KR20190127060A - Apparatus for balancing battery module and battery pack including the same - Google Patents

Abstract

The present invention relates to a battery module balancing apparatus, capable of effectively performing battery module balancing all the time in a battery module balancing process, and a battery pack including the same. According to an embodiment of the present invention, the battery module balancing apparatus comprises: a plurality of battery modules including cell assemblies, connected to a power line configured to flow a charge/discharge current by being connected to the cell assemblies, and electrically connected to each other in parallel through the power line; a balancing line distinguished from the power line, provided between positive and negative terminals of the cell assemblies to electrically connect the cell assemblies in parallel, and transferring the charge/discharge current between the cell assemblies; a plurality of switching units disposed on the balancing line to control conduction of current, and switching a parallel connection relationship between the battery modules; a master BMS provided in a master battery module of the battery modules to control charging/discharging of the cell assemblies mounted in the master battery module, and controlling an operation of the switching units on the basis of state information on the battery modules; and a slave BMS provided in a slave battery module of the battery modules, controlling charging/discharging of the cell assemblies mounted on the slave battery module, transferring state information on the slave battery module to the master BMS, and receiving a control command from the master BMS to control an operation of the switching units connected to the slave battery module.

Description

Battery module balancing device and a battery pack including the same {Apparatus for balancing battery module and battery pack including the same}

The present invention relates to a battery module balancing device and a battery pack including the same, and more particularly, to a battery module balancing device and a battery pack including the same that can be effectively performed in the battery module balancing process.

In recent years, as the demand for portable electronic products such as laptops, video cameras, mobile phones, and the like rapidly increases, and development of energy storage batteries, robots, satellites, and the like is in earnest, high-performance secondary batteries capable of repeating charging and discharging have been developed. Research is actively being conducted.

Commercially available secondary batteries include nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have almost no memory effect compared to nickel-based secondary batteries, and thus are free of charge and discharge. It is attracting much attention because of its low self discharge rate and high energy density.

Batteries are used in various fields. In recent years, battery-intensive fields such as electric powered vehicles or smart grid systems often require large capacity. In order to increase the capacity of the battery pack, there may be a method of increasing the capacity of the secondary battery, that is, the battery cell itself. Has Thus, battery packs are typically widely used in which a plurality of battery modules are connected in series and in parallel.

A plurality of battery modules constituting the battery pack may have a difference in capacity performance between secondary batteries due to intrinsic characteristics, manufacturing environment differences, system application pluralities, etc. as the use time elapses. This causes a difference in the terminal voltage of the module or a SOC (State Of Charge) difference.

Secondary cells constituting the battery module may not have the same electrochemical characteristics. In addition, as the number of charge / discharge cycles of the battery module increases, the degree of degeneration varies for each secondary battery, so that the variation in performance of the secondary batteries may be greater. Therefore, while the battery module is being charged and discharged, the state of charge of each secondary battery may rise or fall at a different speed.

When a plurality of battery modules having such a difference in performance are driven as one battery pack, the capacity of the battery pack as a whole may be limited by the deteriorated specific battery module, the battery pack may age, the overvoltage, etc. Problems may arise.

Conventionally, in order to solve the difference in state of charge between battery modules, balancing is mainly used to supply power from a battery module having a relatively high state of charge to a battery module having a low state of charge through a power line through which the main charge / discharge current flows. It became. However, balancing through the power line has a problem in that the balancing between the battery modules cannot be performed when the power line is turned off.

The present invention has been made under the background of the prior art, and relates to an improved battery module balancing device and a battery pack including the same, which can efficiently perform battery module balancing in a battery module balancing process.

 Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the invention may be realized by the means and combinations thereof indicated in the claims.

Battery module balancing device according to an embodiment of the present invention for achieving the above object, has a cell assembly, is connected to the power line is connected to the cell assembly configured to flow the charge and discharge current, the power line A plurality of battery modules electrically connected in parallel to each other through; Distinguished from the power line, provided between the positive terminal and the negative terminal of the plurality of cell assemblies, the plurality of cell assemblies are electrically connected in parallel to each other, and configured to transfer charge and discharge currents between the plurality of cell assemblies. Balancing line; A plurality of switching units positioned on the balancing line to control conduction of current and configured to switch parallel connection relationships between battery modules; A master of the plurality of battery modules is provided in the master battery module to control the charge and discharge of the cell assembly mounted on the master battery module, and configured to control the operation of the plurality of switching unit based on the state information of the plurality of battery modules BMS; And controlling charging and discharging of a cell assembly installed in the slave battery module among the plurality of battery modules, transferring state information of the slave battery module to the master BMS, and controlling commands from the master BMS. And a slave BMS configured to receive and control an operation of a switching unit connected to the slave battery module.

The state information may include a voltage across each cell assembly, a current flowing through each cell assembly, and a temperature of each switching unit.

In addition, the master BMS may be configured to calculate the current deviation between each cell assembly based on the state information collected from the slave BMS to control the operation of the plurality of switching units based on the calculated current deviation value. .

The master BMS may store temperature thresholds of the plurality of switching units in advance, and the temperature of the switching unit connected to each cell assembly exceeds the temperature threshold based on the state information collected from the slave BMS. In this case, it may be configured to control the operation of the switching unit.

In addition, the master BMS calculates the voltage deviation between the cell assemblies at intervals based on the state information collected from the slave BMS, and operates the plurality of switching units based on the calculated change in the voltage deviation value. Can be configured to control.

In addition, the battery module balancing device according to an embodiment of the present invention, which is located on the balancing line, is provided separately for each battery module, further comprises a plurality of resistors configured to be electrically connected to the other end of the switching unit. Can be.

The balancing line may include a positive electrode line and a negative electrode line, and the positive electrode line may be configured such that one side is directly connected to the positive terminal of each cell assembly and electrically connects the positive terminal of the plurality of cell assemblies to each other. The cathode line may be configured such that one side of the cathode line is directly connected to the cathode terminals of each cell assembly to electrically connect the cathode terminals of the plurality of cell assemblies to each other.

In addition, the plurality of switching units may be provided separately for each battery module, and may be configured such that one end is directly electrically connected to the positive terminal of each cell assembly.

The master BMS may further include: converting an operation mode of the master BMS from a BMS sleep mode to a wake up mode; Collecting at least one of a voltage across each cell assembly, a current flowing through each cell assembly, and a temperature of a switching unit connected to each cell assembly from the slave BMS; Calculating a voltage deviation or a current deviation between cell assemblies based on the information collected in the collecting step, or comparing the temperature of the switching unit with a previously stored temperature threshold value; Controlling operations of the plurality of switching units based on the voltage deviation value, the current deviation value, or the temperature value detected by the calculating and comparing step; And sending a diagnostic code to an external device.

Battery pack according to an embodiment of the present invention for achieving the above object includes a battery module balancing device according to the present invention.

According to an aspect of the present invention, by using a balancing line that is distinguished from a power line, there is an advantage in that the balancing can be performed at all times even when the power line is turned off.

In particular, according to an embodiment of the present invention, an improved battery module balancing device capable of diagnosing a balancing operation based on state information of a cell assembly may be provided when performing constant balancing.

In addition to the present invention may have a variety of other effects, these other effects of the present invention can be understood by the following description, it will be more clearly understood by the embodiments of the present invention.

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to.
1 is a view schematically showing a part of a configuration of a battery module balancing device according to an embodiment of the present invention.
2 is a diagram schematically illustrating some components of a battery module included in the battery module balancing device according to an embodiment of the present invention.
3 to 6 are flowcharts schematically illustrating a battery module balancing method according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the present specification and claims should not be construed as being limited to the common or dictionary meanings, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof is omitted.

Throughout the specification, when a part is said to "include" a certain component, it means that it may further include other components, without excluding the other components unless otherwise stated. In addition, terms such as 'BMS', 'monitoring unit' and 'memory unit' described in the specification mean a unit for processing at least one function or operation, which may be implemented by hardware or software, or a combination of hardware and software. Can be.

In addition, throughout the specification, when a part is "connected" to another part, it is not only "directly connected" but also "indirectly connected" with another element in between. Include.

In the present specification, the cell assembly refers to an assembly of a plurality of secondary batteries in which a plurality of secondary batteries are connected in series and / or in parallel. Here, the secondary battery means one independent cell having a negative electrode terminal and a positive electrode terminal, and physically separable. For example, one pouch type lithium polymer cell may be regarded as a secondary battery.

The battery module balancing device according to the present invention is a device for balancing a battery module. For example, the battery module balancing device according to an embodiment of the present invention may be provided in the battery pack. Here, the battery pack may include a plurality of battery modules electrically connected in parallel with each other. In addition, the battery pack may include a power line P and main relays 50, 51, and 52. The power line P may be a power line provided between a battery module and an upper system to which charge and discharge current flows. The main relays 50, 51, and 52 may be provided on the power line P and may be switches for controlling conduction of charge and discharge currents.

1 is a view schematically showing a part of the battery module balancing device according to an embodiment of the present invention, Figure 2 is a part of the battery module provided in the battery module balancing device according to an embodiment of the present invention It is a figure which shows schematically.

1 and 2, a battery module balancing device according to an embodiment of the present invention includes a plurality of battery modules 100, balancing lines L1 and L2, a switching unit 110, and a master BMS 140. And slave BMS 170.

The battery module 100 may include a cell assembly 10. In addition, the battery module 100 may be connected to the power line P. FIG. In addition, the battery modules 100 may be electrically connected to each other in parallel through a power line P. Here, the power line P may be connected to the cell assembly 10 so that charge and discharge current flows.

The balancing lines L1 and L2 may be distinguished from the power line P. FIG. That is, the balancing lines L1 and L2 may be separate paths electrically separated from the power line P. FIG. In this case, the balancing lines L1 and L2 may be configured to be distinguished from the power line P so that a separate charge / discharge current flows.

In addition, the balancing lines L1 and L2 may be provided between the positive terminals and the negative terminals of the plurality of cell assemblies 10 to electrically connect the plurality of cell assemblies 10 to each other in parallel. For example, as shown in the configuration of FIGS. 1 and 2, the balancing line L1, according to an embodiment of the present invention, is directly connected to the positive terminal of the plurality of cell assemblies 10, thereby providing a plurality of The anode terminals of the cell assembly 10 may be electrically connected to each other. In addition, the balancing line L2 may be directly connected to the negative terminals of the plurality of cell assemblies 10, and may electrically connect the negative terminals of the plurality of cell assemblies 10.

In addition, the balancing lines L1 and L2 may transfer charge / discharge currents between the plurality of cell assemblies 10. For example, as shown in the configuration of FIGS. 1 and 2, the balancing lines L1 and L2 according to the embodiment of the present invention may be disposed between the positive terminal and the negative terminal of the plurality of cell assemblies 10. By connecting, the charge and discharge current may be transferred from the cell assembly 10 having the high voltage or the SOC of the cell assembly 10 to the cell assembly 10 having the low voltage or the SOC of the cell assembly 10.

Preferably, the balancing lines L1 and L2 according to the embodiment of the present invention may include an anode line L1 and a cathode line L2. More specifically, as shown in the configuration of Figures 1 and 2, the anode line (L1) according to an embodiment of the present invention, one side is directly connected to the positive terminal of each cell assembly 10 a plurality of It may be configured to electrically connect between the positive terminal of the cell assembly 10 with each other. In addition, the cathode line L2 may be configured such that one side is directly connected to the cathode terminals of each cell assembly 10 to electrically connect the cathode terminals of the plurality of cell assemblies 10 to each other.

The switching unit 110 may be positioned on the balancing lines L1 and L2 to control conduction of current. In addition, the switching unit 110 may be configured to switch the parallel connection relationship between the battery modules 100. For example, as shown in the configuration of FIGS. 1 and 2, the switching unit 110 may be located on the balancing lines L1 and L2.

More specifically, the switching unit 110 may be located on the anode line L1. Here, the switching unit 110 may control the conduction of current flowing through the balancing lines L1 and L2 according to a control command of the master BMS 140 or the slave BMS 170. In addition, the switching unit 110 may switch the parallel connection relationship between the battery modules 100 according to the turning on and off of the switching unit 110.

 More specifically, as shown in the configuration of FIGS. 1 and 2, the switching unit 110 may include a balancing line L1 when all of the switching units 110 located on the balancing lines L1 and L2 are turned on. All cell assemblies 10 connected to L2 may be electrically connected in parallel. In addition, when the at least one switching unit 110 located on the balancing lines L1 and L2 is turned off, the switching unit 110 excludes the cell assembly 10 connected to the turned off switching unit 110. The remaining cell assemblies 10 may be electrically connected in parallel.

Preferably, as shown in the configuration of Figures 1 and 2, a plurality of switching unit 110, according to an embodiment of the present invention, is provided separately for each battery module 100, each cell assembly One end may be directly electrically connected to the positive terminal of (10).

The master BMS 140 may be provided in the master battery module 100 of the plurality of battery modules 100. In addition, the master BMS 140 may control charging and discharging of the cell assembly 10 mounted on the master battery module 100. For example, the master BMS 140 may be electrically connected to an upper control device so as to transmit and receive electrical signals. In an embodiment of the present invention, the master BMS 140 may exchange electrical signals with an upper control device through the communication unit 150. Here, the higher level control device may be an ECU (Electronic Control Unit) of the vehicle. In this case, the master BMS 140 controls the turn on and / or turn off operation of the main relay 50 mounted on the master battery module 100 according to a command received from the higher level control device, thereby controlling the master battery module 100. Charge and discharge of the cell assembly 10 mounted on the) can be controlled.

In addition, the master BMS 140 may control operations of the plurality of switching units 110 based on state information of the plurality of battery modules 100. For example, the master BMS 140 may turn on and / or turn off the plurality of switching units 110 based on the state information of the master battery module 100 and the state information of the slave battery module 100. Can be controlled. In this case, the master BMS 140 may control the operation of the switching unit 110 included in the slave battery module 100 by transmitting a control command to the slave BMS 170.

The slave BMS 170 may be provided in a slave battery module among a plurality of battery modules 100. In addition, the slave BMS 170 may control charging and discharging of the cell assembly 10 mounted on the slave battery module. For example, the slave BMS 170 may be electrically connected to the master BMS 140 to transmit and receive electrical signals. In an embodiment of the present invention, the slave BMS 170 may exchange electrical signals with the master BMS 140 through the communication unit 150. Here, the communication unit 150 may be provided in each of the battery modules 100. In this case, the slave BMS 170 controls the turn on and / or turn off operations of the main relays 51 and 52 mounted on the slave battery module according to a command received from the master BMS 140 to the slave battery module. Charge and discharge of the mounted cell assembly 10 can be controlled. In addition, the slave BMS 170 may control the operation of the switching unit 110 connected to the slave battery module by receiving a control command from the master BMS 140.

Preferably, the battery module balancing device according to an embodiment of the present invention may further include a monitoring unit 130. Here, the monitoring unit 130 may be provided in each of the plurality of battery modules 100. The monitoring unit 130 may measure the voltage of the cell assembly, the current flowing through the cell assembly, and the temperature of the switching unit. In addition, the monitoring unit 130 may monitor the state of each cell assembly 10 using the voltage measurement value, the current measurement value, and the temperature measurement value.

The monitoring unit 130 may measure voltages at both ends of each cell assembly 10. For example, as shown in the configuration of FIG. 2, the monitoring unit 130 may be electrically connected to the cell assembly 10. In addition, the monitoring unit 130 may measure the voltage at both ends of the secondary battery provided in the cell assembly 10 at intervals of time and output a signal indicating the magnitude of the measured voltage. In this case, the monitoring unit 130 may determine the voltage of the cell assembly 10 from the voltage measurement value. For example, the monitoring unit 130 may be implemented using a voltage measuring circuit generally used in the art.

The monitoring unit 130 may measure the magnitude of the charging current for each cell assembly 10. For example, as shown in the configuration of FIG. 2, the monitoring unit 130 may be connected to the balancing line L2. For example, the monitoring unit 130 may be connected to the current sensor 160 located on the balancing line L2. In addition, the monitoring unit 130 may repeatedly measure the magnitude of the charging current or the discharging current of the cell assembly 10 at a time interval and output a current measurement value indicating the magnitude of the measured current. In this case, the monitoring unit 130 may determine the magnitude of the current from the current measurement value. For example, current sensor 160 may be implemented using Hall sensors or sense resistors commonly used in the art.

The monitoring unit 130 may measure the temperature of the switching unit 110 connected to each cell assembly 10. For example, as shown in the configuration of FIG. 2, the monitoring unit 130 may be connected to the switching unit 110 to measure the temperature of the switching unit 110. In addition, the monitoring unit 130 may repeatedly measure the temperature of the switching unit 110 at a time interval and output a temperature measurement value as a signal indicating the magnitude of the measured temperature. In this case, the monitoring unit 130 may determine the temperature of the switching unit 110 from the temperature measurement value. For example, the monitoring unit 130 may be implemented using a thermocouple commonly used in the art.

The monitoring unit 130 calculates a state of charge (SOC) of the cell assembly 10 by using the voltage measurement value and the current measurement value of the cell assembly 10. The remaining amount can be estimated. In addition, the monitoring unit 130 may calculate the estimated SOC using the estimated remaining amount of the cell assembly 10. Here, the estimated SOC may be calculated as a value corresponding to the remaining amount of the cell assembly 10 in the range of 0% to 100%.

In one aspect of the present invention, the monitoring unit 130 may estimate the state of charge of the cell assembly 10 by integrating the charge current and the discharge current of the cell assembly 10. Here, the initial value of the state of charge when the charging or discharging of the cell assembly 10 starts may be determined using an open circuit voltage (OCV: Open Circuit Voltage) of the cell assembly 10 measured before the charging or discharging starts. . To this end, the monitoring unit 130 may include an open voltage-charge state lookup table defining charge states for each open voltage, and may map a charge state corresponding to the open voltage of the cell assembly 10 from the lookup table.

In another aspect of the present invention, the monitoring unit 130 may calculate the state of charge of the cell assembly 10 using the extended Kalman filter. Extended Kalman filter refers to a mathematical algorithm that adaptively estimates the state of charge of the cell assembly 10 using the voltage, current, and temperature of the cell assembly 10. Here, the estimation of the state of charge using the Extended Kalman filter is, for example, Gregory L. Plett's article "Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs Parts 1, 2 and 3". (Journal of Power Source 134, 2004, p. 252-261).

The state of charge of the cell assembly 10 may be determined by other known methods capable of estimating the state of charge by selectively utilizing the voltage and current of the cell assembly 10 in addition to the above-described current integration method or the extended Kalman filter.

According to an embodiment of the present invention, the master BMS 140 and the slave BMS 170 may be electrically connected to each monitoring unit 130 to transmit and receive electrical signals. The master BMS 140 and the slave BMS 170 may receive state information of the master battery module and the slave battery module, respectively, from the monitoring unit 130.

Preferably, the state information according to an embodiment of the present invention may include a voltage across each cell assembly, a current flowing through each cell assembly 10, and a temperature of each switching unit 110.

In addition, the slave BMS 170 may transmit state information of the slave battery module to the master BMS 140. In addition, the master BMS 140 may transmit state information of the plurality of battery modules 100 to the higher level control device.

According to an embodiment of the present invention, the battery module balancing device may perform balancing even when the power line P is turned off and the BMS is switched to the sleep mode. More specifically, the master BMS 140 may periodically wake up in the BMS sleep mode. In this case, the master BMS 140 may receive a wakeup command from the host controller.

Subsequently, the master BMS 140 and the slave BMS 170 may estimate the SOC of each cell assembly 10. Alternatively, the master BMS 140 and the slave BMS 170 may receive the SOC of each cell assembly 10 from each monitoring unit 130. In this case, the slave BMS 170 may transfer the SOC of each cell assembly 10 to the master BMS 140.

Subsequently, the master BMS 140 and the slave BMS 170 may selectively turn on the plurality of switching units 110 to balance the plurality of cell assemblies 10.

Through such a configuration, when the battery module balancing device according to the present invention cannot perform balancing through the power line P without using a battery pack, a balancing line L1 provided separately from the power line P , L2) has the advantage that can be performed at all times balancing.

Preferably, the master BMS 140 according to an embodiment of the present invention calculates the current deviation between each cell assembly 10 based on the state information collected from the slave BMS 170, the calculated current deviation value Based on the operation of the plurality of switching unit 110 can be controlled. More specifically, the master BMS 140 may receive a current value flowing through each cell assembly 10 from the monitoring unit 130 and the slave BMS 170. In addition, the master BMS 140 may calculate the deviation of the current between each cell assembly 10. In addition, the master BMS 140 may selectively turn off the plurality of switching units 110 when the current deviation between the cell assemblies 10 increases. In this case, the master BMS 140 may transmit a turn-off command to the switching unit 110 to the slave BMS 170. In addition, the master BMS 140 may calculate the deviation of the current flowing through each cell assembly 10 at a time interval. In this case, the master BMS 140 may selectively turn off the plurality of switching units 110 when the deviation of the current flowing through the cell assembly 10 increases at a time interval.

Also, preferably, the master BMS 140 stores the temperature threshold values for the plurality of switching units 110 in advance, and the respective cell assembly 10 is based on the state information collected from the slave BMS 170. When the temperature of the connected switching unit 110 exceeds the temperature threshold value, the operation of the switching unit 110 may be controlled. More specifically, the master BMS 140 may receive the temperature of the switching unit 110 connected to each cell assembly 10 from the monitoring unit 130 and the slave BMS 170. In addition, the master BMS 140 may compare the temperature of each switching unit 110 with a pre-stored temperature threshold value. In addition, the master BMS 140 may selectively turn off the plurality of switching units 110 when the temperature of the switching unit 110 is greater than the temperature threshold. In this case, the master BMS 140 may transmit a switch turn off command to the slave BMS 170. In addition, the master BMS 140 may measure the temperature of each switching unit 110 at intervals of time. In this case, the master BMS 140 may selectively turn off the plurality of switching units 110 when the temperature of the switching unit 110 increases at a time interval.

Also, preferably, the master BMS 140 calculates the voltage deviation between the cell assemblies 10 at time intervals based on the state information collected from the slave BMS 170, and changes the calculated voltage deviation value. Based on the operation of the plurality of switching unit 110 can be controlled. More specifically, the master BMS 140 may receive a voltage value of each cell assembly 10 from the monitoring unit 130 and the slave BMS 170. In addition, the master BMS 140 may calculate the voltage deviation between the cell assemblies 10. In addition, the master BMS 140 may selectively turn off the plurality of switching units 110 when the voltage deviation between the cell assemblies 10 increases. In this case, the master BMS 140 may transmit a turn-off command to the switching unit 110 to the slave BMS 170. In addition, the master BMS 140 may calculate the voltage deviation of each cell assembly 10 at a time interval. In this case, the master BMS 140 may selectively turn off the plurality of switching units 110 when the voltage deviation of the cell assembly 10 increases at a time interval.

On the other hand, the master BMS 140, the slave BMS 170 and the monitoring unit 130, to perform the operation as described above, a processor, an application-specific integrated circuit (ASIC), other chipsets, logic known in the art It may be implemented in a form that optionally includes a circuit, a register, a communication modem and / or a data processing device.

Preferably, the master BMS 140, the slave BMS 170 and the monitoring unit 130 according to the present invention may further include a memory unit. The memory unit may include an open voltage-remaining amount lookup table that defines a remaining amount for each open voltage of the battery. In addition, the memory unit may include information necessary for calculating the estimated SOC by the monitoring unit 130. The memory section is not particularly limited as long as it is a storage medium capable of recording and erasing information. For example, the memory unit may be a RAM, a ROM, a register, a hard disk, an optical recording medium, or a magnetic recording medium. The memory unit may also be electrically connected to the BMS, for example via a data bus or the like, to be accessible by the BMS. The memory unit may also store and / or update and / or erase and / or transmit a program including various control logics performed by the BMS, and / or data generated when the control logic is executed. The memory unit can be logically divided into two or more.

Preferably, as shown in the configuration of FIGS. 1 and 2, the battery module balancing device according to an embodiment of the present invention may further include a plurality of resistor units 120.

The resistor unit 120 may be positioned on the balancing line L1 and provided separately for each battery module 100 to be electrically connected to the other end of the switching unit 110. In addition, the resistance unit 120 may be provided with a resistance value set to limit the maximum value of the current flowing in the balancing line L1.

Preferably, the master BMS 140 may change the operation mode of the master BMS 140 from the BMS sleep mode to the wake up mode. For example, the master BMS 140 may be switched to a sleep mode when the power line P is turned off. In addition, the master BMS 140 may be converted to the wakeup mode by a command of the higher level controller.

In addition, the master BMS 140, from the slave BMS 170, the voltage across each cell assembly 10, the current flowing through each cell assembly 10, and the temperature of the switching unit 110 connected to each cell assembly 10. One or more of may be collected. For example, the master BMS 140 may receive state information of each cell assembly 10 from the slave BMS 170 and transfer the received state information to the higher level control device. In addition, the master BMS 140 may perform balancing by selectively controlling the plurality of switching units 110 based on the state information of the cell assembly 10.

In addition, the master BMS 140 may calculate a voltage deviation or current deviation between the cell assemblies 10 based on the information collected in the collecting step, or compare the temperature of the switching unit 110 with a pre-stored temperature threshold. . In addition, the master BMS 140 may control operations of the plurality of switching units 110 based on the voltage deviation value, the current deviation value, or the temperature value detected by the calculation and comparison steps.

In addition, the master BMS 140 may send a diagnostic code to the external device. For example, the master BMS 140 may send a diagnostic code to an upper control device when the voltage deviation value or the current deviation value increases or the temperature value is larger than a temperature threshold value. In this case, the user can check the voltage abnormality, the current abnormality, or the temperature abnormality of the balancing lines L1 and L2 based on the diagnostic code.

The battery module balancing device according to the present invention may be provided in the battery pack itself. That is, the battery pack according to the present invention may include the above-described battery module balancing device according to the present invention. Here, the battery pack may include a plurality of battery modules, the battery module balancing device, electrical appliances (BMS, relays, fuses, etc.) and cases.

3 to 6 are flowcharts schematically showing a battery module balancing method according to an embodiment of the present invention. In Figures 3 to 6, the performing agent of each step may be referred to as each component of the battery module balancing apparatus according to the present invention described above.

First, as shown in FIG. 3, the master BMS may turn off the power line and switch the operation mode from the wakeup mode to the BMS sleep mode (S100).

Subsequently, the master BMS may be switched to the wakeup mode (S110). In this case, the master BMS may be switched to the wakeup mode periodically according to a preset time. Alternatively, the master BMS may be switched to the wakeup mode according to a command of the higher level controller.

Subsequently, the master BMS and the slave BMS may estimate the SOC of each cell assembly (S120). In this case, the master BMS may transmit an SOC estimation command to the slave BMS. In addition, the master BMS and the slave BMS can receive the SOC of each cell assembly from each monitoring unit. In addition, the master BMS can receive the SOC of each cell assembly from each slave BMS.

Subsequently, the master BMS may selectively turn on the plurality of switching units (S130). For example, the master BMS may selectively turn on and / or turn off the plurality of switching units to selectively open and close the balancing line based on the SOC of each cell assembly.

As shown in FIG. 4, the master BMS and the slave BMS may be switched to the sleep mode when balancing is performed through the balancing line. In addition, the master BMS and the slave BMS may be switched to the wakeup mode (S200). In this case, the master BMS and the slave BMS may be switched to the wakeup mode periodically according to a preset time.

Subsequently, the master BMS may receive current data of each cell assembly from the monitoring unit and each slave BMS (S210).

Subsequently, the master BMS may calculate the deviation of the current between the cell assemblies and determine whether the current deviation increases (S220). When the current deviation increases, the master BMS may turn off the plurality of switching units (S230). Subsequently, the master BMS may send a diagnostic code to the host controller (S240). On the other hand, if the current deviation does not increase, the master BMS may be switched to the sleep mode (S250).

As shown in FIG. 5, the master BMS and the slave BMS may be switched to the sleep mode when balancing is performed through the balancing line. In addition, the master BMS and the slave BMS may be switched to the wakeup mode (S300). In this case, the master BMS and the slave BMS may be switched to the wakeup mode periodically according to a preset time.

Subsequently, the master BMS may receive temperature data of the switching unit connected to each cell assembly from the monitoring unit and each slave BMS (S310).

Subsequently, the master BMS may compare the temperature of each switching unit with a temperature threshold and determine whether the temperature of the switching unit is greater than the temperature threshold (S320). When the temperature of the switching unit is greater than the temperature threshold, the master BMS may turn off the plurality of switching units (S330). Subsequently, the master BMS may send a diagnostic code to the host controller (S340). On the other hand, when the temperature of the switching unit is not greater than the temperature threshold, the master BMS may be switched to the sleep mode (S350).

As shown in FIG. 6, the master BMS and the slave BMS may be switched to the sleep mode when balancing is performed through the balancing line. In addition, the master BMS and the slave BMS may be switched to the wakeup mode (S400). In this case, the master BMS and the slave BMS may be switched to the wakeup mode periodically according to a preset time.

Subsequently, the master BMS may turn off the plurality of switching units (S410).

Subsequently, the master BMS may receive voltage data of each cell assembly from the monitoring unit and each slave BMS (S420).

Subsequently, the master BMS may calculate a deviation of the voltage between each cell assembly and determine whether the voltage deviation increases (S430). When the voltage deviation increases, the master BMS may turn off the plurality of switching units (S440). Subsequently, the master BMS may send a diagnostic code to the host controller (S450). On the other hand, if the voltage deviation does not increase, the master BMS may turn on the plurality of switching units (S460). Subsequently, the master BMS may be switched to the sleep mode (S470).

In addition, when the control logic is implemented in software, the master BMS and the slave BMS (hereinafter, referred to as BMS) may be implemented as a set of program modules. In this case, the program module may be stored in the memory device and executed by the processor.

In addition, various control logics of the battery management system (BMS) may be combined with at least one, and the combined control logics may be written in a computer readable code system so that the computer readable access is possible. none. In one example, the recording medium includes at least one selected from the group consisting of a ROM, a RAM, a register, a CD-ROM, a magnetic tape, a hard disk, a floppy disk, and an optical data recording device. In addition, the code system may be distributed and stored and executed in a networked computer. In addition, functional programs, code, and segments for implementing the combined control logics can be easily inferred by programmers in the art to which the present invention pertains.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

10: cell assembly
50, 51, 52: main relay
100: battery module
110: switching unit
120: resistance
130: monitoring unit
140: master BMS
150: communication unit
160: current sensor
170: slave BMS
L1, L2: balancing lines
P: power line

Claims (10)

A plurality of battery modules having a cell assembly, connected to the cell assembly and connected to a power line configured to flow a charge / discharge current, and electrically connected in parallel to each other through the power line;
Distinguished from the power line, provided between the positive terminal and the negative terminal of the plurality of cell assemblies, the plurality of cell assemblies are electrically connected in parallel to each other, and configured to transfer charge and discharge currents between the plurality of cell assemblies. Balancing line;
A plurality of switching units positioned on the balancing line to control conduction of current and configured to switch parallel connection relationships between battery modules;
A master of the plurality of battery modules is provided in the master battery module to control the charge and discharge of the cell assembly mounted on the master battery module, and configured to control the operation of the plurality of switching unit based on the state information of the plurality of battery modules BMS; And
It is provided in the slave battery module of the plurality of battery modules to control the charge and discharge of the cell assembly mounted on the slave battery module, transfer the status information of the slave battery module to the master BMS, and the control command from the master BMS A slave BMS configured to receive and control operation of a switching unit coupled to the slave battery module
Battery module balancing device comprising a.
The method of claim 1,
The state information may include a voltage across each cell assembly, a current flowing through each cell assembly, and a temperature of each switching unit.
The method of claim 2,
The master BMS is configured to calculate the current deviation between each cell assembly based on the state information collected from the slave BMS, the battery is configured to control the operation of the plurality of switching unit based on the calculated current deviation value Module Balancer.
The method of claim 2,
The master BMS stores a temperature threshold value for the plurality of switching units in advance, and when the temperature of the switching unit connected to each cell assembly exceeds the temperature threshold based on the state information collected from the slave BMS. Battery module balancing device, characterized in that configured to control the operation of the switching unit.
The method of claim 2,
The master BMS calculates a voltage deviation between cell assemblies based on the state information collected from the slave BMS at time intervals to control the operation of the plurality of switching units based on a change in the calculated voltage deviation value. Battery module balancing device, characterized in that configured.
The method of claim 1,
Located on the balancing line, each battery module is provided separately for each of the plurality of resistors configured to be electrically connected to the other end of the switching unit
Battery module balancing device further comprising.
The method of claim 1,
The balancing line has a positive line and a negative line,
The anode line is configured such that one side is directly connected to the anode terminals of each cell assembly to electrically connect the anode terminals of the plurality of cell assemblies to each other.
The cathode line is a battery module balancing device, characterized in that the one side is directly connected to the negative terminal of each cell assembly is configured to electrically connect between the negative terminal of the plurality of cell assembly.
The method of claim 1,
The plurality of switching units are provided separately for each battery module, the battery module balancing device, characterized in that the one end is configured to be directly electrically connected to the positive terminal of each cell assembly.
The method of claim 1,
The master BMS,
Converting an operation mode of the master BMS from a BMS sleep mode to a wake-up mode;
Collecting at least one of a voltage across each cell assembly, a current flowing through each cell assembly, and a temperature of a switching unit connected to each cell assembly from the slave BMS;
Calculating a voltage deviation or a current deviation between cell assemblies based on the information collected in the collecting step, or comparing the temperature of the switching unit with a previously stored temperature threshold value;
Controlling operations of the plurality of switching units based on the voltage deviation value, the current deviation value, or the temperature value detected by the calculating and comparing step; And
Steps to Send Diagnostic Code to External Device
Battery module balancing device, characterized in that configured to perform.
A battery pack comprising the battery module balancing device according to any one of claims 1 to 9.

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