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 the remaining charging time of a battery.

[0002] This application claims priority based on 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, and the contents disclosed in the specifications and drawings of those applications are incorporated herein in their entirety. [Background technology]

[0003] Recently, as demand for portable electronic products such as notebook PCs, video cameras, and mobile phones has skyrocketed and development of electric vehicles, energy storage batteries, robots, and satellites has gained momentum, research into high-performance batteries that can be repeatedly charged and discharged is actively underway.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Of these, lithium batteries are attracting attention due to their advantages of having almost no memory effect compared to nickel-based batteries, being freely chargeable and dischargeable, having a very low self-discharge rate, and having a high energy density.

[0005] When charging a battery, if the charging rate (current rate, also known as "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, the battery will deteriorate quickly. Therefore, it is necessary to gradually adjust the charging current according to the battery's condition during constant current charging. For reference, the charging rate (C-rate) is the value obtained by dividing the charging current by the maximum capacity of the battery, and is expressed in units of "C."

[0006] A "multi-stage constant-current charging protocol" may be utilized to gradually change multiple predetermined charging rates for constant current charging. A charging map may be created for each of multiple temperature ranges, and each charging map is a table or function that records the relationship between multiple reference current values ​​(charging rates) associated with a specific temperature range and multiple switching conditions. If the battery state meets a specific switching condition (e.g., SOC reaches 60%) during charging using one of the multiple reference current values ​​recorded in a specific charging map, a charging current with the next sequential charging rate 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 SOC reaches a target SOC (for example, a fully charged state).

[0008] Conventionally, the remaining charging time to the target SOC is predicted by assuming 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 a charger may sometimes be less than the charging power required for constant current charging of the battery. In such cases, the battery is charged in constant power charging mode instead of constant current charging mode. The battery charging speed differs significantly depending on whether constant current charging mode or constant power charging mode is used. Therefore, when the charger's output power is insufficient, there is a problem in that the difference between the predicted remaining charging time and the actual charging time is large. [Prior art document] [Patent documents] Patent Document 1: International Publication No. 2019 / 026143 Patent Document 2 Special Publication No. 2022-516264 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 battery SOC 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 battery charging time that can be implemented in the battery management system.

[0011] Other objects and advantages of the present invention will become apparent from the following description and the following examples, which are merely illustrative of the principles of the present invention and can be realized by the means and combinations thereof set forth in the claims. [Means for solving the problem]

[0012] A battery management system according to one 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 the voltage, current, and temperature of a battery, and a control unit configured to determine an estimated SOC value of the battery based on the detected voltage and current values ​​of the battery. The plurality of reference charging maps include first through M reference current values ​​and first through M reference power curves associated with first through M SOC intervals (M is a natural number equal to or greater than 2), respectively. The control unit may be configured to 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 less than M) to which the estimated SOC value belongs, from the reference charging map associated with the temperature interval to which the detected temperature value of the battery belongs. The control unit may be configured to determine an mth predicted charging time value indicating the time required for the SOC of the battery to reach the end point of the mth SOC interval 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, the difference between the end point of the mth SOC interval 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.

[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, a time expected 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 estimated SOC value, as the mth predicted charging time 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, the mth predicted charging time value as 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 SOC estimated 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 predicted charging time value based on the SOC estimate 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 prediction 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 SOC crossover from the SOC estimate value. The control unit may be configured to determine an mth constant power charging time prediction 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 the end point of the mth SOC interval from the SOC crossover. The control unit may be configured to determine the mth charging time prediction value to be equal to the sum of the mth constant current charging time prediction value and the mth constant power charging time prediction value.

[0017] The control unit may be configured to further determine a temperature prediction value at the start of the (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.

[0018] The control unit may be configured to determine a predicted amount of temperature change from the estimated SOC value until the SOC of the battery reaches a start point of the (m+1)th SOC interval, based on the mth reference current value and the mth 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 mth SOC interval to the detected temperature value, and determine a predicted temperature value at the start point of the (m+1)th SOC interval.

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

[0020] The control unit may be configured to sum the m to Mth predicted charging time values ​​determined for the m 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.

[0023] According to yet another aspect of the present invention, a method for predicting a battery charging time 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 predicted charging time value indicating the time required for the SOC of the battery to reach the end point of the mth SOC interval based on a difference between the end point of the mth SOC interval 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.

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

[0025] In the step of determining the mth predicted charging time value, if the maximum output power of the charger is equal to or less than the minimum power value of the mth reference power curve, the mth predicted charging time value may be determined as the estimated time required when a constant power charging mode using the maximum output power is performed until the SOC of the battery reaches the end point of the mth SOC interval from the estimated SOC value.

[0026] Determining the mth predicted charging time value may include: determining, from the mth reference power curve, a crossover SOC associated with the same power value as 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; determining an mth constant current predicted charging time 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 crossover SOC from the estimated SOC value; determining an mth constant power predicted charging time 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 the end point of the mth SOC interval from the crossover SOC; and determining the mth predicted charging time value to be equal to the sum of the mth constant current predicted charging time value and the mth constant power predicted charging time value. [Effects 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 the target SOC.

[0028] Furthermore, according to at least one embodiment of the present invention, the accuracy of predicting the required charging time for each stage can be improved by predicting the amount of change in battery temperature at each stage and selecting a charging map to be used to predict the required charging time for the subsequent stage using the predicted amount of change in battery temperature.

[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 concept of the present invention, so the present invention should not be interpreted as being limited to the matters described in the drawings. [Brief explanation of the drawings]

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

[0033] [Figure 2] FIG. 10 is a diagram illustrating a reference charging map used in a charging process using a multi-stage constant current charging protocol.

[0034] [Figure 3] FIG. 10 is a diagram illustrating a reference charging map used in a charging process using a multi-stage constant current charging protocol.

[0035] [Figure 4] FIG. 10 is a diagram illustrating a reference charging map used in a charging process using a multi-stage constant current charging protocol.

[0036] [Figure 5] FIG. 10 is a diagram illustrating 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 illustrating 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 subroutine 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. 2 is a schematic diagram illustrating first and second thermal models used to predict the amount of temperature change for each SOC section according to a multi-stage constant current charging protocol.

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

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

[0043] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as having meanings and concepts corresponding 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 explain 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 to distinguish one of various components from the rest, and do not limit the components.

[0046] Furthermore, throughout the specification, when a part "includes" a certain element, this does not mean that it excludes other elements, but that it may further include other elements, unless otherwise specified. Furthermore, terms such as "unit" in the specification refer to a unit that processes at least one function or operation, and this 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 "coupled" to another part, this includes not only "directly coupled" but also "indirectly coupled" via 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+ and 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 at 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 communicates with the vehicle controller 2 and can supply constant current or constant voltage charging power via the charging and 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 the 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 series-parallel mixture.

[0055] The relay 20 is electrically connected in series with 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 MOSFET (Metal Oxide Semiconductor Field Effect Transistor).

[0056] An inverter 30 is provided to convert 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 using 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 is configured to detect the 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 implemented 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 the battery temperature and generate a temperature signal indicative of the detected battery temperature. The battery temperature sensor 115 may be disposed within the case 13 to detect a temperature close to the 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 the outside air temperature (ambient temperature), which is the temperature at a predetermined location 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 location outside the case 13 where heat exchange between the battery 11 and the outside air occurs.

[0064] The battery temperature sensor 115 and the ambient 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, etc.

[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, CAN (controller area network) 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 (e.g., 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 operative coupling of two components 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 can 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 can 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 the control unit 130.

[0068] The control unit 130 may also 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, such as a flash memory type, a hard disk type, a solid state disk (SSD) type, a silicon disk drive (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), or a programmable read-only memory (PROM). The memory 140 may store data and programs required for calculations performed by the control unit 130. The memory 140 may store data indicating the results of calculations performed by the control unit 130. Although FIG. 1 shows memory 140 as being physically separate from control unit 130, it is also possible for memory 140 to be incorporated within control unit 130.

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

[0071] The control unit 130 can turn on the relay 20 in response to a key-on signal. The control unit 130 can turn off the relay 20 in response to a key-off signal. The key-off signal indicates switching from an in-use state to an inactive state. Alternatively, the on / off control of the relay 20 can 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 a use state. Conversely, while the relay 20 is turned off, the battery 11 is in a rest state. The 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 rest 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 determines a detected voltage value, a detected current value, a detected battery temperature value, and a detected outside temperature value based on the voltage signal, the current signal, the battery temperature signal, and the outside air temperature signal, and then determines (estimates) a State of Charge (SOC) of the battery 11 based on the detected voltage value, the detected current value, and / or the detected battery temperature value. The SOC is the ratio of the remaining capacity to the fully charged capacity (maximum capacity) of the battery 11, and is typically calculated in the range of 0 to 1 or 0 to 100%. Known methods such as ampere counting, an OCV (Open Circuit Voltage)-SOC curve, and / or a Kalman filter may be used to determine the SOC. For reference, the mere term "detected temperature value" in this specification may refer to the detected temperature value of the 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 (the 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 plurality 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 CM2. 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 One of the reference charge 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 that indicates the change in charging current with respect to SOC over the entire SOC range. In the present invention, the entire SOC range is divided into first through Mth SOC intervals Z[1] to Z[M] (M is a natural number equal to or greater than 2). For ease of explanation, Figures 2 to 4 show M=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 intervals Z[1] to Z[M], and each reference current value indicates a charging current for constant current charging in the associated SOC interval. According to reference current profile 200, there is a single reference current value for a specific SOC interval, which indicates that the reference current value is for constant current charging in the associated SOC interval. That is, if charger 3 can supply a sufficiently large output power, battery 11 can be constant current charged with a charging current according to reference current profile 200.

[0082] In a multi-stage constant current charging protocol, a decrease in charging current may be required as the SOC increases to protect the battery. Referring to Figure 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, 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. 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 battery 11 is charged according to reference current profile 200 while periodically measuring the voltage of each battery sample. Reference voltage profile 300 may be recorded in memory 151 as a time series or a multi-dimensional function of battery voltage versus SOC.

[0084] 4 shows a reference power profile 400 that indicates the change in charge power versus SOC over the entire SOC range. The reference power profile 400 may be previously obtained from the results of repeated charging tests in which at least one battery sample having the same specifications as battery 11 is charged according to reference current profile 200 while periodically measuring the charge power supplied to each battery sample. The reference power profile 400 may be stored in memory 151 as a time series or a multi-dimensional function of charge 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 over 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 and the current value in the reference current profile 200 at that specific SOC. It should be noted that in each SOC interval, the voltage of the battery 11 increases while the reference current value remains constant, so the charging power gradually increases. A portion of the reference power profile 400 that shows the power change in a specific SOC interval 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, and therefore, there is a difference in charging power between two adjacent reference power curves (for example, 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 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, the reference voltage profile 300 (see FIG. 2) can be calculated (generated) 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 profiles 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 reference charging map 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 one 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, and external shape of the battery 11. Therefore, Figures 2 to 4 should be understood as merely an example 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 less 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 The symbol I#m may indicate a reference power curve associated with SOC interval Z[m] among the first through Mth reference power curves P#1 through P#M recorded in the table 1. Furthermore, the 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 the maximum charging current allowable for charging the battery 11 from the start point (e.g., 0%) to the end point (e.g., 50%) of the associated SOC interval (e.g., Z[1]) without irreversible damage.

[0094] When x is a natural number less than or equal to M, the size (width) of the SOC section Z[x] is the difference between the start point and end point of the SOC section Z[x], and is indicated by the symbol ΔZ[x]. In Figures 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 or may be determined differently from Figure 2.

[0095] FIG. 5 is a reference diagram for explaining the influence of the maximum output power of a charger on the 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 corresponds to 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 SOC section.

[0098] The 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 charge power required for all SOC intervals. FIG. 5 shows that the maximum charge power is determined at the end point of SOC interval Z[1]. In this case, only the constant current charging mode is performed, in which different charge currents I#1 to I#M are sequentially switched according to the multi-stage constant current charging protocol. That is, since the battery 11 is constantly charged with a charge current of the reference current value I[x] in SOC interval Z[x], the change over time in the charge power supplied to the battery 11 can be treated as matching the reference power profile 400.

[0099] The horizontal line 520 represents the maximum output power P MAX is equal to or less than the minimum charging power required for the entire SOC interval. In FIG. 5, it is shown 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 of the charger 3. 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 is performed.

[0100] The horizontal line 530 represents the maximum output power PMAX This indicates a situation where the minimum charging power required for the entire SOC section is greater than the minimum charging power required for the entire SOC section, but is smaller than the maximum charging power required for the entire SOC section.

[0101] Looking at horizontal line 530, the maximum output power P MAX is above the reference power curve P#1 at the beginning of the SOC interval 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 where the maximum output power P MAX This is the point at which the charger 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 values ​​I#3 and I#4.

[0103] Conventionally, the charging power supplied to the battery 11 during charging is the maximum output power P MAX There was no way to reflect this limitation in the remaining charging time prediction process. For example, if the maximum output power P MAX When the horizontal line 530 shown in FIG. 5 is used to predict the remaining charging time in each of the two SOC sections Z[1] and Z[2], if the 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 according to the reference power curves P#1 and P#2 in the entire SOC section Z[2], and the maximum output power P of charger 3 MAXThe remaining charge 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 charge time for the two SOC intervals Z[1] and Z[2], as well as the total remaining charge time until the target SOC is reached, often differs 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 and determine whether only one of the constant current charging mode and 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 section using the characteristics of the determined charging mode.

[0105] Figure 6 is a flowchart showing a method for predicting a battery charging time according to a first embodiment of the present invention. Figure 7 is a flowchart showing a subroutine of step S630 shown in Figure 6. Figure 8 is a flowchart showing a subroutine of step S750 shown in Figure 7. The method of Figure 6 can be performed by the battery management system 100 at set intervals 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 also be used to determine 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, the detected outside air temperature value T ATM (See FIG. 9) can further be determined.

[0107] In step S620, the control unit 130 calculates a plurality of reference charging maps CM1 to CM2. Na reference charging map CM associated with the temperature range to which the detected temperature value belongs n The mth reference current value I#m and the mth reference power curve P#m associated with the 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 from the above. In this specification, the mth SOC interval Z[m] may refer to the 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 and the mth reference power curve P#m, based on the SOC estimation value and the end point of the mth SOC interval Z[m], and the mth reference current value I#m, the maximum output power P MAX and the mth reference power curve (P#m), an mth predicted charging time value indicating the time required for the SOC of the battery 11 to reach the 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 the 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 is equal to or greater than the maximum power value of the m-th reference power curve P#m. For example, if the horizontal line 510 in FIG. 5 is MAX , the value of step S710 is "Yes." On the other hand, if the horizontal line 520 or the horizontal line 530 in FIG. 5 indicates the maximum output power P MAX If the value of step S710 is "yes", the process proceeds to step S720. If the value of step S710 is "no", the process proceeds to step S730.

[0110] In step S720, the control unit 130 determines the mth predicted charging time based on the estimated SOC 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 estimated SOC value from the end point of the mth SOC interval Z[m]. The mth predicted charging time determined in step S720 may indicate the charging time in the constant current charging mode. The control unit 130 may determine the mth predicted charging time 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 charging time in constant current charging mode.

[0112] (Equation 1)

number

[0113] In Equation 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 = charging time. For reference, although Equation 1 is expressed using three equal signs for ease of understanding, it may be stored in memory 151 to include only the rightmost term of the three terms on the right.

[0114] For example, Q MAX =10,000mAh, z f -z i = End point of m-th SOC interval Z[m] - Estimated SOC = 50% - 2% = ΔZ[m] = 48%, and assume 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 is equal to or less than the minimum power value of the m-th reference power curve P#m. For example, if the horizontal line 520 in FIG. 5 is 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", the process proceeds to step S740. If the value of step S730 is "no", 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 answer to step S730 is "No", the process proceeds to step S750.

[0116] In step S740, the control unit 130 calculates the estimated SOC value, 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 is determined. The mth predicted charging time determined in step S740 may be the charging time in the constant power charging mode. The following Equation 2 is an example of a function that can be used to determine the charging time in the constant power charging mode.

[0117] (Equation 2)

number

[0118] In Equation 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 CHGCharging power at z during constant current charging, 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 so as to include only the rightmost term of the four terms on the right.

[0119] The battery 11 has a maximum capacity of 10,000mAh, 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 estimated SOC value, 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 reference power curve P#m, an mth predicted charging time value Δt#m is determined.

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

[0122] Referring to FIG. 8, in step S810, the control unit 130 calculates the mth reference power curve P#m and the maximum output power P MAX The crossover SOC is determined by referring to FIG. 5, where the maximum output power P MAXWhen coincident with the horizontal line 530, X indicates the intersection point, and Z X indicates the crossover SOC.

[0123] In step S820, the control unit 130 determines the intersection 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 less than the maximum output power P MAX This means that only a constant power charging mode limited to 1000 W is performed. If the value of step S820 is "No", the process 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 for the charging time to reach the predetermined value, is determined. The above-mentioned Equation 1 can be used to determine the mth constant current charging time prediction value. That is, when the current SOC is 2%, z in Equation 1 is f The end point of the first SOC interval Z[1] is 50% instead of the crossing SOC Z X Δt when 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 prediction 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 When >2% = current SOC, z in Equation 2 iInstead of SOC estimates, cross SOC Z X Δt when CP is determined as the mth constant power charging time prediction value.

[0127] In step S850, the control unit 130 determines the mth predicted charging time value, which is equal to the sum of the mth predicted constant current charging time value determined in step S830 and the mth predicted constant power charging time 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 interval index of the SOC interval to which the current SOC belongs, is less than M, this means that there is at least one SOC interval following the mth SOC interval Z[m] in which the charging process is currently in progress. For example, when m=1<4=M, charging is scheduled in three SOC intervals Z[2] to Z[4], so step S640 may be performed.

[0129] In step S640, the control unit 130 calculates 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 predicted charging time value Δt#m. MAX The temperature predicted 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 predicted 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]. In step S610, the detected outside air temperature T ATM If the detected outside air temperature T ATM A temperature prediction value at the start 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 estimated SOC value 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 calculates the predicted temperature change amount (for example, ΔT CC , ΔT CP or ΔT CC +ΔT CP ) and the detected temperature value obtained in step S610, the predicted temperature value at the start point of the (m+1)th SOC interval Z[m+1] is determined.

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

[0134] In Figure 9, T BAT is the battery temperature (detected or predicted value), 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 can use at least one of the first thermal model and the second thermal model to calculate a predicted temperature change amount that indicates 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 assigned, the temperature change amount ΔT CCThe following Equation 3 may be used as the first thermal model.

[0137] (Equation 3)

number

[0138] In Equation 3, α is an adjustment coefficient (predetermined), β is a heat exchange coefficient (predetermined), and C H denotes the thermal capacity (predetermined) of the battery 11. In the first thermal model, T ATM can be a predetermined value (for example, 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 and the difference between each of the output variables ΔT CC A 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 assigned, the temperature change ΔT CP The second thermal model may be a function predetermined to output the following equation:

[0141] (Equation 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 and the difference between each of the output variables ΔT CP A 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 both Figures 5 and 9, the SOC estimate Z est Intersects SOC Z X If the mth constant current charging time prediction value is input to Δt in Equation 3, the ΔT CC and ΔT output when the mth constant power charging time prediction value is input into Δt in Equation 4. CP The sum of and can be determined as the predicted temperature change in the SOC interval Z[1]. est Intersects SOC Z X If it is equal to or greater than ΔT in Equation 4, CP can be determined as the predicted temperature change in SOC interval Z[1]. The predicted temperature change in SOC interval Z[2] can be determined using Equation 4. The predicted temperature change in each of the remaining two SOC intervals Z[3] and Z[4] can be determined using Equation 3.

[0145] Still referring to FIG. 7, steps S720, S740 and S750 are performed alternatively.

[0146] When step S720 is performed, the control unit 130 calculates the input variables (T BAT , Δt, I CC) are assigned the battery temperature detection value, the mth predicted charging time value, and the mth reference current value I#m, and the temperature change amount ΔT output from the first thermal model is calculated. CC and the detected temperature value to determine the 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 calculates the input variables (T BAT , Δt, P CP ) respectively represent the battery temperature detection value, the mth predicted charging time 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 to determine the 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 variables (T BAT , Δt, I CC ) respectively represent the battery temperature detection value, the mth constant current charging time prediction value (Δt CC ) and mth reference current value I#m, and the temperature change ΔT output from the first thermal model CC Add the battery temperature detection value to the SOC Z X Subsequently, the input variables of the second thermal model (T BAT , Δt, P CP ) respectively, cross SOC Z X the predicted temperature value at the mth constant power charging time (Δt in Equation 2) CP ) and m's reference current value I#m, and the temperature change ΔT output from the second thermal model CP Crossing SOC Z X The predicted temperature values ​​at the m+1-th SOC interval Z[m+1] may be summed to determine the predicted temperature value at the start of the m+1-th SOC interval Z[m+1].

[0149] The calculation of the predicted temperature change 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 predicted battery temperature 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 assigned as I CC The calculation operation for the predicted temperature change amount in the SOC section Z[m] is the same as that described above, except that the temperature change amount is assigned as

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

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

[0152] Fig. 10 is a flowchart showing a method for predicting battery charging time according to a second embodiment of the present invention. The method of Fig. 10 can be performed following the method of Fig. 5, provided that m is less than M. m being less than M means that there is at least one SOC interval in the first to mth SOC intervals Z[1] to Z[M] that follows the mth SOC interval Z[m] to which the current SOC belongs.

[0153] 1 to 10, in step S1010, the control unit 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 complete. 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 operation S1030, the control unit 130 calculates a plurality of reference charging maps CM1 to CM2 associated with one of the plurality of temperature sections to which the temperature predicted value at the start point of the k-th SOC section Z[k] belongs. N One of the standard charging map CM u The kth reference power curve P#k and the kth reference current value I#k associated with the kth SOC interval Z[k] are determined from the above.

[0156] In step S1040, the control unit 130 calculates the kth reference current value I#k and 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 predicted charging time value is determined, which indicates 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].

[0157] The operation of determining the kth predicted charging time value is the same as the operation 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 interval index k is equal to M. M can be said to be the identification number of the last SOC interval Z[M] to which the target SOC belongs. If the interval index k is equal to M, it means that the determination of the predicted charging time value for the last SOC interval 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 predicted temperature value at the start point of the kth SOC interval Z[k] and the predicted charging time value. MAX The 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 the start of the kth SOC interval Z[k] to the start of the k+1th SOC interval Z[k+1] of the battery 11. The predicted amount of temperature change during the SOC interval Z[k] may be determined using at least one of the first thermal model and the second thermal model.

[0162] In step S1064, the control unit 130 determines a temperature prediction value at the start 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 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 predicted charging time 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 battery SOC reaches the target SOC). The mth to Mth predicted charging time values ​​correspond one-to-one to the mth to Mth SOC ranges Z[m] to Z[M].

[0165] Figure 11 is a flowchart showing a method for predicting a battery charging time according to a third embodiment of the present invention. The method of Figure 11 can be performed to adjust at least one SOC zone, for which a charging time prediction value has been determined according to any one of the first and second embodiments described above with reference to Figures 6 to 10, on the condition that constant current charging for that SOC zone is actually completed. In describing Figure 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 the 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 detected temperature value of the battery at the start of charging and the detected temperature value of the battery at the end 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 detected temperature values ​​of both batteries at the start and end of the SOC interval (Z[M]) may be determined as the actual temperature change amount in the SOC interval Z[M].

[0167] In step 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 j-th SOC interval Z[j] based on the detected outside air temperature values ​​at both the start and end points of the j-th SOC interval Z[j], and then compare the corrected predicted temperature change amount with the actual temperature change amount in the j-th SOC interval Z[j]. Specifically, when determining the predicted temperature change amount in the j-th 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 during the jth SOC interval Z[j], the predicted temperature change during the jth SOC interval Z[j] can be corrected by calculating a temperature correction value using Equation 5 below and adding the temperature correction value to the predicted temperature change during the jth SOC interval Z[j].

[0169] (Equation 5)

number

[0170] In Equation 5, T ATM_1 is the detected outside air temperature at the start point of the j-th SOC interval Z[j], and T ATM_2 is 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 amount in the j-th SOC interval 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 interval Z[j] is reduced by the correction.

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

[0172] In operation S1130, the control unit 130 adjusts the j-th SOC interval Z[j] according to the difference between the actual temperature change amount and the predicted temperature change amount in the j-th 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 that has a predetermined positive correlation with the difference. As a result, the size of the jth SOC interval Z[j] decreases by the adjustment value. Furthermore, moving the end point of the jth SOC interval Z[j] forward by the adjustment value also means moving the start point of the j+1th SOC interval Z[j+1] forward 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 Figure 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 initiated early. As can be seen from reference current profile 200 described above with reference to Figure 2, if the profile is created to have a tendency for relatively low reference current values ​​to be associated with relatively high SOC sections, the reference current value that caused the excessive temperature rise can be quickly switched to another lower reference current value, thereby safely continuing the charging process using the multi-stage constant current charging protocol.

[0175] Furthermore, the control unit 130 calculates a plurality of reference charge 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 are not necessarily embodied through devices and methods, 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 a person having ordinary skill in the art to which the present invention pertains within the technical spirit of the present invention and the scope of the claims.

[0178] Furthermore, since the above-mentioned present invention can be variously replaced, modified, and changed by a person having ordinary knowledge in the technical field to which the present invention belongs without departing from the technical concept of the present 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 that detects 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 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 less 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 predicted charging time value indicating a time required for the SOC of the battery to reach the end point of the mth SOC interval, based on a difference between the end point of the mth SOC interval 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, by comparing a maximum output power of a charger that supplies charging power to the battery with the mth reference power curve.

2. The control unit 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, the battery management system is configured to determine, as the mth predicted charging time value, a time expected to be required when a constant current charging mode using the mth reference current value is performed until the SOC of the battery reaches an end point of the mth SOC interval from the estimated SOC value.

3. The control unit 2. The battery management system according to claim 1, wherein, in response to the maximum output power of the charger being equal to or less than the minimum power value of the mth reference power curve, the battery management system is configured to determine, as the mth predicted charging time value, 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 estimated SOC value.

4. The control unit In response to the maximum output power of the charger being between the minimum power value and the 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 predicted charge time value based on the SOC estimate value, 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 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 estimation value; determining an m-th 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 m-th SOC interval from the crossover SOC; 5. The battery management system of claim 4, configured to determine the mth predicted charging time value to be equal to the sum of the mth predicted constant current charging time value and the mth predicted constant power charging time value.

6. The control unit 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 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 according to claim 6, configured to determine the predicted temperature value at the start point of the (m+1) SOC interval by adding 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.

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

9. The control unit In response to completion of determination of the predicted charging time 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 interval from the estimated SOC value by summing the m to M predicted charging time values ​​determined for the m to M SOC intervals.

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

11. An electric vehicle including 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; a step of acquiring 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 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 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 predicted charging time value indicating a required time for the SOC of the battery to reach the end point of the mth SOC interval based on a difference between the end point of the mth SOC interval 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.

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, 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 expected to be required when a constant current charging mode using the mth reference current value is performed until the SOC of the battery reaches an end point of the mth SOC interval from the estimated SOC value is determined as the mth predicted charging time value.

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, 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 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 estimated SOC value is determined as the mth predicted charging time value.

15. The step of determining the mth predicted charging time value includes: In response to the maximum output power of the charger being between the minimum power value and the 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 m-th constant power charging time prediction 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 m-th SOC interval from the crossover SOC; 13. The method of claim 12, further comprising: determining the mth predicted charging time value to be equal to the sum of the mth predicted constant current charging time value and the mth predicted constant power charging time value.

Images