Intelligent power management system and method for monitoring battery integrity

Abstract

The invention relates to an intelligent power management system and method for monitoring battery integrity. A battery monitoring system for a battery of a battery power system includes a sensor array, a processor, and a memory. A processor executes instructions according to a method such that the processor receives battery parameters from a sensor array, calculates a rate of increase ([Delta] R ratio) of internal resistance of the battery across a plurality of states of charge of the battery, compares the [Delta] R ratio to one or more degradation thresholds, and determines a state of charge of the battery based on the one or more degradation thresholds. And recording a corresponding degradation level of the battery in a memory when the [delta] R ratio exceeds a degradation threshold. A health status notification may be transmitted to a remote device.

Description

[0001] INTRODUCTION

[0002] The present disclosure relates to circuit topologies and control methods for monitoring the performance and structural integrity of electrochemical cells. Electric vehicles, backup power sources, power plants, and other mobile and stationary battery power systems utilize rechargeable batteries as direct current (DC) energy storage devices. For example, lithium-ion batteries are commonly used to power electric motors for countless industries, as well as to energize actuators, sensors, displays, and control circuits for medical devices, industrial systems, and consumer products.

[0003] While lithium-ion and other high-energy batteries are integral components of modern battery power systems, their use can present potential risks. Over time, aging-related degradation can reduce the reliability and performance of the batteries. The internal temperature of a degraded battery can increase rapidly relative to a new / normal operating battery. Thermal management techniques such as coolant / air circulation or the use of heat sinks or battery cell exhaust ports are therefore used to help regulate battery temperature. However, when the temperature of a battery cell increases beyond a certain point, the materials of the battery and its constituent battery cells can begin to melt or combust. In turn, the resulting pressure level increase within the battery cell can cause the external cell can or foil to rupture. When a rupture occurs, the battery cell can expel high-temperature gases, molten materials, soot, and other ejecta, which can spread to adjacent battery cells. This thermal runaway condition can have adverse effects on the operation of the battery and the battery power system. SUMMARY

[0004] Disclosed herein are battery monitoring systems and automated methods for monitoring the state of health of electrochemical cells within a battery power system. While representative lithium-ion batteries are described herein, the present teachings are not limited to lithium-based batteries. Rather, the solutions described below are extendable to other battery configurations such as, but not limited to, nickel-cadmium (NiCd), nickel-metal hydride (NiMH), lead-acid, etc.

[0005] The monitoring strategies set forth herein seek to protect the battery power system and any surrounding surfaces from thermal damage. This is accomplished by detecting a potentially dangerous state of degradation of the battery via an electronic monitoring unit (EMU). As detection occurs before the danger actually materializes, the present teachings enable proactive issuance of an alert, warning of an impending battery failure well in advance. As a result, there is sufficient time to perform preventative measures such as replacing the battery or disconnecting the circuit, where the EMU performs one or more such control measures in accordance with aspects of the present disclosure.

[0006] In one specific implementation, a system for monitoring a battery of a battery power system includes a sensor array, a processor, and a non-transitory computer readable storage medium ("memory"). The sensor array is configured to measure voltage, current, and temperature of the battery as a set of battery parameters. The memory includes instructions executable by the processor. Execution of the instructions causes the processor to receive the battery parameters from the sensor array during a predetermined operating mode of the battery, and to calculate a rate of increase of internal resistance of the battery across a plurality of states of charge of the battery. This rate of increase is referred to herein as a delta-resistance (AR) ratio. The processor is also caused to determine a level of degradation of the battery using the AR ratio, and to record the level of degradation of the battery in the memory.

[0007] Execution of the instructions can also cause the processor to perform a control measure of the battery in response to the level of degradation. In one or more implementations, for example, the control measure includes transmitting a state of health (SOH) notification to a remote device (e.g., a server or a smartphone in networked communication with the processor / EMU).

[0008] In other implementations, the processor calculates a first internal resistance and a second internal resistance (R1 and R2) of the battery at respective first and second states of charge (SOC-1, SOC-2) of the battery using the battery parameters. In one possible implementation, the AR value can include an AR ratio, where the AR ratio is a function (f) of the first internal resistance (R1) and the second resistance (R2), f = (R2 - R1) / R1 x 100%.

[0009] Execution of the instructions can also cause the processor to compare the AR ratio to (i) a first degradation threshold corresponding to a negligible level of degradation of the battery; (ii) a second degradation threshold corresponding to a mild level of degradation of the battery; (iii) a third degradation threshold corresponding to a moderate level of degradation of the battery; and (iv) a fourth degradation threshold corresponding to a severe level of degradation of the battery. Such thresholds are based on the AR ratio. In non-limiting example implementations, the first degradation threshold is about 25% to about 35%, the second degradation threshold is about 45% to about 55%, the third degradation threshold is about 55% to about 65%, and the fourth degradation threshold is about 80% to about 90%.

[0010] In one or more implementations, the battery can be configured as a lithium-ion battery pack. In this case, the processor can calculate the AR value of the battery across a first SOC (SOC-1) of, for example, about 50% and a second SOC (SOC-2) of, for example, about 10%, where the different states of charge of the battery include the first and second SOCs (SOC-1, SOC-2).

[0011] The battery monitoring system can optionally include a disconnect switch. In such embodiments, the battery is connectable to a load via the disconnect switch. The processor commands the disconnect switch to open and thereby disconnect the battery from the load, wherein the control measure is performed in response to the determined level of degradation of the battery. In some implementations, the load is part of a battery power system.

[0012] Also disclosed herein is a method for monitoring a battery in a battery power system. In one or more implementations, the method includes measuring a set of battery parameters of the battery using a sensor array of a battery monitoring system, and calculating, via a processor, a rate of increase of internal resistance (ΔR value) of the battery across different states of charge of the battery. The method further includes comparing the ΔR value to one or more predetermined degradation thresholds. When the ΔR value exceeds one or more of the degradation thresholds, the EMU / processor records a corresponding level of degradation of the battery in a computer-readable storage medium / memory.

[0013] Also disclosed herein is a battery power system. According to one embodiment, the battery power system includes a disconnect switch, a battery connectable to a load via the disconnect switch, a sensor array, and an EMU. The sensor array is configured to measure voltage, current, and temperature of the battery as battery parameters. The EMU is configured to perform the method outlined above, including calculating, using the battery parameters, a first internal resistance and a second internal resistance (R1 and R2) of the battery at respective first and second states of charge (SOC-1 and SOC-2) of the battery, wherein the first state of charge (SOC-1) exceeds the second state of charge (SOC-2).

[0014] The above summary is not intended to represent each embodiment or every aspect of the present disclosure. Rather, the above summary merely illustrates certain novel aspects and features of the present disclosure. When taken in conjunction with the drawings and the following detailed description, representative embodiments and modes of performing the present disclosure will become apparent to those skilled in the art. BRIEF DESCRIPTION OF DRAWINGS

[0015] The drawings described herein are intended for illustrative purposes, are schematic in nature, and are exemplary rather than limiting the scope of the present disclosure.

[0016] Figure 1 A battery power system with a battery monitoring system and a rechargeable battery constructed in accordance with the present disclosure is illustrated.

[0017] Figure 2A 、 Figure 2B and Figure 2C are illustrated Figure 1 representative embodiments for batteries of various capacity levels are illustrated.

[0018] Figure 3A andFigure 3B The model illustrates representative batteries in both their new and normal operating states.

[0019] Figure 4 yes Figure 1 A schematic circuit diagram of a battery monitoring system according to one possible implementation.

[0020] Figure 5 The battery cell voltage based on varying capacity is illustrated, with voltage depicted on the vertical axis and percentage state of charge (SOC) / remaining capacity depicted on the horizontal axis.

[0021] Figure 6 An example is given of the internal resistance (R). INT The SOC-based variation is shown on the horizontal axis, which represents the percentage capacity or SOC, while the ohmic resistance is shown on the vertical axis.

[0022] Figure 7 It describes the use of monitoring Figure 1 A flowchart of a battery-powered system.

[0023] This disclosure may be modified or embodied in alternative forms, with representative embodiments shown in the accompanying drawings and described in detail below. The inventive aspects of this disclosure are not limited to the disclosed embodiments. Rather, this disclosure is intended to cover alternatives that fall within the scope of this disclosure as defined by the appended claims. Detailed Implementation

[0024] Referring to the accompanying drawings, similar reference numerals throughout the several views denote the same or similar parts. Figure 1 A battery power system 10 is schematically illustrated. In a simplified embodiment, the battery power system 10 includes a rechargeable battery 12, wherein the degradation level and state of health (SOH) of the rechargeable battery are monitored according to this disclosure. As mentioned above, battery degradation is associated with various potential risks, including possible overheating, battery failure, or thermal runaway. Therefore, this strategy enables earlier detection and handling of potentially hazardous states of the battery 12, wherein this is achieved by sensing an increase in internal resistance across different capacity ranges, as detailed below.

[0025] Figure 1 An exemplary battery power system 10 includes a power-off switch 14 and a DC-powered load (L). A 11 and battery monitoring system 15. Battery monitoring system 15 then includes sensor array 16 and electronic monitoring unit (EMU) 18. Sensor array 16 is electrically connected to battery 12, for example, via one or more hardwired conductors and / or wireless path / network connection.

[0026] According to this disclosure, the EMU 18 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 perform method 50, as referred to below. Figure 7 A non-limiting example implementation of the method is described. Among other measures, the EMU 18 also transmits a measurement request signal (CC) to the sensor array 16. R This initiates the battery monitoring process.

[0027] In other embodiments, battery 12 (described hereinafter as representative lithium-ion (Li) for illustrative purposes only) may optionally be configured with different rechargeable battery chemistry, such as lithium metal oxide (LMO), lithium metal, nickel metal hydride (NiMH), nickel cadmium (NiCd), etc. In various embodiments, Figure 1 The battery power system 10 can be used as part of a device powered by a mobile or stationary battery. For example... Figure 1 As shown, battery 12 can be used to power portable electronic devices such as computer 21A (e.g., tablet, desktop or laptop computer) or cellular phone 21B.

[0028] Other applications may use battery 12 as part of medical devices, such as handheld surgical tools 21C or wearable devices 21D. The optional wearable device 21D can be configured as a continuous glucose monitor (CGM) as shown, or alternatively as an automated external defibrillator (AED), blood oxygen monitor, or infusion pump, etc. Similarly, battery 12 can be used to power mobile systems 21E, such as electric vehicles, etc. Figure 1 As shown, this may occur during battery charging. Other applications can still be readily envisioned, including but not limited to video game systems, consoles, or other industrial, medical, or transportation systems. Unless otherwise stated, the exemplary use, chemical composition, construction, and simplified depiction of battery 12 herein are therefore illustrative of the teachings and not limiting thereof.

[0029] In different implementation schemes, Figure 1 A representative battery monitoring system 15 may include other components. For example, a DC-DC converter 22 may be used with the battery 12 to increase or decrease the battery voltage before energizing the connected load 11. A battery charger 13 may be connected to the battery 12 and used to recharge the battery 12 on demand. In an AC configuration of the battery power system 10, the battery 12 may be connected to a DC-to-AC inverter circuit 23, wherein the inverter circuit 23 is capable of operating to output an AC waveform to the coupled AC-powered load (L). B)111. Depending on the application, loads 11 and 111 may be manifested differently as electric motors, rotary actuators, linear actuators, displays, transducers and / or electrical or electromechanical equipment.

[0030] As part of this battery monitoring strategy, various sensors S1, S2, ..., SN of the sensor array 16 are used to measure or sense battery parameters during the charging and discharging modes of the battery 12, where "N" represents any Nth sensor in the sensor array 16. th An integer representing the number of sensors. The measurements and usage are as follows: Figure 7 The battery parameters of the illustrated method 50 include at least the voltage, current, and temperature of battery 12, wherein, Figure 1 The EMU 18 is also configured to determine the state of charge (SOC) and open-circuit voltage (OCV) of the battery 12 and its current state of charge / discharge.

[0031] As part of the envisioned battery monitoring process described herein, the input signal (CC) from sensor array 16 IN The signal is transmitted to EMU 18. EMU 18 then transmits the electronic control signal (CC). OUT Output to remote device 24, for example, marked in Figure 1 The graphical user interface (GUI) and / or display screen, circuit breaker 14, etc. Circuit breaker 14 can be embodied in various ways as an electromechanical contactor or a relay such as a solid-state relay (SSR), operable to disconnect battery 12 under specific fault conditions. In such embodiments, the circuit breaker can be placed in... Figure 1 Other parts of the schematic circuit include between the inverter circuit 23 and the AC-powered load 111.

[0032] Although in order to make the example simple and clear... Figure 1 The details are omitted, but the battery power system 10 may also be equipped with a thermal management system, such as a cooling plate, heat sink, radiator, coolant pipes, etc., as outlined above, to help regulate the temperature of the battery 12 during its normal operation. Similarly, other circuit components such as fuses may be implemented to ensure the safety and reliability of the battery power system 10 during its operation.

[0033] Figure 2A , Figure 2B and Figure 2C A battery 12, in a non-limiting representative form, is illustrated with a cylindrical battery cell having a positive (+) terminal and a negative (-) terminal. Figure 2A , Figure 2B and Figure 2CThree different levels of charge depletion and corresponding internal resistances due to aging-related degradation or other degradation are depicted for a representative battery 12. Figure 2A A new / normal operating battery 12 is depicted with a nominal available capacity 26 of 100% and an internal resistance (R INT ) of 0 ohms. Figure 2B and Figure 2C Exemplary progressive aging and degradation of the battery 12 is illustrated with nominal available capacities 26 of 75% and 50% (corresponding to respective unavailable capacities 28 of 25% ( Figure 2B ) and 50% ( Figure 2C ), respectively. Relative to the new state of the battery 12 shown in Figure 2A , in the present exemplary instance, Figure 2B the internal resistance (R INT ) of the battery 12 has increased to As the battery 12 continues to degrade, in the present exemplary case, the internal resistance (R INT ) can continue to increase to a level of twice that of Figure 2A , i.e., 2R INT . In other words, the aging-related degradation of the battery 12 results in a significant increase in its internal resistance. This change in internal resistance is used herein as part of the method 50 to facilitate diagnosing the degraded state of the battery 12 and proactively enabling proactive responses as needed. Figure 7

[0034] With reference to Figure 3A and Figure 3B , a battery model 29 is used herein as part of the present strategy. The above-mentioned internal resistance (R INT ) of the battery 12 represents the internal resistance of the battery 12 as determined during a predetermined mode of operation of the battery 12. Such a mode can be a charging mode during which an off-board charging station (not shown) dumps a charging current to the battery 12 to increase the state of charge / capacity of the battery 12. However, in other embodiments, battery monitoring can be performed during a discharging mode of the battery 12 and thus implementations of the present teachings are not limited to a charging mode.

[0035] As shown in Figure 3A , the above-mentioned battery parameters (i.e., voltage, current, and temperature) are used herein to determine the internal resistance (R INT ) of the battery 12. For example, the internal resistance at a state of charge (SOC) of about 50% as shown can be determined, where this value corresponds to a first state of charge (SOC-1). Then, at a different second SOC (SOC-2) (e.g., as shown in Figure 3B ​The calculation is repeated at 10% (as shown), where, in this example, the first state of charge exceeds the second state of charge, i.e., SOC-1 > SOC-2. 50% and 10% apply to the lithium-ion battery 12 and are therefore exemplary and not limiting. However, for the same 50% and 10% SOC levels, the internal resistance of the degraded battery 12 will differ from that of a normally operating / new battery.

[0036] In terms of general battery physics, charging a lithium-ion battery 12 will cause lithium ions to migrate within the battery 12 and be absorbed onto the electrode surfaces. For a new battery 12, this process is generally stable. However, abnormal growth and the formation of unstable lithium deposits can be caused by, for example, repeated charging cycles and / or increased charging rates during repeated DC fast charging of the battery 12. Deposit clusters may form elongated, branching structures, i.e., dendrites. Dendrites and other lithium deposits increase internal resistance, and therefore internal resistance can be used as an indicator of the level of degradation of the battery 12 in this paper.

[0037] therefore, Figure 3A and Figure 3B The illustrated battery 12 can display its internal resistance at different charging states, indicating negligible degradation of the battery 12, or a moderate level such as mild or moderate degradation, up to severe degradation. The corresponding thresholds can be recorded in... Figure 1 The memory 20 is used to determine the degradation level of the battery 12. Consistent with an example where the first state of charge (SOC-1) is about 50% and the second state of charge (SOC-2) is about 10%, an increase in internal resistance of about 30% to 35% may correspond to negligible degradation, while at the same two SOC levels, an increase in internal resistance of, for example, 80% to 90% may correspond to severe degradation. Figure 1 The EMU 18, which uses this type of analysis, can then enable control or correction measures as needed to protect the battery 12, the battery power system 10, and its users.

[0038] refer to Figure 4 , Figure 1 The various parts of the battery power system 10 are schematically illustrated as a battery monitoring system 15 and a load (L) 11. The open-circuit voltage (OCV) along with the voltage difference (ΔV) is illustrated. Figure 5 The representative voltage plot 55 illustrates the battery voltage in millivolts (mV) along with... Figure 4 The battery has a capacity of 12. The remaining capacity is... Figure 5SOC is expressed as a percentage (%), e.g. the first SOC (SOC-1) is 50% and the second SOC (SOC-2) is 10%. The traces 56 and 156 represent the battery voltage during the battery 12 in the respective charge and discharge mode at a given temperature. The shift between the trace 56 and the trace 156 represents the voltage difference (AV) with respect to a baseline, which in this case is the above-mentioned open circuit voltage (OCV). Thus, at a given temperature and capacity, the OCV acts as a stable reference against which the voltage difference (AV) can be determined. As understood in the art, the OCV, e.g. referenced or indexed by the SOC and the temperature, in a temperature-specific look-up table can be used to determine the voltage difference (AV) for either the charge mode or the discharge mode as shown. That is, AV is the difference between the measured battery voltage and the OCV, i.e. AV = Vmeasured - OCV. M - OCV.

[0039] Referring again to Figure 4 , the battery 12 is disconnected from the load 11 during charging by opening the disconnect switch 14, i.e. the disconnect switch 14 + and / or one or both of the charge switch (SW1) 30 and the disconnect switch 14 - , where + and - indicate the connection to the positive and negative voltage rails of the battery power system 10, respectively). The optional charge switch (SW1) 30 can be commanded to close, e.g. by the EMU 18 or another charge controller 300, as indicated by the arrow CC 30 and the corresponding label "ON / OFF". This measure electrically connects the battery 12 to the battery charger 13. As understood in the art, the battery charger 13 can be connected to an off-board power source (not shown), such as the power grid. When the power source is an AC outlet, the battery charger 13 comprises an AC-to-DC converter operable to convert, filter and output a suitable DC voltage and current waveform to the battery 12 for charging.

[0040] The current sensor (S I ) S1 can be used to detect the direction of current flow, which is a component of the sensor array 16 of the above-mentioned Figure 1 . This information can be helpful to determine whether the battery 12 is in a charge mode or a discharge mode, as pre-determined above. Then, when the battery 12 is in use (discharge mode), the battery 12 is removed from the battery charger 13, where removing the battery 12 from the battery charger 13 automatically opens the charge switch 30.

[0041] In a possible implementation of the EMU 18, corresponding hardware modules or blocks and software modules or blocks can be implemented to perform the method 50 (see Figure 7The necessary processing functions are provided. The State of Charge (SOC) block 33 can be used to determine the current SOC of the battery 12. The SOC block 33 can be implemented in several ways (such as, but not limited to, coulomb counting). By using such methods, the current flowing into and out of the battery 12 over time is closely tracked and integrated to determine the amount of charge transferred. Other methods may include, for example, machine learning, voltage and temperature-based lookup tables, temperature-specific OCV-SOC tables or curves, or other possible methods.

[0042] Figure 4 The EMU 18 may also include a voltage measurement block (V B 35. A sensor array of 16 ( Figure 1 Voltage sensor (S) V S2 achieves this feature by periodically measuring the voltage and transmitting it to the voltage measurement block 35 and storing it. Figure 1 The non-volatile portion of memory 20 contains an internal resistance calculation block 37 that receives the measured battery voltage (V). B And as described below, this parameter, along with the measured current value from the current measurement block (IDD) 39, is used to calculate the internal resistance (R). INT The current sensor S1 also measures and transmits the measured current value I. B The data is transmitted to the internal resistance calculation block 37, and possibly to the charge / discharge detection block (CHG / DISCHG) 40, to determine when the battery 12 is charging or discharging. This is achieved by detecting the direction of the current flowing through the battery 12.

[0043] Figure 4 The EMU 18 also considers battery temperature (T) when assessing the degradation level and health status of battery 12. B For this purpose, the EMU 18 is equipped with temperature sensors such as thermistors or thermocouples. T The S3 communication temperature measurement block (Temp) 42. With the assistance of the analog-to-digital converter 43, the measured battery temperature (T) B The battery temperature (T) can be requested by temperature measuring block 42, transmitted to that temperature measuring block, and recorded by that temperature measuring block. B The signal is then transmitted to battery status block 44, which is operational to determine the degradation level and health status of battery 12. As discussed above, EMU 18 uses an internal resistor (R... INT ) to perform this function.

[0044] As described below, when the internal resistance (R) INTWhen the degradation threshold is high relative to one or more degradation thresholds, the EMU 18 can take measures. This may occur when the rate of increase of the internal resistance of the battery 12 across different states of charge of the battery 12 (i.e., the value of Δresistance (ΔR)) exceeds one or more predetermined degradation thresholds corresponding to different degradation levels of the battery 12. In such cases, the EMU 18 can take measures through the output signal (CC). OUT The alarm will be transmitted to, for example, GUI 24 or another external audio and / or visual device.

[0045] Depending on the application, alarms may involve audible alerts, indicator lights, text messages, haptic feedback, etc., and may include requests to discard or replace battery 12. When EMU 18 determines that battery 12 is about to fail, EMU 18 may take other preventative measures, such as disconnecting load 11 or preventing charging via battery charger 13. Such measures may help prevent thermal damage to the surrounding environment, or, for the wearable version of the battery power system 10, prevent damage to the battery. Figure 1 Thermal damage caused by users of the 21D wearable device.

[0046] Figure 6 A set of traces 60 illustrates the internal resistance (R) in ohms (Ω) of the battery 12 at a given state of charge (SOC) at a specific temperature, such as 25°C. INT As in the previous example, the first SOC (SOC-1) and the second SOC (SOC-2) are set to 50% and 10%, respectively, without limiting the application to these representative values. Trace 60, or alternatively, a lookup table or other benchmark, can be recorded in... Figure 1 In memory 20 and during execution Figure 7 The method 50 is accessed by processor 19. Trace 60 is labeled D-1 (no degradation / negligible degradation), D-2 (slight degradation), D-3 (moderate degradation), and D-4 (severe degradation). In other embodiments, more or fewer threshold degradation levels may be achieved. Since the various levels are relative, each level is application-specific. Similarly, the method 50 may use application-specific low and medium states of charge (i.e., SOC-2 and SOC-1, respectively) to determine the aforementioned rate of increase or ΔR value. For the lithium-ion chemistry described above, EMU 18 may use approximately 50% SOC-1 and approximately 10% SOC-2, but is not limited to this.

[0047] In one or more embodiments, the instructions in memory 20, when executed by processor 19, cause processor 19 to compare the above-described AR values to predetermined degradation thresholds, of which a representative set are represented by traces 60 labeled D-1, D-2, D-3, and D-4. In such implementations, processor 19 can compare the AR values to a first degradation threshold (e.g., D-1) corresponding to negligible degradation of battery 12. Processor 19 can also compare the AR values to a second degradation threshold (e.g., D-2) corresponding to mild degradation of battery 12, a third degradation threshold (D-3) corresponding to moderate degradation of battery 12, and a fourth degradation threshold (D-4) corresponding to moderate degradation of battery 12. The highest exceeded threshold thus indicates the level of degradation.

[0048] As an illustrative example, Figure 6 The first degradation threshold (i.e., D-1) in method 50 can be about 25% to about 35%. The second degradation threshold (D-2) in the method can be about 45% to about 55%, while the third degradation threshold (D-3) can be about 55% to about 65. The fourth degradation threshold (D-4) can be about 80% to about 90% or above. In other embodiments, other percentage ranges can be used, for example based on the application and electrochemical composition of battery 12. By comparing the relatively smaller AR values of degradation threshold D-1 (no degradation) to the relatively larger AR values of degradation threshold D-4 (severe degradation), one can see the dramatic change in internal resistance that can be observed in an aged or otherwise degraded battery 12.

[0049] The method 50 of Figure 7 is described below as a series of steps or logical blocks, each of which can be represented as computer readable instructions. Such instructions can be recorded in Figure 1 memory 20 of EMU 18 as shown, or in another accessible non-volatile, non-transitory memory location, and executed by processor 19 to cause EMU 18 to perform the described functions.

[0050] The functionality of method 50 is specifically embodied in computer-readable instructions and executed from memory 20, which is, for example, magnetic or optical media, CD-ROM, and / or solid-state / semiconductor memory (e.g., various types of RAM or ROM). 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 components of memory 20 include non-transitory computer-readable storage devices, such as read-only memory, programmable read-only memory, hard disk drives, etc. The non-transitory components of memory 20 as used herein are capable of storing machine-readable instructions in the form of one or more software or firmware programs or routines, combinational logic circuits, input / output circuits and devices, signal conditioning and buffering circuits, and other components accessible by one or more of processors 19 to provide the described functionality.

[0051] Typically, executing these instructions from memory 20 can cause generation Figure 1 The measurement request signal (CC) shown R This data is then transmitted to the sensor array 16. This, in turn, causes the processor 19, and therefore the EMU 18, to receive measured battery parameters—voltage, current, and temperature—from the sensor array 16 during a predetermined operating mode of the battery 12. The sensor array 16 uses these battery parameters as input signals (CC...). IN A portion of the battery parameters is transmitted to EMU 18. Once the battery parameters have been transmitted and received, processor 19 uses the battery parameters to calculate the internal resistance (R) of battery 12. INT ), and then use the internal resistor (R) INT The EMU 18 determines the degradation level of battery 12. It may perform one or more protective measures in response to a degradation level exceeding a calibration threshold and / or the health status of battery 12.

[0052] Figure 7 An exemplary implementation of method 50 is illustrated below. Beginning at box B52 (“Determining SOC-1, SOC-2”), method 50 includes determining two distinct SOC points to be used when evaluating the degradation level and state of health (SOH) of battery 12. Such levels are related to… Figure 5 and Figure 6 The first SOC (SOC-1) and the second SOC (SOC-2) correspond to each other and are later used to calculate the ΔR value. Although the actual SOC is used for the corresponding first SOC and second SOC (SOC-1 and SOC-2), for the sake of exemplary consistency, this document uses non-limiting example implementations of 50% and 10%.

[0053] Brief reference again Figure 6The selected SOC values of block B52 are sufficiently different from one another such that one value (e.g., SOC-1) occupies the steady state / intermediate range of the trace and the other value (SOC-2 in this case) corresponds to the falling (or rising) tail of the trace. The EMU 18 can be programmed to have a first SOC (SOC-1) level calibrated to be about 25% to about 75% and a second SOC level (SOC-2) calibrated to be about 0 to 25%, consistent with Figure 6 representative traces of FIG. 2, where the exemplary 50% and 10% levels fall within these wider ranges.

[0054] To determine the true SOC of the battery 12, Figure 1 The EMU 18, via its processor 19, can determine the true SOC of the battery 12 at a predetermined temperature, such as at 25°C or another application-specific operating temperature. The SOC can be determined via the SOC block 33 of FIG. 3, for example, using Coulomb counting, machine learning, voltage and temperature-based lookup tables, open circuit voltage (OCV) to SOC curves, or other possible methods as described above. The temperature measurement block 42 described above with reference to FIG. 3 can be used to determine the temperature of the battery 12.

[0055] Factors that influence the selection of SOC-1 and SOC-2 include the composition or construction of the battery 12. For example, the battery 12 can be offline generated Figure 5 and Figure 6 plots 55 and traces 60, respectively, and use them to determine the optimal values of SOC-1 and SOC-2. These values are then programmed into the memory 20. The method 50 proceeds to block B54 thereafter.

[0056] At block B54 (SOC = SOC-1 or SOC-2), Figure 1 The EMU 18 waits until the true SOC of the battery 12 reaches the first SOC (SOC-1) or the second SOC (SOC-2) recorded in block B52. The method 50 waits at block B54 until the first SOC or the second SOC (SOC-1 or SOC-2) has been reached before proceeding to block B56.

[0057] Block B56 (“Determine R INT INT at SOC-1 or SOC-2”) includes determining the internal resistance (RINT) at the SOC level (i.e., SOC-1 or SOC-2) detected at block B54. The battery parameters measured as part of block B56 include Figure 4 for example, the battery voltage (V B ) and current (I B ) via blocks 35 and 39, respectively. The internal resistance (RINT) is then determined from, for example, Ohm’s Law, such as Figure 5The open-circuit voltage (OCV) information at the SOC level (i.e., SOC-1 or SOC-2) can be extracted using a curve such as plot 55 or a lookup table. This information can be stored in EMU 18 during the execution of method 50. Figure 1 ) in memory 20.

[0058] To calculate the internal resistance (R) INT The processor 19 of EMU 18 can solve the following equation:

[0059]

[0060] Wherein, subscripts 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... Figure 4 Battery voltage (V) B Correspondingly, and IDD1 and IDD2 are... Figure 4 The measured battery current (I) B Correspondingly, when performing method 50, if the predetermined operating mode of battery 12 is discharge mode, OCV will exceed the battery voltage, i.e., OCV > V. During charging mode, the opposite relationship is maintained, i.e., V > OCV. When determining the internal resistance (R... INT After that, method 50 proceeds to box B58.

[0061] At box B58 (“ΔR ratio (%) > CAL?”), it involves via Figure 1 The EMU 18 performs a ΔR ratio level check. As part of box B58, processor 19 can calculate... Figure 1 The internal resistance (i.e., R) of battery 12 across different states of charge (i.e., SOC-1 and SOC-2) of battery 12 INT The rate of increase of the internal resistance (R1). For example, the EMU 18 can calculate the ΔR value as a ratio of Δresistance (ΔR), where the ΔR ratio is a function (f) of the first internal resistance (R1) and the second internal resistance (R2). Therefore, as part of this method, the EMU 18 can use the ΔR ratio to determine the degradation level of the battery 12. Figure 6 Several examples of the ΔR ratio are shown. The processor 19 can calculate the ΔR ratio using the following function (f):

[0062]

[0063] Where ΔR equals R2-R1.

[0064] Still referencing Figure 7In a representative implementation of method 50, EMU 18, as part of box B58, determines whether the ΔR ratio exceeds one or more calibrated degradation thresholds. One possible implementation includes setting a single degradation level, such as... Figure 6 The D-4 or multiple degradation thresholds correspond to severe degradation, wherein the severity of each degradation threshold increases progressively. As an example of the latter, four example thresholds are illustrated in... Figure 6 They are labeled as D-1 (no degradation or negligible degradation), D-2 (slight degradation), D-3 (moderate degradation), and D-4 (severe degradation). In other implementations, more or fewer threshold degradation levels can be achieved.

[0065] Therefore, box B58 may involve comparing the ΔR ratio with a single degradation threshold (e.g., D-4) or with several different levels of degradation thresholds (e.g., D-1, D-2, D-3, and D-4). The advantage of the latter approach is that it provides a measure of the true state of health (SOH) of battery 12 at a given point in time without battery failure. For example, EMU 18 may record degradation thresholds exceeding [a certain threshold]. Figure 1 In memory 20, a performance history of battery 12 is established, where degradation trends can be used as a metric to enable a more proactive response. Method 50 proceeds to box B60 when the ΔR ratio value has exceeded a degradation threshold, and instead returns to box B54 when it has not yet exceeded the degradation threshold.

[0066] At box B60 (“Implement control measures”), Figure 1 The EMU 18 can perform control measures on the battery 12 in response to the registered degradation level. The measures are performed using the degradation level determination results described above, based on whether the battery 12 is healthy enough to continue use without intervention. For example, the EMU 18 can determine that the degradation level exceeds... Figure 6 Choose the appropriate response based on which degradation threshold is met. For example, when it exceeds... Figure 6 When the representative degradation threshold D-1 is reached, EMU 18 can begin to monitor the state of health (SOH) of battery 12 more closely to understand that the SOH remains at an acceptablely high level but has begun to degrade. In contrast, in the same example, EMU 18 can begin to escalate its control response or preventative response measures when the degradation thresholds D-2 or D-3 have been exceeded, with more aggressive control or preventative measures being initiated when the highest degradation threshold D-4 has been exceeded.

[0067] In some implementations, each degradation threshold may be associated with a specific preventative control measure. As envisioned herein, "preventative" refers to... Figure 1The battery power system 10 notifies the user of the state of harm (SOH) of battery 12 or measures taken to address any impairment of its performance in some way. When battery 12 has only deteriorated to a minor extent, less urgent preventative measures or mechanisms can be taken, and typically the EMU 18 does not intervene in the operation of battery 12. In such cases, text messages, audio / visual alarms, or other information can be sent to the user. However, as the level of degradation becomes more severe, such as exceeding [a certain threshold], [further measures may be taken]. Figure 6 When the exemplary degradation thresholds D-3 or D-4 are reached, EMU 18 can escalate preventative response measures in terms of urgency, and may intervene in the control of the battery 12 itself.

[0068] Communication within the scope of box B68 may include transmitting health status (SOH) notifications to remote devices, such as to Figure 1 The GUI 24 transmits electronic alarm signals. Different levels of alarm or warning messages can be transmitted in this way. Alarm messages transmitted by the EMU 18 in response to less urgent situations are themselves less urgent compared to alarm messages transmitted in response to more urgent situations.

[0069] Using an illustrative example, an SMS text message can be transmitted to GUI 24 to suggest replacement or maintenance of battery 12 within an extended time frame or with unspecified urgency, such as "Battery lifespan is nearing its end, maintenance recommended." If configured in this way... Figure 1 The battery power system 10 can illuminate a light or light source in a corresponding color, such as amber or yellow, to visually alert the user that the battery 12 has partially degraded but is still functioning normally. The urgency of the alarm / message can also be escalated when the maximum degradation threshold t is exceeded. For example, more urgent wording such as "Battery in poor condition - immediate repair recommended" could be used instead of the text example above. Optional lights can illuminate in a generally understood color (such as red in this example), and / or the lights can pulsate or flash to distinguishably heighten the alarm status. An audible warning tone can also be emitted to draw the user's attention to the possible impending failure of the battery 12.

[0070] At some point, Figure 1 The EMU 18 can determine that continued use of battery 12 will potentially harm the battery power system 10 and may cause harm to the health and safety of its users. In this case, the EMU 18 can command the circuit breaker 14 ( Figure 1The protective measure is performed by disconnecting and thus disconnecting battery 12 from load 11 (or 111). Disconnecting circuit breaker 14 effectively removes battery 12 from the voltage bus connecting battery 12 to load 11 / 111, and thus protects load 11 / 111 from discharge from the now disconnected battery 12. Similarly, EMU 18 can prevent charging switch 30 from closing to prevent charging operation, for example, by transmitting an override or bypass signal to the control logic of battery charger 13 and / or charging switch 30. Battery 12 is thus isolated from the charging and discharging sides of battery power system 10.

[0071] High-energy batteries can be safely managed in a wide range of applications by using method 50 or its implementation. The solution presented herein utilizes the relationship between internal resistance and state of charge (SOC) to enable early detection of such batteries (e.g., Figure 1 The potential hazardous states of the battery 12. For example, changes in electrode structure, such as physical and chemical transformations like the formation of a solid electrolyte interphase (SEI) layer or electrode degradation due to lithium-ion structure, increase the internal resistance of ion flow within the battery 12. At lower capacities, fewer lithium ions are available to be transported between the electrodes during charge and discharge cycles. This, in turn, increases 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 more pronounced at lower capacities, leading to polarization effects that manifest as higher internal resistance. Therefore, Method 50 operates by utilizing the relationship between internal resistance and SOC when monitoring the health of the battery 12, for example, by monitoring the relative trends of internal resistance at different states of charge (nominal SOC-1 and SOC-2).

[0072] The level of degradation can be expressed as a State of Health (SOH) value, such as SOH "1" corresponding to a fully healthy battery 12 and SOH "0" corresponding to a fully degraded / inoperable battery 12. Values ​​between the normalized extremes of this exemplary range can correspond to a gradual degradation state of the battery (e.g., battery 12 as described herein), where an SOH value closer to 0 indicates greater degradation than an SOH value closer to SOH 1. Those skilled in the art who have benefited from the foregoing disclosure will now understand these and other beneficial effects of the teachings.

[0073] While several modes for carrying out the present teachings have been described in detail, those familiar with the art to which these teachings relate will recognize alternatives as being within the scope of the appended claims. The above description and drawings are illustrative and exemplary of the entire range of alternatives that are implicitly and explicitly present in the contents of the specification and are not limiting of the scope of the concepts described. Furthermore, the concepts are expressly intended to encompass alternative embodiments, not explicitly described herein. The detailed description and drawings are merely illustrative of the present teachings, the scope of which is to be limited only by the claims.

Claims

1. A system for monitoring batteries in a battery power system, the system comprising: A sensor array configured to measure the voltage, current, and temperature of the battery as a set of battery parameters; processor; and A non-transitory computer-readable storage medium ("memory"), the memory including instructions executable by the processor to cause the processor to: The set of battery parameters is received from the sensor array during a predetermined operating mode of the battery. The rate of increase of the internal resistance of the battery across various states of charge is calculated as the Δresistance (ΔR) ratio. The degradation level of the battery is determined using the ΔR ratio; as well as The level of degradation of the battery is recorded in the memory.

2. The system according to claim 1, wherein, The instructions can be executed by the processor to cause the processor to: The battery parameters are used to calculate the first internal resistance (R1) of the battery in the first state of charge (SOC-1); Calculate the second internal resistance (R2) of the battery in the second state of charge (SOC-2) using the battery parameters, where the first state of charge (SOC-1) exceeds the second state of charge (SOC-2); and Calculate the ΔR ratio as a function (f) of the first internal resistance (R1) and the second resistance (R2), where f = (R2 - R1) / R1 x 100%.

3. The system according to claim 1, wherein, The instructions can be executed by the processor to cause the processor to: Control measures for the battery are executed in response to the degradation level, including transmitting a health status notification to a remote device.

4. The system according to claim 1, wherein, The instruction can be executed by the processor to cause the processor to compare the ΔR ratio with a degradation threshold by comparing the ΔR ratio with each of the following: (i) A first degradation threshold corresponding to negligible degradation of the battery; (ii) A second degradation threshold corresponding to the mild degradation of the battery; (iii) A third degradation threshold corresponding to moderate degradation of the battery; and (iv) A fourth degradation threshold corresponding to moderate degradation of the battery.

5. The system according to claim 4, wherein, The first degradation threshold is about 25% to about 35%, the second degradation threshold is about 45% to about 55%, the third degradation threshold is about 55% to about 65%, and the fourth degradation threshold is about 80% to about 90%.

6. The system according to claim 2, wherein, The battery includes a lithium-ion battery pack, and the instructions are executable by the processor to cause the processor to: Calculate the ΔR ratio of the battery across the first state of charge (SOC-1) of approximately 50% and the second state of charge (SOC-2) of approximately 10%.

7. The system according to claim 1, further comprising: A power-off switch, wherein the battery can be connected to a load via the power-off switch, and wherein the instruction can be executed by the processor to cause the processor to command the power-off switch to open in response to the degradation level of the battery and thereby disconnect the battery from the load.

8. A method for monitoring batteries in a battery power system, the method comprising: A set of battery parameters of the battery are measured using a sensor array of a battery monitoring system; The processor of the battery monitoring system calculates the rate of increase (ΔR ratio) of the internal resistance of the battery across various states of charge of the battery; The degradation level of the battery is determined using the ΔR ratio; The corresponding degradation level of the battery is recorded in the memory of the battery monitoring system; as well as In response to recording the degradation level, control measures are performed on the battery, including transmitting a health status notification to a remote device.

9. The method according to claim 8, wherein, The sensor array includes a voltage sensor, a current sensor, and a temperature sensor, and wherein measuring the set of battery parameters of the battery using the sensor array includes measuring the voltage, current, and temperature of the battery via the voltage sensor, the current sensor, and the temperature sensor, respectively.

10. The method according to claim 9, further comprising: Calculate the first internal resistance (R1) of the battery in the first state of charge (SOC-1) of the battery using the voltage, the current and the temperature; The second internal resistance (R2) of the battery in the second state of charge (SOC-2) of the battery is calculated using the voltage, the current and the temperature, wherein the multiple states of charge of the battery include the first state of charge (SOC-1) and the second state of charge (SOC-2) of the battery. Calculate the ΔR ratio as a function (f) of the first internal resistance (R1) and the second resistance (R2); and The degradation level of the battery is determined by comparing the ΔR ratio with one or more predetermined degradation thresholds, where f = (R2 - R1) / R1 x 100%.

11. The method according to claim 10, wherein, Determining the level of degradation of the battery by comparing the ΔR ratio with one or more predetermined degradation thresholds includes comparing the ΔR ratio with a single degradation threshold.

12. The method according to claim 11, further comprising: The ΔR ratio is compared with a number of degradation thresholds, including comparing the ΔR ratio with the following: (i) A first degradation threshold corresponding to negligible degradation of the battery; (ii) A second degradation threshold corresponding to the mild degradation of the battery; (iii) A third degradation threshold corresponding to moderate degradation of the battery; as well as (iv) A fourth degradation threshold corresponding to moderate degradation of the battery.

13. The method according to claim 12, wherein, The first degradation threshold is about 25% to about 35%, the second degradation threshold is about 45% to about 55%, the third degradation threshold is about 55% to about 65%, and the fourth degradation threshold is about 80% to about 90%.

14. The method of claim 10, wherein, The battery includes a lithium-ion battery pack, with a first state of charge (SOC-1) of approximately 50% and a second state of charge (SOC-2) of approximately 10%.

15. The method according to claim 8, wherein, The battery power system includes a power-off switch, and the battery can be connected to a load via the power-off switch. The method further includes: In response to the level of degradation of the battery, the power-off switch is commanded to open, thereby disconnecting the battery from the load.

16. A battery power system for supplying power to a load, the battery power system comprising: Power off switch; A battery that can be selectively connected to the load via the power-off switch; A sensor array connected to the battery and configured to measure the battery's voltage, current, and temperature as battery parameters; and An electronic monitoring unit (EMU) has a processor and a non-transitory computer-readable storage medium ("memory"), the memory including instructions executable by the processor to cause the EMU to: The battery parameters are received from the sensor array during a predetermined operating mode of the battery; The battery parameters are used to calculate the first internal resistance (R1) of the battery in the first state of charge (SOC-1); The battery parameters are used to calculate the second internal resistance (R2) of the battery in the second state of charge (SOC-2), where the first state of charge (SOC-1) exceeds the second state of charge (SOC-2). Calculate the Δresistance (ΔR) ratio as a function (f) of the first internal resistance (R1) and the second resistance (R2), where f = (R2 - R1) / R1 x 100%; and The degradation level of the battery is determined using the ΔR ratio.

17. The battery power system according to claim 16, further comprising: The load.

18. The battery power system according to claim 17, wherein, The payload includes wearable medical devices.

19. The battery power system according to claim 16, wherein, The instruction can be executed by the processor to cause the EMU to compare the ΔR ratio with the following: (i) A first degradation threshold corresponding to negligible degradation of the battery; (ii) A second degradation threshold corresponding to the mild degradation of the battery; (iii) A third degradation threshold corresponding to moderate degradation of the battery; as well as (iv) A fourth degradation threshold corresponding to moderate degradation of the battery.

20. The battery power system according to claim 16, wherein, The EMU is configured to command the power-off switch to open and thereby disconnect the battery from the load in response to the degradation level exceeding a degradation threshold.

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