] According to the electric powertrain system of technical solution 12, the controller is configured to process the cell sensing data and at least one additional powertrain control factor via an arbitration logic block, and to partially automatically adjust the usage level of the battery pack by assigning relative weights to each of the plurality of battery state functions and the additional powertrain control factor via the arbitration logic block.

[0044] According to the electric powertrain system of technical solution 12, the at least one additional powertrain control factor includes a life modeling limit and / or an energy / regeneration optimization limit.

[0045] According to the electric powertrain system of technical solution 12, the rotary motor is an electric propulsion motor for a motor vehicle, and the additional powertrain control factor includes a motor vehicle limit based on navigation / route planning, in which full charging is delayed until a preferred charging position is reached.

[0046] According to the electric power system of technical solution 12, the rotary motor is an electric propulsion motor for a motor vehicle, and the controller is configured to automatically identify a charging termination limit (CTL) modification requester and thereafter arbitrate the CTL modification requester.

[0047] The above and other features and advantages of this disclosure will become apparent from the following detailed description of embodiments and the best mode for carrying out this disclosure when taken in conjunction with the accompanying drawings and appended claims. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of an exemplary motor vehicle having an electric powertrain, a high-voltage propulsion battery pack, and a controller configured to perform the method.

[0049] Figure 2 yes Figure 1 A schematic diagram of the representative control logic of the controller shown.

[0050] Figure 3 It is a description that can be made Figure 1 A schematic logic flowchart illustrating the application of this method on motor vehicles.

[0051] Figure 4 This is a flowchart describing an exemplary embodiment of the method. Detailed Implementation

[0052] This disclosure allows for numerous different forms of embodiments. Representative examples of this disclosure are shown in the accompanying drawings and are described in detail herein as non-limiting examples of the disclosed principles. Therefore, elements and limits described in the abstract, introduction, summary, and detailed description sections but not expressly set forth in the claims should not be incorporated into the claims, alone or in combination, by implication, inference, or otherwise.

[0053] For the purposes of this specification, unless otherwise stated, the use of the singular includes the plural, and vice versa; the terms “and” and “or” should be connected and separate; “any” and “all” should both mean “any and all”; and the words “including,” “contains,” “comprising,” “has,” etc., should mean “including but not limited to.” Furthermore, approximate words such as “approximately,” “almost,” “substantially,” “generally,” “approximately,” etc., may be used herein to mean “in,” “nearly,” or “within the range of 0-5%,” or “within acceptable manufacturing tolerances,” or logical combinations thereof.

[0054] Referring to the accompanying drawings, where the same reference numerals refer to the same parts, Figure 1 A motor vehicle 10 having an electrified powertrain system 11 is schematically depicted. The electrified powertrain system 11 includes a high-voltage propulsion battery pack 16, such as a multi-cell lithium-ion, nickel-metal hydride, or another suitable electrochemical battery. In the exemplary configuration shown, the motor vehicle 10 also includes a body 12 connected to a set of wheels 14, wherein the propulsion battery pack 16 is mounted to the body 12 in a suitable location, such as below a floor panel (not shown) in a typical low-profile / planar arrangement.

[0055] The electrified powertrain system 11 envisioned in this paper also includes a controller (C) 50 programmed with control logics 50L and 150L, ​​which execute instructions of implementation method 100. References are made below for each. Figure 2 and 3 Representative embodiments of control logics 50L and 150L are described, while exemplary embodiments of method 100 are described in... Figure 4 As shown below, the execution of method 100 allows controller 50 to closely monitor the behavior of the battery cells in the propulsion battery pack 16 to characterize the health of individual cells and then determine available thresholds for maintaining the lifespan of the propulsion battery pack 16 and sustaining its operation. As mentioned above, this solution can be used alone or as part of an overall battery charging / battery control arbitration strategy that also includes other factors for ensuring desired battery life extension and energy utilization.

[0056] Regarding the charging of the propulsion battery pack 16, in various embodiments, the motor vehicle 10 and its electrified powertrain system 11 may be configured to provide charging current to the propulsion battery pack 16 during regenerative events, i.e., by capturing kinetic energy during braking and using that kinetic energy to power the rotary motor 18 or another suitable device as a generator. The propulsion battery pack 16 may also be charged via an off-board charging station 23, such as a direct current (DC) fast charging station or a household charging socket known in the art. The motor vehicle 10 may also be equipped with one or more solar panels 26, thereby enabling the motor vehicle 10 to generate on-board charging current. Therefore, various charging schemes and associated limitations are factors considered herein as part of this strategy, as detailed below.

[0057] like Figure 1 The motor vehicle 10 depicted in the simplified exemplary embodiment includes an alternating current (AC) embodiment of a rotating electric motor 18. Although the rotating electric motor 18, as a motor-generator unit, is capable of both driving and generating functions in terms of its capabilities, for simplicity, the rotating electric motor 18 is referred to hereinafter as a traction motor 18. The phase windings 19 of the traction motor 18 are electrically connected to a power inverter module 20, which in turn includes a direct current (DC) link capacitor 21 (C L Alternatively, it can be connected in parallel. The power inverter module 20 is connected to the DC voltage bus 25, wherein the link capacitor 21 is connected between the positive (+) and negative (-) rails of the DC voltage bus 25, as shown in the figure.

[0058] As understood in the art, a power inverter, such as a representative power inverter module 20, includes semiconductor switching dies 22, such as the metal-oxide-semiconductor field-effect transistor (MOSFET), insulated-gate bipolar transistor (IGBTS), silicon-controlled rectifier (SCR), thyristor, etc., arranged in nominal top and bottom positions. Therefore, Figure 1 Each electrical phase of the traction motor 19 shown has a corresponding top / high / positive and bottom / low / negative switch pair. The traction motor 18 in... Figure 1 In a non-limiting embodiment, it is implemented as a three-phase device, and therefore the power inverter module 20 has three-phase leads 19, as shown. Single-phase embodiments as well as embodiments with more than three phases are conceivable within the scope of this disclosure, and therefore the number of traction motors 18 and corresponding phases will vary depending on the intended application and construction of the motor vehicle 10 or another mobile platform.

[0059] The main torque function of motor 18 is achieved via a control signal from controller (C) 50 (arrow CC). O Real-time adjustment. The instructions for implementing the control strategy according to this disclosure are implemented as method 100, examples of which will be referenced below. Figure 3This instruction can be recorded in the memory (M) of the controller 50 and executed by one or more of its processors (P) to provide the benefits described herein.

[0060] Figure 1 Other components not depicted may be included in the electrified powertrain system 11, such as, but not limited to, DC-DC converters and auxiliary batteries. As mentioned above, the auxiliary voltage level is typically 12-15V, and therefore, as understood in the art, the DC-DC converter can be operated via internal switching and signal filtering to receive a relatively high DC voltage from the DC voltage bus 25 and output a lower auxiliary voltage to the auxiliary battery. Thus, the traction motor 18 is just one of several devices on the motor vehicle 10 that may need to release electrical energy from the propulsion battery pack 16.

[0061] As part of this method 100, controller 50 determines the battery limits for controlling the high-voltage propulsion battery pack and, in particular, for maximizing its availability and lifespan. While the term “high voltage” is relative to the typical 12-15V auxiliary / low voltage level described above, and therefore “high voltage” may need to exceed its voltage level, exemplary hybrid electric vehicle or all-battery electric vehicle propulsion applications of the type envisioned herein may require propulsion battery pack 16 to have, for example, a voltage capability of 300 volts or higher.

[0062] Within the scope of this disclosure, controller 50 determines Figure 1 The method 100 monitors the health status of the constituent battery cells of the propulsion battery pack 16 and adjusts the charge / discharge limits accordingly. As a result of method 100, vehicle availability is expected to increase as the propulsion battery pack 16 ages or begins to fail. Therefore, when determining the available thresholds for maintaining the lifespan of the propulsion battery pack 16 and sustaining desired operation, method 100 is based on real-time monitoring of the behavior of individual cells by controller 50.

[0063] Therefore, the controller 50 is configured to use a cell sensing circuit (CSC) 40 of a type known in the art to measure cell sensing data (arrow CC) of each corresponding cell in the battery cell 16C of the propulsion battery pack 16. 16 ), where unit sensing data (arrow CC) 16 This includes unit voltage, unit current, and unit temperature, either as separate data streams or as a set of input signals to controller 50 (arrow CC). I As understood in the art, resistance and other possible values ​​can be derived from such exemplary data and are therefore included in this set of input signals (arrow CC). I Within the range of ).

[0064] As part of the general function of controller 50, during discharge mode, where electrical energy from propulsion battery pack 16 is directed to individual phase windings 19 of traction motor 18, controller 50 receives input signals (arrow CC). I This input signal, in turn, collectively indicates the total power demand, such as the driver's request and / or autonomously determined output torque or speed request. The controller 50 then discharges the propulsion battery pack 16 based on a set of battery control limits (e.g., voltage, current, and temperature limits).

[0065] For simplicity, the term "controller" as used herein may include one or more electronic control modules, units, processors, and their associated hardware components, such as application-specific integrated circuits (ASICs), system-on-a-chip (SoCs), electronic circuits, and other hardware required to provide programmable functionality. Controller 50 may be implemented in response to input signals (arrow CC). I One or more electronic control units or computing nodes. The controller 50 includes a dedicated amount and type of memory (M) and one or more processors (P), such as microprocessors or central processing units, as well as other associated hardware and software, such as digital clocks or timers, input / output circuits, buffer circuits, etc.

[0066] refer to Figure 2 The control logic 50L is schematically shown in the form of logic blocks B52 and B54, which can be implemented as a combination of electronic hardware and corresponding software to provide the described functions. In the illustrated configuration, for example, logic block B52 can... Figure 1 The unit sensing circuit 40 shown receives unit sensing data (arrow CC). 16 This includes unit voltage, temperature, and current, as well as other possible values. The unit sense data is processed through the first set of functions F(x)1 (arrow CC). 16 To generate N different output signals (CC) 52 ), which serves as the digital cell degradation value or CDV in the context of the method 100 described below. Figure 2 In the non-limiting illustrative embodiments, for clarity, such an output signal (CC) 52 ) are individually labeled as 52(1), 52(2), ..., 52(N).

[0067] Although the first set of functions F(x)1 can vary depending on the intended end use and application, one or more of the example output signals (CC) shown 52This can be used in typical propulsion applications. For example, outputs 52(1) and 52(2) can correspond to the number of intermittent soft short circuits and hard short circuits observed and counted by controller 50 within predetermined intervals, respectively. In such an embodiment, outputs 52(3) and 52(4) can correspond to the duration and amplitude of such intermittent short conditions observed. Similarly, outputs 52(5) and 52(6) can be used to track persistent soft short circuits and persistent hard short circuits, where output 52(7) may correspond to the amplitude of the latter. Additional outputs 52(8) and 52(9) can track the capacity and temperature of the components of battery cell 16C.

[0068] Output 52(10) is particularly likely an estimated coating level for battery cell 16C, for example, using a time-based model and / or a formula-based method. As understood in the art, coating occurs in response to a strong charging or discharging current. During coating, active material is deposited as a solid film, for example, as metallic lithium when using a typical lithium-ion battery composition. The presence of a coating on battery cell 16C, if left untreated, can lead to electrical failures such as the short-circuit conditions described above, and adversely affect the lifespan, charging rate, and durability of the battery pack 16.

[0069] exist Figure 2 Other outputs nominally labeled 52(N) can also be provided by logic block B52, including, for example, the electrolyte leakage level from a given battery cell 16C. The various outputs 52(1), 52(2), ..., 52(N) will again vary depending on the application, and therefore the outputs shown are only those that can be obtained from cell sense data (CC). 16 There are some possible faults in the instantaneous values ​​and / or trend detection or estimation in ).

[0070] Still referencing Figure 2 Logic block B54 includes a second set of functions F(x)2, which is configured to receive the output signal (CC) from logic block B52. 52 ), and subsequently generate control Figure 1 The control signals (CC) of the electrified power system 11 54 Therefore, the control signal (CC) 54 )yes Figure 1 The broader group of control signals shown (arrow CC) O Part of ). Similar to logic block B52 upstream of logic block B54, the control signal (CC) 54This includes a corresponding set of outputs, in this case outputs 54(1), 54(2), ..., 54(N). Representative outputs 54(1) and 54(2) may respectively include a charge permission (“allowed charging”) and a charge limit. Similarly, outputs 54(3) and 54(4) may correspond to a discharge permission (“allowed propulsion”) and a propulsion limit, for example, in the case of other thrusters. Figure 1 The traction motor 18 and / or the motor vehicle 10 are defined as the overall torque and / or speed limits. Output 54(5) can be assigned thermal limits, such as by allowing the propulsion battery pack 16 to operate further at reduced temperatures, as an additional control action, which can be consistent with the flow control of the thermal regulation system (not shown). Other outputs nominally labeled 54(N) (“Other Limits”) can be provided separately by logic block B54, or in addition to the representative outputs 54(1), 54(2), ..., 54(N), and therefore Figure 2 The various examples are intended to illustrate this teaching and not to limit it.

[0071] refer to Figure 3 The control logic 150L is schematically shown in the form of logic blocks B51, B52, B53, and B54, where logic blocks B52 and B54 are roughly referenced. Figure 2 Description. Similar to logic blocks B52 and B54, logic blocks B51 and B53 can be implemented as a combination of electronic hardware and corresponding software to provide the described functions. In the illustrated configuration, logic block B51 can be used as... Figure 1 A portion of the cell sensing board 40 is schematically shown in the diagram, used to measure cell sensing data for each of the individual battery cells 16C, namely 16C(1), ..., 16C(N) (arrow CC). 16 As shown in the figure. In typical measurements, this unit senses data (arrow CC). 16 This can include the corresponding cell voltage, cell current, and cell temperature, as well as other possible measurement characteristics. Cell sensing data (arrow CC) 16 Then it is transmitted to logic block B52.

[0072] exist Figure 2 The logic block B52, shown more generally, provides a set of battery state functions. When the various outputs 52(1), ..., 52(N) are determined, the various functions may be implemented via the corresponding function blocks B152-B552. These outputs collectively define the output signal (arrow CC). 52 This itself acts as the aforementioned digital battery degradation value or CDV. For example, in a simplified... Figure 3In this embodiment, logic block B52 may include a dedicated function block B152 for detecting short-circuit conditions, and another function block B252 for detecting the plating on battery cell 16C. For example, function blocks B152 and B252 may observe battery voltage and patterns and then compare them to a calibrated performance table to see if instantaneous values ​​or trends indicate such a fault condition. Similarly, a separate function block B352 may process cell sensing data (arrow CC). 16 It can detect temperature conditions, such as being higher or lower than the expected cell temperature, and function block B452 can relay calibrated battery life constraints, such as from the memory (M) of controller 50.

[0073] Downstream of logic block B52, logic block B53 can be used to process one or more output signals (CC) individually through corresponding functions. 52 For example, function block B153 (“Cell Lifetime / Health Determination”) can output a numerical state of health (SOH), for example as a normalized value, where 0 corresponds to a fully depleted or failed battery cell 16C, and 1 corresponds to a new battery cell 16C operating normally, while function block B253 (“Lifetime Modeling”) can output an estimated remaining lifetime (arrow L). Function block B353 (“Energy / Regeneration Optimization”) can provide an optimized value (arrow OPT) based on the current state of battery cell 16C (e.g., according to a cost function informed by the current state). When in response to a signal (arrow CC) 53 When certain control actions are taken, logic block B54 can use such optimized values ​​downstream. Similarly, another function block B453 can be implemented to consider navigation / route planning expectations, thereby outputting a navigation request (arrow NAV) to logic block B54. Regarding possible navigation functions, this method can modify control limits based on navigation / route planning information, when possible, to protect capacity, for example, to satisfy such navigation requests (arrow NAV).

[0074] Regarding logic block B54, it is also described above and in Figure 3 As described, this aspect of the programming functionality of controller 50 is designed for arbitration during both charging and discharging operations. Figure 1 The use of the propulsion battery pack 16. Like other representative logic blocks B51, B52, and B53, logic block B54 can be constructed with individual functional blocks, i.e. Figure 3 In the simplified example, B154, B254, and B354 are shown. In this example, function block B154 can be used in... Figure 1The electrified powertrain system 11 is subject to forced propulsion limits, such as by setting lower maximum torque or speed limits, taking into account conditions analyzed upstream by logic block B52. Therefore, function block B154 operates during discharge mode to protect the propulsion battery pack 16, while simultaneously extending its service life in response to detected short-circuit conditions, as opposed to control methods that prevent or significantly reduce propulsion operation.

[0075] Figure 3 Functional block B254 is similar to functional block B154, operating during charging modes to enforce charging current or voltage limits, or to reduce or extend charging duration as needed to protect the propulsion battery pack 16. Like functional block B154, functional block B254 sets limits in a manner that extends the use of the battery pack 16 relative to a control method that responds to a detected short-circuit condition by preventing or significantly reducing charging operation. Functional block B354 (“thermal limit”) can be used in a similar manner by adjusting the calibrated maximum / minimum operating thermal limits of the battery pack 16; such control action may include controlling the operation of a thermal management system (not shown), for example, by circulating coolant through the propulsion battery pack 16 at a higher rate to maintain a lower battery temperature. The various outputs of functional blocks B154, B254, and B354 collectively form the above reference. Figure 3 The control signal described (arrow CC) 54 ), which is ultimately used for control Figure 1 The electrified power system 11.

[0076] Depend on Figure 1 The controller 50 shown is respectively in Figure 2 and 3 Method 100, executed with the help of exemplary control logic 50L and 150L, ​​therefore requires the use of Figure 1 The cell sensing circuit 40 measures the cell sensing data (CC) of each corresponding cell in the battery cell 16C. 16 As described above and as understood in the art, for each respective battery cell 16C, cell sensing data (CC) 16 This includes cell voltage, cell current, and cell temperature, which can be measured using corresponding sensor traces (not shown), such as sensor traces on a printed circuit board mounted to the exposed electrode tabs or other suitable surfaces of the battery cell 16C.

[0077] Method 100 includes, for example, using Figure 2 and Figure 3 The logic block B52 processes the measured cell sensing data (CC) of each corresponding battery cell 16C through multiple battery state functions of the controller 50. 16 This generates multiple numerical cell degradation values ​​(CDV), which are then used to output the signal CC.52 Within the scope of this disclosure, Figure 2 The multiple battery state functions, commonly labeled F(x)1, are cell sensing data (CC). 16 The calibration relationship between the controller 50 and predetermined battery fault conditions, such as the amplitude and duration of a short circuit, and the fault conditions of battery cell 16C, such as the amplitude, frequency, and duration of the short circuit, cell capacity, cell temperature, plating estimation, and / or other characteristics suitable for the application. Thereafter, the controller 50... Figure 1 During operation of the propulsion battery pack 16, the usage level of the propulsion battery pack 16 is automatically adjusted based on numerical CDV, such as through formula-based or threshold-based adjustments and / or lookup table-assisted control actions, which are at least to some extent used to extend the operation of the battery pack 16, regardless of the indicated fault condition.

[0078] Exemplary control actions taken by controller 50 include modifying the calibrated charging limits and / or thermal limits of propulsion battery pack 16 during its charging operation. Similarly, controller 50 may modify the calibrated discharging limits and / or thermal limits of propulsion battery pack 16 during discharging operations (such as drive mode), such as during drive mode. Figure 1 The traction motor 18 is used to propel the motor vehicle 10 in torque or speed mode.

[0079] As per the above reference Figure 2 and Figure 3 The predetermined battery fault conditions within the scope of this disclosure may include intermittent or continuous electrical short circuit conditions within the corresponding battery cell 16C, wherein... Figure 2 The multiple battery state functions of logic block B52 may include an electrical short-circuit function indicating an intermittent or persistent electrical short-circuit condition. Such a battery fault condition may also include the active material plating of the corresponding battery cell 16C; in such an embodiment, the multiple battery state functions include a plating function indicating the level of the active material plating.

[0080] Other examples of battery failure conditions include a reduced energy retention capacity of the corresponding battery cell 16C, wherein multiple battery state functions of logic block B52 include capacity functions indicating the reduced energy retention capacity. A temperature increase or decrease in the corresponding battery cell 16C may also be a relevant failure condition, wherein the battery state functions of logic block B52 include temperature functions indicating the temperature increase or decrease. Other failure conditions may also be considered, such as an electrolyte leakage condition in the corresponding battery cell 16C, in which case the battery state functions may include an electrolyte leakage function indicating the electrolyte leakage condition.

[0081] The cell sensing data (CC) is processed using the aforementioned multiple battery state functions in logic block B52. 16This may include processing unit sense data (CC) via an arbitration logic block of controller 50. 16 )and Figure 1 The arbitration logic block can reside in at least one additional powertrain control factor of the motor vehicle 10 shown. Figure 3 Within logic block B54. In such an exemplary embodiment, controller 50 can automatically adjust the usage level of battery pack 16 by assigning relative weights to each of the various battery state functions and additional powertrain control factors in logic block B52 via an arbitration logic block. By way of example and not limitation, additional powertrain control factors include lifespan modeling limits, energy / regenerative optimization limits, or changes or limits to the electric powertrain based on navigation / route planning. That is, not all modifications are limitations in themselves. For example, controller 50 may simply switch from a Level 2 charger to a Level 3 charger due to an early warning of an impending or actual failure, or controller 50 may use different paths to route to different charging sources. This effort indirectly protects and extends battery pack 16, but will be perceived by the user as a simple route modification.

[0082] refer to Figure 4 Method 100 is described according to an embodiment, wherein Figure 1 The controller 50 tracks electrical short-circuit conditions. Those skilled in the art will understand that, within the scope of this disclosure, other fault conditions can be monitored, processed using control logics 50L and 150L, ​​and used by the controller 50 to extend... Figure 1 This extends the lifespan of the battery pack 16. Therefore, the exemplary electrical short-circuit scenario is intended to illustrate this teaching and not to limit it.

[0083] Figure 4 The method 100 shown begins at block B102, where controller 50 detects an electrical short circuit. As described above, controller 50 uses... Figure 1 The unit sensing circuit 40 transmits unit sensing data (arrow CC) 16 This fault can be detected, for example, by comparing the cell voltage or voltage trend / trajectory with the expected “normal” / non-short-circuit voltage performance. When the controller 50 has detected an electrical short-circuit condition, method 100 proceeds to block B104.

[0084] Block B104 includes determining the duration of the short-circuit condition detected at block B102. For example, when a short-circuit condition is detected, controller 50 may start a timer and record the elapsed time of the short-circuit condition in its memory (M). When the short-circuit condition is a persistent short-circuit condition, i.e., the short-circuit condition persists without diminishing for at least the calibrated duration, controller 50 proceeds to block B105. That is, controller 50 can be programmed with a threshold time amount below which the short-circuit condition is considered instantaneous, and above which the short-circuit condition is considered persistent. Relative to such a threshold time, method 100 proceeds to block B105 when the short condition is persistent, or proceeds to block B106 when controller 50 determines that the short condition is intermittent.

[0085] Figure 4 Block B105 needs to assess the severity of a persistent electrical short-circuit condition. For example, controller 50 can compare the magnitude of the short-circuit condition to a predetermined value to determine whether the severity is high or low; this predetermined value is calibrated or may be calibrable to achieve platform-specific flexibility. In an exemplary embodiment, controller 50 can assess the severity of a persistent short-circuit condition... Figure 1 The number of battery cells 16C is counted, and this number and / or the total elapsed time under this sustained short-circuit condition is used to determine whether the severity is high or low for the purposes of block B105. When the controller 50 determines that the severity of the sustained short-circuit condition is low, method 100 proceeds to block B109, or when the severity is considered high, it proceeds to block B112.

[0086] In block B106, Figure 1 The controller 50 registers in its memory (M) (e.g., as a bit flag or diagnostic code) that the short-circuit state detected in block B102 is intermittent, i.e., not continuously exceeding the time threshold evaluated in block B104 as described above. When the intermittent short-circuit state has been recorded, method 100 proceeds to block B108.

[0087] Block B108 is similar to Block B105 described above, and therefore can be performed in a similar manner, thus requiring an assessment of the severity of intermittent electrical short-circuit conditions. However, unlike Block B105, which assesses the magnitude of severity when determining the severity of persistent short-circuit conditions, the assessment at Block B108 can focus on other factors related to intermittency.

[0088] Block B109 includes executing a control action via controller 50 in response to determining at block B105 that the persistent electrical short-circuit condition has objectively low severity. For example, during a representative charge of battery pack 16, this could include allowing charging events to occur at increased state-of-charge (SOC) limits. LIMThis occurs under certain conditions. For example, if the depletion of the propulsion battery pack 16 to a SOC limit of 10-20% would typically occur before charging begins, the controller 50 can, in conjunction with the off-board charging station 23, allow charging to proceed at a higher SOC limit, such as 20-30% or some other suitable SOC level. In different embodiments, additional charging control variables can be used to reduce the electrical stress and load on the propulsion battery pack 16 relative to the default SOC limit used to trigger a charging event for normal operation / a new propulsion battery pack 16. Therefore, control actions can include modifying the charging behavior of the off-board charging station 23, such as a Level 1, Level 2, or Level 3 charger.

[0089] Similar to blocks B110 and B112, controller 50 can prevent charging of the propulsion battery pack 16 via the aforementioned off-board charging station 23 or via the solar panel 26. For example, block B110 is reached when a high-severity intermittent fault is determined in one or more battery cells 16C of the propulsion battery pack 16 at blocks B106 and B108. Similarly, block B112 is executed in response to a high-severity persistent fault being determined in battery cell 16C at blocks B104 and B105.

[0090] In the context of blocks B110 and B112, charging prohibition may include functions to disable charging, such as completely disconnecting the propulsion battery pack 16 via activation of an electrical contactor (not shown). Alternatively, blocks B110 and B112 may allow very limited charging to occur up to a low SOC limit, such as 50-60% or lower, to provide limited propulsion capability, possibly limited to a certain number of charging cycles, and provide an accompanying warning to the operator before disabling charging.

[0091] Optionally, as part of method 100, controller 50 may be configured to automatically identify charging termination limit (CTL) modification requesters, such as those from... Figure 1 The output signals of other component systems of the electrified powertrain system 11, such as the battery controller or vehicle integrated control module (not shown). In such an embodiment, as part of the control actions of blocks B109, B10, and B112, the controller 50 may arbitrate different CTL modification requesters among them. Arbitration may require selecting a lower charging limit, or when a charging limit is requested by the execution of method 100, if such an external requester has a higher priority, it may default to blocks B110 and B112. Some implementations may also be related to... Figure 1 The off-board charging station 23 works in conjunction with the battery pack 16 to maximize its charging rate, for example, for lifespan and / or reliability reasons. Therefore, the adjusted charging limits can be advantageously applied in the state of charge (SOC) domain and / or relative to the actual charging voltage.

[0092] In view of the foregoing disclosure, those skilled in the art will understand that this strategy is applicable to the sensing of electrical faults or other abnormal cell behavior in battery cell 16C. Figure 1 A defined relationship is established between the availability of the illustrated motor vehicle 10 and this relationship. This occurs by observing unit parameters via controller 50 and by detecting potential adverse events, taking into account the frequency and severity of detection conditions indicating possible internal electrical short circuits. Therefore, unlike control strategies that reactively prevent battery charging operation based on detected faults, this strategy determines the severity of intermittent or persistent faults, such as... Figure 4 An exemplary internal electrical short circuit is processed in the middle, and a decision on the availability of motor vehicle 10 is made based on this.

[0093] This reactive approach can cause problems for aging vehicles exhibiting similar cell behavior due to the natural variations in battery cell degradation. Therefore, this teaching helps to establish a framework in which, as… Figure 1 The controller 50 gains a greater understanding of the various failure modes and behaviors of the battery cell 16 during natural aging, increasing the availability of the vehicle 10 in propulsion or charging modes. The controller 50 then uses this relationship to adjust battery usage limits and remedy levels in such a manner as to extend the lifespan of the battery pack 16 while maintaining it within defined operational limits. This disclosure also enables the application of health estimates to an overall battery charge / use arbitration, which may include other factors such as, but not limited to, strategic lifetime protection, navigation / location-based energy optimization, regenerative braking optimization, and / or friction braking minimization. These and other benefits will be readily understood by those skilled in the art in light of the foregoing disclosure.

[0094] Detailed descriptions and accompanying drawings or figures are provided to support and describe this teaching, but the scope of this teaching is defined only by the claims. While some best modes and other embodiments for carrying out this teaching have been described in detail, various alternative designs and embodiments exist to practice the teaching as defined in the appended claims. Furthermore, this disclosure expressly includes combinations and sub-combinations of the elements and features presented above and below.

Claims

1. A method for adjusting the usage level of a battery pack having multiple battery cells, the method comprising: The cell sensing circuit measures cell sensing data for each corresponding cell in the battery cell, the cell sensing data including cell voltage, cell current and cell temperature; The controller processes cell-sensor data for each of the plurality of battery cells using multiple battery state functions to generate multiple numerical battery cell degradation values, wherein the multiple battery state functions are calibration relationships between the cell-sensor data and predetermined battery failure conditions; and During battery pack operation, the battery pack's usage level is automatically adjusted via the controller based on numerical battery cell degradation values. The processing of the cell-sensor data through the plurality of battery state functions includes processing the cell-sensor data and at least one additional powertrain control factor of the motor vehicle through an arbitration logic block of the controller, and wherein automatically adjusting the usage level of the battery pack includes assigning relative weights to each corresponding one of the plurality of battery state functions and the additional powertrain control factor via the arbitration logic block. The additional power system control factors include the vehicle's life modeling limits, energy / regeneration optimization limits, or limits based on navigation / route planning.

2. The method according to claim 1, wherein, The predetermined battery fault conditions include intermittent or persistent electrical short-circuit conditions within the corresponding battery cell, and wherein the plurality of battery state functions include an electrical short-circuit function indicating the intermittent or persistent electrical short-circuit conditions.

3. The method according to claim 1, wherein, The predetermined battery fault condition includes the active material coating of the corresponding battery cell, and wherein the plurality of battery state functions include a coating function indicating the level of the active material coating.

4. The method according to claim 1, wherein, The predetermined battery failure condition includes a reduced energy retention capacity of the corresponding battery cell, and wherein the plurality of battery state functions include a capacity function indicating the reduced energy retention capacity.

5. The method according to claim 1, wherein, The predetermined battery fault condition includes an increase or decrease in the temperature of the corresponding battery cell, and wherein the plurality of battery state functions include a temperature function indicating the increase or decrease in temperature.

6. The method according to claim 1, wherein, The predetermined battery fault condition includes the electrolyte leakage condition of the corresponding battery cell, and wherein the plurality of battery state functions include an electrolyte leakage function indicating the electrolyte leakage condition.

7. The method according to claim 1, wherein, Automatically adjusting the usage level of the battery pack includes modifying the calibrated charging limits, charging rate, and / or thermal limits of the battery pack during charging operations.

8. The method according to claim 1, wherein, Automatically adjusting the usage level of the battery pack includes modifying the calibrated discharge limit and / or thermal limit of the battery pack during discharge operations.

9. The method according to claim 1, wherein, Automatically adjusting the battery pack's usage level during battery pack operation includes modifying the charging behavior of off-board charging stations and / or on-board solar panels during battery pack charging operations.

10. An electric powertrain system, comprising: A battery pack having multiple battery cells and a cell sensing circuit configured to measure cell sensing data for each corresponding one of the battery cells; A rotating motor electrically connected to the battery pack, wherein the battery pack is configured to supply electrical energy to the rotating motor in a discharge mode and receive electrical energy from the rotating motor, an off-board charging station, and / or solar panels in a charging mode; and A controller that communicates with the unit sensing circuit and the rotating motor, wherein the controller is configured to: The cell sensing circuit receives cell sensing data from each corresponding cell in the battery cell, the cell sensing data including cell voltage, cell current and cell temperature; Cell sensing data for each of the plurality of battery cells is processed by multiple battery state functions to generate multiple numerical battery cell degradation values, wherein the plurality of battery state functions are a calibration relationship between the cell sensing data and a predetermined battery failure condition; and The battery pack's usage level is automatically adjusted during battery pack operation based on numerical battery cell degradation values. The controller is configured to process the cell sensing data and at least one additional powertrain control factor via an arbitration logic block, and to partially automatically adjust the usage level of the battery pack by assigning relative weights to each of the plurality of battery state functions and the additional powertrain control factor via the arbitration logic block. The additional power system control factors include the vehicle's life modeling limits, energy / regeneration optimization limits, or limits based on navigation / route planning.

11. The electric powertrain system according to claim 10, wherein, The predetermined battery fault conditions include intermittent or persistent electrical short circuit conditions within the corresponding battery cell, and wherein the plurality of battery state functions include an electrical short circuit function indicating the intermittent or persistent electrical short circuit conditions.

12. The electric powertrain system according to claim 10, wherein, The predetermined battery failure condition includes the active material coating condition and / or electrolyte leakage condition of the corresponding battery cell, and wherein the plurality of battery state functions include a coating function indicating the level of the active material coating condition and / or an electrolyte leakage function indicating the electrolyte leakage condition.

13. The electric powertrain system according to claim 10, wherein, The predetermined battery failure condition includes a reduced energy retention capacity of the corresponding battery cell, and wherein the plurality of battery state functions include a capacity function indicating the reduced energy retention capacity.

14. The electric powertrain system according to claim 10, wherein, Automatic adjustment of battery pack usage levels includes modifying the battery pack's calibrated charging limits, charging rate, and / or thermal limits using off-board charging stations and / or on-board solar panels during the battery pack's charging cycle.

15. The electric powertrain system according to claim 10, wherein, The rotary motor is an electric propulsion motor for a motor vehicle, and wherein the additional power system control factor includes a navigation / route planning-based limit for the motor vehicle, in which full charging is delayed until the charging position is reached.

16. The electric powertrain system according to claim 10, wherein, The rotary motor is an electric propulsion motor for a motor vehicle, and the controller is configured to automatically identify a charging termination limit modification requester and thereafter arbitrate the charging termination limit modification requester.

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