Apparatus, methods and computer programs for updating the current mode of fast charging

Abstract

This invention relates to an apparatus and method for updating the current mode of fast charging, and a computer program stored in a storage medium for performing the method. The apparatus for updating the current mode of fast charging includes: a resistance calculation unit for calculating the internal resistance of a battery module; a storage unit for storing the current mode for fast charging of the battery module; and an arithmetic unit for updating the current mode according to the state of the internal resistance of the battery module, wherein the arithmetic unit calculates a resistance increase rate based on the internal resistance calculated by the resistance calculation unit, calculates an adjustment factor based on the calculated resistance increase rate, and updates the current mode using the calculated adjustment factor and the current mode. Therefore, this invention minimizes the impact of fast charging on the lifespan of the battery module.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This invention claims priority to Korean Patent Application No. 10-2019-0171205, filed on December 19, 2019, and includes all disclosures in that Korean patent application document as part of this specification. Technical Field

[0004] The present invention relates to an apparatus and method for updating the current mode of fast charging, and a computer program stored in a storage medium for executing the method. Background Technology

[0005] Recently, with the widespread adoption of electronic devices such as smartphones and the development of electric vehicles, research on secondary batteries as a power source has been actively underway. Secondary batteries are provided in the form of battery packs, which include battery modules consisting of multiple battery cells connected in series and / or parallel, and a battery management system (BMS) that manages the operation of the battery modules.

[0006] If needed, the battery pack performs fast charging based on the current mode of fast charging, but there are concerns that the battery pack's capacity will decrease rapidly with the number of fast charging cycles. Summary of the Invention

[0007] Technical issues

[0008] In view of this situation, the present invention is proposed, and its object is to provide a fast charging current mode update device and method that can efficiently perform fast charging of a battery pack without affecting the battery pack's lifespan, as well as a computer program stored in a storage medium for executing the method.

[0009] Technical solution

[0010] To address the aforementioned technical problems, according to one aspect of the present invention, an apparatus for updating a fast-charging current mode includes: a resistance calculation unit configured to calculate the internal resistance of a battery module; a storage unit configured to store a fast-charging current mode for the battery module; and a calculation unit configured to update the current mode based on the state of the internal resistance of the battery module, wherein the calculation unit calculates a resistance increase rate based on the internal resistance calculated by the resistance calculation unit, calculates an adjustment coefficient based on the calculated resistance increase rate, and updates the current mode using the calculated adjustment coefficient and the current mode.

[0011] To address the aforementioned technical problems, according to another aspect of the embodiments of the present invention, a method for updating the current mode of fast charging includes: setting a current mode for fast charging of a battery module; calculating the internal resistance of the battery module; calculating the resistance increase rate of the battery module; calculating an adjustment coefficient based on the resistance increase rate; and adjusting the current mode using the adjustment coefficient to generate an adjusted current mode.

[0012] To address the aforementioned technical problems, according to another aspect of the present invention, a computer program is provided, which is stored in a computer-readable storage medium and allows a computer to execute a method for updating the current mode of fast charging.

[0013] Beneficial effects

[0014] The device and method for updating the current mode of fast charging, along with the computer program storing the method in the storage medium, can minimize the impact on the lifespan of the battery module during fast charging. Attached Figure Description

[0015] Figure 1 This is a diagram showing the configuration of a battery pack, including a battery management system.

[0016] Figure 2 This is a block diagram illustrating the functions of a battery management system according to an embodiment of the present invention.

[0017] Figure 3 This is a block diagram illustrating the detailed functions of a computing unit according to an embodiment of the present invention.

[0018] Figure 4 This is a diagram schematically illustrating a method for updating the current mode of fast charging according to an embodiment of the present invention.

[0019] Figure 5 This is test data showing the capacity change of the battery module when the current mode of fast charging is updated according to an embodiment of the present invention.

[0020] Figure 6 This is a curve illustrating the timing of current mode updates during fast charging according to an embodiment of the present invention.

[0021] Figure 7 This is test data showing the capacity change of a battery module when the current mode is updated according to the timing of the current mode update for fast charging, according to an embodiment of the present invention.

[0022] Figure 8 This is a flowchart illustrating a method for updating the current mode of fast charging according to an embodiment of the present invention.

[0023] Figure 9This is a flowchart illustrating a method for determining the timing of updating the current mode for fast charging according to an embodiment of the present invention.

[0024] Figure 10 It shows the basis Figure 4 The diagram shows a modification of the current mode method for updating the implementation of fast charging.

[0025] Figure 11 It shows the basis Figure 4 A diagram showing another modification to the method of updating the current mode of fast charging implementation.

[0026] Figure 12 Is using Figure 4 , Figure 10 and Figure 11 Experimental data on the capacity change of a battery module were obtained by using a current mode update method for fast charging.

[0027] Figure 13 This is a diagram illustrating a method for updating the current mode of fast charging according to another embodiment of the present invention.

[0028] Figure 14 It shows the basis Figure 13 The diagram shows a modification of the current mode method for updating the implementation of fast charging.

[0029] Figure 15 It shows the basis Figure 13 A diagram showing another modification to the method of updating the current mode of fast charging implementation.

[0030] Figure 16 This is a block diagram illustrating the detailed functions of a computing unit according to another embodiment of the present invention.

[0031] Figure 17 This is test data showing the change in battery module capacity when the current mode of fast charging is updated according to another embodiment of the present invention.

[0032] Figure 18 This is a flowchart illustrating a method for determining the point at which to stop using the battery module according to an embodiment of the present invention.

[0033] Figure 19 and Figure 20 This is a curve used to illustrate the time points at which the battery module is discontinued according to an embodiment of the present invention.

[0034] Figure 21 This is a hardware diagram of the battery management system. Detailed Implementation

[0035] In the following, various embodiments of the invention will be described in detail with reference to the accompanying drawings. Throughout this document, the same reference numerals are used for the same components in the drawings, and repeated descriptions of the same components are omitted.

[0036] The specific structural or functional descriptions of the various embodiments of the present invention disclosed in this document are merely for explaining the embodiments of the present invention, and the various embodiments of the present invention can be implemented in various forms and should not be construed as limited to the embodiments described in this document.

[0037] Terms such as “first,” “second,” “first,” and “second” as used herein may refer to various different elements that modify various embodiments of this disclosure, but are not limiting of these elements. For example, a first component may be referred to as a second component without departing from the technical scope of the invention, and vice versa.

[0038] The terminology used herein is for the purpose of describing particular example implementations only and is not intended to limit the scope of other implementations. Singular terms may include plural forms unless they have distinctly different meanings in the context.

[0039] Figure 1 This is a diagram showing the structure of the battery pack 1, including the battery management system 20.

[0040] refer to Figure 1 The battery pack 1 includes a battery module 10 consisting of one or more battery cells and capable of being charged and discharged, a switching unit 30 connected in series to the positive or negative side of the battery module 10 to control the charging / discharging current of the battery module 10, and a battery management system 20 (hereinafter referred to as "BMS") that monitors the voltage, current, temperature, etc. of the battery cells and / or battery module 10 to control and manage and prevent overcharging and over-discharging.

[0041] The battery module 10 includes one or more battery cells 11 that can be charged and discharged. The battery cell 11 may be a lithium-ion battery, a lithium-ion polymer battery, a nickel-cadmium battery, a nickel-metal hydride battery, etc., but is not limited to these.

[0042] The BMS 20 can control the operation of the switching unit 30 to control the charging and discharging of the battery module 10. Furthermore, the BMS 20 can monitor the voltage, current, temperature, etc., of the battery module 10 and / or each battery module and / or battery cell 11 included in the battery module 10. In addition, for monitoring via the BMS 20, sensors or various measurement modules (not shown) can be additionally installed at any location on the battery module 10 or along the charging / discharging path of the battery pack 1. The BMS 20 can calculate parameters indicating the state of the battery module 10, such as SOC or SOH, based on the monitored voltage, current, and temperature measurements.

[0043] BMS 20 controls and manages the overall operation of battery pack 1. For this purpose, BMS 20 may include various components, such as a microcomputer that acts as a controller to execute programs and control the overall operation of BMS 20, input / output devices such as sensors and measuring devices, and other peripheral circuits.

[0044] Furthermore, the BMS 20 can fast charge the battery module 10 according to a preset algorithm. The preset algorithm may be based on a specific current pattern for charging the battery module 10. Specifically, the BMS 20 according to an embodiment of the present invention provides a method for updating the current pattern used for fast charging of the battery module 10 and a method for determining when to update. Furthermore, the BMS 20 according to an embodiment of the present invention also provides a method for determining when to stop using the battery module 10. Details of the functionality of the BMS 20 will be described later.

[0045] Switching unit 30 is a semiconductor switching element that controls the flow of current for charging or discharging the battery module 10, and may, for example, use at least one MOSFET. Those skilled in the art will readily understand that, in addition to semiconductor switching elements, relays or contactors may be used as switching unit 30.

[0046] Battery pack 1 can also be communicatively connected to an external upper-level controller 2. That is, battery pack 1 can send various data from battery pack 1 to upper-level controller 2 and receive control signals from upper-level controller 2 for the operation of battery pack 1. Upper-level controller 2 can be a vehicle controller that controls the operation of the vehicle when battery pack 1 is installed in an electric vehicle. Upper-level controller 2 can be a rack-mounted BMS that manages multiple battery modules or a BMS that controls the overall operation of the energy storage device (ESS) when battery pack 1 is used in an ESS.

[0047] Figure 2 This is a block diagram illustrating the functionality of BMS 20 according to an embodiment of the present invention.

[0048] refer to Figure 2The BMS 20 may include a resistance calculation unit 110, a storage unit 120, a calculation unit 130, and a communication unit 140.

[0049] The resistance calculation unit 110 calculates the internal resistance of the battery module 10. The resistance calculation unit 110 may include a collection of various sensors used to calculate the internal resistance of the battery module 10. For example, the resistance calculation unit 110 may include at least one of the following: a voltage measuring device for measuring the OCV of the battery module 10, a current measuring device for measuring the current used for charging and discharging in the battery module 10, and a temperature measuring device for measuring the temperature of the battery module 10. In addition to the various measuring devices described above, the resistance calculation unit 110 may also include a calculation device for calculating the internal resistance value of the battery module 10 based on the values ​​measured by each measuring device.

[0050] Storage unit 120 can store various programs and data required for the operation of BMS 20. Storage unit 120 can store the algorithm for fast charging battery module 10 as described above. Furthermore, storage unit 20 can store the current mode for fast charging battery module 10 for use during fast charging. The algorithm for fast charging may include methods for updating the current mode for fast charging and information related to when the update is performed.

[0051] The calculation unit 130 updates the current mode based on the internal resistance of the battery module 10. Detailed operation of the calculation unit 130 will be discussed later. Figure 3 Describe it.

[0052] The communication unit 140 can send various information about the battery cell 11, battery module 10, and / or battery pack 1 to the upper-level controller 2 as needed. Furthermore, the communication unit 140 can receive control signals from the upper-level controller 2 for controlling the battery pack 1. If it is determined that the communication unit 140 should stop using the battery module 10, it can send a message to the upper-level controller 2.

[0053] Figure 3 This is a block diagram illustrating the detailed functions of the computing unit 130 according to an embodiment of the present invention.

[0054] refer to Figure 3 The calculation unit 130 includes a resistance increase rate calculation unit 131, an adjustment coefficient calculation unit 132, a current mode calculation unit 133, an update requirement determination unit 134, and a voltage measurement unit 135.

[0055] The resistance increase rate calculation unit 131 calculates the resistance increase rate based on the internal resistance calculated by the resistance calculation unit 110. The resistance increase rate can be calculated as follows.

[0056] [Formula 1]

[0057] Resistance increase rate (%) = (Degraded resistance / Initial resistance - 1) * 100

[0058] The resistance increase rate calculation unit 131 can calculate the rate of change of the internal resistance of the battery module 10 over a predetermined time period. The predetermined time period can be any periodically set. Alternatively, the resistance increase rate calculation unit 131 can calculate the resistance increase rate based on the internal resistance measured just before fast charging and previously measured internal resistance. However, the time points and time periods used to calculate the internal resistance are merely examples and are not limited thereto.

[0059] The adjustment coefficient calculation unit 132 calculates the adjustment coefficient based on the resistance increase rate calculated by the resistance increase rate calculation unit 131. The adjustment coefficient calculation unit 132 calculates the adjustment coefficient so that it decreases as the resistance increase rate increases.

[0060] As an example, the resistance increase rate calculation unit 131 can calculate the adjustment coefficient using the following equation 2.

[0061] [Formula 2]

[0062] Adjustment coefficient = (100 - α * (resistance increase rate (%))) / 100

[0063] In this case, the α value can be a value determined according to the type of battery module 10. That is, the α value can be a value determined according to the chemical composition of the battery cells, such as whether battery module 10 is a lithium-ion battery or a lithium-ion polymer battery. This α value can be a value between 0.5 and 4.

[0064] As another example, the resistance increase rate calculation unit 132 can calculate the adjustment coefficient using the following equation 3.

[0065] [Formula 3]

[0066] Adjustment coefficient = 1 / (α*(1+resistance increase rate (%) / 100))

[0067] The value of α at this point is the same as the value of α in Equation 2.

[0068] That is, the resistance increase rate calculation unit 132 calculates an adjustment coefficient to reduce the current mode. In other words, the algorithm for updating the current mode of fast charging according to an embodiment of the present invention reduces the current amplitude of the current mode.

[0069] The current mode calculation unit 133 updates the current mode using the calculated adjustment coefficient and the current mode stored in the storage unit 120. Specifically, the current mode calculation unit 133 calculates a value obtained by multiplying the previously stored current mode by the adjustment coefficient calculated by the adjustment coefficient calculation unit 132, and uses this value as the new current mode for fast charging for updating.

[0070] Figure 4 This diagram schematically illustrates a method for updating the current mode of fast charging according to an embodiment. As described above, it shows calculating a new current mode b by multiplying the existing current mode used for fast charging by an adjustment factor a. Figure 4 In this case, when charging is performed in a capacity-limited manner, the current gradually decreases according to the state of charge (SOC) of the battery module 10. For example... Figure 4 As shown, the current mode is set to charge using i1 current amplitude until SOC becomes s1, then using i2 current amplitude to charge from s1 to s2, using i3 current amplitude to charge from s3 to full charge, and using i4 current amplitude to charge from s3 to full charge. Furthermore, the current mode is changed by multiplying the adjustment factor by the time point at which the fast-charging current mode needs to be updated, as shown by the dashed line. The currents are changed to i1', i2', i3', and i4', respectively. Here, i1' = i1 * (adjustment factor), i2' = i2 * (adjustment factor), i3' = i3 * (adjustment factor), and i4' = i4 * (adjustment factor). That is, the existing current mode is updated to a current mode with a new amplitude generated by multiplying the current amplitude in the current mode by the adjustment factor (current derating type update).

[0071] The update requirement determination unit 134 determines when to update the fast charging current mode. In this embodiment, such as... Figure 4 As shown, the current mode of fast charging employs a capacity-limited method, which performs charging until the battery module 10 reaches a preset charging capacity. In this case, when the transition curve of the charging end voltage (which is the voltage at which fast charging is completed) meets a preset criterion, the update requirement determination unit 134 determines the updated current mode. The preset criterion for the transition curve of the charging end voltage can be the occurrence of an inflection point in the transition curve. The inflection point can be a signal indicating that an abnormality is occurring in the battery cell 11. Therefore, by monitoring the occurrence of this inflection point, the update time point of the fast charging current mode can be identified.

[0072] When the update requirement determination unit 134 determines that the current mode needs to be updated, the fast charging current mode is updated with the new current mode calculated by the current mode calculation unit 133. In this case, the updated current mode can be stored in the storage unit 120.

[0073] The voltage measurement unit 135 measures the charging end voltage, which is the voltage at which fast charging is completed whenever the battery module 10 is fast charged. The voltage measurement unit 135 may be a voltage sensor that monitors the voltage of the battery cell 11 and / or the battery module 10. Alternatively, the voltage measurement unit 135 may obtain the charging end voltage by monitoring the voltage of the battery module 10 in real time, and may use the voltage at the point in time required to determine update requirements.

[0074] In this embodiment, the update requirement is determined using the charging end voltage, but this is merely exemplary and not limited to this. For example, if the parameter is related to the characteristics of the charging end voltage, it can be used as a factor in determining the update requirement. For instance, the update requirement can be determined using a resistance value calculated using the charging end voltage and the OCV value.

[0075] Figure 5 These are test data showing the capacity change of the battery module 10 when the current mode of fast charging is updated according to an embodiment of the present invention.

[0076] As in Figure 5 As can be seen in the "Comparative Example" curve, when battery module 10 is fast-charged without changing the fast-charging current mode, a rapid decrease in the capacity of battery module 10 can be observed. Specifically, when fast charging is repeated approximately 10 times, the capacity of battery module 10 decreases rapidly.

[0077] On the other hand, as can be seen from the curves in the "Implementation Methods" section, when the battery module 10 is fast-charged according to the present invention by updating the current mode of fast charging, the capacity of the battery module 10 hardly changes. That is, almost no change in the capacity of the battery module 10 with respect to the number of fast-charging cycles is observed.

[0078] When the current mode used for fast charging of battery module 10 continues to be used without changing the previously stored current mode, the capacity of battery module 10 will also be affected due to the change in the internal resistance of battery module 10.

[0079] However, the method for updating the current mode for fast charging according to the embodiment of the present invention, as described above, also changes the current mode taking into account changes in the internal resistance of the battery module 10. Therefore, even when the battery module 10 is fast charged, the capacity change of the battery module 10 can be minimized.

[0080] Figure 6 This is a curve illustrating the timing of current mode updates during fast charging according to an embodiment of the present invention.

[0081] refer to Figure 6The diagram illustrates the transition of the charging termination voltage as measured upon completion of fast charging. The update requires determination unit 134 to detect the inflection point in the charging termination voltage transition curve, as indicated by the arrow.

[0082] Figure 7 This is test data showing the capacity change of the battery module when the current mode is updated according to the update timing of the current mode of fast charging, according to an embodiment of the present invention.

[0083] refer to Figure 7 The curve in "Comparative Example 1" shows the change in the charging end voltage of battery module 10 when the update algorithm for the current mode of fast charging is not applied at all. It was found that after about 20 fast charging cycles, the charging end voltage rises rapidly.

[0084] The curve in "Comparative Example 2" uses the update algorithm of the fast charging current mode, but the update time point is the curve applied at the inflection point. Compared with Comparative Example 1, it was found that the charging end voltage did not change even after a considerable number of fast charging repetitions. However, after about 100 fast charging cycles, a rapid increase in the charging end voltage was observed.

[0085] The “Implementation Method” curve is the curve of the update algorithm for the current mode of fast charging applied immediately after the inflection point occurs. It can be clearly seen from the curve that, despite repeated fast charging 100 times or more, the increase in the charging end voltage of battery module 10 is significantly suppressed.

[0086] When the current mode for fast charging of battery module 10 is not updated, and even if the update timing is delayed, the capacity reduction of battery module 10 cannot be avoided.

[0087] However, the method for determining the timing of updating the current mode of fast charging according to the above-described embodiments of the present invention can accurately and quickly identify the time point when the current mode of fast charging needs to be updated, thereby minimizing the capacity variation of the battery module 10.

[0088] Figure 8 This is a flowchart illustrating a method for updating the current mode of fast charging according to an embodiment of the present invention.

[0089] refer to Figure 8 The fast charging current mode is preset in the storage unit 120 of the BMS 20 (S10). The manufacturer can set the current mode before the battery pack 1 is shipped. Alternatively, the fast charging current mode can be set by the manufacturer or the user even after the battery pack 1 is shipped.

[0090] Subsequently, when battery pack 1 is installed and used in vehicles, etc., BMS 20 monitors the internal resistance of battery module 10 (S11). In other words, it calculates the internal resistance of battery module 10. Furthermore, it calculates the resistance increase rate based on the monitored internal resistance (S12). And, it calculates an adjustment coefficient based on the calculated resistance increase rate (S13). Since the calculation of the resistance increase rate and the adjustment coefficient in operations S12 and S13 have already been performed... Figure 2 and Figure 3 The detailed description is omitted here.

[0091] BMS 20 calls the fast charging current mode stored in storage unit 120 (S14) and determines whether the current mode update requirements are met (S15).

[0092] If the current mode update requirement is met (yes in S16), the current mode is updated. The current mode update can be performed using the adjustment coefficient calculated in operation S13 and the current mode invoked in operation S14. If the current mode update requirement is not met (no in S16), the process returns to operation S11, and the algorithm for updating the current mode is repeated.

[0093] Figure 9 This is a flowchart illustrating a method for determining the timing of updating the current mode for fast charging according to an embodiment of the present invention. Figure 9 It shows Figure 8 Detailed operation S15.

[0094] refer to Figure 9 BMS 20 determines whether battery pack 1 has started charging (S20). If it is determined that charging has started, it determines whether the corresponding charging is fast charging (S21). If charging has not started or the charging is not fast charging, the algorithm according to the embodiment of the present invention is not applied, and the process proceeds to operation S11.

[0095] On the other hand, when fast charging begins (Yes in S21), it waits until fast charging is complete. Then, when fast charging ends, the charging end voltage of battery module 10 is measured (S23). Then, based on the repeatedly measured charging end voltage, the transition of the charging end voltage is determined (S24).

[0096] When an inflection point is detected in the transition curve of the charging end voltage as a requirement to update the current mode for fast charging (Yes in S25), the process proceeds to step S17 to update the current mode. On the other hand, if no inflection point is detected in the transition curve of the charging end voltage (No in S25), it is determined that fast charging can be performed using the existing current mode. Therefore, the process proceeds to operation S11. That is, operation S25 corresponds to... Figure 8Operation S16.

[0097] The operations in steps S23 to S25, such as measuring the charging end voltage and detecting the inflection point, have been referenced. Figure 2 and Figure 3 A detailed description will be omitted here.

[0098] Figure 10 It shows the basis Figure 4 The diagram illustrates a modification to the current mode method for fast charging, based on an updated implementation. Figure 10 In this example, a new current mode is obtained simply by multiplying the current mode by an adjustment factor. Charging is also performed in a capacity-limited manner, and the current gradually decreases according to the SOC of battery module 10.

[0099] However, in this example, the current pattern is changed as shown by the dashed line by multiplying the SOC value at the time point where the current amplitude is set to change by an adjustment factor. In other words, the time point where the current changes from i1 to i2 changes from s1 to s1', the time point where the current changes from i2 to i3 changes from s2 to s2', and the time point where the current changes from i3 to i4 changes from s3 to s3'. Here, s1' = s1 * (adjustment factor), s2' = s2 * (adjustment factor), and s3' = s3 * (adjustment factor). That is, the existing current pattern is updated to a new SOC value (obtained by multiplying the SOC value at the time point where the current amplitude in the current pattern is set to change by an adjustment factor) as a current pattern with the time point where the current amplitude changes (SOC derating type update).

[0100] The adjustment factor can be a value calculated according to Equation 4 or Equation 5 below. That is, it can be a value different from the adjustment factor described in Equations 2 and 3 above.

[0101] [Formula 4]

[0102] Adjustment factor = (100 - β * (resistance increase rate (%))) / 100

[0103] [Formula 5]

[0104] Adjustment coefficient = 1 / (β*(1+resistance increase rate (%) / 100))

[0105] In this case, the β value can be a value determined according to the type of battery module 10. That is, the β value can be a value determined according to the chemical composition of the battery cell (such as whether battery module 10 is a lithium-ion battery or a lithium-ion polymer battery). This β value can be a value between 0.5 and 4.

[0106] Figure 11 It shows the basis Figure 4 A diagram illustrating another modification to the method for updating the current mode of fast charging implementation. Figure 11 In this example, a new current mode is obtained simply by multiplying the current mode by an adjustment factor. Charging is also performed in a capacity-limited manner, and the current gradually decreases according to the SOC of battery module 10.

[0107] In this example, the current mode is updated using a hybrid update method, where, Figure 4 The current derating type update method described in the document and Figure 10 The SOC derating type updates described herein are all applied. Therefore, the current magnitude is based on... Figure 4 The adjustment is based on the adjustment coefficient described in [the document], and the timing for adjusting the current amplitude is determined according to [the specific criteria]. Figure 10 The adjustment is made using the adjustment coefficients described in the text.

[0108] Figure 12 Is using Figure 4 , Figure 10 and Figure 11 Experimental data on the capacity change of a battery module measured using a current mode update method for fast charging. Figure 12 In the experiment, the α and β values ​​were set to 1. Additionally, the experiment was conducted using four cells with a resistance increase rate of 12%. If none of the four cells received a current mode update, the current derating type update method, the SOC derating type update method, and a hybrid update method were applied, and fast charging was repeatedly performed.

[0109] like Figure 12 As shown, when fast charging continues in the initial current mode (BOL), a sudden degradation can be detected because the battery module's capacity decreases rapidly with each repetition of fast charging. On the other hand, the degradation level is similarly improved in both the current derating type update method and the SOC derating type update method. Furthermore, in the case of the hybrid update method, it is evident that the degradation level is lowest, rather than the longest charging time.

[0110] When the current mode for fast charging of battery module 10 is used without changing the previously stored current mode, the capacity of battery module 10 will also be affected due to the change in the internal resistance of battery module 10.

[0111] However, according to various methods for updating the current mode of fast charging as described above, the current mode is also changed while taking into account the change in the internal resistance of the battery module 10. Therefore, even if the battery module 10 is fast charged, the capacity change of the battery module 10 can be minimized.

[0112] Figure 13This is a diagram illustrating a method for updating the current mode of fast charging according to another embodiment of the present invention. Figure 13 In this process, a new current mode is obtained simply by multiplying the current mode by an adjustment factor.

[0113] Figure 13 This refers to a voltage-limited charging method where the current gradually decreases according to the voltage value of battery module 10. For example... Figure 13 As shown, the current mode is set to charge the current amplitude with i1 until the voltage value becomes v1, then charge the current amplitude with i2 in the portion from v1 to v2, charge the current amplitude with i3 in the portion from v2 to v3, and charge the current amplitude with i4 in the portion from v3 to full charge. The current mode is changed by multiplying the adjustment factor by the time point at which the fast-charging current mode needs to be updated, as shown by the dashed line. The currents change to i1', i2', i3', and i4', respectively. Here, i1' = i1 * (adjustment factor), i2' = i2 * (adjustment factor), i3' = i3 * (adjustment factor), and i4' = i4 * (adjustment factor). That is, the existing current mode is updated to a current mode with a new amplitude generated by multiplying the current amplitude in the current mode by the adjustment factor (current derating type update).

[0114] Figure 14 It shows the basis Figure 13 The diagram illustrates a modification to the current mode method for fast charging, based on an updated implementation. Figure 14 In this example, a new current mode is obtained simply by multiplying the current mode by an adjustment factor. Charging is also performed in a voltage-limited manner, and the current is gradually reduced based on the voltage value of battery module 10.

[0115] However, in this example, the current pattern is changed to the dashed line by multiplying the voltage value at the time point where the current amplitude is set to change by an adjustment factor. That is, the time point where the current changes from i1 to i2 changes from v1 to v1', the time point where the current changes from i2 to i3 changes from v2 to v2', and the time point where the current changes from i3 to i4 changes from v3 to v3'. Here, v1' = v1 * (adjustment factor), v2' = v2 * (adjustment factor), and v3' = v3 * (adjustment factor). In other words, the existing current pattern is updated to a new voltage value obtained by multiplying the voltage value at the time point where the current amplitude in the current pattern is set to change by an adjustment factor, as the current pattern with the time point where the current amplitude changes (voltage derating type update).

[0116] In the same example, according to Figure 13 Adjustment coefficient and according to Figure 14 The adjustment factor can be as follows: Figure 4 and Figure 10It is calculated separately, as in the example.

[0117] Figure 15 It shows the basis Figure 13 A diagram illustrating another modification to the method for updating the current mode of fast charging implementation. Figure 15 In this example, a new current mode is obtained simply by multiplying the current mode by an adjustment factor. Charging is also performed in a voltage-limited manner, and the current is gradually reduced based on the voltage value of battery module 10.

[0118] In this example, the current mode is updated using a hybrid update method, where, Figure 13 The current derating type update method described in the document and Figure 14 The voltage derating types described herein are all applied in the hybrid update method. Therefore, the current magnitude is based on... Figure 13 Adjusted according to the adjustment coefficients described in the document, and based on... Figure 14 The adjustment coefficient described herein is used to adjust the timing of the current amplitude.

[0119] Even when fast charging is performed in a voltage-limited manner as described above, fast charging is performed when the current mode is updated by a current derating type update method, a voltage derating type update method, or a hybrid update method, thereby minimizing the capacity variation of the battery module 10.

[0120] Figure 16 This is a block diagram illustrating the detailed functions of a computing unit according to another embodiment of the present invention. Here, the main description will focus on... Figure 3 The differences.

[0121] The update request determination unit 134 determines when to update the fast charging current mode. In this embodiment, the fast charging current mode is applied using a voltage-limited method, which performs charging until the battery module 10 reaches a preset voltage. In this case, the update request determination unit 134 determines when to update the current mode when the transition curve of the charging end capacity (which is the capacity at the end of fast charging) meets a preset criterion. The preset criterion for the transition curve of the charging end capacity can be that an inflection point occurs in the transition curve of the charging end capacity.

[0122] When the update requirement determination unit 134 determines that the current mode needs to be updated, the fast charging current mode is updated with the new current mode calculated by the current mode calculation unit 133. In this case, the updated current mode can be stored in the storage unit 120.

[0123] Whenever fast charging of battery module 10 is performed, capacity calculation unit 136 calculates the end-of-charge capacity, i.e., the capacity of battery module 10 when fast charging is completed. Capacity calculation unit 136 can use sensors that monitor the voltage, current, etc., of battery cells 11 and / or battery module 10. Alternatively, capacity calculation unit 136 can calculate the capacity of battery module 10 by methods such as calculating the capacity of battery module 10 based on values ​​measured using sensors.

[0124] Figure 17 This is test data showing the change in battery module capacity when the current mode of fast charging is updated according to another embodiment of the present invention.

[0125] refer to Figure 17 The curve in "Comparative Example 1" shows the change in the end-of-charge capacity of battery module 10 when the update algorithm for the current mode of fast charging is not applied at all. It was found that the end-of-charge capacity increases rapidly after about 20 fast charging cycles.

[0126] The curve in "Comparative Example 2" applies the update algorithm of the fast charging current mode, but the update time point is the curve applied at the inflection point. Compared with Comparative Example 1, it was found that even after a considerable number of fast charging repetitions, the end-of-charge capacity did not change. However, after approximately 60 fast charging cycles, a rapid increase in the end-of-charge capacity was observed.

[0127] The “Implementation” curve is the curve for applying the current mode update algorithm immediately after the inflection point occurs to perform fast charging. It can be clearly seen from the curve that despite repeating fast charging 100 times or more, the end-of-charge capacity of battery module 10 shows almost no increase.

[0128] When the current mode for fast charging of battery module 10 is not updated, and even if the update timing is delayed, the capacity reduction of battery module 10 cannot be avoided.

[0129] However, the method for determining the timing of updating the current mode for fast charging according to the embodiments of the present invention described above can accurately and quickly identify the time point when the current mode for fast charging needs to be updated. This minimizes the capacity variation of the battery module 10.

[0130] Alternatively, in addition to determining the timing for updating the current mode for fast charging based on the inflection point of the transition curve of the charging end voltage or the transition curve of the charging end capacity as described above, other methods can be used. For example, the current mode can be updated when the rate of increase of the resistance calculated above becomes a preset reference value or greater.

[0131] Figure 18This is a flowchart illustrating a method for determining the point at which to stop using the battery module according to an embodiment of the present invention.

[0132] refer to Figure 18 An algorithm for determining the point at which to stop using the battery module determines whether to perform fast charging (S30). In this embodiment, it is assumed that the current mode of fast charging has been applied to the update algorithm of the embodiment of the present invention. When it is determined that fast charging should be performed, the charging end voltage or charging end capacity is detected (S31). Then, it is determined whether the detected change in charging end voltage or charging end capacity is greater than a reference value (S32). Determining whether the reference value has fluctuated may include determining whether the voltage at the end of charging has exceeded the reference value. Furthermore, determining whether its fluctuation is greater than the reference value may include determining whether the charging end capacity is less than the reference value.

[0133] When the charging end voltage or charging end capacity fluctuation exceeds a reference value, it is determined that the battery module 10 has reached its usage limit, and the use of the battery module 10 is stopped (S33). The purpose of stopping the use of the battery module 10 can be notified to the upper-level controller 2. On the other hand, if the charging end voltage or charging end capacity does not change beyond the reference value, it is determined that the battery module 10 can continue to be used.

[0134] Figure 19 and Figure 20 This is a curve used to illustrate the time points at which the battery module is discontinued according to an embodiment of the present invention.

[0135] like Figure 19 and Figure 20 As shown, during repeated fast charging, the charging termination voltage or charging termination capacity may fluctuate rapidly. In this situation, the battery module 10 cannot provide the required output. Therefore, a serious safety situation may occur in vehicles equipped with the battery pack 1. Therefore, when the charging termination voltage or charging termination capacity fluctuation exceeds a reference value, the battery module 10 should be discontinued.

[0136] Alternatively, the time point for stopping the use of battery module 10 can also be determined using other methods. For example, when the number of times the inflection point appears in the transition curve of the earlier detected charging end voltage or charging end capacity becomes a preset reference number, the battery module 10 can be set to stop being used.

[0137] Figure 21 This is a hardware structure diagram of the battery management system.

[0138] refer to Figure 21 The BMS 20 may include a controller (MCU) 210, a memory 220, an input / output interface 230, and a communication interface 240.

[0139] The MCU 210 performs various operations and calculations in the BMS 20, as well as controls each component.

[0140] The memory 220 contains the operating system program and the program for executing the functions of the BMS 20. Specifically, a computer program containing an algorithm for updating the current mode for fast charging according to an embodiment of the present invention, and an algorithm for determining the timing of updating the current mode and the timing of stopping the use of the battery module 10, can be stored in the memory 220. The memory 220 may include volatile memory and non-volatile memory. For example, at least one of various storage media (such as semiconductor memory like RAM, ROM, and flash memory, magnetic disks, and optical disks) can be used as the memory 220. The memory 220 may be a memory built into the MCU 210 or an additional memory installed separately from the MCU 210.

[0141] The input / output interface 230 performs input / output of various input and output signals. For example, the MCU 210 included in the BMS 20 can receive signals from various sensors through the input / output interface 230.

[0142] The communication interface 240 is a component capable of communicating with the outside world in a wired and / or wireless manner.

[0143] Since the MCU 210 executes the program stored in the memory 220, it can implement modules for performing the functions of the resistance calculation unit 110, the calculation unit 130, the resistance increase rate calculation unit 131, the adjustment coefficient calculation unit 132, the current mode calculation unit 133, the update requirement determination unit 134, and the capacity calculation unit 136. The memory 220 can be used as a storage unit 120. The MCU 210 can operate together with the input / output interface 230 to perform the functions of the resistance calculation unit 110 and the voltage measurement unit 135. In addition, the MCU 210 can operate together with the communication interface 240 to perform the functions of a communication unit 140.

[0144] Furthermore, the terms "comprising," "constituting," "having," etc., used above refer to the fact that the corresponding components may be inherent, unless otherwise stated. Therefore, they should be understood as meaning that other components may be further included, rather than excluded. Unless otherwise defined, all terms (including technical or scientific terms) may be interpreted as having the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Unless expressly defined in this invention, general terms (such as predefined terms) should be understood as having the meaning consistent with the context of the relevant art, and should not be understood as having an ideal or overly formal meaning.

[0145] The above description is merely an illustration of the technical concept of the present invention. Those skilled in the art can make various modifications and variations without departing from the essential characteristics of the invention. Therefore, the embodiments disclosed in this invention are not intended to limit the technical spirit of the invention, but are merely illustrative. The scope of the technical spirit of the invention is not limited by these embodiments. The scope of protection of this invention should be interpreted in accordance with the appended claims, and all technical concepts falling within the scope of protection of this invention should be understood as falling within the scope of protection of this invention.

Claims

1. An apparatus for updating the current mode of fast charging, the apparatus comprising: A resistance calculation unit, configured to calculate the internal resistance of the battery module; A storage unit configured to store current patterns for fast charging of the battery module; as well as A calculation unit configured to update the current pattern based on the state of the internal resistance of the battery module. The computing unit: The resistance increase rate is calculated based on the internal resistance calculated by the resistance calculation unit. The adjustment factor is calculated based on the calculated resistance increase rate, and The current mode is updated using the calculated adjustment factor and the current mode. The calculation unit further includes a voltage measurement unit, which measures the charging completion voltage each time the battery module is fast-charged. The charging completion voltage is the voltage at which the fast charging is completed. Specifically, when the transition curve of the charging end voltage meets a preset standard, the calculation unit updates the current mode.

2. The apparatus according to claim 1, wherein, The fast charging of the battery module is a capacity-limited method performed before reaching the preset charging capacity.

3. The apparatus according to claim 2, wherein, The calculation unit updates the existing current pattern with a current pattern having a new current amplitude generated by multiplying the current amplitude in the current pattern by the adjustment coefficient.

4. The apparatus according to claim 2, wherein, The computing unit updates the existing current pattern with a current pattern in which the new SOC value generated by multiplying the SOC value at the time point for which the amplitude of the current in the current pattern is to be changed by the adjustment coefficient is the time point for which the amplitude of the current is to be changed.

5. The apparatus according to claim 1, wherein, The preset standard is the detection of an inflection point in the transition curve of the charging end voltage.

6. An apparatus for updating the current mode of fast charging, the apparatus comprising: A resistance calculation unit, configured to calculate the internal resistance of the battery module; A storage unit configured to store current patterns for fast charging of the battery module; as well as A calculation unit configured to update the current pattern based on the state of the internal resistance of the battery module. The computing unit: The resistance increase rate is calculated based on the internal resistance calculated by the resistance calculation unit. The adjustment factor is calculated based on the calculated resistance increase rate, and The current mode is updated using the calculated adjustment factor and the current mode. The calculation unit further includes a capacity calculation unit, which calculates the charging completion capacity each time the battery module is fast-charged. The charging completion capacity is the capacity of the battery module at the point where the fast charging is complete. Specifically, when the transition curve of the charging end capacity meets a preset standard, the calculation unit updates the current mode.

7. The apparatus according to claim 6, wherein, The fast charging of the battery module is a voltage-limiting method performed before reaching a preset voltage.

8. The apparatus according to claim 7, wherein, The calculation unit updates the existing current pattern with a current pattern having a new current amplitude generated by multiplying the current amplitude in the current pattern by the adjustment coefficient.

9. The apparatus according to claim 7, wherein, The calculation unit updates the existing current pattern using a current pattern in which a new voltage value is generated by multiplying the voltage value at a time point used to change the amplitude of the current in the current pattern by the adjustment coefficient.

10. The apparatus according to claim 6, wherein, The preset standard is the detection of an inflection point in the capacity transition curve at the end of charging.

11. The apparatus according to any one of claims 1 to 10, wherein, The calculation unit updates the value obtained by multiplying the current pattern by the adjustment coefficient.

12. The apparatus according to any one of claims 1 to 10, wherein, As the resistance increase rate increases, the calculation unit decreases the adjustment coefficient.

13. A method for updating the current mode of fast charging, the method comprising the steps of: Set the current mode for fast charging of the battery module; Calculate the internal resistance of the battery module; Calculate the rate of increase in resistance of the battery module; Calculate the adjustment coefficient based on the aforementioned resistance increase rate; as well as The current pattern is adjusted using the adjustment coefficient to generate an adjusted current pattern. The step of adjusting the current mode includes the following steps: Each time the battery module undergoes fast charging, the charging completion voltage is measured; this charging completion voltage is the voltage at which the fast charging of the battery module is completed. When the transition curve of the charging end voltage meets the preset standard, the current mode is updated.

14. A computer-readable storage medium storing a computer program that allows a computer to perform the method according to claim 13.

15. A method for updating the current mode of fast charging, the method comprising the steps of: Set the current mode for fast charging of the battery module; Calculate the internal resistance of the battery module; Calculate the rate of increase in resistance of the battery module; Calculate the adjustment coefficient based on the aforementioned resistance increase rate; as well as The current pattern is adjusted using the adjustment coefficient to generate an adjusted current pattern. The step of adjusting the current mode includes the following steps: Each time the battery module is fast-charged, the charging completion capacity is measured. This charging completion capacity is the capacity of the battery module at the point where fast charging is complete. When the transition curve of the charging end capacity meets the preset standard, the current mode is updated.

16. A computer-readable storage medium storing a computer program that allows a computer to perform the method according to claim 15.

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