SMART ENERGY MANAGEMENT SYSTEM AND METHOD FOR MONITORING BATTERY INTEGRITY

Abstract

A battery monitoring system for a battery in a battery-electric system includes a sensor array, a processor, and memory. The execution of instructions by the processor, according to a procedure, causes the processor to receive battery parameters from the sensor array, calculate the rate of increase of the battery's internal resistance (ΔR ratio) across multiple charge states, compare the ΔR ratio to one or more damage thresholds, and record a corresponding degree of battery damage in the memory if the ΔR ratio exceeds the damage threshold(s). A notification of the battery's health status can be transmitted to a remote device.

Description

INTRODUCTION

[0001] This disclosure relates to electrical circuit topologies and control methods for monitoring the performance and structural integrity of an electrochemical battery. Electric vehicles, emergency power supplies, power plants, and other mobile and stationary battery-powered electrical systems utilize rechargeable batteries as direct current (DC) energy storage devices. Lithium-ion batteries, for example, are widely used to power electric motors in countless industries, as well as to power actuators, sensors, displays, and control circuits in medical devices, industrial systems, and consumer goods.

[0002] Although lithium-ion batteries and other high-energy batteries are integral components of modern battery-electric systems, their use carries potential risks. Over time, age-related damage can impair the battery's reliability and performance. Compared to new / properly functioning batteries, the internal temperature of a damaged battery can rise rapidly. Therefore, thermal management techniques such as coolant / air circulation or the use of heat sinks or cell vents are employed to help regulate the battery temperature. However, if the temperature of a battery cell exceeds a certain point, the materials of the battery and the individual cells that comprise it can melt or begin to burn. The resulting increase in pressure within the battery cell can, in turn, cause an outer cell casing or film to rupture.In the event of a rupture, the battery cell can expel hot gases, molten material, soot, and other ejected material, which can spread to neighboring battery cells. This thermal runaway can impair the operation of the battery and the battery electrical system. SUMMARY

[0003] This document discloses battery monitoring systems and automated methods for monitoring the health of an electrochemical battery within a battery-electric system. Although a representative lithium-ion battery is described herein, the teachings presented are not limited to lithium-based batteries. Rather, the solutions described below can be extended to other battery designs, such as nickel-cadmium (NiCd), nickel-metal hydride (NiMH), lead-acid, etc., but are not limited to them.

[0004] The monitoring strategy presented herein aims to protect the battery electrical system and all surrounding surfaces from thermal damage. This objective is achieved by detecting a potentially hazardous battery condition via an electronic monitoring unit (EMU). Since detection occurs before the hazard actually arises, the present teachings enable the proactive issuance of a warning as an early warning of impending battery failure. This allows sufficient time to implement preventive measures such as battery replacement or circuit interruption, with the EMU performing one or more such control measures in accordance with aspects of this disclosure.

[0005] In a particular embodiment, a system for monitoring a battery in a battery-electrical system includes a sensor array, a processor, and a non-transient, computer-readable storage medium ("memory"). The sensor array is configured to measure the battery's voltage, current, and temperature as a set of battery parameters. The memory includes instructions that can be executed by the processor. Execution of these instructions causes the processor to receive the battery parameters from the sensor array during a predetermined operating mode of the battery and to calculate the rate of increase of the battery's internal resistance over several battery charge states. This rate of increase is referred to here as the delta-resistance (ΔR) ratio.The processor is also instructed to determine the degree of battery damage using the ΔR ratio and to record the degree of battery damage in memory.

[0006] The execution of the instructions can also cause the processor to perform a battery control action in response to the degree of damage. In one or more embodiments, the control action includes, for example, transmitting a state of health (SOH) message to a remote device, such as a server or a smartphone, in network communication with the processor / EMU.

[0007] In other implementations, the processor calculates the first and second internal resistances (R1 and R2) of the battery at the respective first and second states of charge (SOC-1, SOC-2) using the battery parameters. The ΔR value can include a ΔR ratio, where in one possible implementation the ΔR ratio is a function (f) of the first internal resistance (R1) and the second resistance (R2): f = (R2 - R1) / R1 × 100%.

[0008] The execution of the instructions can also cause the processor to compare the ΔR ratio with (i) a first damage threshold corresponding to a negligible degree of battery damage; (ii) a second damage threshold corresponding to a minor degree of battery damage; (iii) a third damage threshold corresponding to a moderate degree of battery damage; and (iv) a fourth damage threshold corresponding to a severe degree of battery damage. Such thresholds are based on the ΔR ratio. In a non-restrictive example implementation, the first damage threshold is approximately 25% to approximately 35%, the second damage threshold is approximately 45% to approximately 55%, the third damage threshold is approximately 55% to approximately 65%, and the fourth damage threshold is approximately 80% to approximately 90%.

[0009] The battery can be designed as a lithium-ion battery pack in one or more embodiments. In this case, the processor can calculate the ΔR value of the battery across the first SOC (SOC-1) at, for example, approximately 50% and the second SOC (SOC-2) at, for example, approximately 10%, where the different state-of-charge levels of the battery include the first and second SOC (SOC-1, SOC-2).

[0010] The battery monitoring system can optionally include an electrical disconnect switch. In such an embodiment, the battery can be connected to a load via the disconnect switch. The processor commands the disconnect switch to open, thereby disconnecting the battery from the load, with this control action occurring in response to the determined degree of battery damage. In some implementations, the load is part of the battery's electrical system.

[0011] This document also discloses a method for monitoring a battery in a battery-electrical system. The method includes, in one or more implementations, measuring a set of battery parameters using a sensor array of a battery monitoring system and calculating the rate of increase of the battery's internal resistance (ΔR value) across different battery charge states using a processor. The method further includes comparing the ΔR value with one or more predefined damage thresholds. An EMU / processor records a corresponding degree of battery damage in a computer-readable storage medium / memory if the ΔR value exceeds one or more of the damage thresholds.

[0012] This document also discloses a battery-electrical system. According to one embodiment, the battery-electrical system includes an electrical disconnect switch, a battery that can be connected to a load via the disconnect switch, a sensor array, and an EMU. The sensor array is configured to measure battery voltage, current, and temperature as battery parameters. The EMU is configured to perform the method summarized above, including calculating the first and second internal resistances (R1 and R2) of the battery at the respective first and second states of charge (SOC-1 and SOC-2) using the battery parameters, wherein the first state of charge (SOC-1) is higher than the second state of charge (SOC-2).

[0013] The foregoing summary is not intended to represent every embodiment or aspect of the present disclosure. Rather, it illustrates certain novel aspects and features. Such features will become apparent from the following detailed description of representative embodiments and methods for carrying out the present disclosure in conjunction with the accompanying drawings and the attached claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings described herein serve for illustrative purposes, are schematic in nature and are more exemplary than limiting the scope of protection of the disclosure. Fig. Figure 1 illustrates a battery-electric system with a rechargeable battery and a battery monitoring system constructed according to the present disclosure. Fig. 2A, Fig. 2B and Fig. Figures 2C illustrate a representative embodiment of the Fig. 1 battery shown for different capacity levels. Fig. 3A and Fig. 3B illustrates models of a representative battery in a new or properly functioning condition. Fig. Figure 4 is a schematic circuit diagram of the battery monitoring system of Fig. 1 according to one possible embodiment. Fig. Figure 5 illustrates changing capacity-based cell voltages, with the voltage on the vertical axis and the percentage state of charge (SOC) / remaining capacity on the horizontal axis. Fig. Figure 6 illustrates SOC-based variations of internal resistance (R). INT ), where the percentage capacity or SOC is shown on the horizontal axis and the ohmic resistance is shown on the vertical axis. Fig. Figure 7 is a flowchart that describes a procedure for monitoring the battery of the battery-electrical system of Fig. 1 describes.

[0015] The present disclosure may be modified or embodied in alternative forms, representative embodiments being shown in the drawings and described in detail below. The inventive aspects of the present disclosure are not limited to the disclosed embodiments. Rather, the present disclosure is intended to cover alternatives that fall within the scope of protection of the disclosure, as defined in the accompanying claims. DETAILED DESCRIPTION

[0016] Referring to the drawings, in which the same reference numerals in the different views refer to the same or similar components, it is stated in Fig. Figure 1 schematically illustrates a battery-electrical system 10. In a simplified embodiment, the battery-electrical system 10 includes a rechargeable battery 12 whose damage level and state of health (SOH) are monitored according to the disclosure. As mentioned above, battery damage is associated with various potential risks, including possible overheating, battery failure, or thermal runaway. The present strategy therefore enables earlier detection and treatment of potentially hazardous conditions of the battery 12, which, as detailed below, is achieved by detecting an increase in internal resistance across different capacity ranges.

[0017] The exemplary battery-electric system 10 of Fig. 1 closes an electrical disconnect switch 14, a load powered by direct current (DC) (L A) 11 and a battery monitoring system 15. The battery monitoring system 15 in turn includes a sensor arrangement 16 and an electronic monitoring unit (EMU) 18. The sensor arrangement 16 can be electrically connected to the battery 12, for example via one or more hard-wired transmission conductors and / or wireless paths / network connections.

[0018] The EMU 18 according to the present disclosure includes a processor (P) 19 and a non-transitory, computer-readable storage medium (“memory”) (M) 20. The memory 20 includes instructions recorded thereon and executable by the processor 19 to cause the EMU 18 to carry out a method 50, a non-limiting example implementation of which is described below with reference to Fig. 7 is described. Among other measures, the EMU 18 sends a measurement request signal (CC). R) to sensor array 16 to start the current battery monitoring process.

[0019] The battery 12, which for the sake of illustrative consistency is described below as a representative lithium-ion (Li) battery, can alternatively be configured with a different rechargeable battery chemistry in other embodiments, for example lithium metal oxide (LMO), lithium metal, nickel metal hydride (NiMH), nickel cadmium (NiCd), etc. In various implementations, the battery-electric system 10 can be Fig. 1. Can be used as part of a mobile or stationary battery-powered device. As described in Fig. As shown in Figure 1, the battery 12 can be used to power a portable electronic device such as a computer 21A, e.g. a tablet, desktop or laptop computer, or a mobile phone 21B.

[0020] In other applications, the battery 12 can be used as part of a medical device, such as a handheld surgical instrument 21C or a body-worn device 21D. The optional body-worn device 21D can be configured, among other possibilities as shown, as a continuous glucose monitor (CGM) or, alternatively, as an automated external defibrillator (AED), blood oxygen monitor, or infusion pump. Likewise, the battery 12 can be used to power a mobile system 21E, such as an electric vehicle, which is located in Fig. 1 is shown as it might appear during a battery charging process. Other applications are easily conceivable, including, but not limited to, electronic gaming systems, control consoles, or other industrial, medical, or transportation systems. The exemplary use, chemistry, construction, and simplified representation of battery 12 herein therefore serve to illustrate the teachings presented and do not constitute a limitation thereof, unless otherwise stated.

[0021] The representative battery monitoring system 15 of Fig. 1 can include other components in various embodiments. For example, a direct current-to-direct current (DC-DC) converter 22 can be used with the battery 12 to increase or decrease the battery voltage before energizing the connected load 11. A battery charger 13 can be connected to the battery 12 as needed and used to charge the battery 12. In an alternating current (AC) configuration of the battery electrical system 10, the battery 12 can be connected to a DC-to-AC inverter circuit 23, the inverter circuit 23 being capable of converting an AC waveform to a coupled AC-powered load (L). B ) to output 111. The loads 11 and 111 can be implemented differently depending on the application, such as electric motors, rotary drives, linear drives, displays, transducers and / or other electrical or electromechanical devices.

[0022] As part of the present battery monitoring strategy, various sensors S1, S2, ..., SN of the sensor arrangement 16 are used to measure or record battery parameters during the charging and discharging modes of the battery 12, where "N" is an integer representing any Nth sensor in the sensor arrangement 16. The sensors are part of the system described in Fig. The 50 battery parameters measured and used in the 7 exemplary procedures include at least a voltage, a current and a temperature of the battery 12, wherein the EMU 18 of Fig. 1 is also configured to determine the state of charge (SOC) and open-circuit voltage (OCV) of battery 12 as well as its current charge / discharge state.

[0023] As part of the battery monitoring process described herein, input signals (CC) are IN ) from the sensor array 16 to the EMU 18. The EMU 18 then outputs electronic control signals (CC). OUT) to a remote device 24, e.g. a graphical user interface (GUI), as in Fig. 1, and / or a display screen, the disconnect switch 14, etc. The disconnect switch 14, which is located elsewhere in the schematic circuit of Fig. 1 can be placed, including between the inverter circuit 23 and the AC-powered load 111 in such embodiments, and can be implemented in various ways as electromechanical contactors or relays, e.g. solid-state relays (SSRs) capable of disconnecting the battery 12 under certain fault conditions.

[0024] Although it is in Fig. Although Figure 1 has been omitted for the sake of illustrative simplification and clarity, the battery electrical system 10 can also be equipped with a thermal management system as summarized above to assist in regulating the temperature of the battery 12 during its normal operation, for example, cooling plates, fins, heat sinks, coolant lines, etc. Likewise, other circuit components such as fuses can be implemented to ensure the safety and reliability of the battery electrical system 10 during its operation.

[0025] Fig. 2A, Fig. 2B and Fig. Figures 2C together illustrate battery 12 in the non-restrictive representative form of a cylindrical battery cell with positive (+) and negative (-) terminals. Fig. 2A, Fig. 2B and Fig. 2C represent three different charge depletion levels and corresponding internal resistances of the representative battery 12 due to age-related or other damage. Fig. 2A represents a new / properly functioning battery 12 with a usable nominal capacity 26 of 100% and an internal resistance (R) INT ) represents the progressive aging and deterioration of battery 12. Fig. 2B and Fig. 2C for nominal usable capacities 26 of 75% and 50% illustrates which respective unusable capacities 28 of 25% ( Fig. 2B) and Fig. 50% ( Fig. 2C). Referring to the one in Fig. In the new state shown in 2A, battery 12 has a different internal resistance (R). INT ) the battery 12 in Fig. 2B increased, in this exemplary case to 43RINT. As battery 12 deteriorates, the internal resistance (R) can increase. INT) continue to rise, in this example to twice the level of Fig. 2A, i.e. 2R INT In other words, age-related damage to battery 12 leads to a significant increase in its internal resistance. This change in internal resistance is described herein as part of procedure 50. Fig. 7 is used to assist in diagnosing damage conditions of battery 12 and to proactively enable responses when necessary.

[0026] Referring to Fig. 3A and Fig. 3B, a battery model 29 is used here as part of the present strategy. The aforementioned internal resistance (R) INTThe value ) of battery 12 represents the internal resistance of battery 12, which is determined during a predetermined operating mode of battery 12. Such a mode can be a charging mode in which an external charging station (not shown) supplies a charging current to battery 12 to increase its state of charge / capacity. In further embodiments, however, battery monitoring can be performed during a discharge mode of battery 12, which is why the implementation of the present teachings is not limited to the charging mode.

[0027] As in Fig. 3A shows the internal resistance (R INT) for battery 12 herein, using the battery parameters specified above, i.e., voltage, current, and temperature. For example, the internal resistance at a state of charge (SOC) of approximately 50% can be determined as shown, with this value corresponding to the first state of charge (SOC-1). This calculation is then repeated at another second SOC (SOC-2), e.g., 10%, as shown in Fig. Figure 3B shows the first state of charge exceeding the second, i.e., in this example, SOC-1 > SOC-2. 50% and 10% are suitable for lithium-ion battery 12 designs and are therefore exemplary and not limiting. However, at the same SOC levels of 50% and 10%, the internal resistance of a damaged battery 12 differs from that of a properly functioning / new battery.

[0028] In terms of general battery physics, charging a lithium-ion battery 12 causes lithium ions to migrate within the battery 12 and be absorbed onto electrode surfaces. This process is generally stable in a new battery 12. However, repeated charging cycles and / or increased charging rates, e.g., during repeated fast charging of the battery 12 with direct current, can lead to abnormal growth and the formation of unstable lithium deposits. Clusters of deposits can form elongated, branch-like structures, i.e., dendrites. Dendrites and other lithium accumulations increase the internal resistance, and thus the internal resistance can be used as an indicator of the degree of damage to the battery 12.

[0029] Therefore, the in Fig. 3A and Fig. Figure 3B illustrates that battery 12 exhibits internal resistances at various charge states, indicating negligible damage to battery 12 or intermediate degrees such as slight damage, moderate damage, etc., up to severe damage to battery 12. Corresponding threshold values ​​can be stored in memory 20. Fig. 1 recorded and used to determine the degree of damage to battery 12. In accordance with the example where the first state of charge (SOC-1) is approximately 50% and the second state of charge (SOC-2) is approximately 10%, an increase in internal resistance of, for example, approximately 30 to 35% may correspond to negligible damage, whereas an increase in internal resistance of, for example, 80 to 90% at the same two SOC levels may correspond to severe damage. The EMU 18 of Fig. 1 can then, using such an analysis, initiate control or corrective measures as needed to protect the battery 12, the battery electrical system 10 and its user(s).

[0030] Referring to Fig. 4 are sections of the battery-electric system 10 of Fig. Figure 1 schematically illustrates the battery monitoring system 15 and the load (L) 11. The open-circuit voltage (OCV) is illustrated together with a voltage difference (ΔV). As shown in the representative voltage curve 55 of Fig. Figure 5 shows the battery voltage in millivolts (mV) together with the battery capacity. Figure 12 shows the battery voltage in millivolts (mV). Fig. 4 illustrates the remaining capacity. Fig. 5 is expressed as a SOC percentage (%), e.g., the first SOC (SOC-1) is 50%, and the second SOC (SOC-2) is 10%. Curves 56 and 156 represent the battery voltage during the respective charging and discharging modes of battery 12 at a given temperature. The movement between curves 56 and 156 represents the voltage difference (ΔV) relative to a baseline, in this case, the open-circuit voltage (OCV) mentioned above. For a given temperature and capacity, the OCV therefore acts as a stable reference from which the voltage difference (ΔV) can be determined. As is known in the art, the OCV, e.g., from a temperature-specific lookup table referenced or indexed by SOC and OCV, can be used to determine the voltage difference (ΔV) as shown for either the charging or discharging mode. That is, ΔV is the difference between a measured battery voltage and the OCV, i.e., ΔV = V M- OCV.

[0031] Referring again to Fig. 4. The battery 12 is disconnected during charging by opening the disconnect switch 14, i.e., one or both disconnect switches 14. + and / or 14 - , where + and - respectively indicate the connection to the positive and negative voltage rails of the battery electrical system 10, disconnected from the load 11. An optional charging switch (SW1) 30 can be instructed to close, e.g. by the EMU 18 or another charging controller 300, as indicated by an arrow CC. 30and a corresponding "ON / OFF" indicator is displayed. This measure electrically connects the battery 12 to the battery charger 13. As is known in engineering, the battery charger 13 can be connected to an external power supply (not shown), such as mains power. If the power supply is an AC wall socket, the battery charger 13 includes an AC-to-DC converter, which is capable of converting, filtering, and outputting suitable DC voltage and current waveforms to the battery 12 for charging.

[0032] A current sensor (S1) S1, which is a component of the sensor arrangement 16 described above. Fig. The value 1 can be used to detect the direction of current flow. Using this information, it can be determined whether the battery 12 is in a charging mode or a discharging mode as specified above. The battery 12 is then removed from the battery charger 13 when it is in use (discharging mode), with the removal of the battery 12 from the battery charger 13 automatically opening the charging switch 30.

[0033] In a possible implementation of the EMU 18, appropriate hardware and software modules or blocks can be implemented to perform the required processing functions of the procedure 50 (see Fig. 7) A state-of-charge (SOC) block 33 can be used to determine the current SOC of battery 12. The SOC block 33 can be implemented in several ways, such as by coulomb counting, but is not limited to this. Using such an approach, the electric current flowing into and out of battery 12 over time is accurately tracked and integrated to determine the amount of charge transferred. Other approaches may include, for example, machine learning, voltage- and temperature-based lookup tables, temperature-specific OCV-SOC tables or curves, or other possible approaches.

[0034] The EMU 18 from Fig. 4 can also be a voltage measuring block (V B ) 35. This feature can be used with a voltage sensor (S V ) S2 of the sensor arrangement 16 ( Fig. 1) be implemented, wherein the measured voltage is measured periodically and transmitted to the voltage measuring block 35 and stored in non-volatile sections of the memory 20 Fig. 1 is stored. An internal resistance calculation block 37 receives the measured battery voltage (V). B ) and uses this parameter to calculate the internal resistance (R) INT ), as described below, together with a measured current value from a current measuring block (IDD) 39. The current sensor S1 also measures and transmits a measured current value I B to the internal resistance calculation block 37 and possibly to a charge / discharge detection block (CHG / DISCHG) 40 to determine when the battery 12 is being charged or discharged. This can be achieved by detecting the direction of current flow through the battery 12.

[0035] The EMU 18 from Fig. 4 also takes into account the battery temperature (T) when assessing the degree of damage and the health status of battery 12. B For this purpose, the EMU 18 is equipped with a temperature measuring block (Temp) 42, which is connected to a temperature sensor (S T ) S3, e.g., a thermistor or thermocouple, communicates. The measured battery temperature (T B ) can be requested by, transmitted to, and recorded by the temperature measurement block 42, possibly with the support of an analog-to-digital converter 43. The measured battery temperature (T B ) is then transmitted to a battery status block 44, which is operational for determining the degree of damage and the health status of the battery 12. The EMU 18 performs this function using the internal resistance (R). INT ) through, as discussed above.

[0036] The EMU 18 can take action if the internal resistance (R) INT) is high relative to one or more damage thresholds, as described below. This can occur if the rate of increase of the internal resistance of battery 12, i.e., the delta resistance value (ΔR), exceeds one or more predefined damage thresholds corresponding to different degrees of damage to battery 12 across various charge states of battery 12. In such a case, the EMU 18 can issue warnings via the output signals (CC). OUT ) transmit, for example to the GUI 24 or another external audio and / or visual device.

[0037] Depending on the application, warnings may include audible alarms, indicator lights, text messages, haptic feedback, and the like, which may include a request to dispose of or replace the battery 12. If the EMU 18 determines that battery 12 failure is imminent, the EMU 18 may take further preventive measures, such as disconnecting the load 11 or preventing charging via the battery charger 13. Such measures may help to prevent thermal damage to the environment or, in body-worn versions of the battery electrical system 10, to a user of the body-worn device 21D. Fig. 1 to prevent.

[0038] Fig. Figure 6 illustrates the internal resistance (R) using a set of curves 60. INT) in ohms (Ω) for a given state of charge (SOC) of battery 12 at a specific temperature, e.g., 25 °Celsius. As in the previous example, the first SOC (SOC-1) and the second SOC (SOC-2) are set to 50% and 10%, respectively, without restricting the applications to these representative values. The curves 60, or alternatively a lookup table or other reference, can be stored in memory 20 of Fig. 1 recorded and retrieved by processor 19 when the present method 50 of Fig. 7 is performed. The curves 60 are labeled D-1 (no / negligible damage), D-2 (minor damage), D-3 (moderate damage), and D-4 (severe damage). In further embodiments, more or fewer threshold levels of damage can be implemented. Since the different levels are relative, the levels are application-specific for each application. Likewise, application-specific low and medium states of charge, i.e., SOC-2 and SOC-1 respectively, can be used by the present method 50 to determine the aforementioned rate of increase or ΔR value. For the lithium-ion chemistries mentioned above, the EMU 18 can use an SOC-1 of approximately 50% and an SOC-2 of approximately 10% without restriction.

[0039] In one or more embodiments, instructions in the memory 20, when executed by the processor 19, cause the processor 19 to compare the ΔR value specified above with predetermined damage thresholds, wherein the curves 60 designated D-1, D-2, D-3, and D-4 represent a representative set of such predetermined damage thresholds. In such an implementation, the processor 19 can compare the ΔR value with a first damage threshold corresponding to negligible damage to the battery 12, e.g., D-1. The processor 19 can also compare the ΔR value with a second damage threshold, e.g., D-3. B. compare D-2, which corresponds to minor damage to battery 12, a third damage threshold (D-3), which corresponds to moderate damage to battery 12, and a fourth damage threshold (D-4), which corresponds to moderate damage to battery 12.The highest threshold exceeded thus indicates the degree of damage.

[0040] As an illustrative example, the first damage threshold can be in Fig. 6, i.e., D-1, may be approximately 25% to approximately 35%. The second damage threshold (D-2) may be approximately 45% to approximately 55% in this approach, while the third damage threshold (D-3) may be approximately 55% to approximately 65%. The fourth damage threshold (D-4) may be approximately 80% to approximately 90% or more. In other implementations, other percentage ranges may be used, e.g., based on the application and the electrochemical composition of battery 12. By comparing the relatively small ΔR value of damage threshold D-1 (no damage) with the relatively large ΔR value of damage threshold D-4 (severe damage), one can see the large variance in internal resistance that can be observed in an aged or otherwise damaged battery 12.

[0041] The procedure 50 from Fig. 7 is below described as a sequence of steps or logic blocks, each embodied as a computer-readable instruction. Such instructions can be stored in memory 20 of the [system / device] described in the Fig. 1 shown in the EMU 18 or in another accessible non-volatile, non-transient memory location and executed by the processor 19 to cause the EMU 18 to perform the described functions.

[0042] The functions of the method 50 are embodied as computer-readable instructions and are executed from the memory 20, for example, a magnetic or optical medium, a CD-ROM, and / or a solid-state / semiconductor memory (e.g., various types of RAM or ROM). The processor 19 may include one or more control modules, control units, microprocessor chips, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), electronic circuits, or central processing units. Associated memory component(s) of the memory 20 include non-transitory, computer-readable storage devices such as read-only memory, programmable read-only memory, hard disks, etc.Non-transitory components of the memory 20 used herein are capable of storing machine-readable instructions in the form of one or more software or firmware programs or routines, one or more combinational logic circuit(s), one or more input / output circuit(s) and devices, signal conditioning and buffer circuit arrangements, and other components that can be accessed by one or more of the processors 19 to provide a described functionality.

[0043] In general, the execution of instructions from memory 20 can be used to generate the measurement request signal (CC). R ), shown in Fig. 1, and its transmission to the sensor arrangement 16. This in turn causes the processor 19, and thus the EMU 18, to receive the measured battery parameters – voltage, current, and temperature – from the sensor arrangement 16 during a predefined operating mode of the battery 12. The sensor arrangement 16 transmits these battery parameters to the EMU 18 as part of the input signals (CC). IN Once the battery parameters have been transmitted and received, processor 19 calculates the internal resistance (R) using the battery parameters. INT ) of battery 12 and then determines the degree of damage to battery 12 using the internal resistance (R) INT The EMU 18 can perform one or more protective measures in response to a level of damage exceeding a calibrated threshold and / or to the health status of the battery 12.

[0044] An exemplary embodiment of method 50 is described in Fig. Figure 7 illustrates this. Starting with block B52 (“Determine SOC-1, SOC-2”), procedure 50 involves determining two different SOC points to be used in assessing the degree of damage and the state of health (SOH) of battery 12. These grades correspond to the first SOC (SOC-1) and the second SOC (SOC-2) of the Fig. 5 and Fig. 6, which will later be used to calculate the ΔR value. Although the actual SOC is used for the respective first and second SOC (SOC-1 and SOC-2), the non-restrictive example implementation of 50% and 10% is used here for the sake of illustrative consistency.

[0045] Referring again briefly to example curves 60 from Fig. 6. The selected SOC values ​​for block B52 are sufficiently distinct from one another such that one value, e.g., SOC-1, captures a steady / mid-range portion of the trajectory, and the other value, in this case SOC-2, corresponds to a falling (or rising) end of the trajectory. The EMU 18 can be calibrated with a first SOC level (SOC-1) of approximately 25% to approximately 75% and a second SOC level (SOC-2) of approximately 0% to 25%, in accordance with the representative trajectories of Fig. 6 can be programmed, with the exemplary degrees of 50% and 10% falling within these broader ranges.

[0046] To determine the actual SOC of battery 12, the EMU 18 can be used. Fig. 1. The processor 19 determines the actual state of charge (SOC) of the battery 12 at a predefined temperature, for example, 25 °C or another application-specific operating temperature. The SOC can be determined via the SOC block 33. Fig. 3. can be determined, for example, using coulomb counting, machine learning, voltage- and temperature-based lookup tables, open-circuit voltage (OCV)-to-SOC curves, or other possible approaches as mentioned above. The above with reference to Fig. The temperature measuring block 42 described in section 3 can be used to ensure the temperature of the battery 12.

[0047] Factors in selecting SOC-1 and SOC-2 include the composition or construction of battery 12. For example, diagram 55 and curves 60 of the respective Fig. 5 and Fig. 6 offline values ​​are generated for battery 12 and used to determine the optimal values ​​for SOC-1 and SOC-2. These values ​​are then programmed into memory 20. Subsequently, procedure 50 continues with block B54.

[0048] At block B54 (SOC = SOC-1 or SOC-2) the EMU 18 is waiting Fig. 1, until the actual SOC of battery 12 reaches the first SOC (SOC-1) or the second SOC (SOC-2) recorded in block B52. Procedure 50 waits at block B54 until the first or second SOC (SOC-1 or SOC-2) is reached before proceeding to block B56.

[0049] Block B56 (“Determine R”) INT @ SOC-1 or SOC-2“ includes determining the internal resistance (RINT) at the SOC level detected in block B54, i.e., SOC-1 or SOC-2. The battery parameters measured as part of block B56 include the battery voltage (V B ) and the current (I B ) from Fig. 4, e.g. via blocks 35 or 39. Information on the open-circuit voltage (OCV) is then obtained at the SOC level, i.e. SOC-1 or SOC-2, for example from a lookup table or from curves such as diagram 55 of Fig. 5 extracted. Such information can be stored in memory 20 of EMU 18 during the execution of procedure 50 ( Fig. 1) be saved.

[0050] To calculate the internal resistance (R) INT ) the processor 19 of the EMU 18 can solve the following equations: R1=OCV1−V1IDD1 R2=OCV2−V2IDD2 where indices 1 and 2 represent the values ​​taken at SOC-1 and SOC-2 respectively, R1 and R2 are the internal resistances of battery 12, and V1 and V2 are the battery voltage (VB) of Fig. 4 correspond, and IDD1 and IDD2 correspond to the measured battery current (IB) of Fig. 4. If the specified operating mode of battery 12 is a discharge mode when performing procedure 50, the OCV exceeds the battery voltage, i.e., OCV > V. During a charging mode, the reverse relationship applies, i.e., V > OCV. Procedure 50 continues with block B58 after the internal resistance (RINT) has been determined.

[0051] Block B58 (“ΔR ratio (%) > CAL?”) involves performing a check of the ΔR ratio level via the EMU 18 of Fig. 1. As part of block B58, the processor 19 can have a slew rate of internal resistance, i.e., R INT , the battery 12 of Fig. 1. Calculate the different charge states of battery 12, i.e., SOC-1 and SOC-2.

[0052] For example, the EMU 18 can calculate the ΔR value as the delta resistance ratio (ΔR ratio), where the ΔR ratio is a function (f) of the first internal resistance (R1) and the second resistance (R2). As part of the present approach, the EMU 18 can therefore determine the degree of damage to battery 12 using the ΔR ratio. Numerous examples of the ΔR ratio are given in Fig. Figure 6 illustrates that the processor 19 can calculate the ΔR ratio using the following function (f): f=ΔR ratio(%)=ΔRR1⋅100% where ΔR equals R2-R1.

[0053] Still referring to Fig. 7 and the representative embodiment of method 50 determines, as part of block B58, whether the ΔR ratio exceeds one or more calibrated damage thresholds. One possible implementation includes specifying a single damage level, e.g., D-4 in Fig. 6, which corresponds to severe damage, or several damage thresholds, each with a progressively increasing severity. An example of the latter is in Fig. Figure 6 illustrates four example threshold values, labeled D-1 (no damage or negligible damage), D-2 (minor damage), D-3 (moderate damage), and D-4 (severe damage). Further embodiments can implement more or fewer damage threshold levels.

[0054] Thus, block B58 can include a comparison of the ΔR ratio with a single damage threshold, e.g., D-4, or with several different graded damage thresholds, e.g., D-1, D-2, D-3, and D-4. The latter approach would have the advantage of providing a measure of the true state of health (SOH) of battery 12 at a specific time shortly before battery failure. For example, the EMU 18 can store the exceeded damage threshold in its memory 20. Fig. 1. Record the performance history of battery 12, with the damage tendency available as a measurement to enable a more proactive response. Procedure 50 continues to block B60 if the ΔR ratio value has exceeded a damage threshold, and alternatively returns to block B54 if a damage threshold has not been exceeded.

[0055] In block B60 ("Execute tax action"), the EMU 18 can be used by Fig. 1. In response to the registration of the damage level, the EMU 18 executes a control action on battery 12. This action is carried out using the damage level determination described above, based on whether battery 12 is in sufficiently good condition to continue its use without intervention. For example, the EMU 18 can determine which of the damage thresholds of Fig. 6 were exceeded in order to select an appropriate response. When the representative harm threshold D-1 of Fig. For example, EMU 18 can begin to monitor the state of health (SOH) of battery 12 more closely, knowing that while the SOH remains acceptably high, it has begun to deteriorate. Conversely, in the same example, EMU 18 can begin to escalate its control or preventive response measures when damage thresholds D-2 or D-3 are exceeded, with more aggressive control or preventive measures being initiated when the highest damage threshold, D-4, is exceeded.

[0056] In some embodiments, each damage threshold may be linked to a specific preventive control measure. “Preventive,” as considered herein, refers to a measure that a user of the battery-electric system 10 of Fig. 1 indicates that the SOH or the performance of battery 12 is impaired in any way. If the performance of battery 12 has only decreased slightly, the preventive action may take a less urgent tone or mechanism, usually without the EMU 18 interfering with the operation of battery 12. In such a case, text messages, audible / visual warnings, or other information may be transmitted to the user. However, if the degree of damage becomes more significant, e.g., if the exemplary damage thresholds D-3 or D-4 of Fig. If the threshold of 6 is exceeded, the EMU 18 can escalate the response of the preventive measure with regard to its urgency and may also intervene in the control of the battery 12 itself.

[0057] Communication within the scope of Block B68 may include transmitting a health status information (SOH) message to a remote device, e.g., transmitting an electronic alert signal to the GUI 24 of Fig. 1. In this way, different levels of warnings or alerts can be transmitted. An alert transmitted by the EMU 18 in response to a less urgent condition is itself less urgent compared to the alert transmitted in response to the more urgent condition.

[0058] Using an illustrative example, an SMS text message can be transmitted to the GUI 24 recommending the replacement or maintenance of the battery 12 within a longer timeframe or with unspecified urgency, e.g., "Battery nearing the end of its service life - maintenance recommended." If the battery-electrical system 10 of Fig. If the device is equipped accordingly, a light or lamp in a suitable color, such as amber or yellow, can illuminate to visually alert users to the partially damaged but still functional condition of battery 12. If the highest damage thresholds are exceeded, the urgency of the warning / notification can also be increased. For example, instead of the text example above, a more urgent wording such as "Battery condition poor - immediate maintenance recommended" can be used. The optional light can illuminate in a globally understood color, such as red in this example, and / or a light can pulse or flash to noticeably increase the warning status.

[0059] Similarly, acoustic warning tones can sound to alert the user to a possible imminent failure of battery 12.

[0060] At a certain point, the EMU 18 can be Fig. 1 determine that continued use of battery 12 could be harmful to the health and safety of the battery electrical system 10 and its potential users. In this case, the EMU 18 can be caused to execute the protective measure by sending the disconnect switch 14 ( Fig. 1) commands the disconnect switch 14 to open, thereby disconnecting battery 12 from load 11 (or 111). Opening the disconnect switch 14 effectively disconnects battery 12 from a main voltage line connecting battery 12 to load 11 / 111, thus protecting load 11 / 111 from energy discharge from the now disconnected battery 12. Similarly, the EMU 18 can prevent the charging switch 30 from closing to prevent charging, for example, by transmitting an override or bypass signal to the control logic of the battery charger 13 and / or the charging switch 30. Battery 12 is thus isolated from the charging and discharging sides of the battery electrical system 10.

[0061] Using Method 50 or embodiments thereof, high-energy batteries can be safely managed in a variety of applications. The solutions presented herein use a relationship between internal resistance and state of charge (SOC) to enable early detection of potentially hazardous conditions in such batteries, e.g., battery 12 of Fig.1. Changes in the electrode structure, such as physical and chemical transformations like the formation of solid-electrolyte interfaces (SEI layers) or electrode damage in a lithium-ion design, lead to an increase in the internal resistance to ion flow within the battery 12. At lower capacities, fewer lithium ions are available for transport between the electrodes during charge and discharge cycles. This, in turn, can increase the resistance within the electrolyte and at the electrode interfaces of the battery 12, resulting in a higher overall internal resistance. Similarly, voltage drops become larger at lower capacities, leading to polarization effects that manifest as a higher internal resistance. Method 50 thus operates by using the relationship between internal resistance and state of charge (SOC) when monitoring the health of the battery 12, e.g.,by monitoring the relative trend of the internal resistance at different charge levels, nominally SOC-1 and SOC-2.

[0062] The degrees of damage can be represented as numerical SOH values, where, for example, an SOH of "1" corresponds to a perfectly healthy battery 12 and an SOH of "0" corresponds to a completely damaged / non-functional battery 12. Values ​​between the normalized extremes of this exemplary range can correspond to progressively deteriorating states of the battery, e.g., the battery 12 described herein, where an SOH value closer to 0 indicates greater damage than values ​​closer to an SOH value of 1. The person skilled in the art, now having the benefit of the foregoing disclosure, will appreciate these and other advantages of the present teachings.

[0063] Although several ways of implementing the present teachings have been described in detail, the person skilled in the art will recognize various alternative aspects for the practical implementation of these teachings, which fall within the scope of protection of the accompanying claims. The foregoing description and the accompanying drawings are illustrative and exemplary of the entire range of alternative embodiments that the person skilled in the art would recognize as implicitly, structurally and / or functionally equivalent, or otherwise obvious, based on the included content, and are not limited exclusively to the embodiments explicitly depicted and / or described. Furthermore, the present concepts expressly include combinations and subcombinations of the described elements and features.The detailed description and the drawings support and describe the present teachings, the scope of protection of the present teachings being defined exclusively by the claims.

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