WO2018235995A1

WO2018235995A1 - Method for fast charging and maximum discharging while reducing degradation of electric vehicle battery, and apparatus therefor

Info

Publication number: WO2018235995A1
Application number: PCT/KR2017/010111
Authority: WO
Inventors: 이정환
Original assignee: 이정환
Priority date: 2017-06-23
Filing date: 2017-09-15
Publication date: 2018-12-27
Also published as: KR101998069B1; KR20190000445A

Abstract

The present invention relates to a method for fast charging and maximum discharging while reducing degradation of an electric vehicle battery, and an apparatus therefor. The charge state and discharge state of a battery used in electric vehicles are closely monitored in order to enable fast charging and maximum discharging while adjusting the maximum charge current or maximum discharge current in accordance with the state of the battery, so that fast charging and maximum discharging of the battery can be performed while preventing performance degradation due to high voltage or high temperature.

Description

A method and apparatus for performing fast charging and discharging while reducing the occurrence of deterioration of a battery for an electric vehicle

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for performing fast charging and discharging while reducing the occurrence of deterioration of a battery for an electric vehicle, and more particularly, And the maximum charge current and the maximum discharge current are adjusted according to the state of the battery, so that the fast charge and the maximum discharge are performed, thereby preventing the performance from being deteriorated due to the high voltage or the high temperature. And more particularly, to a method and apparatus for performing fast charging and discharging of a battery for an electric vehicle.

Recently, environmental pollution caused by gasoline automobiles has been emerging, and research and development of environmentally friendly electric vehicles and hybrid electric vehicles have been actively conducted by various automobile manufacturers.

The electric vehicle refers to an automobile that uses an electric battery and an electric motor without using petroleum fuel and an engine, and drives an automobile by rotating an electric motor that is stored in a battery.

Further, the hybrid electric vehicle refers to a vehicle that drives a vehicle by combining two or more different kinds of power sources, that is, an engine that obtains a driving force by using fuel and a vehicle that acquires a driving force by an electric motor driven by battery power. Such an hybrid electric vehicle is an environmentally friendly automobile in which an electric motor and an engine are appropriately driven according to the traveling speed, and is an automobile that improves fuel economy by charging an electric motor to charge the battery and auxiliary driving the motor at low- .

Typical hybrid electric vehicles include an MCU (Motor Control Unit) that controls motor operation, a BMS (Battery Management System) that performs battery power management, a Hybrid Control Unit (HCU) that controls the entire vehicle, An engine control unit (ECU) for controlling the engine, a motor for driving the vehicle, and a transmission control unit (TCU) for controlling the transmission.

These controllers are connected to a high-speed CAN (Controller Area Network) communication line (communication system developed by Bosch for sharing data between ECUs in the vehicle) centered on the HCU as an upper controller and exchange information among the controllers, To transmit the command to the lower controller. For example, the HCU substantially controls the driving of the electric motor through the MCU. At this time, the MCU controls the driving torque and the driving speed of the driving electric motor according to the control signal applied from the HCU, .

The main driving mode of the hybrid electric vehicle constructed as described above is an EV (electric vehicle) mode, which is a pure electric vehicle mode using only motor power, an auxiliary mode in which the rotational force of the engine is used as the main driving force and the rotational force of the motor is used as auxiliary power A hybrid electric vehicle (HEV) mode, a regenerative braking (RB) mode in which the braking and inertial energy of the vehicle is recovered through power generation at the time of braking or inertia of the electric vehicle and charged into the battery.

In addition, the HEV mode is a parallel type hybrid which mainly uses an engine and is assisted by an electric motor, and a Strong HEV which has a merit of generating a powerful force, and a single HEV that uses one engine and two motors, It is a direct-parallel type hybrid that produces electricity by a motor and assists in parallel operation through another motor, and can be classified into a mild HEV having excellent fuel economy and driving ability.

In addition, a vehicle such as the hybrid electric vehicle is equipped with an internal combustion engine driven by gasoline and a battery engine, and drives the vehicle using either or both of them. However, the vehicle is equipped with a large- The plug-in hybrid electric vehicle (PHEV) has also been developed, which can be used continuously, since the charging station can charge the cell phone or charge the electricity just like gasoline.

The hybrid electric vehicle uses a large capacity battery, which is a secondary battery. The battery is an energy source for driving a motor of a hybrid electric vehicle. The battery monitors the voltage, current, and temperature of the battery through the BMS, .

FIG. 1 is a view for schematically explaining an operation performed in a BMS (battery management system) of such a general electric vehicle, wherein the BMS is a function of the safety of a secondary battery supplying power required by a drive system of an electric vehicle It is a key element of electric vehicles and hybrid electric vehicles because it plays a role in ensuring reliability.

The functions of the BMS can be roughly classified into the following two types. In other words, it can be classified into the thermal management control technology that can uniformly cool the weak battery in the heat and the uniform performance at all times, and the battery charge state (SOC: state of charge) control technology that determines the state of the battery and operates at the optimum efficiency point It is.

The thermal management control technology monitors the voltage, current, and temperature of the system to maintain it in an optimal state, and can take an alarm and advance safety precautions for safe operation of the system. In addition, overcharge and overdischarge of the battery are suppressed to uniformly control the voltage between the cells, thereby prolonging the energy efficiency and the life of the battery. It is possible to save the alarm history status and to preserve the data and to diagnose the system through external diagnosis system or monitoring PC.

The battery charge state control technique is realized by a cell balance that keeps all the cells always in a uniform charge state. Furthermore, the battery management system comprehensively analyzes various change factors to predict the remaining travelable distance, and provides the information to an upper vehicle electronic control unit (ECU). In-vehicle communications typically utilize CAN, an ISO standard network.

The software supporting the functions of the BMS includes measuring algorithms for voltage, current and temperature, state of charge calculation (SOC), state of health (SOH) estimation, Cell balancing algorithm, Thermal management, Diagnostic algorithm, Protection algorithm and Communication with vehicle.

On the other hand, as the battery is repeatedly charged and discharged, its performance deteriorates and its service life is shortened. At this time, the degradation degree of the performance of the battery can be quantitatively evaluated through the SOH parameter. That is, the SOH is evaluated in the BMS to calculate the replacement time of the battery, and the charging and discharging capacity of the battery is controlled according to the use period of the battery, thereby preventing overcharging and over discharge of the battery.

Conventional battery aging is detected by measuring the change in the internal resistance of a battery. When the battery is first manufactured and shipped from the factory, the internal resistance is very small. As the battery is repeatedly charged and discharged, the internal resistance becomes large. The internal resistance becomes large enough to transmit electric power. Therefore, it is necessary to effectively manage charging and discharging in order to increase the life of the battery.

As the internal resistance of the battery changes, the capacity of the battery changes, and SOH can be estimated by the internal resistance and temperature of the battery. In the estimation process, the internal resistance of the battery is measured each time charging and discharging are repeated, and the capacity of the battery is measured by temperature. Then, the battery capacity is relatively quantified based on the initial capacity of the battery, And stored in a table. Then, the SOH of the battery can be estimated by measuring the internal resistance and temperature of the battery in an actual battery usage environment, and mapping the SOH corresponding to the internal resistance and the temperature from the mapping table.

However, an electric vehicle requiring a large-capacity power source as described above can not define the maximum electric power because the discharge battery electric power depends on the battery voltage and the load electric current, thereby deteriorating battery performance.

In addition, a typical CC (Constant Current, constant current mode that does not exceed the current set by maintaining the current by fluctuating voltage) Charge mode, CV (Constant Voltage, Constant Voltage Mode) Since the charging current can not be changed in CC (Constant Charging), the charging mode can not effectively prevent overcharge and overdischarge based on the current adjustment according to the state of the battery.

In addition, there is a problem that battery deterioration is accelerated due to high voltage and temperature inside the battery.

Therefore, in the present invention, charging and discharging are performed while adjusting the maximum charging current or the maximum discharging current based on the voltage or temperature information by monitoring the charging and discharging states of the battery for an electric vehicle, thereby causing deterioration due to high voltage or high temperature And to propose a method of performing the fast charge and the maximum discharge while suppressing the maximum discharge.

Next, a brief description will be given of the prior arts that exist in the technical field of the present invention, and technical matters which the present invention intends to differentiate from the prior arts will be described.

Korean Patent Registration No. 0949260 (Mar. 16, 2010) relates to a battery charging system for an electric vehicle, and more particularly, to a battery charging system for a hybrid electric vehicle, which optimizes a set value of a battery charge state quantity (SOC [%] (State of Charge) And more particularly, to a battery charging system for an electric vehicle capable of extending energy consumption efficiency of an electric vehicle and battery life.

The prior art provides an effect of improving the energy consumption efficiency of a battery of a hybrid electric vehicle by determining a weighted filling rate and a predicted charging rate, and increasing the lifetime of the battery by reducing overcharge and overcharging of the battery. There is some similarity between the charging and discharging of the battery of the present invention by monitoring the charging and discharging states of the battery of the present invention in that the overcharging is reduced and the battery life is increased.

However, as the charging / discharging according to the present invention is repeated, the process of changing the resistance of the battery pack resistance and the weak cell is learned to precisely monitor the charging state and the discharging state of the battery, And the maximum discharge current can be adjusted according to the state of the battery including the combination of the charge current and the maximum discharge current to perform the fast charge and the maximum discharge are not described in the prior art at all, It is the characteristic composition of the invention only.

U.S. Patent No. 8459978 (May 31, 2013) discloses a method for monitoring the state of a rechargeable battery, which repeatedly acquires at least one measured value with respect to the battery during discharging of the battery, (The state of the battery is dependent on the previously calculated state of the battery, the measured value, and the at least one battery parameter), and the state of the battery is measured at a first rate Updating the parameter of the battery, updating the parameter of the battery at a second rate faster than the first rate after the status of the battery exceeds the threshold value, and calibrating the status of the battery in response to each update of the parameter .

However, in the prior art, there are some similarities to the present invention in that the parameter of the battery is updated to monitor the battery condition. However, in the prior art, the voltage, temperature, It is clear that there is no difference in technical structure because there is no suggestion, suggestion or description about the configuration that can perform the fast charge and the maximum discharge while adjusting the maximum charge current or the maximum discharge current according to the battery condition.

Some of similar configurations are proposed for the configuration for increasing the battery life by reducing over-discharge overcharging of the battery, and for monitoring the battery status by updating the parameters of the battery status. However, There is no description of a structure for monitoring the state of charge and discharge of the battery, which is a technical feature to be presented, to perform the fast charge and the maximum discharge while adjusting the maximum charge current or the maximum discharge current according to the battery state, will be.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a battery used in an electric vehicle capable of performing a fast charging and a maximum discharge while preventing performance deterioration due to high voltage and high temperature .

Another object of the present invention is to learn the process of changing the resistance of the battery pack resistance and the resistance of the wick cell as the charging and discharging are repeated, and precisely monitor the charging state and the discharging state of the battery based on the learning contents.

In addition, the present invention precisely monitors the charged state and the discharged state of a battery used in an electric automobile and adjusts the maximum charging current or the maximum discharging current according to the battery state including voltage, temperature, or a combination thereof, So that the user can perform the operation.

An apparatus for performing fast charging while reducing the occurrence of deterioration of a battery for an electric vehicle according to an embodiment of the present invention includes an learning unit for learning charge state information of a battery pack according to deterioration or temperature, And a charge processing unit for adjusting the maximum charge current according to a wick cell state of the battery pack to charge the battery pack based on a state of charge of the battery pack, A temperature and a resistance for the OCV, an OCV variation according to the SOC, a maximum set voltage at the current OCV point, or a combination thereof.

At this time, the maximum charging current is set by the following equation: CCmax = (OCVanode - Vmax) / WR [i] [j] Where CCmax is the maximum charge current, Vmax is the maximum voltage preset for each SOC, OCVanode is the Anode OCV voltage mapped to the open circuit voltage, WR is the resistance of the wick cell, i is the point of the measured resistance, j is the temperature range to be.

Cathode Voltage and Anode Voltage can be measured through the internal ground. When the charge is dropped, the anode voltage is dropped, and when it drops below the anode potential voltage, lithium plating occurs and the cell deterioration is accelerated. Therefore, the anode voltage is prevented from dropping below the potential voltage during charging, thereby preventing cell deterioration. However, when the cell development is completed, the cell usually consists of +/- two terminals. Therefore, it is necessary to measure each OCV profile data before applying it to actual application, and OCV is mapped to OCVanode according to the SOC section, In the application, OCV is measured to obtain OCVanode. Therefore, Vmax is set to anode potential voltage + tolerance voltage.

Also, the charge processing unit detects the current OCV point of the battery pack using the recently measured OCV and the passed charge, and calculates a maximum charge current with reference to the wick cell temperature and resistance of the battery pack at the detected current OCV point And determines whether the current wick cell voltage is the highest among all the battery cells in the process of charging the battery pack with the maximum charging current. If the wick cell voltage is the highest among all the battery cells, The charging of the battery pack is performed at the maximum charging current until the SOC of the battery pack reaches the SOC threshold value.

Also, the charging processor determines that the current wick cell voltage is the highest among all the battery cells in the process of charging the battery pack with the maximum charging current, and the current wick cell voltage is the highest voltage among all the battery cells The cell having the highest voltage is changed to the Weck cell, and the resistance of all the battery cells is remeasured. If the voltage measured at the weck cell is greater than the predetermined maximum voltage, the resistance is measured again. And when the voltage measured by the weak cell is less than a preset maximum voltage, the battery pack is charged with the maximum charge current until the current SOC reaches the SOC threshold, The charging operation is performed.

Also, the charging processor may determine whether the current temperature of the battery pack exceeds a predetermined temperature limit in the process of charging the battery pack with the maximum charging current. If it is determined that the current temperature of the cell is less than a predetermined temperature limit The maximum charge current is adjusted so that the charge can be performed while the temperature of the cell is kept below the temperature limit, and then the charge of the battery pack is performed at the maximum charge current until the current SOC reaches the SOC threshold , Thereby preventing deterioration occurring when charging is performed at a temperature exceeding a predetermined range of temperature.

In addition, an apparatus for performing maximum discharge while reducing the occurrence of deterioration of a battery for an electric vehicle according to an embodiment of the present invention includes an learning unit for learning discharge status information of a battery pack according to deterioration or temperature, And a discharge processor for adjusting the maximum discharge current and the maximum power according to the wick cell state of the battery pack based on the state information to perform discharge of the battery pack, And a total voltage, a temperature and a resistance for each battery cell, an OCV change amount according to SOC, a cutoff voltage as a preset discharge end voltage, a margin setting voltage before a cutoff voltage, or a combination thereof.

At this time, the maximum discharge current and the maximum power are set by a formula of MAXdisc = (OCV - (cutoff voltage + delta voltage)) / WR [i] [j], MAXp = current battery pack voltage * MAXdisc . In this case, MAXdisc is the maximum discharge current, OCV is the open circuit voltage, the cutoff voltage is the discharge end voltage, the delta voltage is the margin setting voltage before the cutoff voltage, WR is the resistance of the wick cell, i is the point of the measured resistance, Range, MAXp is the maximum power.

Also, the discharge processor may detect a current OCV point of the battery pack using recently measured OCV and pass charge, and determine a wick cell temperature, a resistance, a cutoff voltage, and a margin setting of the battery pack at the detected current OCV point Determining whether the current wick cell voltage is the lowest among all the battery cells in the process of discharging the battery pack with the maximum discharge current and the maximum power, setting the maximum discharge current and the maximum power with reference to the voltage, Off voltage and a margin setting voltage when the current wick cell voltage is the lowest voltage among all the battery cells, and determines whether the voltage measured by the wick cell is less than the sum of the cut- If the current SOC is less than the SOC threshold value or the maximum power is less than the predetermined minimum power And discharging the battery pack with the maximum discharge current and the maximum power until the voltage is less than the threshold value.

When the current wick cell voltage is not the lowest voltage among all the battery cells, it is determined that the current wick cell voltage is the lowest among all the battery cells in the process of discharging the battery pack. The battery cell having a low voltage is changed to a wick cell and the resistance of all the cells is remeasured to determine whether the voltage measured in the corresponding weak cell based on the resistance measurement result is less than the sum of the cut- If the measured voltage at the weak cell is smaller than the sum of the cutoff voltage and the margin set voltage, the resistance is calculated again, and then the discharge is performed by adjusting the maximum charge current and the maximum power. If the sum of the cutoff voltage and the margin setting voltage is larger than the sum of the cutoff voltage and the margin setting voltage, the current SOC is less than the SOC threshold value, Until it is below a predetermined minimum power threshold, characterized in that to perform the discharge of the battery pack to the maximum discharging current and maximum power.

Also, the discharge processor may determine whether a current temperature of the battery pack exceeds a predetermined temperature limit in a process of discharging the battery pack. If the measured temperature of the currently measured cell exceeds a predetermined temperature limit, The maximum discharge current and the maximum power are adjusted so that the discharge can be performed while the temperature of the cell is kept below the temperature limit, and then the maximum discharge current and the maximum power are adjusted until the current SOC is less than the SOC threshold value or the maximum power is less than the predetermined minimum power threshold And discharging the battery pack at a current and a maximum power, thereby preventing deterioration occurring when discharging is performed at a temperature exceeding a predetermined range of temperature.

In addition, a method for performing fast charging while reducing the occurrence of deterioration of a battery for an electric vehicle according to an embodiment of the present invention includes a learning step of learning charge state information of a battery pack according to deterioration or temperature, And a charging processing step of adjusting the maximum charging current according to the wick cell state of the battery pack based on the state information to perform charging of the battery pack, wherein the charging state information includes a total resistance of the battery pack according to SOC A temperature and a resistance of the battery cell, an OCV variation amount according to the SOC, a maximum setting voltage at a current OCV point, or a combination thereof.

The charging process may further include detecting a current OCV point of the battery pack using a recently measured OCV and a passed charge, calculating a maximum OCV point by referring to a wick cell temperature and a resistance of the battery pack at the detected current OCV point Determining whether the current wick cell voltage is the highest among all the battery cells in the process of charging the battery pack with the maximum charging current, determining whether the current wick cell voltage is the highest among all the battery cells, And charging the battery pack with the maximum charge current until the current SOC reaches the SOC threshold value when the battery voltage is a high voltage.

In the charging process, it is determined that the current wick cell voltage is the highest among all the battery cells in the process of charging the battery pack with the maximum charging current. If the current wick cell voltage is the highest among all the battery cells Measuring the resistance of all the battery cells after changing the cell having the highest voltage if the voltage is not higher than the maximum cell voltage, measuring the resistance again if the voltage measured at the corresponding wick cell is greater than a preset maximum voltage, Adjusting the maximum charge current based on the temperature and the resistance to proceed with charging; and, if the measured voltage at the weak cell is less than a preset maximum voltage, changing the maximum charge current until the current SOC reaches the SOC threshold And performing charging of the battery pack.

The charging process may further include determining whether a current temperature of the battery pack exceeds a predetermined temperature limit in a process of charging the battery pack with the maximum charging current, If the temperature limit is exceeded, the maximum charge current is adjusted so that the charge can be maintained while the temperature of the cell is kept below the temperature limit, and then the charge of the battery pack is charged to the maximum charge current until the current SOC reaches the SOC threshold So as to prevent deterioration occurring when charging is performed at a temperature exceeding a predetermined range of temperatures.

In addition, a method for performing maximum discharge while reducing the occurrence of deterioration of a battery for an electric vehicle according to an embodiment of the present invention includes a learning step of learning discharge status information of a battery pack according to deterioration or temperature, And a discharge processing step of adjusting the maximum discharge current and the maximum power according to the wick cell state of the battery pack based on the state information to perform discharge of the battery pack, A resistance and a total voltage, a temperature and a resistance for each battery cell, an OCV variation amount according to SOC, a cutoff voltage as a preset discharge end voltage, a margin setting voltage before a cutoff voltage, or a combination thereof.

The discharging process may further include detecting a current OCV point of the battery pack using a recently measured OCV and a pass charge, detecting a wick cell temperature and a resistance of the battery pack at the detected current OCV point, a cutoff voltage, Determining a maximum discharge current and a maximum power with reference to a margin setting voltage, determining whether a current wick cell voltage is the lowest among all the battery cells in a process of discharging the battery pack, Determining whether a voltage measured by the weak cell is less than a sum of the cut-off voltage and a margin setting voltage when the voltage is the lowest voltage among all the battery cells, and determining whether the voltage measured by the weak cell is less than the sum of the cut- Sum, the current SOC is less than the SOC threshold, or the maximum power is less than the predetermined minimum power threshold Discharging the battery pack with the maximum discharge current and the maximum power until the maximum discharge current is less than the maximum discharge current.

Also, the discharging process may be performed such that if the current weak cell voltage is the lowest among all the battery cells in the process of discharging the battery pack, if the current weak cell voltage is not the lowest voltage among all the battery cells The battery cell having the lowest voltage is changed to the Weck cell and the resistance of all the cells is remeasured to determine whether the voltage measured at the detected weak cell based on the resistance measurement result is less than the sum of the cut- Calculating a resistance when the voltage measured by the weak cell is less than the sum of the cut-off voltage and the margin setting voltage, and adjusting the maximum charge current and the maximum power to proceed with discharging; If a voltage is greater than the sum of the cutoff voltage and the margin set voltage, the current SOC is less than the SOC threshold Or until the maximum power is less than a predetermined minimum power threshold, it characterized in that it further comprises the step of performing discharge of the battery pack to the maximum discharging current and maximum power.

The discharging process may further include determining whether a current temperature of the battery pack exceeds a predetermined temperature limit in a process of discharging the battery pack, and if the measured temperature of the currently measured cell exceeds a predetermined temperature limit The maximum discharge current and the maximum power are adjusted so that the discharge can be performed while the temperature of the corresponding cell is kept below the temperature limit, and then the maximum discharge current and the maximum power are adjusted until the current SOC is less than the SOC threshold value or the maximum power is less than the predetermined minimum power threshold And discharging the battery pack at a maximum discharge current and a maximum power so as to prevent deterioration occurring when discharging is performed at a temperature exceeding a predetermined range of temperature.

As described above, according to the method and apparatus for performing the fast charge and the maximum discharge while reducing the deterioration of the battery for an electric vehicle according to the present invention, the charging and discharging state of the battery for an electric vehicle is monitored, Charging and discharging are performed while adjusting the maximum charging current or the maximum discharging current on the basis of the maximum charging current and the maximum discharging current so that the fast charging and the maximum discharging can be performed while suppressing the occurrence of deterioration due to the high voltage or the high temperature.

In addition, by learning how the resistance of the battery pack and the resistance of the wick cell are changed, the charge and discharge states of the battery are precisely monitored, and the charge and discharge are controlled based on the battery charge resistance and the discharge state. The battery can be restrained as much as possible, thereby improving the quality of the battery, and can be used stably for a long time.

FIG. 1 is a schematic view for explaining an operation performed in a BMS of a general electric vehicle.

2 is a view schematically showing a configuration of an embodiment of a battery management system to which the present invention is applied.

3 is a view schematically showing a configuration of another embodiment of a battery management system to which the present invention is applied.

4 is a diagram schematically showing a configuration of another embodiment of a battery management system to which the present invention is applied.

5 is a view showing a first cycle for learning data for charging and discharging state monitoring of a battery pack applied to the present invention.

6 is a diagram illustrating a second cycle for learning data for charging and discharging state monitoring of a battery pack according to the present invention.

7 is a detailed view showing a configuration of a battery management device applied to each embodiment of the present invention.

FIG. 8 is a flowchart illustrating an operation procedure of a method for performing fast charging while reducing occurrence of deterioration of a battery for an electric vehicle according to an embodiment of the present invention. Referring to FIG.

9 is a flowchart illustrating an operation of a method for performing a maximum discharge while reducing occurrence of deterioration of a battery for an electric vehicle according to an embodiment of the present invention.

FIG. 10 is a flowchart illustrating an operation procedure of a temperature control method for preventing deterioration due to high temperature of a battery for an electric vehicle according to an embodiment of the present invention. Referring to FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Like reference symbols in the drawings denote like elements. Furthermore, specific structural and functional descriptions for embodiments of the present invention are presented for the purpose of describing an embodiment of the present invention only, and, unless otherwise defined, all terms used herein, including technical or scientific terms Have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as ideal or overly formal in the sense of the art unless explicitly defined herein .

FIG. 2 is a view schematically showing the configuration of an embodiment of a battery management system to which the present invention is applied, FIG. 3 is a view schematically showing a configuration of another embodiment of a battery management system to which the present invention is applied, FIG. Fig. 2 is a schematic view showing the configuration of another embodiment of the applied battery management system.

2, the battery management system 10 according to an exemplary embodiment of the present invention monitors the state of the battery pack 200 to perform a quick charge and a maximum discharge while causing less deterioration, A battery charger 700 for charging the battery pack 200 and the battery pack 200 through an external terminal or a charger 700 for charging the battery pack 200 through the external terminal, The charging FET 300, the discharging FET 400, and the battery pack 200, such as an electric motor driven by receiving power from the battery pack 200, A temperature sensing unit 500, and a current sensing unit 600 that senses the current of the battery pack 200.

The battery management apparatus 100 controls the charging FET 300 and the discharging FET 400 constituted by field effect transistors (FETs) and controls the external device connected to the external terminals (i.e., the charger 700 or the load So that the battery pack 200 can be charged or discharged. At this time, the battery management device 100 monitors the state of the battery pack 200, and based on the result of the monitoring, the battery management device 100 generates less deterioration due to a high voltage or a high temperature depending on the state of the battery pack 200, The fast charge and the maximum discharge of the pack 200 proceed.

For example, when the charger 700 is connected to the external terminal, the battery management device 100 turns on the charging FET 300 and turns off the discharging FET 400, So that the battery pack 200 can be charged with a constant voltage and current. Conversely, when a load such as an electric motor is connected to the external terminal, the battery management apparatus 100 turns off and on the charging FET 300 and the discharging FET 400, respectively, So that the power can be applied to the load.

The battery management apparatus 100 learns the total resistance of the battery pack 200 according to the temperature and the resistance of the battery cells constituting the battery pack 200 to weak battery cells (i.e., weak cells) The charge / discharge is repeated based on the resistance change of the battery pack 200 due to deterioration so that the state of the used battery pack 200 can be immediately recognized. The battery management apparatus 100 accurately gauges the remaining capacity due to temperature and deterioration of the battery pack 200 when the battery pack 200 is charged or discharged, The charging or discharging of the battery pack 200 is controlled to prevent deterioration and defects due to overcharge or overdischarge of the battery pack 200. [

That is, the battery management device 100 monitors the state of charge of the battery pack 200, detects the state of the battery pack 200 before the battery pack 200 enters the overcharged state, and turns off the charge FET 300, So that defects and deterioration of the pack 200 can be prevented. Similarly, the battery management device 100 monitors the discharging state of the battery pack 200, detects the discharging state of the battery pack 200 before the battery pack 200 enters the over-discharge state, and turns off the discharging FET 400, Thereby preventing the battery pack 200 from being damaged or deteriorated.

Meanwhile, the battery management apparatus 100 must know or monitor the power used in the electric motor and the system. For example, if the maximum power that can be supplied from the battery pack 200 is 50 KW, the power used in the motor drive and the system should be controlled to 50 KW or less. In order to do this, the power budget must be measured and set at the development stage according to the system operation.

Further, the electric vehicle to which the battery pack of the present invention is applied can limit the maximum speed to the maximum power with battery voltage, sends a signal to the user when the maximum power that can be set by the automobile manufacturer is too low, It has two modes: low-speed mode and high-speed mode at the expense of runtime.

The battery pack for an electric vehicle according to the present invention should be controlled such that the cell temperature does not exceed the temperature threshold in any case in order to prevent deterioration at a high temperature and acceleration of the deterioration at a high temperature or a high voltage . It is therefore natural that battery energy must be managed to lower the temperature and lower the voltage.

The battery pack 200 includes a plurality of battery cells, and the number of the battery cells may be varied according to the purpose or use of the battery pack 200, or a load connected to the battery pack 200 The battery pack 200 can be configured.

The battery cells may be connected in series, in parallel, or a combination thereof, and may be charged or discharged to a predetermined voltage through a charger 700 or a load connected to an external terminal.

Also, the battery pack 200 may be constructed of all kinds of secondary batteries such as a lithium ion battery, a lithium ion polymer battery, a nickel cadmium battery, and the like.

The charging FET 300 and the discharging FET 400 refer to a switch for charging or discharging the battery pack 200 at a constant voltage. In addition to the FET, an insulated gate bipolar transistor (IGBT) or a relay for charging / discharging relay, and the like.

The temperature sensing unit 500 senses the temperature of the battery pack 200 or the battery cell 200 during charging / discharging of the battery pack 200 and provides the sensed temperature to the battery management device 100.

The current sensing unit 600 includes a sense resistor for sensing a current and is connected in series with the external terminal and the battery pack 200 to detect a charge / discharge current of the battery pack 200 And provides it to the battery management apparatus 100.

The battery management apparatus 100 may be configured to perform rapid charging and maximum discharge of the battery pack 200 while causing less deterioration due to high voltage or high temperature depending on the state of the battery pack 200 The OCV for the battery pack 200 in a no-load state to accurately gauge the total resistance of the battery pack 200, the resistance to each battery cell, and the remaining capacity and the total usable capacity of the battery pack 200, the change of the open circuit voltage and the resistance change of the battery pack 200 according to the temperature are learned. At this time, the learning is performed through a total of two learning cycles including a first cycle and a second cycle, and a detailed description thereof will be described with reference to FIGS. 5 and 6. FIG.

The total resistance of the battery pack 200 and the resistance of each battery cell (i.e., the internal resistance), which are learned by the battery management apparatus 100 according to a temperature change, are determined by a function Which is used to perform the fast charging or the maximum discharge of the battery pack 200 while adjusting the maximum charging current or the maximum discharging current so that deterioration that may be caused by a high voltage or a temperature is less generated.

Meanwhile, a process of performing fast charging or discharging of the battery pack 200 while performing less deterioration and performing a temperature control will be described in detail with reference to FIGS. 8 to 10.

The battery management device 100 learns the total resistance of the battery pack 200 and the resistance to each battery cell and learns the maximum charge current and the maximum discharge current of the battery pack 200 according to the temperature. Derive the factor for adjustment and analyze the characteristics of the load. Accordingly, the battery pack 200 can be quickly charged or discharged at a maximum while causing less deterioration due to high voltage or temperature.

That is, the battery management apparatus 100 determines whether or not the battery pack 200 (200) including the total resistance of the battery pack 200 according to the SOC, the resistance to each battery cell, the OCV variation amount, So that the state of charge and discharge of the battery pack 200 can be accurately confirmed.

As shown in FIG. 3, the battery management system 10 according to another embodiment of the present invention may further include the configuration of FIG. 2 and a plurality of current / voltage measurement units 800.

That is, the battery management system 10 described in the embodiment of FIG. 2 directly measures the voltage of each battery cell to calculate the resistance of each battery cell and the resistance to a weak battery cell, The battery management system 10 according to the present invention includes a separate current / voltage measurement unit 800 to measure the resistance of the battery cell.

At least one current / voltage measuring unit 800 is provided, and each current / voltage measuring unit 800 is connected to at least one battery cell.

Also, the current / voltage measuring unit 800 measures current and voltage for each battery cell that the current / voltage measuring unit 800 itself provides to the battery management apparatus 1000, and the battery management apparatus 1000 measures the current / Learning is performed based on the resistance of each battery cell and the resistance of the weak battery cell using the current and voltage for each battery cell provided from the measuring unit 800. [

When measuring the resistance of the battery cell, the battery management apparatus 100 in the embodiment of FIG. 2 uses the total current for the battery pack 200 and the voltage for each battery cell, The battery management apparatus 1000 in the embodiment of FIG. 3 measures the resistance of each battery cell by measuring the voltage and current for each battery cell and using it to measure the resistance of each battery cell more accurately, Can be measured. The resistance may be calculated by the current / voltage measuring unit 800 and provided to the battery management apparatus 1000 or may be calculated by the battery management apparatus 1000.

As shown in FIG. 4, the battery management system 10 according to another embodiment of the present invention may further include the configuration of FIG. 2 and a plurality of battery data processing units 900.

The battery data processing unit 900 includes a plurality of battery management apparatuses 100 as shown in FIG. 2. The battery management apparatus 100 processes data related to status information monitoring of the battery pack 200 The centralized processing can be performed by a plurality of modules so that the centralized load can be distributed and processed.

At this time, the battery data processor 900 is connected to at least one battery cell, and learns the internal resistance of each battery cell according to the temperature change, and provides the result to the battery management device 2000.

Also, the battery management apparatus 2000 integrates data related to battery monitoring provided from each battery data processing unit 900, so that the maximum charge current or maximum discharge current, voltage and temperature information of the battery pack 200, And the state of health (SOH) of the battery pack 200 are accumulated and stored, and the charging and discharging states of the battery pack 200 are monitored. Based on the monitoring information, deterioration due to high voltage or temperature is less So that the battery pack 200 is rapidly charged or discharged.

Meanwhile, the battery data processing unit 900 and the battery management device 2000 are connected to the charging and discharging state using various communication methods such as an inter-integrated circuit (I2C), a server message block (SMB), and a controller area network Related monitoring data can be transmitted and received.

5 and 6, a method of learning data for monitoring the charging and discharging states of the battery pack 200 so as to perform the fast charging and the discharging of the battery pack 200 will be described in detail Explain.

FIG. 5 is a diagram showing a first cycle for learning data for charging and discharging state monitoring of a battery pack applied to the present invention. FIG. 6 is a diagram for explaining the data for monitoring charging and discharging states of the battery pack, Lt; RTI ID = 0.0 > 2 < / RTI >

5, the battery management apparatus 100 measures an OCV curve of the battery pack 200 in a first cycle (first cycle), accumulates and stores the measured OCV curve, The OCV variation amount is learned every time the battery pack 200 is discharged. That is, the battery management apparatus 100 preferentially controls the OCV of the battery pack 200 at the SOC through the first cycle to gauges the resistance change and the capacity of the battery pack 200 due to temperature and deterioration (aging) (I.e., the OCV curve).

In the first cycle, the battery pack 200 is discharged at a constant C-rate (for example, 1/20 C) in a no-load state. The battery pack 200 is divided into a plurality of SOC grid points, The change amount of the OCV can be measured. The SOC grid point is shown in FIG.

On the other hand, the OCV change amount can be measured through self-discharge of the battery pack 200, but it takes a long time to complete discharge in the case of self-discharge, so that the OCV change amount is measured by flowing a very small current, It is considered to be equal to the change in OCV measured.

In addition, the battery management apparatus 100 detects a flat region in which the OCV variation amount is moderate or not in the OCV curve on the measured SOC.

The flat region is detected by finding an a point and a b point, as shown in FIG. 5, where the a point and the b point are locations where the amount of voltage change per unit time changes abruptly.

That is, a point is a point where the amount of voltage change per unit time drastically decreases, and a point b means a place where the amount of voltage change per unit time increases sharply. In this case, the flat region is located between the points a and b, and means a period in which the amount of voltage change is moderate or substantially equal.

On the other hand, a point is a point at which a point larger than a predetermined value is differentiated by unit time and the point b is differentiated by the unit time and a point smaller than a preset value is detected first Quot;

According to an embodiment of the present invention, a point of dV / dT> 30 uV / S can be detected as a point, and a point of dV / dT <30 uV / S can be detected as a point b. On the other hand, it is natural that the reference value of 30 uV / S for detecting each point can be set differently according to the characteristics of the battery cell.

Also, the battery management apparatus 100 calculates the total capacity of the battery pack 200 through the first cycle. The total capacity may be calculated by calculating the total amount of charges flowing while discharging the battery pack 200 from no-load state to a discharge termination voltage, or may be calculated by calculating an area of the OCV voltage curve.

That is, the total capacity of the battery pack 200 may be measured by calculating a total coulomb of the battery pack 200, or the OCV voltage curve and the shapes formed by the x and y axes, The total capacity of the battery pack 200 can be measured.

6, the battery management apparatus 100 measures the resistance value of each battery pack 200 according to the SOC grid point through a second cycle (second cycle).

Also, the battery management apparatus 100 discharges the battery pack 200 at a rate of 1/5 C-rate in order to measure a resistance value for each SOC grid point, The resistance to a weak battery cell (i.e., a weak cell) that outputs a weak voltage is measured.

The second cycle is performed at least three times for each temperature (e.g., low temperature, normal temperature, and high temperature), and the total resistance of the battery pack 200 and the resistance of the weak battery cell are measured for each temperature. The temperatures of the battery pack 200 and the battery cell 200 are measured at a room temperature of 25 degrees, a high temperature of 40 degrees, and a low temperature of 5 degrees or less. At this time, the above temperature can be set differently according to the use purpose of the battery, the usage environment, the user's setting, and the like. In order to more precise precision, many temperature ranges (e.g., -5 degrees, 0 degrees, 5 degrees, , 25 degrees, 40 degrees or more) can be set.

As described above with reference to FIG. 5, the total voltage for each SOC grid point can be measured through the following equation (1) because the voltage curve for each interval has already been measured through the first cycle.

[Equation 1]

Vm [i] = OCV [i] - IR [i]

- > R [i] = OCV [i] - Vm [i]) / I

Here, Vm denotes the total measured voltage of the battery pack 200, which means an open circuit voltage in a no-load state measured through the first cycle. Also, i represents a point at which a resistance value is calculated by a virtual grid point preset in the SOC.

Also, the battery management apparatus 100 can measure the resistance of each battery cell by SOC grid point using Equation (1). Here, Vm denotes a voltage measured for each battery cell, and I denotes a current measured for each battery cell.

The battery management apparatus 100 learns a change in the internal resistance of the battery pack 200 at each temperature to accurately measure the internal resistance of the battery pack 200 when the battery pack 200 is discharged Can be measured. Therefore, it is possible to sense the process of the resistance change of the battery pack due to repetitive charging and discharging of the battery pack 200 and the resistance of the weak battery cell, and the internal resistance of the battery pack 200 can be detected The charging or discharging of the battery pack 200 can be stopped so that the risk of heat generation and explosion of the battery pack 200 can be prevented in advance.

7 is a detailed view showing the configuration of a battery management apparatus according to the present invention.

7, the battery management apparatus 100 of the present invention includes a learning unit 110, a measurement unit 120, a charge processing unit 130, a discharge processing unit 140, a

temperature control unit

150, 160, a storage unit 170, a control unit 180, and the like.

The learning unit 110 is a part that performs a function of measuring and measuring the resistance of the battery pack 200 according to the temperature. The OCV curve of the battery pack 200 according to deterioration and temperature, Learn how to change the resistance.

The learning cycle includes the first cycle and the second cycle described with reference to FIGS. 5 and 6. The OCV curve (i.e., the OCV variation) of the battery pack 200 through the first cycle and the OCV curve 200), and learns a change in resistance due to temperature and deterioration of the battery pack 200 through the second cycle.

The first cycle discharges the battery pack 200 at a specific C-rate (for example, 1/20 C-rate) in a no-load state and a normal temperature, and learns an OCV curve for the battery pack 200. This can be performed periodically or non-periodically according to a preset period or a user.

Also, the learning unit 110 detects a flat region of the OCV curve in the first cycle, and as described with reference to FIG. 5, the flat region is obtained by finding two points in which the variation amount of the OCV curve rapidly changes .

Also, the learning unit 110 learns by calculating the total capacity in a no-load state. The calculation of the total capacity means that the total capacity of the battery pack 200 is measured by discharging the battery pack 200 to the discharge termination voltage at a constant C-rate in the battery pack 200 to be. At this time, it is natural that the battery pack 200 deteriorates as it is used in connection with a load, so that the total capacity of the battery pack 200 learned through the first cycle must be changed (that is, reduced).

The learning unit 110 accumulates the measured OCV curves and the total capacity of the battery pack 200 in the storage unit 170 through the first cycle so that the OCV curve and the total number of the battery packs 200 Learn about changes in capacity. At this time, the C-rate is not limited to 1/20 C-rate, and may be set differently depending on the use purpose of the battery pack 200, the purpose of use, and the user.

Also, the learning unit 110 learns the resistance of the battery pack 200 through the second cycle shown in FIG. The resistance is learned by measuring the total resistance of the battery pack 200, the resistance of each battery cell constituting the battery pack 200, and the resistance of the weak cell outputting the lowest voltage.

In the second cycle, the battery pack is discharged at a constant C-rate at a normal temperature, a high temperature, and a low temperature, and the battery pack 200, Learning by measuring the resistance of the cell. The second cycle may be performed periodically or non-periodically according to a preset period or a user.

Also, the second cycle divides the SOC of the battery pack 200 into a plurality of intervals (i.e., grid points) and measures a resistance value of each of the grid points. The OCV curve for each grid point is obtained through the first cycle The measured voltage in the second cycle becomes OCV-IR. Therefore, the voltage Vm [i] measured for each grid point is OCV [i] - IR [i], and R [i] becomes (OCV [i] - Vm [i]) / I. Where i represents each grid point.

On the other hand, the resistance is measured by dividing the SOC grid point by a small amount because the amount of change of the voltage is little or gradual in the flat region, and the amount of change of the voltage rapidly changes at other positions. Therefore, the SOC grid point is more finely divided than the flat region, The point-by-point resistance is measured and stored in the storage unit 170.

Further, the learning unit 110 calculates a variable (i.e., a temperature factor) that each temperature has on the resistance through the second cycle, reflects the calculated temperature factor on the measured resistance value, .

In the present invention, instead of the cell resistance of each battery, only the resistance of several wick cells having the largest pack resistance or resistance is learned for each temperature through the learning unit 100, so that the cell voltage or the pack voltage The cell to be reached can be determined as a wick cell and the wick cell can be found. The discharge is terminated when one battery cell first reaches the discharge end voltage of the cell before the pack voltage reaches the discharge end voltage of the pack. It is necessary to protect the cell because the lifetime of the cell is greatly lowered at the low voltage. The method of learning the change of the resistance value to the Weak cell is the same as learning the pack resistance. However, the difference is that finding the Weeks cell finds the lowest voltage in the cell. Thus, the voltage measurement of a wick cell can be represented as a sum of the wick cell self-voltage measurement multiplied by the current multiplied by the wire resistance between the cells. The voltage measurements of these Weck cells can be used to learn the Weck cell resistance.

The measurement unit 120 includes a voltage / current measurement unit 121, a temperature measurement unit 123, a resistance measurement unit 125, and the like, which measure current, voltage, temperature, and resistance of the battery pack 200 do.

The voltage / current measuring unit 121 measures the current and voltage of the battery pack 200 when the battery pack 200 is charged or discharged. That is, the current and voltage for the entire battery pack 200 as well as the current and voltage for each battery cell constituting the battery pack 200 are measured. At this time, the current and voltage for the battery pack 200 or each battery cell can be measured through the current sensor and the voltage sensor.

3 and 4, the voltage / current measuring unit 121 may be configured as a plurality of current / voltage measuring units 800 and a battery data processing unit 900 that cover a plurality of battery cells, respectively, have. At this time, the battery management apparatus 100 may receive voltage and current for each battery cell measured through the plurality of modularized current / voltage measurement units 800 and the battery data processing unit 900.

The temperature measuring unit 123 measures the temperature of the battery pack 200 and the battery cell at the time of charging or discharging the battery pack 200 so that the charging unit 130, the discharging unit 140, the temperature controller 150 ) Or the like so that the amount of change in temperature at the time of charging or discharging can be confirmed.

The resistance measuring unit 125 measures the resistance of the battery pack 200 connected to the load due to the learning result of the learning unit 110 for each SOC grid point. That is, the total resistance of the battery pack 200 and the resistance of each battery cell are measured for each of the preset SOC grid points. At this time, the total resistance of the battery pack 200 and the resistance of the battery cell are measured in the same manner as the method of calculating the resistance value through the second cycle.

When the total resistance of the battery pack 200 exceeds a preset value or the resistance of each of the measured battery cells exceeds a predetermined value, the resistance measuring unit 125 measures the resistance of the battery pack 200 The charging or discharging of the battery pack 200 can be blocked through the charging processor 130 or the discharging processor 140 based on the control of the controller 180. [ Accordingly, an external device or user using the battery pack 200 can be protected from defects (e.g., explosion) of the battery pack 200.

The charging processing unit 130 is a part that functions to charge the battery pack 200 by receiving power from a charger 700 connected through an external terminal and is connected to the learning unit 110 and the measurement unit 120 And charges the battery pack 200 while adjusting the maximum charge current based on the measured charge state information of the battery pack 200. Speed charging of the battery pack 200 while causing less deterioration due to high voltage or temperature.

A method for performing the fast charging of the battery for an electric vehicle performed in the charge processing unit 130 will be described in detail with reference to FIG.

Meanwhile, the charging processor 130 determines whether the current temperature of the battery pack 200 exceeds a predetermined temperature limit in the process of charging the battery pack 200 by setting the maximum charging current, When charging is performed at a temperature higher than a preset range by adjusting the charging current so that the charging can be performed while the temperature of the cell is kept below the temperature limit when the temperature of the cell exceeds a predetermined temperature limit, To prevent possible deterioration.

The discharge processing unit 140 is a part for supplying power charged in the battery pack 200 to a load (for example, an electric motor) connected via an external terminal. The discharge unit 140 includes a learning unit 110, The maximum power is supplied to the load side while adjusting the maximum discharge current based on the discharge state information of the battery pack 200 measured through the battery 120, thereby achieving the maximum discharge. That is, the charge voltage of the battery pack 200 is discharged to the load side with the maximum power while causing less deterioration due to high voltage or temperature as in the case of the charge processing unit 130.

A method for performing the maximum discharge of the battery for an electric vehicle performed in the discharge processing unit 140 will be described in more detail with reference to FIG.

Meanwhile, the discharge processor 140 determines whether the current temperature of the battery pack 200 exceeds a predetermined temperature limit in the course of performing the discharge of the battery pack 200 by setting the maximum discharge current and the maximum power, When the temperature of the currently measured cell exceeds a predetermined temperature limit, discharge is performed at a temperature higher than a predetermined range by adjusting the discharge current so that the discharge can be performed while the temperature of the cell is maintained below the temperature limit Thereby preventing degradation that can be accelerated.

Further, the maximum power set in the discharge processing unit 140 is basically useful for increasing the vehicle speed in the electric motor.

The temperature controller 150 compares the cell temperature of the battery pack 200 performing charging or discharging with a predetermined temperature threshold value (i.e., a maximum temperature set value at which deterioration of the battery pack is accelerated) And functions to allow the temperature of the pack 200 to operate at a normal range of temperatures (e.g., about 35 degrees Celsius).

That is, when the temperature of each cell constituting the battery pack 200 is higher than a preset temperature threshold, the temperature controller 150 performs thermal modeling When the current SOC for temperature control becomes less than the SOC threshold or the current MAXp becomes less than the MAXp threshold or the voltage of the weak cell becomes less than the cutoff voltage of the discharge termination voltage Temperature control is performed. At this time, the temperature modeling may be configured in various control methods including a maximum charge current adjustment, a maximum discharge current adjustment, a maximum power adjustment, or a combination thereof.

Meanwhile, when the current temperature of the battery pack 200 exceeds a preset temperature threshold value, the temperature controller 150 provides the user terminal with the temperature control necessity information so that the user can immediately perform the temperature control .

The communication unit 160 performs communication connection between the battery management system 10 and the user terminal of the user using the electric vehicle and transmits various data related to the temperature control and the like necessary for charging or discharging the battery for the electric vehicle Lt; / RTI >

The storage unit 170 stores the learning result performed by the learning unit 110 and the currents measured in each battery cell constituting the battery pack 200 and the battery pack 200 processed by the measurement unit 120, Voltage, temperature, resistance, and so on.

The storage unit 170 accumulates information about the battery pack 200 that changes as charging or discharging is repeated and accumulates information of the battery pack 200 in the charging processor 130, the discharging processor 140, the temperature controller 150, And stores and manages the processing result.

The controller 180 performs a function of collectively managing various operations of the battery management device 100.

Next, embodiments of a method for performing fast charging, a method for performing maximum discharge, and a temperature control method according to the present invention will be described in detail with reference to FIGS. 8 to 10. FIG. At this time, each step according to the method of the present invention may be changed in the use environment or the order by a person skilled in the art.

FIG. 8 is a flowchart for explaining an operation procedure of a method for performing fast charging while reducing the occurrence of deterioration of a battery for an electric vehicle, FIG. 9 is a flowchart illustrating a method for performing maximum discharge while reducing occurrence of deterioration of a battery for an electric vehicle FIG. 10 is a flowchart for explaining an operation procedure of a temperature control method for preventing generation of deterioration due to high temperature of an electric vehicle battery.

A method for performing fast charging of an electric vehicle battery will be described with reference to FIG.

The charge processing unit 130 of the battery management apparatus 100 detects the current OCV position using the recently measured OCV point and the passed charge according to the discharge of the battery pack 200 at step S101.

In this case, the OCV point means the SOC grid point. The SOC grid point is set in advance according to a previously performed learning cycle, and the total capacity of the battery pack 200 is measured. Therefore, since the previously measured OCV point is already known, the current OCV position can be detected based on the corresponding OCV point.

The Passed Charge means a coulomb that has already flown. Since the OCV curve is already known and the total capacity of the battery pack 200 is already known according to the learning result, The current SOC can be obtained through the amount of charge flowing at the voltage obtained from the previous OCV.

After detecting the current OCV position in step S101, the charge processing unit 130 sets the maximum charge current CCmax according to the following formula (2) (S103). At this time, the maximum charge current CCmax is continuously set to the charge current according to Equation (2) up to the SOC [%] set by the user. That is, the charging processor 130 sets the maximum charging current CCmax to the charging current of the battery pack 200 to charge the battery pack 200.

&Quot; (2) "

CCmax = (OCVanode - Vmax) / WR [i] [j]

Where CCmax is the maximum charge current, Vmax is the maximum voltage preset for each SOC, OCVanode is the Anode OCV voltage mapped to the open circuit voltage, WR is the resistance of the wick cell, i is the point of the measured resistance, j is the temperature range to be. At this time, Vmax is the maximum voltage preset in consideration of the maximum voltage affecting the deterioration as the SOC through the engineer's open circuit anode voltage check during cell development, that is, the maximum voltage preset for each SOC.

In addition, the cell's total voltage consists of Cathode Voltage + Anode Voltage, and Cathode Voltage and Anode Voltage can also be measured through the internal ground. When the charge is dropped, the anode voltage is dropped, and when it drops below the anode potential voltage, lithium plating occurs and the cell deterioration is accelerated. Therefore, the anode voltage is prevented from dropping below the potential voltage during charging, thereby preventing cell deterioration. However, when the cell development is completed, the cell usually consists of +/- two terminals. Therefore, it is necessary to measure each OCV profile data before applying it to actual application, and OCV is mapped to OCVanode according to the SOC section, In the application, OCV is measured to obtain OCVanode. Therefore, Vmax is set to anode potential voltage + tolerance voltage.

After the maximum charge current CCmax is set in step S103, the charge processing unit 130 performs temperature control such that the temperature of each battery cell is controlled in a temperature range for normal operation in the process of charging the battery pack 200 (S105), and determines whether the current cell temperature is lower than a predetermined temperature limit according to a result of the temperature control (S107).

If it is determined that the current cell temperature is higher than the preset temperature limit, the charge processing unit 130 recognizes that the temperature control is required and the charging can be performed while the temperature of the corresponding cell is maintained below the temperature limit The charging current is adjusted (S109). That is, the charge processing unit 130 prevents deterioration that may occur when the currently measured cell temperature is charged at a temperature higher than a predetermined range.

If it is determined in step S107 that the current cell temperature is lower than the predefined temperature limit, the charge processing unit 130 recognizes the normal operation and sets the maximum charge current CCmax set in step S103 as the charge current , This value is set as a new charging current to control the driving of the charging FET 300 to charge the battery pack 200 (S111).

In the process of charging the battery pack 200 using the maximum charge current CCmax set in step S103 as a charge current, the charge processor 130 determines whether the voltage measured in the current wake cell is greater than the voltage (S113).

If it is determined in step S113 that the voltage of the current wake cell is not the highest among all cells, the charge processing unit 130 changes the battery cell having the highest voltage to the wake cell and then measures all the resistances again (step S115 ), It is determined whether the voltage Vmeasured measured at the weak cell is greater than a preset maximum voltage Vmax at the corresponding point (S117). The reason why the charging processor 130 performs the step S117 is that if the voltage Vmeasured measured by the weak cell is greater than the preset maximum voltage Vmax at the corresponding point, This is because deterioration due to charging is accelerated.

More specifically, for example, when the OCV is set to 3 V, the resistance is set to 1 ohm, and the Vmax is set to 4 V at SOC 0%, the maximum charging current CCmax becomes 1 A according to the formula (2). However, if the resistance of the actual cell is 2 ohms, the voltage Vmeasured measured at that point becomes 3 V + 2 ohms / 1A = 5 V. If the charging is performed by applying this state as it is, the measured voltage Vmeasured becomes the maximum Becomes higher than the voltage Vmax, the deterioration due to the high voltage is accelerated. In order to solve this problem, the charge processing unit 130 checks whether the voltage Vmeasured measured at the corresponding wick cell is larger than a preset maximum voltage Vmax at the corresponding point, and charging is performed in a state where Vmeasured does not exceed Vmax .

If it is determined in step S117 that Vmeasured is greater than Vmax, the charge processing unit 130 calculates the resistance of the battery cell again (S119), and repeats the steps after step S103 to set the maximum charge current again.

However, if it is determined in step S117 that Vmeasured is less than Vmax, the charge processing unit 130 determines whether the current SOC has reached a preset SOC threshold, and if the current SOC reaches a preset SOC threshold The battery pack 200 is charged while the maximum charge current is adjusted until the battery pack 200 becomes fully charged (S121). At this time, the SOC threshold value means the 100% full charge capacity in the present battery state according to the learning result in the learning unit 110. [

Also, if it is determined in step S113 that the current wic cell has the highest voltage among all the cells, if the current wic cell voltage is the highest among all the cells, And the charging of the battery pack 200 is performed at the maximum charging current set in the step S103 until the current SOC reaches the preset SOC threshold value.

Meanwhile, the temperature control process described in steps S105 to S109 may be omitted, and temperature control may be separately performed through the temperature controller 150 as shown in FIG.

Next, a method for performing the maximum discharge of the battery for an electric vehicle will be described with reference to Fig.

First, the discharge processing unit 140 of the battery management device 100 detects the current OCV position using the recently measured OCV point and the passed charge according to the discharge of the battery pack 200 (S201).

After detecting the current OCV position in step S201, the discharge processing unit 140 sets the maximum discharge current MAXdisc and the maximum power MAXp according to the following formula (3) (S203). That is, the discharge processor 140 supplies the power charged in the battery pack 200 to the load side (i.e., the electric motor) through the maximum discharge current MAXdisc and the maximum power MAXp.

&Quot; (3) "

(cutoff voltage + delta voltage) = OCV - MAXdisc * WR [i] [j]

-> MAXdisc = (OCV- (cutoff voltage + delta voltage)) / WR [i] [j]

MAXp = current battery pack voltage * MAXdisc

Here, the cutoff voltage means a discharging termination voltage, and the delta voltage means a margin setting voltage before a cutoff voltage.

At this time, the discharge processor 140 stops discharging when the voltage of the battery pack 200 reaches the cutoff voltage. This is related to the life of the battery, which can cause the system to shut down at low voltages. The reason for setting the delta voltage is that when a momentary load is applied, the voltage of the battery pack 200 may be lowered below the cutoff voltage and deteriorated.

After the maximum discharge current MAXdisc and the maximum power MAXp are set in step S203, the discharge processor 140 controls the temperature of each battery cell in the temperature range for normal operation in the process of discharging the battery pack 200 (S205). Then, it is determined whether the current cell temperature is lower than a preset temperature limit according to the temperature control result (S207).

If it is determined in step S207 that the current cell temperature is higher than the predetermined temperature limit, the discharge processing unit 140 recognizes that the temperature control is required and discharges can be performed while the temperature of the relevant cell is maintained below the temperature limit The maximum discharge current and the maximum power are adjusted (S209). That is, the discharge processor 130 prevents deterioration that may occur when the currently measured cell temperature is discharged at a temperature higher than a predetermined range.

If it is determined in step S207 that the current cell temperature is lower than the predefined temperature limit, the discharge processing unit 140 recognizes the normal operation as the normal operation, and outputs the maximum discharge current MAXdisc and the maximum power MAXp set in step S203, (S213), and the power of the battery pack 200 is discharged to the load side (i.e., the electric motor) according to the maximum discharge current MAXdisc and the maximum power MAXp.

In the discharging process of the battery pack 200 according to the maximum discharging current MAXdisc and the maximum power MAXp through step S213, the discharging unit 140 discharges the voltage measured in the current wick cell to all the battery cells It is determined whether the voltage is the lowest voltage (S215).

If it is determined in step S215 that the voltage of the current wake cell is not the lowest among all cells, the discharge processing unit 140 changes the battery cell having the lowest voltage to the wake cell and then measures all the resistances again (S217 ).

Then, the discharge processing unit 140 changes the current wake cell to the battery cell having the lowest voltage and then measures all the resistances again as in step S217, or after the determination of step S215, If it is the lowest voltage among all the cells, it is determined whether the measured weak cell voltage of the weak cell is less than the sum of the cutoff voltage, the discharge end voltage, and the delta voltage, which is the margin setting voltage before the cutoff voltage (S219) . This is because when the voltage measured at the weak cell is smaller than the sum of the cutoff voltage and the delta voltage, the deterioration due to the overdischarge is accelerated below the discharge end voltage.

If it is determined in step S219 that the voltage measured by the weak cell is less than the sum of the cutoff voltage and the delta voltage, the discharge processor 140 calculates the resistance again in step S221, and sets the maximum charge current and the maximum power The process is repeated.

If it is determined in step S219 that the voltage measured by the weak cell is greater than the sum of the cutoff voltage and the delta voltage, the discharge processor 140 determines whether the current SOC is less than the predetermined SOC threshold, (Minimum power set by the system engineer) threshold (S223).

As a result of the determination in step S223, the discharge is performed while adjusting the maximum discharge current MAXdisc and the maximum power MAXp until the current SOC becomes smaller than the predetermined SOC threshold value or MAXp becomes smaller than the MINp threshold value. Here, the SOC threshold value or the MINp threshold value indicates the maximum discharge state in the current battery state according to the learning result in the learning unit 110.

Meanwhile, the temperature control process during the discharging process described in steps S205 to S209 may be omitted, and temperature control may be separately performed through the temperature controller 150 as shown in FIG.

Next, a method of performing temperature control of a battery for an electric vehicle will be described with reference to Fig.

First, the temperature controller 150 controls the temperature of each battery cell constituting the battery pack 200, which performs charging or discharging, to a predetermined temperature threshold value (i.e., a maximum temperature set value that is a reference for accelerating deterioration of the battery pack) (S301).

If it is determined in step S301 that the cell temperature of the battery pack 200 is higher than a predetermined temperature threshold value, the temperature controller 150 may perform temperature modeling The thermal control is performed through thermal modeling (S303). At this time, the temperature modeling may be configured in various control methods including a maximum charge current adjustment, a maximum discharge current adjustment, a maximum power adjustment, or a combination thereof.

If the current temperature of the battery pack 200 during charging or discharging exceeds a preset temperature threshold value, the temperature controller 150 performing the temperature control in step S303 may notify the user of the temperature of the battery pack 200 through the communication unit 160 A user terminal including a smart phone or a mobile device may be provided with information indicating that temperature control is required and a user who has confirmed the related information may perform an operation for temperature control.

After performing the temperature control to bring the cell temperature exceeding the threshold value to the normal temperature through the step S303, the temperature control unit 150 determines whether the current SOC for temperature control is less than the SOC threshold value It is determined whether the current MAXp is less than the MAXp threshold or the voltage of the weak cell is less than the cutoff voltage (S305). If the current SOC for temperature control becomes less than the SOC threshold value, The temperature control is continuously performed until the MAXp of the wick cell becomes less than the MAXp threshold or the voltage of the wick cell becomes less than the cutoff voltage of the discharge end voltage.

At this time, the SOC threshold value means the minimum SOC% at which the battery can be used, and the minimum SOC% is set by the automobile manufacturer. And the MAXp threshold is the minimum max power threshold at which the battery can be used and is similarly set by the car manufacturer. And the SOC threshold for temperature control is the minimum SOC% that can control the temperature system and can be set by the vehicle manufacturer or owner.

As described above, the present invention monitors charging and discharging states of a battery for an electric vehicle and performs charging and discharging while adjusting a maximum charging current or a maximum discharging current based on voltage or temperature information. It is possible to perform the fast charging and the maximum discharge while suppressing the occurrence as much as possible.

In addition, by learning the process of changing the battery pack resistance and the resistance of the wick cell, the charge and discharge states of the battery are monitored, and charge and discharge are controlled based on this, so that the occurrence of overcharge and overdischarge deterioration can be minimized , The quality of the battery can be improved, and the battery can be used stably for a long time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, I will understand the point. Accordingly, the technical scope of the present invention should be determined by the following claims.

The present invention monitors the charging and discharging states of an electric vehicle battery and performs charging and discharging while adjusting the maximum charging current or the maximum discharging current based on voltage or temperature information to thereby prevent occurrence of deterioration due to high voltage or high temperature It is possible to perform the fast charge and the maximum discharge while suppressing the maximum.

Claims

A learning unit for learning charge state information of the battery pack according to deterioration or temperature; And

And a charge processing unit for adjusting the maximum charge current according to the wake cell state of the battery pack to charge the battery pack based on the learned charge state information,

The charge state information includes at least one of a total resistance of the battery pack according to a state of charge (SOC), a temperature and a resistance of each battery cell, an OCV (open circuit voltage) variation according to the SOC, Or a combination thereof. 2. An apparatus for performing fast charging while reducing the occurrence of deterioration of a battery for an electric vehicle.
The method according to claim 1,

Wherein the maximum charge current is set by Equation (2). &Lt; RTI ID = 0.0 > 11. < / RTI >

&Quot; (2) "

CCmax = (OCVanode - Vmax) / WR [i] [j]

Where CCmax is the maximum charge current, Vmax is the maximum voltage preset for each SOC, OCVanode is the Anode OCV voltage mapped to the open circuit voltage, WR is the resistance of the wick cell, i is the point of the measured resistance, j is the temperature range to be.
The method according to claim 1,

The charge processing unit

The current OCV point of the battery pack is detected using the recently measured OCV and passed charge,

Setting a maximum charge current with reference to the wick cell temperature and resistance of the battery pack at the detected current OCV point,

And determines whether the current wick cell voltage is the highest among all the battery cells in the process of charging the battery pack with the maximum charging current,

Charging the battery pack with the maximum charge current until the current SOC reaches the SOC threshold value if the current weak cell voltage is the highest voltage among all the battery cells. To perform high-speed charging while reducing power consumption.
The method of claim 3,

The charge processing unit

If it is determined that the current wick cell voltage is the highest among all the battery cells in the process of charging the battery pack with the maximum charging current, if the current wick cell voltage is not the highest among all the battery cells, And the resistance of all the battery cells is remeasured,

If the measured voltage at the wick cell is greater than a preset maximum voltage, the resistance is measured again, and then the maximum charging current is adjusted based on the temperature and resistance of the wick cell,

And charging the battery pack with the maximum charge current until the current SOC reaches the SOC threshold value when the voltage measured at the weak cell is less than a preset maximum voltage. An apparatus for performing fast charging while reducing occurrence.
The method according to claim 1,

The charge processing unit

Determining whether the current temperature of the battery pack exceeds a preset temperature limit in the process of charging the battery pack with the maximum charging current,

As a result of the determination, when the temperature of the currently measured cell exceeds the predetermined temperature limit, the maximum charge current is adjusted so that the charging can be performed while the temperature of the cell is maintained below the temperature limit, and when the current SOC reaches the SOC threshold Wherein the battery pack is charged at the maximum charging current to prevent deterioration occurring when the battery pack is charged at a temperature exceeding a preset range. An apparatus for performing a fast charge.
A learning unit for learning discharge status information of the battery pack according to deterioration or temperature; And

And a discharge processor for adjusting the maximum discharge current and the maximum power according to the wake cell state of the battery pack based on the learned discharge state information to perform discharge of the battery pack,

The discharge status information includes at least one of a total resistance and a total voltage of the battery pack according to a state of charge (SOC), a temperature and a resistance for each battery cell, an OCV (open circuit voltage) A cutoff voltage, a cutoff voltage, a delta voltage prior to the cutoff voltage, or a combination thereof. The apparatus for performing the maximum discharge while reducing the occurrence of deterioration of the battery for an electric vehicle.
The method of claim 6,

Wherein the maximum discharge current and the maximum power are set by Equation (3).

&Quot; (3) "

I = [OCV - (cutoff voltage + delta voltage) / WR [i] [j]

MAXp = current battery pack voltage * MAXdisc

In this case, MAXdisc is the maximum discharge current, OCV is the open circuit voltage, the cutoff voltage is the discharge end voltage, the delta voltage is the margin setting voltage before the cutoff voltage, WR is the resistance of the wick cell, i is the point of the measured resistance, Range, MAXp is the maximum power.
The method of claim 6,

The discharge processing unit

The current OCV point of the battery pack is detected using the recently measured OCV and passed charge,

Setting a maximum discharge current and a maximum power with reference to a wick cell temperature, a resistance, a cut-off voltage, and a margin setting voltage of the battery pack at the detected current OCV point,

Determining whether the current wake cell voltage is the lowest among all the battery cells in the process of discharging the battery pack with the maximum discharge current and the maximum power,

Determines whether a voltage measured by the wick cell is less than a sum of the cut-off voltage and a margin setting voltage when the current wick cell voltage is the lowest among all the battery cells,

When the measured voltage at the weak cell is greater than the sum of the cut-off voltage and the margin set voltage, the SOC is less than the SOC threshold or the maximum power is less than a predetermined minimum power threshold, Wherein the discharging of the battery pack is carried out while the discharge of the battery pack is performed.
The method of claim 8,

The discharge processing unit

If it is determined that the current wick cell voltage is the lowest among all the battery cells in the process of discharging the battery pack, if the current wick cell voltage is not the lowest among all the battery cells, The resistance value of all the cells is measured again to determine whether the voltage measured at the corresponding weak cell based on the resistance measurement result is smaller than the sum of the cutoff voltage and the margin setting voltage,

If the measured voltage at the weak cell is less than the sum of the cut-off voltage and the margin setting voltage, the resistance is calculated again, and then the discharge is performed by adjusting the maximum charge current and the maximum power,

When the measured voltage at the weak cell is greater than the sum of the cut-off voltage and the margin set voltage, the SOC is less than the SOC threshold or the maximum power is less than a predetermined minimum power threshold, Wherein the discharging of the battery pack is carried out while the discharge of the battery pack is performed.
The method of claim 6,

The discharge processing unit

Determining whether a current temperature of the battery pack exceeds a predetermined temperature limit in a process of discharging the battery pack,

If the measured cell temperature exceeds the predetermined temperature limit, the maximum discharge current and the maximum power are adjusted so that the discharge can be performed while the temperature of the corresponding cell is maintained below the temperature limit. If the current SOC is less than the SOC threshold Or discharging the battery pack at the maximum discharge current and maximum power until the maximum power is less than a predetermined minimum power threshold, thereby preventing deterioration caused when discharging occurs at a temperature exceeding a predetermined range of temperatures And the maximum discharge is performed while reducing the occurrence of deterioration of the battery for an electric vehicle.
A learning step of learning charge state information of the battery pack according to deterioration or temperature; And

And charging the battery pack by adjusting a maximum charging current according to the wick cell state of the battery pack based on the learned charging state information,

The charge state information includes at least one of a total resistance of the battery pack according to a state of charge (SOC), a temperature and a resistance of each battery cell, an OCV (open circuit voltage) variation according to the SOC, Or a combination thereof. 2. A method for performing fast charging while reducing the occurrence of deterioration of a battery for an electric vehicle.
The method of claim 11,

Wherein the maximum charge current is set by Equation (2). &Lt; Desc / Clms Page number 20 >

&Quot; (2) "

CCmax = (OCVanode - Vmax) / WR [i] [j]

Where CCmax is the maximum charge current, Vmax is the maximum voltage preset for each SOC, OCVanode is the Anode OCV voltage mapped to the open circuit voltage, WR is the resistance of the wick cell, i is the point of the measured resistance, j is the temperature range to be.
The method of claim 11,

Wherein the charging processing step includes:

Detecting a current OCV point of the battery pack using a recently measured OCV and a passed charge;

Setting a maximum charging current with reference to the wick cell temperature and resistance of the battery pack at the detected current OCV point;

Determining whether the current wick cell voltage is the highest among all the battery cells in the process of charging the battery pack with the maximum charging current; And

And charging the battery pack with the maximum charge current until the current SOC reaches the SOC threshold if the current weak cell voltage is the highest voltage among all the battery cells. A method for performing a fast charge while reducing the occurrence of deterioration of a battery for a battery.
14. The method of claim 13,

Wherein the charging processing step includes:

If it is determined that the current wick cell voltage is the highest among all the battery cells in the process of charging the battery pack with the maximum charging current, if the current wick cell voltage is not the highest among all the battery cells, Changing a cell having a wake cell to a wake cell and remeasuring the resistance of all the battery cells;

If the measured voltage at the wick cell is greater than a preset maximum voltage, measuring the resistance again and then adjusting the maximum charging current based on the temperature and resistance of the wick cell to proceed with charging; And

And charging the battery pack with the maximum charge current until the current SOC reaches the SOC threshold value if the measured voltage at the weak cell is less than a preset maximum voltage A method for performing fast charging while reducing the occurrence of deterioration of a battery for an electric vehicle.
The method of claim 11,

Wherein the charging processing step includes:

Determining whether a current temperature of the battery pack exceeds a predetermined temperature limit in a process of charging the battery pack with the maximum charging current; And

As a result of the determination, when the temperature of the currently measured cell exceeds the predetermined temperature limit, the maximum charge current is adjusted so that the charging can be performed while the temperature of the cell is maintained below the temperature limit, and when the current SOC reaches the SOC threshold Further comprising charging the battery pack with the maximum charging current to prevent deterioration occurring when charging is performed at a temperature exceeding a predetermined range of temperature, Wherein the fast charging is performed while reducing the occurrence of deterioration of the battery.
A learning step of learning discharge status information of the battery pack according to deterioration or temperature; And

And discharging the battery pack by adjusting a maximum discharge current and a maximum power according to the wick cell state of the battery pack based on the learned discharge state information,

The discharge status information includes at least one of a total resistance and a total voltage of the battery pack according to a state of charge (SOC), a temperature and a resistance for each battery cell, an OCV (open circuit voltage) A cut-off voltage, a delta voltage prior to the cut-off voltage, or a combination thereof. &Lt; RTI ID = 0.0 > 11. < / RTI >
18. The method of claim 16,

Wherein the maximum discharge current and the maximum power are set by Equation (3).

&Quot; (3) "

I = [OCV - (cutoff voltage + delta voltage) / WR [i] [j]

MAXp = current battery pack voltage * MAXdisc

In this case, MAXdisc is the maximum discharge current, OCV is the open circuit voltage, the cutoff voltage is the discharge end voltage, the delta voltage is the margin setting voltage before the cutoff voltage, WR is the resistance of the wick cell, i is the point of the measured resistance, Range, MAXp is the maximum power.
18. The method of claim 16,

In the discharge processing step,

Detecting a current OCV point of the battery pack using a recently measured OCV and a passed charge;

Setting a maximum discharge current and a maximum power with reference to a wick cell temperature, a resistance, a cutoff voltage, and a margin setting voltage of the battery pack at the detected current OCV point;

Determining whether a current wick cell voltage is the lowest among all the battery cells in a process of discharging the battery pack;

Determining whether a voltage measured by the weak cell is less than a sum of the cut-off voltage and a margin setting voltage when the current weak cell voltage is the lowest voltage among all the battery cells; And

When the measured voltage at the weak cell is greater than the sum of the cut-off voltage and the margin set voltage, the SOC is less than the SOC threshold or the maximum power is less than a predetermined minimum power threshold, And performing discharging of the battery pack. The method for performing the maximum discharge while reducing the occurrence of deterioration of the battery for an electric vehicle.
19. The method of claim 18,

In the discharge processing step,

If it is determined that the current wick cell voltage is the lowest among all the battery cells in the process of discharging the battery pack, if the current wick cell voltage is not the lowest among all the battery cells, Measuring a resistance of all the cells and determining whether a voltage measured at the corresponding weak cell based on the resistance measurement result is less than a sum of the cutoff voltage and the margin setting voltage;

If the measured voltage at the weak cell is less than the sum of the cut-off voltage and the margin set voltage, calculating the resistance again, and then adjusting the maximum charge current and the maximum power to progress the discharge; And

When the measured voltage at the weak cell is greater than the sum of the cut-off voltage and the margin set voltage, the SOC is less than the SOC threshold or the maximum power is less than a predetermined minimum power threshold, And performing discharging of the battery pack when the voltage of the battery pack is less than a predetermined voltage.
18. The method of claim 16,

In the discharge processing step,

Determining whether a current temperature of the battery pack exceeds a predetermined temperature limit in a process of discharging the battery pack; And

If the measured cell temperature exceeds the predetermined temperature limit, the maximum discharge current and the maximum power are adjusted so that the discharge can be performed while the temperature of the corresponding cell is maintained below the temperature limit. If the current SOC is less than the SOC threshold Or discharging the battery pack at the maximum discharge current and maximum power until the maximum power is less than a predetermined minimum power threshold, thereby preventing deterioration caused when discharging occurs at a temperature exceeding a predetermined range of temperatures The method of claim 1, further comprising the step of: determining whether the battery is charged with a predetermined voltage.