Battery management system, battery pack, electric vehicle, and method for predicting battery charging time

Abstract

A battery management system, a battery pack, an electric vehicle, and a method for predicting a battery charging time are provided. The battery management system includes a memory storing a plurality of reference charging maps, a sensing unit configured to detect a voltage, a current, and a temperature of a battery, and a control unit determining an estimated SOC value of the battery. Each reference charging map includes first to M reference current values ​​and first to M reference power curves associated with first to M SOC ranges. The control unit obtains an mth reference power curve and an mth reference current value associated with an mth SOC range to which the estimated SOC value belongs, from a reference charging map associated with a temperature range to which a temperature detection value of the battery belongs. The control unit determines a required time to reach an end point of the mth SOC range based on a difference between an end point of the mth SOC range and the estimated SOC value, and at least one of the mth reference current value, the maximum output power, and the mth reference power curve, according to a comparison result between a maximum output power of a charger and the mth reference power curve.

Description

[Technical field]

[0001] The present invention relates to a technique for estimating remaining charging time of a battery.

[0002] This application claims priority to Korean Patent Application No. 10-2022-0116578 filed on September 15, 2022 and Korean Patent Application No. 10-2023-0057146 filed on May 2, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings. [Background technology]

[0003] Recently, as the demand for portable electronic products such as notebook PCs, video cameras, and mobile phones has increased sharply and the development of electric vehicles, energy storage batteries, robots, satellites, etc. has progressed in earnest, research into high-performance batteries that can be repeatedly charged and discharged is progressing actively.

[0004] Currently, commercial batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Of these, lithium batteries are in the spotlight due to their advantages over nickel-based batteries, such as almost no memory effect, freedom to charge and discharge, a very low self-discharge rate, and high energy density.

[0005] When charging a battery, if the charging rate (current rate, also called "C-rate") of the charging current is small, it takes a very long time to fully charge the battery. On the other hand, if the charging rate is too high, it has the side effect of causing the battery to deteriorate quickly. Therefore, it is necessary to gradually adjust the charging current according to the state of the battery during constant current charging. For your reference, the charging rate (C-rate) is the value obtained by dividing the charging current by the maximum capacity of the battery, and the unit used is "C."

[0006] A "multi-stage constant-current charging protocol" may be utilized to gradually change a number of charging rates predefined for constant current charging. A charging map may be created for each of a number of temperature intervals, and each charging map is a table or function that records a relationship between a number of reference current values ​​(charging rates) associated with a particular temperature interval and a number of switching conditions. When the battery state meets a particular switching condition (e.g., SOC reaches 60%) during charging using any one of the reference current values ​​recorded in a particular charging map, a charging current with the next charging rate in the sequence may be supplied to the battery.

[0007] Incidentally, while the battery is being charged, it is necessary to notify the user of how much time remains until the battery's SOC reaches a target SOC (eg, a fully charged state).

[0008] Conventionally, the remaining charging time to the target SOC has been predicted on the assumption that the output power from the charger is large enough that the charging current at the charging rate according to the multi-stage constant current charging protocol can flow through the battery.

[0009] However, the maximum output power of the charger is sometimes less than the charging power required for constant current charging of the battery, and in such a case, the battery is charged in a constant power charging mode instead of a constant current charging mode. There is a large difference in the battery charging speed depending on whether the constant current charging mode or the constant power charging mode is performed. Therefore, under charging conditions where the output power of the charger is insufficient, there is a problem that there is a large difference between the predicted remaining charging time and the actual charging time. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in consideration of the above problems, and aims to provide a battery management system that can improve the accuracy of predicting the total remaining time until the SOC of the battery reaches a target SOC by repeating the process of predicting the time required for charging at each stage (SOC range) based on the result of comparing the charging power required at that stage with the maximum output power of the charger during charging of a battery using a multi-stage constant current charging protocol, a battery pack including the battery management system, an electric vehicle including the battery pack, and a method for predicting a battery charging time that can be executed by the battery management system.

[0011] Other objects and advantages of the present invention can be understood from the following description and will become more clearly understood from the embodiments of the present invention. Also, the objects and advantages of the present invention can be realized by the means and combinations thereof as claimed in the claims. [Means for solving the problem]

[0012] A battery management system according to an aspect of the present invention includes a memory configured to store a plurality of reference charging maps associated with a plurality of temperature intervals, a sensing unit configured to detect a voltage, a current, and a temperature of a battery, and a control unit configured to determine an estimated SOC value of the battery based on a detected voltage value and a detected current value of the battery. The plurality of reference charging maps each include first to M reference current values ​​and first to M reference power curves associated with first to M SOC intervals (M is a natural number equal to or greater than 2). The control unit may be configured to obtain an mth reference power curve and an mth reference current value associated with an mth SOC interval (m is a natural number equal to or less than M) to which the estimated SOC value belongs, from a reference charging map associated with a temperature interval to which the detected temperature value of the battery belongs. The control unit may be configured to determine an mth charging time prediction value indicating the time required for the SOC of the battery to reach the end point of the mth SOC range based on a difference between the end point of the mth SOC range and the SOC estimated value, and at least one of the mth reference current value, the maximum output power, and the mth reference power curve, based on a comparison result between the maximum output power of a charger that supplies charging power to the battery and the mth reference power curve.

[0013] The control unit may be configured to determine, when the maximum output power of the charger is equal to or greater than the maximum power value of the mth reference power curve, an expected time required when performing a constant current charging mode using the mth reference current value until the SOC of the battery reaches an end point of the mth SOC section from the SOC estimated value, as the mth charging time predicted value.

[0014] The control unit may be configured to determine, when the maximum output power of the charger is equal to or less than the minimum power value of the mth reference power curve, an expected time required when performing a constant power charging mode using the maximum output power until the SOC of the battery reaches an end point of the mth SOC interval from the SOC estimated value, as the mth charging time predicted value.

[0015] The control unit may be configured to determine an intersection SOC indicating an SOC at an intersection between the mth reference power curve and the maximum output power when the maximum output power of the charger is between the minimum power value and the maximum power value of the mth reference power curve, and to determine the mth charging time predicted value based on the SOC estimated value, the intersection SOC, an end point of the mth SOC interval, the mth reference current value, the maximum output power and the mth reference power curve.

[0016] The control unit may be configured to determine an mth constant current charging time predicted value indicating an expected required time when a constant current charging mode using the mth reference current value is performed until the SOC of the battery reaches the crossing SOC from the SOC estimated value. The control unit may be configured to determine an mth constant power charging time predicted value indicating an expected required time when a constant power charging mode using the maximum output power is performed until the SOC of the battery reaches an end point of the mth SOC interval from the crossing SOC. The control unit may be configured to determine the mth charging time predicted value to be equal to the sum of the mth constant current charging time predicted value and the mth constant power charging time predicted value.

[0017] The control unit may be configured to further determine a temperature prediction value at a start point of the m+1 SOC interval when there is at least one SOC interval subsequent to the m SOC interval among the first to M SOC intervals.

[0018] The control unit may be configured to determine a predicted amount of temperature change from the estimated SOC value to the start point of the m+1 SOC interval, based on the m reference current value and the m predicted charging time value. The control unit may be configured to add a predicted amount of temperature change from the estimated SOC value to the end point of the m SOC interval to the detected temperature value, and determine a predicted temperature value at the start point of the m+1 SOC interval.

[0019] When k is a natural number greater than or equal to m+1 and less than or equal to M, the control unit may be configured to acquire a kth reference power curve and a kth reference current value associated with the kth SOC zone from a reference charging map associated with a temperature zone to which the temperature predicted value at the start point of the kth SOC zone belongs in response to completion of determination of the temperature predicted value at the start point of the kth SOC zone. The control unit may be configured to determine a kth charging time predicted value indicating a time required for the SOC of the battery to reach an end point of the kth SOC zone from a size of the kth SOC zone and based on at least one of the kth reference current value, the maximum output power, and the kth reference power curve according to a comparison result between a maximum output power of the charger and the kth reference power curve.

[0020] The control unit may be configured to sum the mth to Mth charging time predicted values ​​determined for the mth to Mth SOC intervals upon completion of determination of the predicted charging time value in the Mth SOC interval, and determine a total remaining time until the SOC of the battery reaches the end point of the Mth SOC interval from the SOC estimated value.

[0021] A battery pack according to another aspect of the present invention includes the battery management system.

[0022] According to yet another aspect of the present invention, an electric vehicle includes the battery pack described above.

[0023] A method for predicting a battery charging time according to yet another aspect of the present invention includes the steps of determining an estimated SOC value of the battery based on detected voltage and current values ​​of the battery, and generating a plurality of reference charging maps associated with a plurality of temperature ranges, each reference charging map including first through M reference current values ​​and first through M reference power curves associated with first through M SOC ranges (M is a natural number greater than or equal to 2). and determining an mth charging time predicted value indicating a time required for the SOC of the battery to reach an end point of the mth SOC zone based on a difference between an end point of the mth SOC zone and the SOC estimated value, and at least one of the mth reference current value, the maximum output power, and the mth reference power curve, based on a comparison result between a maximum output power of a charger that supplies charging power to the battery and the mth reference power curve.

[0024] The step of determining the mth predicted charging time value may determine, as the mth predicted charging time value, an expected time required when performing a constant current charging mode using the mth reference current value until the SOC of the battery reaches an end point of the mth SOC section from the estimated SOC value, when the maximum output power of the charger is equal to or greater than the maximum power value of the mth reference power curve.

[0025] The step of determining the mth predicted charging time value may determine, as the mth predicted charging time value, an expected time required when performing a constant power charging mode using the maximum output power until the SOC of the battery reaches an end point of the mth SOC section from the estimated SOC value, when the maximum output power of the charger is equal to or less than the minimum power value of the mth reference power curve.

[0026] Determining the mth predicted charging time value may include: determining a crossing SOC associated with the same power value as the maximum output power from the mth reference power curve, when the maximum output power of the charger is between a minimum power value and a maximum power value of the mth reference power curve; determining an mth constant current charging time predicted value indicating an expected time required when a constant current charging mode using the mth reference current value is performed until the SOC of the battery reaches the crossing SOC from the estimated SOC value; determining an mth constant power charging time predicted value indicating an expected time required when a constant power charging mode using the maximum output power is performed until the SOC of the battery reaches an end point of the mth SOC interval from the crossing SOC; and determining the mth constant power charging time predicted value to be equal to a sum of the mth constant current charging time predicted value and the mth constant power charging time predicted value. Effect of the Invention

[0027] According to at least one embodiment of the present invention, during battery charging using a multi-stage constant current charging protocol, the process of predicting the time required for charging at each stage (SOC range) based on the result of comparing the charging power required at that stage with the maximum output power of the charger can be repeated, thereby improving the accuracy of predicting the total remaining time until the battery SOC reaches a target SOC.

[0028] In addition, according to at least one embodiment of the present invention, by predicting a temperature change amount of a battery in each stage and selecting a charging map to be used for predicting a required charging time in a subsequent stage using the predicted temperature change amount of the battery, it is possible to improve prediction accuracy of a required charging time for each stage.

[0029] In addition, according to at least one embodiment of the present invention, the end point of each stage is adjusted according to the difference between the predicted temperature change amount for that stage and the actual temperature change amount, thereby improving the safety of the charging process that is resumed later and extending the battery life.

[0030] The effects of the present invention are not limited to the effects described above, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0031] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical ideas of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters described in the drawings. [Brief description of the drawings]

[0032] [Figure 1] 1 is a diagram showing the configuration of an electric vehicle according to the present invention;

[0033] [Diagram 2] FIG. 2 is a diagram for explaining a reference charging map used in a charging process using a multi-stage constant current charging protocol.

[0034] [Diagram 3] FIG. 2 is a diagram for explaining a reference charging map used in a charging process using a multi-stage constant current charging protocol.

[0035] [Figure 4] FIG. 2 is a diagram for explaining a reference charging map used in a charging process using a multi-stage constant current charging protocol.

[0036] [Diagram 5] FIG. 1 is a diagram for explaining the influence of the maximum output power of a charger in a charging process using a multi-stage constant current charging protocol.

[0037] [Figure 6] 2 is a flowchart showing a method for predicting a battery charging time according to a first embodiment of the present invention.

[0038] [Figure 7] 7 is a flowchart showing a sub-routine of step S630 shown in FIG. 6.

[0039] [Figure 8] 8 is a flowchart showing a subroutine of step S750 shown in FIG. 7.

[0040] [Figure 9] FIG. 4 is a schematic diagram illustrating first and second thermal models used to predict the amount of temperature change in each SOC section according to a multi-stage constant current charging protocol.

[0041] [Figure 10] 5 is a flowchart showing a method for predicting a battery charging time according to a second embodiment of the present invention.

[0042] [Figure 11] 10 is a flowchart showing a method for predicting a battery charging time according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as having meanings and concepts according to the technical ideas of the present invention, in accordance with the principle that the inventor himself can appropriately define the concepts of terms in order to best describe the invention.

[0044] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0045] Terms including ordinal numbers such as "first", "second", etc. are used for the purpose of distinguishing one of various components from the rest, and are not intended to limit the components.

[0046] In addition, throughout the specification, when a certain part "includes" a certain component, this does not mean excluding other components, but means that other components may be further included, unless otherwise specified. Furthermore, terms such as "~part (unit)" in the specification indicate a unit that processes at least one function or operation, which may be embodied by hardware, software, or a combination of hardware and software.

[0047] Furthermore, throughout this specification, when a part is said to be "connected" to another part, this includes not only when it is "directly connected" to another part, but also when it is "indirectly connected" through another element in between.

[0048] FIG. 1 is a diagram showing the configuration of an electric vehicle according to the present invention.

[0049] 1, an electric vehicle 1 includes a vehicle controller 2, a battery pack 10, a relay 20, an inverter 30, and an electric motor 40. Charging and discharging terminals P+, P- of the battery pack 10 may be electrically coupled to a charger 3 via a charging cable or the like. The charger 3 may be included in the electric vehicle 1 or may be provided in a charging station.

[0050] The vehicle controller 2 (e.g., ECU: Electronic Control Unit) is configured to transmit a key-on signal to the battery management system 100 in response to a start button (not shown) provided on the electric vehicle 1 being switched to an on position by a user. The vehicle controller 2 is configured to transmit a key-off signal to the battery management system 100 in response to a start button being switched to an off position by a user. The charger 3 may communicate with the vehicle controller 2 to supply constant current or constant voltage charging power via the charging / discharging terminals P+, P- of the battery pack 10.

[0051] The battery pack 10 includes a battery 11 and a battery management system 100 .

[0052] The battery 11 includes a cell group 12 and a case 13. The case 13 defines the overall outer shape of the battery 11 and provides an internal space in which the cell group 12 is disposed. The case 13 is fixed to a battery room provided in the electric vehicle 1 by bolts or the like.

[0053] The cell group 12 is disposed (housed) in an internal space provided by the case 13 and includes at least one battery cell BC. The type of the battery cell BC is not particularly limited as long as it can be repeatedly charged and discharged, such as a lithium ion cell.

[0054] When the cell group 12 includes a plurality of battery cells, the plurality of battery cells may be connected in series, in parallel, or in a mixed series-parallel configuration.

[0055] The relay 20 is electrically connected in series to the battery 11 through a power path connecting the battery 11 and the inverter 30. In FIG. 1, the relay 20 is shown connected between the positive terminal of the battery 11 and the charge / discharge terminal P+. The relay 20 is controlled to be turned on and off in response to a switching signal from the battery management system 100. The relay 20 may be a mechanical contactor that is turned on and off by the magnetic force of a coil, or may be a semiconductor switch such as a metal oxide semiconductor field effect transistor (MOSFET).

[0056] An inverter 30 is provided to switch the direct current from the cell group 12 to alternating current in response to commands from the battery management system 100 or the vehicle controller 2 .

[0057] The electric motor 40 is driven by AC power from the inverter 30. As the electric motor 40, for example, a three-phase AC motor 40 may be used.

[0058] The battery management system 100 includes a voltage sensor 111, a current sensor 113, a battery temperature sensor 115, and a control unit 130. The battery management system 100 may further include an outside air temperature sensor 117. The battery management system 100 may further include a communication circuit 150.

[0059] The voltage sensor 111 is connected in parallel to the battery 11 and configured to detect a battery voltage, which is the voltage across the battery 11, and generate a voltage signal indicative of the detected battery voltage.

[0060] The current sensor 113 is connected in series to the battery 11 through a current path between the battery 11 and the inverter 30. The current sensor 113 is configured to detect a battery current, which is a current flowing through the battery 11, and generate a current signal indicative of the detected battery current. The current sensor 113 may be embodied by one or a combination of two or more known current detection elements, such as a shunt resistor, a Hall element, etc.

[0061] The battery temperature sensor 115 is configured to detect a battery temperature and generate a temperature signal indicative of the detected battery temperature. The battery temperature sensor 115 may be disposed in the case 13 to detect a temperature close to an actual temperature of the battery 11. For example, the battery temperature sensor 115 may be attached to a surface of at least one battery cell BC included in the cell group 12 and detect the surface temperature of the battery cell BC as the battery temperature.

[0062] The voltage sensor 111, the current sensor 113 and the battery temperature sensor 115 may be referred to as a "sensing unit."

[0063] The outside air temperature sensor 117 is configured to detect an outside air temperature (ambient temperature), which is a temperature at a predetermined position separated from the battery 11, and generate a temperature signal indicating the detected outside air temperature. The outside air temperature sensor 117 may be disposed at a predetermined position outside the case 13 where heat exchange between the battery 11 and the outside air takes place.

[0064] The battery temperature sensor 115 and the outside air temperature sensor 117 may each be implemented by one or a combination of two or more known temperature detection elements such as a thermocouple, a thermistor, a bimetal, and the like.

[0065] The communication circuit 150 is configured to support wired or wireless communication between the control unit 130 and the vehicle controller 2. The wired communication may be, for example, a controller area network (CAN) communication, and the wireless communication may be, for example, ZigBee (registered trademark) or Bluetooth (registered trademark) communication. Of course, the type of communication protocol is not particularly limited as long as it supports wired or wireless communication between the control unit 130 and the vehicle controller 2. The communication circuit 150 may include an output device (for example, a display, a speaker) that provides information received from the control unit 130 and / or the vehicle controller 2 in a form that can be recognized by a user.

[0066] The control unit 130 is operatively coupled to the relay 20, the voltage sensor 111, the current sensor 113, the battery temperature sensor 115, the outside air temperature sensor 117, and the communication circuit 150. The fact that two components are operatively coupled means that the two components are directly or indirectly connected to each other so that signals can be transmitted and received unidirectionally or bidirectionally.

[0067] The control unit 130 may collect a voltage signal from the voltage sensor 111, a current signal from the current sensor 113, a temperature signal from the battery temperature sensor 115 (which may be referred to as a "battery temperature signal"), and / or a temperature signal from the outside air temperature sensor 117 (which may be referred to as an "outside air temperature signal"). The control unit 130 may convert and record each of the analog signals collected from the sensors 111, 113, 115, and 117 into digital values ​​using an ADC (Analog to Digital Converter) provided inside.

[0068] The control unit 130 may be referred to as a "control circuit" or a "battery controller", and may be implemented in hardware using at least one of an ASIC (application specific integrated circuit), a DSP (digital signal processor), a DSPD (digital signal processing device), a PLD (programmable logic device), an FPGA (field programmable gate array), a microprocessor, or other electrical unit for performing a function.

[0069] The memory 140 may include at least one type of storage medium, for example, a flash memory type, a hard disk type, a solid state disk type (SSD type), a silicon disk drive type (SDD type), a multimedia card micro type, a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), and a programmable read-only memory (PROM). The memory 140 may store data and programs required for the calculation operation by the control unit 130. The memory 140 may store data indicating the result of the calculation operation by the control unit 130. Although FIG. 1 shows memory 140 as being physically separate from control unit 130, it is possible for memory 140 to be incorporated within control unit 130.

[0070] The memory 140 may store at least one reference charging map associated with a multi-stage constant current charging protocol for the battery 11. Each reference charging map is described in more detail below.

[0071] The control unit 130 may turn on the relay 20 in response to a key-on signal. The control unit 130 may turn off the relay 20 in response to a key-off signal. The key-off signal indicates switching from a use state to a pause state. Alternatively, the on / off control of the relay 20 may be performed by the vehicle controller 2 instead of the control unit 130.

[0072] While the relay 20 is turned on, the battery 11 is in an in-use state. Conversely, while the relay 20 is turned off, the battery 11 is in a hibernation state. The in-use state refers to a state in which the battery 11 is being charged or discharged, and may also be called a "cycle state." The hibernation state refers to a state in which charging or discharging of the battery 11 is stopped, and may also be called a "calendar state."

[0073] While the battery 11 is in use, the control unit 130 may determine a voltage detection value, a current detection value, a battery temperature detection value, and an outside air temperature detection value based on a voltage signal, a current signal, a battery temperature signal, and an outside air temperature signal, and then determine (estimate) a state of charge (SOC) of the battery 11 based on the voltage detection value, the current detection value, and / or the battery temperature detection value. The SOC is a ratio of remaining capacity to a fully charged capacity (maximum capacity) of the battery 11, and is usually processed in a range of 0 to 1 or 0 to 100%. The SOC may be determined using known methods such as ampere counting, an OCV (Open Circuit Voltage)-SOC curve, and / or a Kalman filter. For reference, a mere description of a "temperature detection value" in this specification may refer to a temperature detection value of a battery.

[0074] The maximum capacity of the battery 11 can be estimated by any one or a combination of two or more of various known methods. In one example, the control unit 130 may calculate the current maximum capacity of the battery 11 by dividing the integrated amount of current applied during a period from when the SOC of the battery 11 is at a first value until it reaches a second value by the amount of change in SOC (i.e., the difference between the first value and the second value). Alternatively, the control unit 130 may determine the current maximum capacity of the battery 11 by multiplying the SOH (State Of Health) calculated by any one or a combination of two or more of various known methods by a predetermined design capacity (maximum capacity of a new battery).

[0075] 2 to 4 are reference diagrams for explaining a reference charging map used in a charging process using a multi-stage constant current charging protocol.

[0076] The memory 151 stores a number of reference charge maps CM1 to CM N The plurality of reference charging maps may be stored in a plurality of temperature ranges CM1 to CM N (N is a natural number greater than or equal to 2.)

[0077] 2 to 4 show a plurality of reference charging maps CM1 to CM2 associated with any one of a plurality of temperature ranges (e.g., less than 0° C., 0° C. or more and less than 10° C., 10° C. or more and less than 25° C., 25° C. or more and less than 40° C., and 40° C. or more). N Either one of the reference charging map CM n (n is a natural number less than or equal to N.)

[0078] Specifically, the graph shown in Figure 2 shows a reference current profile 200 illustrating the change in charging current versus SOC over the entire SOC range. In the present invention, the entire SOC range is divided into first to Mth SOC intervals Z[1] to Z[M] (M is a natural number equal to or greater than 2). For ease of explanation, M=4 is shown in Figures 2 to 4.

[0079] In the first to Mth SOC intervals Z[1] to Z[M], the start point of the first SOC interval Z[1] is the same as the start point of the entire SOC range (e.g., SOC 0%), and the end point of the Mth SOC interval Z[M] is the same as the end point of the entire SOC range (e.g., SOC 100%). The end point of the entire SOC range can be preset as the target SOC.

[0080] Of the first to Mth SOC sections Z[1] to Z[M], the end point of the preceding section may coincide with the start point of the following section. For example, the end point (e.g., 50%) of the first SOC section Z[1] coincides with the start point (e.g., 50%) of the second SOC section Z[2].

[0081] 2, first to Mth reference current values ​​I#1 to I#M are associated one-to-one with first to Mth SOC ranges Z[1] to Z[M], and each reference current value indicates a charging current for constant current charging in the associated SOC range. According to the reference current profile 200, the reference current value for a specific SOC range is single, which indicates that the reference current value is for constant current charging in the associated SOC range. That is, if the charger 3 is capable of supplying a sufficiently large output power, the battery 11 can be constant current charged by the charging current according to the reference current profile 200.

[0082] In the multi-stage constant current charging protocol, a reduction in the charging current may be required as the SOC increases to protect the battery. Referring to Fig. 3, the first to fourth reference current values ​​I#1 to I#4 may be predetermined to decrease in stages as the SOC increases, for example, to 8 [A], 6 [A], 4 [A], and 2 [A].

[0083] 3 shows a reference voltage profile 300 that indicates the change in battery voltage versus SOC over the entire SOC range. The reference voltage profile 300 may be previously obtained from the results of repeated charging tests in which at least one battery sample having the same specifications as the battery 11 is charged according to the reference current profile 200 while periodically measuring the voltage of each battery sample. The reference voltage profile 300 may be recorded in the memory 151 as a time series or a multi-dimensional function of the battery voltage versus SOC.

[0084] 4 shows a reference power profile 400 illustrating the change in charging power versus SOC over the entire SOC range. The reference power profile 400 may have been previously obtained from the results of repeated charging tests in which at least one battery sample having the same specifications as the battery 11 is charged according to the reference current profile 200 while periodically measuring the charging power supplied to each battery sample. The reference power profile 400 may be recorded in the memory 151 as a time series or a multi-dimensional function of charging power versus SOC.

[0085] The reference power profile 400 is substantially the same as the product of the reference current profile 200 and the reference voltage profile 300 in the entire SOC range. That is, the charging power in the reference power profile 400 at a specific SOC is the same as the product of the voltage value in the reference voltage profile 300 at the specific SOC and the current value in the reference current profile 200. It should be noted that in each SOC section, the voltage of the battery 11 increases while the reference current value is constant, so that the charging power increases gradually. A portion of the reference power profile 400 showing the power change in a specific SOC section is hereinafter referred to as a "reference power curve". That is, the reference power profile 400 includes first to fourth consecutive reference power curves P#1 to P#4. For reference, in the reference current profile 200 shown in FIG. 2, the reference current value is switched at the boundary between two SOC sections, so that there is a difference in charging power between two adjacent reference power curves (for example, between P#2 and P#3) among the first to fourth reference power curves P#1 to P#4 shown in FIG. 4.

[0086] On the other hand, the reference charging map CM associated with a specific temperature range n may include a reference current profile 200, a reference voltage profile 300, and a reference power profile 400 that are previously obtained by testing in the same temperature range.

[0087] Incidentally, a very large storage space is required to record all of the reference current profile 200, the reference voltage profile 300, and the reference power profile 400 in the memory 151. Also, it is possible to calculate (generate) the reference voltage profile 300 (see FIG. 2) by dividing the reference power profile 400 (see FIG. 4) by the reference current profile 200 (see FIG. 2). Therefore, a plurality of reference charging maps CM1 to CM N At least one of the reference current profile 200 and the reference power profile 400 may be created to include only the reference current profile 200 and the reference power profile 400 .

[0088] To summarize the above, multiple reference charging maps CM1 to CM N At least one of the reference charging maps includes first to Mth reference power curves P#1 to P#M and first to Mth reference current values ​​I#1 to I#M that are one-to-one associated with the first to Mth SOC zones Z[1] to Z[M].

[0089] In the same SOC range, the reference power curve of a reference charging map associated with a certain temperature range (e.g., above 0°C and below 10°C) may differ from the reference power curve of another reference charging map associated with another temperature range (e.g., above 10°C and below 25°C).

[0090] Similarly, within the same SOC range, the reference current value recorded in a reference charging map associated with one temperature range (e.g., above 0°C and below 10°C) may differ from the reference current value recorded in another reference charging map associated with another temperature range (e.g., above 10°C and below 25°C).

[0091] The relationship of the charging current, battery voltage, and charging power to the SOC and temperature of the battery 11 depends on the size, weight, active material, external shape, etc. of the battery 11. Therefore, Figures 2 to 4 are understood as merely examples in describing the present invention.

[0092] For reference, the upper limit of the entire SOC range (i.e., the target SOC) may be set to a value less than 100% (e.g., 98%). In this case, from when the SOC of the battery 11 reaches the target SOC until the buffer time, the battery 11 may be charged in the constant voltage charging mode instead of the constant current charging mode or the constant power charging mode.

[0093] Assuming that m is a natural number equal to or smaller than M, in this specification, m is used as a section index of the SOC section to which the current SOC of the battery 11 belongs. Then, the symbol P#m used in this specification represents the reference charging map CM associated with the temperature section to which the battery temperature (detected value or predicted value) belongs. n Symbol I#m may indicate a reference power curve associated with SOC interval Z[m] among the first to Mth reference power curves P#1 to P#M recorded in . Also, symbol I#m may indicate a reference current value associated with SOC interval Z[m]. Each reference current value (e.g., I#1) may be a predetermined value indicating a maximum charging current allowed for charging battery 11 from the start point (e.g., 0%) to the end point (e.g., 50%) of the SOC interval associated therewith (e.g., Z[1]) without irreversible damage.

[0094] When x is a natural number equal to or less than M, the size (width) of the SOC section Z[x] is the difference between the start point and the end point of the SOC section Z[x], and is indicated by the symbol ΔZ[x]. In Figs. 2 to 4, the sizes of the first to fourth SOC sections Z[1] to Z[4] are shown as 50%, 20%, 15%, and 15%, respectively. Of course, the first to Mth SOC sections Z[1] to Z[M] may have the same size as each other or may be determined differently from Fig. 2.

[0095] FIG. 5 is a reference diagram for explaining the influence of the maximum output power of a charger on a charging process using a multi-stage constant current charging protocol.

[0096] 5 shows three horizontal lines 510, 520, and 530 together with the reference power profile 400 of FIG. 4. Any one of these three horizontal lines 510, 520, and 530 represents the maximum output power P that can be supplied from the charger 3 to the battery 11. MAX The control unit 130 receives the maximum output power P MAX can be identified.

[0097] In each of the constant current charging mode, constant power charging mode, and constant voltage charging mode, the voltage of the battery 11 gradually increases during charging in the corresponding charging mode in the respective SOC sections.

[0098] A horizontal line 510 represents the maximum output power P that can be supplied from the charger 3 to the battery 11. MAX is equal to or greater than the maximum charging power required in all SOC intervals. FIG. 5 shows that the maximum charging power is required at the end point of SOC interval Z[1]. In this case, only the constant current charging mode in which different charging currents I#1 to I#M are sequentially switched according to the multi-stage constant current charging protocol is performed. That is, in SOC interval Z[x], battery 11 is constantly charged with a charging current of reference current value I[x], so that the change over time in the charging power supplied to battery 11 can be processed as matching reference power profile 400.

[0099] Horizontal line 520 represents the maximum output power P MAX is equal to or less than the minimum charging power required in the entire SOC interval. FIG. 5 shows that the minimum charging power is required at the start point of the SOC interval Z[1]. In this case, the charging power supplied to the battery 11 over the entire SOC interval is equal to or less than the maximum output power P MAX That is, the different charging currents are sequentially switched according to the multi-stage constant current charging protocol, and the maximum output power P MAX Only constant power charging mode with

[0100] Horizontal line 530 represents the maximum output power PMAX This indicates a situation where the charging power is greater than the minimum charging power and less than the maximum charging power required in the entire SOC section.

[0101] Looking at the horizontal line 530, the maximum output power P MAX is above the reference power curve P#1 at the beginning of the SOC section Z[1], while X From this point on, the horizontal line 530 is below the reference power curve P#1. That is, within the SOC section Z[1], there is an intersection X between the horizontal line 530 and the reference power curve P#1. This intersection X is the point at which the maximum output power P MAX This is the point at which the charging mode switches to constant power charging mode.

[0102] In addition, in the SOC section Z[2], the maximum output power P MAX is below the reference power curve P#1, while the maximum output power P MAX is above the reference power curve P#3 and the reference power curve P#4. Therefore, in the SOC section Z[2], the maximum output power P MAX In SOC intervals Z[3] and Z[4], the battery 11 is charged in a constant power charging mode with reference current value I#3 and reference current value I#4.

[0103] Conventionally, the charging power supplied to the battery 11 during charging is the maximum output power P MAX There was no method to reflect the limitation of the maximum output power P of the charger 3 in the remaining charging time prediction process. MAX 5, when predicting the remaining charging time in each of the two SOC sections Z[1] and Z[2], if it is assumed that charging power is supplied according to the reference power curves P#1 and P#2, the remaining charging time in the latter part of the SOC section Z[1] (Z X ~50%) and the charging power by the reference power curves P#1 and P#2 in the entire SOC section Z[2] and the maximum output power P MAXThe remaining charging time prediction error accumulates by the difference in power between the two SOC intervals Z[1] and Z[2]. As a result, the predicted remaining charging time for the two SOC intervals Z[1] and Z[2], as well as the total remaining charging time until the target SOC is reached, often differed greatly from the actual value.

[0104] Therefore, in order to reduce the prediction error of the remaining charging time for each SOC section, the charging power according to the reference power profile 400 and the maximum output power P of the charger 3 are calculated for each SOC section. MAX It is necessary to compare the above to determine whether the constant current charging mode or the constant power charging mode will be used, or whether both will be used, and then calculate (predict) the remaining charging time for each SOC range using the characteristics of the determined charging mode.

[0105] Fig. 6 is a flowchart showing a method for predicting a battery charging time according to a first embodiment of the present invention. Fig. 7 is a flowchart showing a subroutine of step S630 shown in Fig. 6. Fig. 8 is a flowchart showing a subroutine of step S750 shown in Fig. 7. The method of Fig. 6 can be performed by the battery management system 100 at set times during charging of the battery 11 using a multi-stage constant current charging protocol.

[0106] 1 to 6, in step S610, the control unit 130 determines an estimated SOC value of the battery 11 based on the detected voltage value and current value of the battery 11. The detected temperature value of the battery may be further used in determining the estimated SOC value. The detected voltage value, detected current value, detected temperature value, and estimated SOC value in step S610 may indicate the current voltage, current, temperature, and SOC of the battery 11, respectively. The control unit 130 records the detected voltage value, detected current value, detected temperature value, and estimated SOC value, which are determined at every set time, in the memory 140. In step S610, an outside air temperature detected value T indicating the current outside air temperature is stored in the memory 140. ATM (See FIG. 9) can further be determined.

[0107] In step S620, the control unit 130 selects a plurality of reference charging maps CM1 to CM NThe reference charging map CM associated with the temperature range to which the temperature detection value belongs. n From the above, an mth reference current value I#m and an mth reference power curve P#m associated with an mth SOC interval Z[m] (m is a natural number equal to or less than M) to which the SOC estimated value determined in step S610 belongs are obtained. In this specification, the mth SOC interval Z[m] may refer to an SOC interval to which the current SOC of the battery 11 belongs.

[0108] In step S630, the control unit 130 determines the maximum output power P MAX Based on the comparison result of the mth reference power curve P#m and the SOC estimated value and the end point of the mth SOC section Z[m], the mth reference current value I#m, the maximum output power P MAX and mth reference power curve (P#m), an mth predicted charging time value indicating a time required for the SOC of the battery 11 to reach an end point of the mth SOC interval Z[m] from the SOC estimated value determined in step S610. For example, if the SOC estimated value determined in step S610 is 2%, the mth SOC interval Z[m]=Z[1], and the mth predicted charging time value (first predicted charging time value) may be a time required for the SOC of the battery 11 to reach 50% from 2%. Step S630 includes steps S710 to S750 as its subroutines.

[0109] Referring to FIG. 7, in step S710, the control unit 130 determines the maximum output power P MAX For example, the horizontal line 510 in FIG. 5 is equal to or greater than the maximum power value of the m-th reference power curve P#m. MAX 5 indicates the maximum output power P MAX If so, the value of step S710 is "No." If the value of step S710 is "Yes," proceed to step S720. If the value of step S710 is "No," proceed to step S730.

[0110] In step S720, the control unit 130 determines the mth predicted charging time value based on the SOC estimated value, the end point of the mth SOC interval Z[m], and the mth reference current value I#m. The SOC difference ΔZ[m] is a value obtained by subtracting the SOC estimated value from the end point of the mth SOC interval Z[m]. The mth predicted charging time value determined in step S720 may indicate a charging time in a constant current charging mode. The control unit 130 may determine the mth predicted charging time value by calculating a required charging capacity corresponding to the SOC difference ΔZ[m] and then dividing the calculated required charging capacity by the mth reference current value I#m.

[0111] Equation 1 below is an example of a function that can be used to determine the charge time in the constant current charge mode.

[0112] (Formula 1)

number

[0113] In formula 1, z = SOC, z f = SOC to be reached by charging, z i =z f SOC at a specific point in time before reaching I CHG = charging current, Q MAX = Maximum capacity of battery 11, ΔQ = Required charging capacity, Δz = z f -z i The capacitance corresponding to Δt CC For reference, although Equation 1 is represented with three equal signs for ease of understanding, it may be stored in memory 151 to include only the rightmost term of the three right-hand sides.

[0114] For example, Q MAX = 10,000mAh, z f -z i = End point of m-th SOC interval Z[m] - SOC estimate = 50% - 2% = ΔZ[m] = 48%, and assume that I#m = 10 A. Then, ΔQ = 4800 mAh, so Δt#m = 4800 mAh / 10 A = 0.48 hours.

[0115] In step S730, the control unit 130 determines the maximum output power P MAX For example, the horizontal line 520 in FIG. 5 is equal to or smaller than the maximum output power P MAX , the value of step S730 is "Yes." On the other hand, if the horizontal line 530 in FIG. 5 indicates the maximum output power P MAX If the value of step S730 is "yes", proceed to step S740. If the value of step S730 is "yes", the maximum output power P MAX is between the minimum and maximum power values ​​of the m-th reference power curve P#m. If the value of step S730 is "No", proceed to step S750.

[0116] In step S740, the control unit 130 receives the SOC estimate, the end point of the m-th SOC interval Z[m], the maximum output power P MAX and the mth reference power curve P#m, the mth predicted charging time value is determined. The mth predicted charging time value determined by step S740 may be a charging time in a constant power charging mode. The following Equation 2 is an example of a function that can be used to determine the charging time in a constant power charging mode.

[0117] (Formula 2)

number

[0118] In formula 2, z = SOC, z f = SOC to be reached by charging, z i =z f SOC at a specific point in time before reaching I CHG = charging current, V(z)=I CHG The estimated voltage of battery 11 at z during constant current charging, V AV =z i ~z f Average V(z) in the range of P CHG (z)=I CHGThe charging power at z during constant current charging is P CP =Actual charging power supplied (constant power), ΔWh CP = Required charging energy, ΔQ = Required charging capacity, Δt CP = charging time, for reference, ΔWh CP For reference, although Equation 2 is expressed using four equal signs to facilitate understanding, it may be stored in memory 151 to include only the rightmost term of the four terms on the right side.

[0119] Battery 11 has a maximum capacity of 10,000 mAh, an estimated SOC of 2%, and a maximum output power P MAX Assume that z coincides with the horizontal line 520 in FIG. 5. Then, in Equation 2, i =2%, z f =50%, z f -z i =ΔZ[1]=48%, Q=4800mAh, I CHG =I#1=10A,P CHG (z)=P#1. If V AV =3.3V, P CP =P MAX = 20W (Watt), then Δt CP ={4800mAh×3.3V} / 20W=0.792 hours=Δt#1.

[0120] In step S750, the control unit 130 receives the SOC estimate, the end point of the m-th SOC interval Z[m], the m-th reference current value I#m, the maximum output power P MAX and the mth charging time predicted value Δt#m is determined based on the mth reference power curve P#m.

[0121] Step S750 includes steps S810 to S850 as its subroutines.

[0122] Referring to FIG. 8, in step S810, the control unit 130 determines whether the mth reference power curve P#m and the maximum output power P MAX With reference to FIG. 5, the maximum output power P MAXWhen coincides with the horizontal line 530, X indicates the intersection point, and Z X indicates the cross SOC.

[0123] In step S820, the control unit 130 determines whether the crossover SOC Z X is greater than the estimated SOC value (current SOC). If the value of step S820 is "yes", proceed to steps S830 and S840. If the value of step S820 is "no", it means that the charging power is equal to or greater than the maximum output power P MAX This means that only a constant power charging mode limited to 100% is performed. If the value of step S820 is "No", the method proceeds to step S740 of FIG.

[0124] In step S830, the control unit 130 calculates the SOC estimate, the crossover SOC Z X Based on the reference current value I#m of m, the SOC of the battery 11 crosses the SOC Z X The mth constant current charging time prediction value, which indicates the time required to reach the current SOC, is determined. The mth constant current charging time prediction value can be determined using the above-mentioned Equation 1. That is, when the current SOC is 2%, z f The first SOC interval Z[1] ends at 50% instead of the crossing SOC Z X When Δt is input, CC is determined as the mth constant current charging time prediction value.

[0125] In step S840, the control unit 130 determines whether the crossover SOC Z X , the end point of the mth SOC section Z[m]. Maximum output power P MAX Based on the mth reference power curve P#m, the SOC of the battery 11 crosses SOC Z X The mth constant power charging time predicted value indicating the time required to reach the end point of the mth SOC interval Z[m] is determined.

[0126] The mth constant power charging time prediction value can be determined using the above-mentioned Equation 2. That is, Z X If >2% = current SOC, then z in formula 2 iInstead of SOC estimates, cross SOC Z X When Δt is input, CP is determined as the mth constant power charging time prediction value.

[0127] In step S850, the control unit 130 determines an mth predicted charging time value, which is equal to the sum of the mth constant current charging time predicted value determined in step S830 and the mth constant power charging time predicted value determined in step S840.

[0128] Step S640 described below may be performed on the condition that m is less than M. When m, which is the section index of the SOC section to which the current SOC belongs, is less than M, it means that there is at least one SOC section following the m-th SOC section Z[m] in which the charging process is currently in progress. In one example, when m=1<4=M, charging is scheduled in three SOC sections Z[2] to Z[4], so step S640 may be performed.

[0129] In step S640, the control unit 130 determines the mth reference current value I#m and the maximum output power P based on the detected temperature value of the battery and the mth charging time prediction value Δt#m. MAX The temperature prediction value at the start point of the m+1-th SOC interval Z[m+1] is determined based on at least one of the following: The temperature prediction value at the start point of the m+1-th SOC interval Z[m+1] indicates the temperature of the battery 11 at the end point of the m-th SOC interval Z[m]. ATM If the detected outside air temperature T ATM A temperature prediction value at the beginning of the m+1-th SOC interval Z[m+1] may be determined based further on:

[0130] Step S640 may include step S642 and step S644.

[0131] In step S642, the control unit 130 determines a predicted amount of temperature change during a period from the SOC estimate indicating the current SOC of the battery 11 to the start point of the (m+1)th SOC interval Z[m+1]. At least one of a first thermal model and a second thermal model, which will be described later, may be used to determine the predicted amount of temperature change.

[0132] In step S644, the control unit 130 determines the temperature change prediction amount (for example, ΔT CC , ΔT CP or ΔT CC +ΔT CP ) and the temperature detection value obtained in step S610 to determine a temperature prediction value at the start point of the (m+1)th SOC interval Z[m+1].

[0133] FIG. 9 is a schematic diagram for explaining a first thermal model and a second thermal model used for predicting the amount of temperature change in each SOC section according to a multi-stage constant current charging protocol.

[0134] In FIG. 9, T BAT is the battery temperature (detected or predicted), Δt is the charging time, I CC is a constant current, P CP is the maximum output power P of charger 3 MAX , T ATM is the detected outside air temperature.

[0135] The control unit 130 may use at least one of the first thermal model and the second thermal model to calculate a temperature change prediction amount indicating the amount of temperature change until the SOC of the battery 11 within a specific SOC interval reaches the end point of the SOC interval.

[0136] The first thermal model is generated by the control unit 130 using the input variable T BAT , Δ t , I CC , T ATM According to the value of , the temperature change amount ΔT CCThe following Equation 3 may be used as the first thermal model.

[0137] (Formula 3)

number

[0138] In Equation 3, α is an adjustment coefficient (predetermined), β is a heat exchange coefficient (predetermined), C H denotes the thermal capacity of the battery 11 (predetermined). In the first thermal model, T ATM may be a predetermined value (e.g., 25° C.) instead of the detected outside air temperature.

[0139] Equation 3 is merely an example of the first thermal model, and the first thermal model is not limited to Equation 3. That is, the input variable I CC , Δt and T ATM and T BAT Each of the differences and the output variable ΔT CC Any function or algorithm other than Equation 3 may be used as the first thermal model as long as it provides a positive interlayer relationship between

[0140] The second thermal model is generated by the control unit 130 using the input variable T BAT , Δt, P CP , T ATM According to the value of , the temperature change amount ΔT CP The following Equation 4 may be used as the second thermal model.

[0141] (Formula 4)

number

[0142] In Equation 4, γ is an adjustment coefficient (predetermined), and the remaining variables and coefficients are the same as in Equation 3.

[0143] Equation 4 is merely an example of the second thermal model, and the second thermal model is not limited to Equation 4. That is, the input variable P CP , Δt and T ATM and T BAT Each of the differences and the output variable ΔT CP Any function or algorithm other than Equation 4 may be used as the second thermal model as long as it provides a positive interlayer relationship between

[0144] Referring to Figures 5 and 9 together, the SOC estimate Z est Cross SOC Z X If it is less than ΔT, the ΔT output when the mth constant current charging time prediction value is input to Δt in Equation 3 is CC and ΔT output when the mth constant power charging time prediction value is input to Δt in Equation 4. CP The sum of and can be determined as the predicted temperature change in the SOC interval Z[1]. est Cross SOC Z X If it is equal to or greater than ΔT CP can be determined as the predicted temperature change amount in SOC interval Z[1]. In addition, the predicted temperature change amount in SOC interval Z[2] can be determined by Equation 4. The predicted temperature change amounts in the remaining two SOC intervals Z[3] and Z[4] can be determined by Equation 3.

[0145] Still referring to FIG. 7, steps S720, S740 and S750 may be performed on alternative days.

[0146] When step S720 is performed, the control unit 130 calculates the input variable (T BAT , Δt, I CC) are assigned the battery temperature detection value, the mth charging time prediction value, and the mth reference current value I#m, respectively, and the temperature change amount ΔT CC , and the detected temperature value may be added to determine a predicted temperature value at the start of the (m+1)th SOC interval Z[m+1].

[0147] When step S740 is performed, the control unit 130 sets the input variable (T BAT , Δt, P CP ) are the battery temperature detection value, the mth charging time prediction value, and the maximum output power P MAX and the temperature change ΔT output from the second thermal model CP , and the detected temperature value may be added to determine a predicted temperature value at the start of the (m+1)th SOC interval Z[m+1].

[0148] When step S750 is performed, the control unit 130 calculates the input variable (T BAT , Δt, I CC ) are the battery temperature detection value, the mth constant current charging time prediction value (Δt CC ) and the mth reference current value I#m, and the temperature change amount ΔT CC Add the battery temperature detection value to the crossover SOC Z X Then, the input variables of the second thermal model (T BAT , Δt, P CP ) each cross SOC Z X The predicted temperature value at CP ) and the mth reference current value I#m, and the temperature change amount ΔT CP Crossover to SOC Z X The predicted temperature values ​​at the start of the (m+1)th SOC interval Z[m+1] may be summed to determine a predicted temperature value at the start of the (m+1)th SOC interval Z[m+1].

[0149] The operation of calculating the temperature change prediction amount for the SOC interval Z[k] (k is a natural number greater than m and less than M) following the current SOC interval Z[m] is performed by calculating the battery temperature prediction value at the start point of the following SOC interval Z[k] as shown in FIG. BAT and the reference current value I#k associated with the subsequent SOC section Z[k] is I CC , is the same as the calculation operation of the temperature change prediction amount in the SOC section Z[m] described above.

[0150] The temperature prediction value at the start point of the SOC section Z[k] is calculated using multiple reference charging maps CM1 to CM N One of the reference charge map CM u (u is a natural number equal to or smaller than N), and the specified reference charging map CM u to obtain the kth reference power curve P#k and the kth reference current value I#k.

[0151] The control unit 130 may perform the above process for each SOC interval until the predicted charging time value for the last SOC interval (e.g., Z[M]) to which the target SOC belongs is determined. Thus, the predicted charging time value for each of the current SOC interval Z[m] to the last SOC interval Z[M] may be determined sequentially. Thus, by adding up all the predicted charging time values ​​determined for the current SOC interval Z[m] to the last SOC interval Z[M], the total remaining time required to reach the target SOC from the current SOC may be determined.

[0152] Fig. 10 is a flow chart showing a method for predicting a battery charging time according to a second embodiment of the present invention. The method of Fig. 10 may be performed following the method of Fig. 5 on condition that m is less than M. m being less than M means that there is at least one SOC range following the m-th SOC range Z[m] to which the current SOC belongs among the first to M-th SOC ranges Z[1]~Z[M].

[0153] 1 to 10, in step S1010, the controller 130 sets the interval index k to be equal to m+1.

[0154] In step S1020, the control unit 130 determines whether the determination of the temperature prediction value at the start point of the k-th SOC interval Z[k] is completed. If the value of step S1020 is "yes", the control unit 130 proceeds to step S1030. If the value of step S1020 is "no", the control unit 130 may wait until the value of step S1020 becomes "yes".

[0155] In step S1030, the control unit 130 calculates a plurality of reference charging maps CM1 to CM2 associated with any one of a plurality of temperature sections to which the temperature prediction value at the start point of the k-th SOC section Z[k] belongs. N One of the following charging maps CM u From the above, the kth reference power curve P#k and the kth reference current value I#k associated with the kth SOC zone Z[k] are determined.

[0156] In step S1040, the control unit 130 determines the kth reference current value I#k, the maximum output power P based on the magnitude ΔZ of the kth SOC section Z[k]. MAX and the kth reference power curve P#k, a kth charging time predicted value indicating the time required for the SOC of the battery 11 to reach the end point of the kth SOC interval Z[k] from the start point of the kth SOC interval Z[k] is determined.

[0157] The operation of determining the kth predicted charging time value is the same as that described above with reference to Figures 7 and 8, except that the interval index m is replaced by k and the SOC estimate is replaced by the start point of the kth SOC interval Z[k].

[0158] In step S1050, the control unit 130 determines whether the section index k is equal to M. M can be said to be an identification number of the last SOC section Z[M] to which the target SOC belongs. The section index k being equal to M means that determination of the predicted charging time value for the last SOC section Z[M] has been completed. If the value of step S1050 is "No", the control unit 130 proceeds to step S1060. If the value of step S1050 is "Yes", the control unit 130 proceeds to step S1080.

[0159] In step S1060, the control unit 130 calculates the kth reference current value I#k and the maximum output power P based on the temperature prediction value at the start point of the kth SOC interval Z[k] and the kth charging time prediction value. MAX A temperature prediction value at the start point of the k+1-th SOC interval Z[k+1] is determined based on at least one of the above.

[0160] Step S1060 may include step S1062 and step S1064.

[0161] In operation S1062, the control unit 130 determines a predicted amount of temperature change during a period from when the SOC of the battery 11 reaches the start point of the kth SOC interval Z[k] to when the SOC of the battery 11 reaches the start point of the k+1th SOC interval Z[k+1]. At least one of the first thermal model and the second thermal model described above may be used to determine the predicted amount of temperature change during the SOC interval Z[k].

[0162] In step S1064, the control unit 130 determines a temperature prediction value at the start point of the k+1th SOC interval Z[k+1], which is equal to the sum of the temperature change prediction amount determined in step S1062 and the temperature prediction value at the start point of the kth SOC interval Z[k].

[0163] In step S1070, the control unit 130 increments the interval index k by 1, and then returns to step S1030. That is, steps S1030 to S1070 may be repeated until k reaches M.

[0164] In step S1080, the control unit 130 sums the mth to Mth charging time prediction values ​​to determine the remaining charging time until the charging process using the multi-stage constant current charging protocol is completed (i.e., until the SOC of the battery reaches the target SOC). The mth to Mth charging time prediction values ​​correspond one-to-one to the mth to Mth SOC ranges Z[m] to Z[M].

[0165] Fig. 11 is a flow chart showing a method for predicting a battery charging time according to a third embodiment of the present invention. The method of Fig. 11 may be performed to adjust at least one SOC section, for which a charging time prediction value is determined according to any one of the first and second embodiments described above with reference to Figs. 6 to 10, on the condition that the constant current charging for that SOC section is actually completed. In describing Fig. 11, it is assumed that j is a natural number greater than or equal to m and less than or equal to M.

[0166] 1 to 11, in step S1110, the control unit 130 determines an actual temperature change amount in the jth SOC interval Z[j]. If the jth SOC interval Z[j] is an SOC interval (e.g., Z[m]) at the start of charging using the multi-stage constant current charging protocol, the difference between the temperature detection value of the battery at the start of charging and the temperature detection value of the battery at the end point of the SOC interval Z[m] may be determined as the actual temperature change amount in the SOC interval Z[m]. Alternatively, if the jth SOC interval Z[j] is an SOC interval (e.g., Z[M]) different from the SOC interval (e.g., Z[m]) at the start of charging, the difference between the temperature detection values ​​of both batteries at the start and end points of the SOC interval (Z[M]) may be determined as the actual temperature change amount in the SOC interval Z[M].

[0167] In operation S1120, the control unit 130 determines whether the actual temperature change amount in the j-th SOC interval Z[j] is greater than the predicted temperature change amount in the j-th SOC interval Z[j].

[0168] Alternatively, the control unit 130 may correct the predicted temperature change amount in the jth SOC interval Z[j] based on the detected outside air temperature values ​​at the start and end points of the jth SOC interval Z[j], and then compare the corrected predicted temperature change amount with the actual temperature change amount in the jth SOC interval Z[j]. Specifically, when determining the predicted temperature change amount in the jth SOC interval Z[j], T ATM may indicate the outside air temperature at the start of the jth SOC interval Z[j]. Because the outside air temperature may change in the jth SOC interval Z[j], the predicted temperature change in the jth SOC interval Z[j] may be corrected by calculating a temperature correction value using Equation 5 below and adding the temperature correction value to the predicted temperature change in the jth SOC interval Z[j].

[0169] (Formula 5)

number

[0170] In Equation 5, T ATM_1 is the detected outside air temperature at the start point of the jth SOC interval Z[j], and T ATM_2 may be the detected outside air temperature at the end point of the j-th SOC interval Z[j]. Other parameter values ​​are the same as those in Equation 4. According to Equation 5, T ATM_2 >T ATM_1 In the case of ΔT correct is a positive number, and the predicted temperature change in the j-th SOC section Z[j] increases due to the correction. ATM_2 <T ATM_1 In the case of ΔT correct is a negative number, and the predicted amount of temperature change in the j-th SOC zone Z[j] is decreased by the correction.

[0171] If the value of step S1120 is "YES", proceed to step S1130.

[0172] In operation S1130, the controller 130 adjusts the jth SOC interval Z[j] according to the difference between the actual temperature change amount and the predicted temperature change amount in the jth SOC interval Z[j].

[0173] In one example, the controller 130 may decrease the end point of the jth SOC interval Z[j] by an adjustment value having a predetermined positive correlation with the difference. As a result, the size of the jth SOC interval Z[j] decreases by the adjustment value. In addition, the end point of the jth SOC interval Z[j] being moved up by the adjustment value means that the start point of the j+1th SOC interval Z[j+1] is also moved up by the adjustment value. As a result, the size of the j+1th SOC interval Z[j+1] increases by the adjustment value.

[0174] According to the third embodiment described above with reference to Fig. 11, when a multi-stage constant current charging protocol is subsequently performed, the charging process for the SOC section in which an unexpected temperature rise has occurred is terminated early, while the charging process for the SOC section following the SOC section is started early. As can be seen from the reference current profile 200 described above with reference to Fig. 2, if the reference current profile 200 is created to have a tendency that a relatively small reference current value is associated with a relatively high SOC section, the reference current value that induces an excessive temperature rise can be quickly switched to another reference current value that is lower, and the charging process using the multi-stage constant current charging protocol can be safely continued.

[0175] In addition, the control unit 130 stores a plurality of reference charging maps CM1 to CM N The reference charging map may also be corrected to correspond to any one of the corrections (adjusting the size of a specific SOC section). For example, if a specific SOC section of the reference charging map is adjusted, the specific SOC section of the reference charging map may also be adjusted accordingly.

[0176] The embodiments of the present invention described above may not necessarily be embodied through an apparatus and method, but may be embodied through a program that realizes functions corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation should be easily embodied by a person skilled in the art to which the present invention pertains from the description of the above-mentioned embodiments.

[0177] Although the present invention has been described above with reference to limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and various modifications and variations can be made by those having ordinary skill in the art to which the present invention pertains within the scope of the technical spirit of the present invention and the scope of the claims.

[0178] Furthermore, since the above-mentioned invention can be variously replaced, modified, and altered by a person having ordinary knowledge in the technical field to which the invention belongs without departing from the technical concept of the invention, it is not limited to the above-mentioned embodiments and the attached drawings, and can be configured by selectively combining all or part of each embodiment to make various modifications.

Claims

1. a memory for storing a plurality of reference charge maps associated with a plurality of temperature intervals; a sensing unit for detecting the voltage, current and temperature of the battery; a control unit that determines an estimated SOC value of the battery based on a detected voltage value and a detected current value of the battery, Each reference charging map includes first to Mth reference current values ​​and first to Mth reference power curves associated with first to Mth SOC intervals (M is a natural number equal to or greater than 2); The control unit is obtain an m-th reference power curve and an m-th reference current value associated with an m-th SOC interval (m is a natural number equal to or smaller than M) to which the SOC estimation value belongs from a reference charging map associated with a temperature interval to which the temperature detection value of the battery belongs; a battery management system configured to determine an mth charging time predicted value indicating a time required for the SOC of the battery to reach an end point of the mth SOC range based on a difference between the end point of the mth SOC range and the SOC estimated value, and at least one of the mth reference current value, the maximum output power, and the mth reference power curve, based on a comparison result between a maximum output power of a charger that supplies charging power to the battery and the mth reference power curve.

2. The control unit is 2. The battery management system according to claim 1, wherein, in response to a maximum output power of the charger being equal to or greater than a maximum power value of the mth reference power curve, a time predicted to be required when a constant current charging mode is performed using the mth reference current value until the SOC of the battery reaches an end point of the mth SOC interval from the SOC estimated value is determined as the mth charging time predicted value.

3. The control unit is 2. The battery management system according to claim 1, wherein, in response to a maximum output power of the charger being equal to or less than a minimum power value of the mth reference power curve, a time predicted to be required when a constant power charging mode is performed using the maximum output power until the SOC of the battery reaches an end point of the mth SOC interval from the SOC estimated value is determined as the mth charging time predicted value.

4. The control unit is in response to the maximum output power of the charger being between a minimum power value and a maximum power value of the mth reference power curve; determining an intersection SOC indicating an SOC at an intersection point between the mth reference power curve and the maximum output power; 2. The battery management system of claim 1, configured to determine the mth charge time prediction value based on the SOC estimate, the crossover SOC, an end point of the mth SOC interval, the mth reference current value, the maximum output power, and the mth reference power curve.

5. The control unit is determining an m-th constant current charging time prediction value indicating a time expected to be required when a constant current charging mode using the m-th reference current value is performed until the SOC of the battery reaches the crossover SOC from the SOC estimated value; determining an mth constant power charging time prediction value indicating a time expected to be required when a constant power charging mode using the maximum output power is performed until the SOC of the battery reaches an end point of the mth SOC section from the crossover SOC; 5. The battery management system of claim 4, configured to determine the mth charge time prediction value to be equal to the sum of the mth constant current charge time prediction value and the mth constant power charge time prediction value.

6. The control unit is 2. The battery management system of claim 1, further configured to determine a temperature prediction value at a start point of an (m+1)th SOC interval when there is at least one SOC interval subsequent to the mth SOC interval among the first to Mth SOC intervals.

7. The control unit is determining a predicted amount of temperature change until the SOC of the battery reaches a start point of the (m+1) SOC interval from the estimated SOC value based on the mth reference current value and the mth predicted charging time value; 7. The battery management system of claim 6, configured to determine a temperature prediction value at a start point of the m+1 SOC interval by adding a temperature change prediction amount from the SOC estimation value to an end point of the m SOC interval to the temperature detection value.

8. The control unit is When k is a natural number greater than or equal to m+1 and less than or equal to M, In response to completing the determination of the temperature prediction value at the start point of the kth SOC interval, obtain a kth reference power curve and a kth reference current value associated with the kth SOC range from a reference charging map associated with a temperature range to which the temperature prediction value at the start point of the kth SOC range belongs; 7. The battery management system of claim 6, further comprising: a charging time prediction value indicating a time required for the SOC of the battery to reach an end point of the kth SOC range based on a comparison result between the maximum output power of the charger and the kth reference power curve, and based on a magnitude of the kth SOC range and at least one of the kth reference current value, the maximum output power, and the kth reference power curve.

9. The control unit is In response to completion of determination of a charging time prediction value in the M SOC section, 9. The battery management system of claim 8, configured to determine a total remaining time until the SOC of the battery reaches an end point of the M SOC range from the SOC estimated value by adding up the m to M charging time prediction values ​​determined for the m to M SOC ranges.

10. A battery pack comprising the battery management system according to any one of claims 1 to 9.

11. An electric vehicle comprising the battery pack of claim 10.

12. determining an estimated SOC value of the battery based on a detected voltage value and a detected current value of the battery; obtaining an m-th reference power curve and an m-th reference current value associated with an m-th SOC interval (m is a natural number equal to or less than M) to which the SOC estimated value belongs from a reference charging map associated with a temperature interval to which the temperature detection value of the battery belongs, the reference charging maps including first to M-th reference current values ​​and first to M-th reference power curves associated with first to M-th SOC intervals (M is a natural number equal to or greater than 2); and determining an mth charging time predicted value indicating a time required for the SOC of the battery to reach an end point of the mth SOC range based on a difference between the end point of the mth SOC range and the SOC estimated value and at least one of the mth reference current value, the maximum output power, and the mth reference power curve, based on a comparison result between a maximum output power of a charger that supplies charging power to the battery and the mth reference power curve.

13. The step of determining the mth predicted charging time value includes:

13. The method for predicting a battery charging time according to claim 12, further comprising: determining, as the mth charging time predicted value, a time predicted to be required when a constant current charging mode is performed using the mth reference current value until the SOC of the battery reaches an end point of the mth SOC range from the SOC estimated value, in response to a maximum output power of the charger being equal to or greater than a maximum power value of the mth reference power curve.

14. The step of determining the mth predicted charging time value includes:

13. The method for predicting a battery charging time according to claim 12, further comprising: determining, as the mth charging time predicted value, a time predicted to be required when a constant power charging mode is performed using the maximum output power until the SOC of the battery reaches an end point of the mth SOC interval from the SOC estimated value, in accordance with the maximum output power of the charger being equal to or less than a minimum power value of the mth reference power curve.

15. The step of determining the mth predicted charging time value includes: in response to the maximum output power of the charger being between a minimum power value and a maximum power value of the mth reference power curve; determining a crossover SOC from the mth reference power curve that is associated with a power value equal to the maximum output power; determining an m-th constant current charging time prediction value indicating a time expected to be required when a constant current charging mode using the m-th reference current value is performed until the SOC of the battery reaches the crossover SOC from the estimated SOC value; determining an mth constant power charging time prediction value indicating a time expected to be required when a constant power charging mode using the maximum output power is performed until the SOC of the battery reaches an end point of the mth SOC interval from the crossover SOC; 13. The method of claim 12, further comprising: determining the mth charge time prediction value equal to the sum of the mth constant current charge time prediction value and the mth constant power charge time prediction value.

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