KR102622789B1 - Modular battery management system - Google Patents

Abstract

A modular battery management system is disclosed. A modular battery management system according to an aspect of the present invention includes a battery pack consisting of a plurality of battery modules to which a plurality of battery cells are connected, a plurality of battery packs each connected to the plurality of battery modules and monitoring the voltage and temperature of each battery module. A local management unit, and a central management unit electrically connected to the plurality of local management units to monitor the voltage and temperature of the battery pack using the voltage and temperature of the battery module transmitted from each local management unit. .

Description

Modular battery management system {MODULAR BATTERY MANAGEMENT SYSTEM}

The present invention relates to a modular battery management system, and more specifically, to a modular battery management system that accurately measures the cell voltage of each of a plurality of battery cells in a battery pack composed of a plurality of battery modules and performs cell balancing. It's about the system.

In general, a large-capacity battery (battery module) that can generate large amounts of power to drive energy storage systems (ESS), electric vehicles, hybrid vehicles, and electric motorcycles (E-Scooters). can be used.

In particular, with the spread of new and renewable energy, interest in the energy storage system (ESS), which is the core of the smart grid and can maximize the storage and quality of power and the efficiency of energy use, is also increasing. . The energy storage system (ESS) may include a large-capacity battery module with a large number of battery cells, and is connected to the grid to supply remaining power (remaining energy) when and where it is needed. ) refers to a system that can optimize the quality and efficiency of power.

A battery management system is a device that manages battery modules more efficiently and stably. The battery management system is connected to a plurality of battery cells, reads the voltage value of each battery cell through an A/D converter (analog to digital converter), and then controls the charging or discharging of the battery cells.

When multiple battery cells are connected and used as a single battery module, a voltage difference may occur between each battery cell due to chemical differences, physical property differences, or differences in usage period of the battery cells that make up the battery module. You can. The lifespan of the battery module may be shortened due to the voltage difference between battery cells, ultimately resulting in a problem in which the entire packaged battery module must be replaced with a new battery module due to performance degradation such as the voltage drop of one single cell (single battery cell). You can. Therefore, when charging or discharging large-capacity batteries used in energy storage systems (ESS) and electric vehicles, a cell balancing process by a battery management system that maintains the same voltage of each battery cell may be necessary.

In addition, the conventional battery management system had poor compatibility, so when the cell structure of the battery was changed, the battery management system (BMS) had to be discarded and a new one had to be manufactured.

The background technology of the present invention is disclosed in Republic of Korea Patent No. 10-1571954 (Battery energy storage system capable of emergency operation when an error occurs in the battery rack and emergency operation method of the battery energy storage system).

The present invention was created to improve the above problems, and an object of one aspect of the present invention is to provide a modular battery management system that does not require a new battery management system even if the cell structure of the battery is changed.

An object according to another aspect of the present invention is to provide a modular battery management system that accurately measures the cell voltage of each of a plurality of battery cells in a battery pack composed of a plurality of battery modules and performs cell balancing.

The problem to be solved by the present invention is not limited to the problem(s) mentioned above, and other problem(s) not mentioned will be clearly understood by those skilled in the art from the description below.

A modular battery management system according to an aspect of the present invention includes a battery pack consisting of a plurality of battery modules to which a plurality of battery cells are connected, a plurality of battery packs each connected to the plurality of battery modules and monitoring the voltage and temperature of each battery module. A local management unit, and a central management unit electrically connected to the plurality of local management units to monitor the voltage and temperature of the battery pack using the voltage and temperature of the battery module transmitted from each local management unit. .

In the present invention, the local management unit includes a voltage monitoring unit that measures the analog cell voltage of each battery cell included in the battery module, a temperature monitoring unit that measures the temperature of the battery module, the voltage monitoring unit, and the temperature monitoring unit. A battery monitoring unit that receives analog cell voltage and battery module temperature from the battery module and converts the received analog cell voltage and battery module temperature into digital cell voltage and battery module temperature, and digital cells of all battery cells included in the battery module. It may include a local MCU that adds the voltages to calculate the battery module voltage and transmits the battery module voltage and battery module temperature to the central management unit.

In the present invention, the voltage monitoring unit includes a discharge switch unit that measures the analog cell voltage of each battery cell and performs voltage balancing of the battery cells, and a filtering unit that filters transient voltage generated when the switching element of the discharge switch unit operates. can do.

In the present invention, the discharge switch unit includes a switching element that is turned on or off according to a balancing control signal from the battery monitoring unit, and a discharge resistor connected to the switching element and the corresponding battery cell, wherein the switching When the device is turned on, the discharge resistor is connected in parallel to the battery cell to discharge the battery cell to perform voltage balancing, and when the switching device is turned off, the discharge resistor is not connected to the battery cell and the The battery cell can operate normally.

In the present invention, the temperature monitoring unit may include a thermistor that measures the temperature of the battery module, and a first buffer that maintains an output signal of the thermistor or amplifies the output signal of the thermistor.

In the present invention, the battery monitoring unit measures the voltage difference between two adjacent battery cells, compares it with a preset threshold, and provides a balancing control signal to perform a voltage balancing operation of the battery cell when overvoltage or undervoltage occurs as a result of the comparison. It can be transmitted to the discharge switch unit of the voltage monitoring unit.

In the present invention, the central management unit includes a communication unit for communication with the local management unit, a current measurement unit connected between the battery pack and the load to measure an analog current charged or discharged in the battery pack, and the current measurement unit. It may include a central MCU that converts the analog current measured in the unit into digital current and calculates the voltage of the battery pack by summing the voltages of the battery modules each received from a plurality of local management units through the communication unit.

In the present invention, the communication unit may include a Serial Communication Interface (SCI) signal line and a level shifter that adjusts the voltage level between the local management unit and the central management unit.

In the present invention, the current measuring unit may include a shunt resistor connected between the battery pack and the load, and an operational amplifier that amplifies the voltage measured through both ends of the shunt resistor.

The modular battery management system according to an embodiment of the present invention can provide high compatibility by distinguishing between a local management unit and a central management unit and modularizing the local management unit, even if the cell structure of the battery is changed. This has the effect of eliminating the need to manufacture a new BMS.

The modular battery management system according to an embodiment of the present invention can increase the lifespan of the battery module by accurately measuring the cell voltage of each of a plurality of battery cells in a battery pack composed of a plurality of battery modules and performing cell balancing. You can.

Meanwhile, the effects of the present invention are not limited to the effects mentioned above, and various effects may be included within the range apparent to those skilled in the art from the contents described below.

1 is a diagram for explaining a modular battery management system according to an embodiment of the present invention.
Figure 2 is a diagram for explaining a local management unit according to an embodiment of the present invention.
FIG. 3 is a diagram for explaining the discharge switch unit shown in FIG. 2.
FIG. 4 is a diagram for explaining the filtering unit shown in FIG. 2.
FIG. 5 is a diagram for explaining the interface unit shown in FIG. 2.
Figure 6 is a diagram for explaining a central management unit according to an embodiment of the present invention.
FIG. 7 is a diagram for explaining the communication unit shown in FIG. 6.
FIG. 8 is a diagram for explaining the current measurement unit shown in FIG. 6.

Hereinafter, a modular battery management system according to an embodiment of the present invention will be described with reference to the attached drawings. In this process, the thickness of lines or sizes of components shown in the drawing may be exaggerated for clarity and convenience of explanation.

In addition, the terms described below are terms defined in consideration of functions in the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, definitions of these terms should be made based on the content throughout this specification.

Additionally, implementations described herein may be implemented as, for example, a method or process, device, software program, data stream, or signal. Although discussed only in the context of a single form of implementation (eg, only as a method), implementations of the features discussed may also be implemented in other forms (eg, devices or programs). The device may be implemented with appropriate hardware, software, firmware, etc. The method may be implemented in a device such as a processor, which generally refers to a processing device that includes a computer, microprocessor, integrated circuit, or programmable logic device. Processors also include communication devices such as computers, cell phones, portable/personal digital assistants (“PDAs”) and other devices that facilitate communication of information between end-users.

1 is a diagram for explaining a modular battery management system according to an embodiment of the present invention.

Referring to FIG. 1, the modular battery management system according to an embodiment of the present invention includes a battery pack 100 and local management units 200a, 200b,..., 200n, hereinafter referred to as 200, connected to the battery pack 100. may include a central management unit 300) and a central management unit 300.

The battery pack 100 may be configured through serial and parallel connection of a plurality of battery modules (110a, 110b,...110n, hereinafter referred to as 110). That is, the battery module 110 can be configured by connecting battery cells in series or parallel, and the battery pack 100 can be configured by connecting the battery modules 110 in series. The number of battery modules 110 included in the battery pack 100 may vary depending on the application environment, and a different number of battery modules 110 may be included in one battery pack 100. Such a battery cell may be one selected from the group consisting of a lithium ion battery, a lithium polymer battery, and their equivalents, but the present invention is not limited thereto.

The battery pack 100 can be charged by receiving power or can be discharged by supplying the electric energy charged in the battery pack 100 to a load. That is, the plurality of battery modules 110 store power in the plurality of battery modules 110 according to the charging command of the corresponding local management unit 200 or the central management unit 300, and store power in the plurality of battery modules 110 according to the discharging command. The power stored in the module 110 can be discharged.

Each of the plurality of local management units 200 is electrically connected to the corresponding battery module 110, can sense the voltage and temperature of the battery cell, and manage charging, discharging, and cell balancing of the battery cell. Of course, one local management unit 200 can manage one battery module 110.

The plurality of local management units 200 may be respectively connected to the plurality of battery modules 110 included in the battery pack 100 to control charging and discharging of each of the plurality of battery modules 110.

The local management unit 200 is connected to the battery module 110 and may perform a function of controlling the battery module 110. The control function of the local management unit 200 may include charge/discharge control of battery cells included in the battery module 110, balancing control, switching, measurement and monitoring of electrical characteristics, error indication, on-off control, etc. In addition, various electrical and electronic control functions known at the time of filing of the present invention may be included in the control function of the local management unit 200.

The local management unit 200 may be equipped with algorithms for measuring battery cell voltage, measuring battery module 110 temperature, and balancing battery cells.

The central management unit 300 is electrically connected to a plurality of local management units 200, and uses the voltage and temperature of the battery module 110 transmitted from each local management unit 200 to manage the overall battery pack 100. It can manage charging, discharging and/or pack balancing.

The central management unit 300 may receive battery module voltage data transmitted from each local management unit 200 and monitor the battery module voltage and temperature.

The central management unit 300 may be equipped with an algorithm for monitoring battery pack voltage and measuring battery pack current.

FIG. 2 is a diagram for explaining a local management unit according to an embodiment of the present invention, FIG. 3 is a diagram for explaining the discharge switch unit shown in FIG. 2, and FIG. 4 is a diagram for explaining the filtering unit shown in FIG. 2. , FIG. 5 is a diagram for explaining the interface unit shown in FIG. 2.

Referring to FIG. 2, the local management unit 200 according to an embodiment of the present invention includes a voltage monitoring unit 210, a temperature monitoring unit 220, a battery monitoring unit 230, an interface unit 240, and a local MCU. It may include (250).

The voltage monitoring unit 210 may measure the analog cell voltage of each battery cell of the battery module 110.

This voltage monitoring unit 210 may include a discharge switch unit 212 and a filtering unit 216 connected to each battery cell.

The discharge switch unit 212 is connected to the battery cell, measures the analog cell voltage of each battery cell, and transmits the measured analog cell voltage to the battery monitoring unit 230 through the filtering unit 216.

Additionally, the discharge switch unit 212 may discharge battery cells. That is, the discharge switch unit 212 can be used to lower the voltage of the battery cell with the higher voltage when the voltage of a specific battery cell is higher than that of other battery cells.

This discharge switch unit 212 may be made of a field effect transistor (FET) and a discharge resistor (R), as shown in FIG. 3.

A field effect transistor (FET) can be connected to limit current flow from the battery cell. Here, the field effect transistor is a switching device, and the technical scope of the present invention is not limited thereto, and other types of electrical devices performing a switching function may be used. The FET may be implemented as a MOSFET, for example.

If there is a difference in the voltage of each battery cell provided in the battery module 110, the discharge switch unit 212 may perform a voltage balancing operation of the battery cells. To this end, the discharge switch unit 212 may be configured in such a way that a current path is formed at both ends of each battery cell and a FET is provided in this current path. At this time, the battery monitoring unit 230 can lower or increase the voltage of each battery cell by controlling the FET, and through this, voltage balancing of multiple battery cells can be performed. That is, the battery monitoring unit 230 monitors the voltage of each battery cell and, if there is a difference in the voltage of the battery cell, transmits a balancing control signal to the discharge switch unit 212 to perform a voltage balancing operation of the battery cell. You can. The discharge switch unit 212 that receives the balancing control signal can perform voltage balancing of the battery cells by turning on the FET.

For example, the difference between the nth battery cell voltage (C(n)) and the (n+1)th battery cell voltage (C(n+1)) is compared with a preset threshold, and the comparison results in overvoltage or undervoltage. When this occurs, the battery monitoring unit 230 sends a balancing control signal to perform a balancing operation between the nth battery cell voltage (C(n)) and the (n+1)th battery cell voltage (C(n+1)). (S(n)) can be transmitted to the discharge switch unit 212. The FET of the discharge switch unit 212 that receives the balancing control signal is turned on to perform voltage balancing between the two battery cells.

Additionally, the discharge switch unit 212 may be provided with a discharge resistance (R). In this case, the discharge switch unit 212 connects a specific battery cell and a discharge resistor (R), so that the power of the specific battery cell is consumed by the discharge resistance (R), thereby performing a balancing operation to lower the voltage of the battery cell. It can be done.

The FET can act as a switch to connect and disconnect the discharge resistance (R) to each battery cell. When the FET is in the ON state, the discharge resistor is connected in parallel to the corresponding battery cell, and the corresponding cell can be discharged by supplying power to the discharge resistor (R) connected in parallel. On the other hand, when the FET is in the OFF state, the discharge resistor (R) is not connected to the battery cell, so the battery cell can operate normally.

Additionally, the discharge switch unit 212 may include a Zener diode. The Zener diode can serve to remove noise generated during the on/off operation of the FET and maintain the voltage between the source and gate required for the FET operation.

Meanwhile, small voltage transients occur when the FET is turned on or off, which can reduce the accuracy of analog-to-digital (ADC) conversion in electrical circuits. Accordingly, the filtering unit 216 can be connected to the discharge switch to filter transient voltage and reduce errors during ADC conversion.

The filtering unit 216 may filter transient voltage generated when the FET of the discharge switch unit 212 operates. This filtering unit 216 may be implemented as an RC filtering circuit as shown in FIG. 4. That is, the filtering unit 216 may be composed of a series resistor and a shunt capacitor.

The filtering unit 216 may transmit the battery cell voltage from which the transient voltage has been filtered to the battery monitoring unit 230.

The temperature monitoring unit 220 may measure the temperature of the battery module 110. For example, the temperature monitoring unit 220 may measure the external temperature and/or internal temperature of the battery module 110. Additionally, the temperature monitoring unit 220 can determine the temperature of the battery module 110 for each part in more detail by measuring the temperature at several points inside the battery module 110. Meanwhile, the temperature monitoring unit 220 may transmit the measured temperature information of the battery module 110 to the battery monitoring unit 230.

This temperature monitoring unit 220 may include a thermistor 222 and a first buffer 226.

The thermistor 222 can measure the temperature of the battery module 110. At this time, the thermistor 222 may be implemented as, for example, a negative temperature coefficient (NTC) thermistor (Negative Temperature Coefficient-thermic).

The NTC thermistor 222 operates so that resistance decreases as the temperature of the battery module 110 increases, and the thermistor voltage is proportional to the temperature, so the temperature of the battery module 110 can be calculated from the voltage of the thermistor 222. The first buffer 226 may be used to supply a preset constant voltage (eg, 3.065V) to the NTC thermistor 222.

The first buffer 226 may maintain the output signal of the thermistor 222 or amplify the output signal of the thermistor 222. That is, the output signal of the thermistor 222 may be lost. Accordingly, the first buffer 226 can prevent loss of the output signal of the thermistor 222 by storing the output signal of the thermistor 222, thereby maintaining the output signal of the thermistor 222. there is. Additionally, because the output signal of the thermistor 222 is to convert voltage into temperature, the output signal of the thermistor 222 may be weak. Accordingly, the first buffer 226 may amplify the output signal of the thermistor 222.

The battery monitoring unit 230 receives the analog cell voltage and battery module temperature from the voltage monitoring unit 210 and the temperature monitoring unit 220, and converts the received analog cell voltage and battery module temperature into a digital cell voltage and battery module temperature. It can be converted.

Additionally, the battery monitoring unit 230 may control the discharge switch unit 212 to perform a battery protection operation. If an abnormal condition such as overdischarge, overcharge, short circuit, or overcurrent occurs within the battery module 110, the battery monitoring unit 230 can protect the BMS circuit and battery from the abnormal condition by controlling the discharge switch unit 212. there is.

That is, the battery monitoring unit 230 monitors the voltage of each battery cell, compares the voltage difference between the two battery cells with a preset threshold, and performs a voltage balancing operation of the battery cell when overvoltage or undervoltage occurs as a result of the comparison. A balancing control signal to perform the balancing operation may be transmitted to the discharge switch unit 212. Here, the threshold may include an overvoltage threshold for determining whether there is an overvoltage and an undervoltage threshold for determining whether there is an undervoltage.

For example, if the voltage difference between the nth battery cell and the (n+1)th battery cell is greater than the overvoltage threshold (e.g., 35 mV), the battery monitoring unit 230 determines that the n+1th battery cell is the nth battery cell. The FET of the n+1th battery cell can be turned on by determining that it has a higher voltage. Additionally, if the voltage difference between the nth battery cell and the (n+1)th battery cell is less than the low voltage threshold (e.g., -35mV), the battery monitoring unit 230 determines that the nth battery cell is higher than the n+1th battery cell. It is determined that the voltage is high and the FET of the nth battery cell can be turned on.

The battery monitoring unit 230 may transmit the digital cell voltage and battery module temperature to the local MCU 250 through the interface unit 240.

The interface unit 240 may be composed of an SPI signal line 242 and a second buffer (buffer circuit 2, 246). That is, the battery monitoring unit 230 and the local MCU 250 communicate through SPI, and SPI is divided into clock (SCLK), chip select (CS), master output slave input (MOSI), and master input slave output (MISO). It can be configured. When the SPI signal line 242 communicates, the second buffer 246 can be used to prevent influence from the surroundings.

The second buffer 246 can be used to prevent loss of signals from the SPI signal line 242. This second buffer 246 may be composed of, for example, LT1719 and NC7WZ, with LT1719 serving as a buffer for the MISO signal and NC7WZ serving as a buffer for SCLK, CS, and MOSI signals.

The local MCU 250 may monitor the battery cell voltage, calculate the battery module voltage as the sum of all battery cell voltages, and then transmit the battery module voltage and temperature to the central management unit 300 through serial communication.

The local MCU 250 can set and control the monitoring mode, monitoring speed, number of cells to be monitored per battery module, discharge resistance connection configuration, overvoltage/undervoltage threshold, etc. of the battery monitoring unit 230.

The local MCU 250 may transmit various commands, such as battery cell voltage, battery module temperature, and specific battery cell discharge degree, to the battery monitoring unit 230 and obtain the corresponding information.

FIG. 6 is a diagram for explaining a central management unit according to an embodiment of the present invention, FIG. 7 is a diagram for explaining the communication unit shown in FIG. 6, and FIG. 8 is a diagram for explaining the current measuring unit shown in FIG. 6. am.

Referring to FIG. 6, the central management unit 300 may include a communication unit 310, a central MCU 320, and a current measurement unit 330.

The communication unit 310 is a component for connecting the local management unit 200 and the central management unit 300, and may include an SCI signal line 312 and a level shifter 314, as shown in FIG. 7.

Unlike SPI, SCI (Serial Communication Interface) only has a line from the local management unit 200 to (RX) of the central management unit 300 and a line from the central management unit 300 to (TX) of the local management unit 200. there is. Both lines can be connected directly to the SCI RX and TX ports of the central MCU 320.

Meanwhile, the local MCU 250 and the central MCU 320 have different voltage levels. Accordingly, the level shifter 314 can be used to ensure stable communication between two MCUs with different voltage levels.

The level shifter 314 may enable communication between the central management unit 300 (3.3V) and the local management unit 200 (5V) having different voltage levels. Level shifter 314 may use an N-channel logic level enhancement mode field effect transistor to step down a 5V signal to 3.3V and boost a 3.3V signal to 5V. The level shifter 314 converts the 3.3V and 5V serial communication interface signals between the central management unit 300 and the local management unit 200, and the SCI exchanges data between the central management unit 300 and the local management unit 200. A communication interface that enables can be provided.

The current measuring unit 330 is connected between the battery pack 100 and the charger/load, and can measure analog charging/discharging current and convert it into digital voltage.

The current measuring unit 330 is electrically connected between the battery pack 100 and the load (charger) and can detect the current input (charge) and/or output (discharge) current to the battery pack 100. there is. The current measuring unit 330 may be any one selected from the group consisting of a Hall sensor, a shunt resistor, and their equivalents, but the present invention is not limited thereto.

The analog voltage measured through the current measurement unit 330 may be transmitted to the ADC pin of the central MCU 320.

The current measurement unit 330 may be composed of a shunt resistor 332 and an operational amplifier 336, as shown in FIG. 8.

Since the resistance value of the shunt resistor 332 is very low at 2 mΩ, the charge/discharge current passing through the shunt resistor 332 can induce a voltage proportional to the current. Therefore, the charge/discharge current can be measured by measuring the voltage across the shunt resistor 332.

However, small voltage readings reduce the accuracy of current measurements, so operational amplifier 336 can be connected through shunt resistor 332 to solve this problem. The operational amplifier 336 can amplify the voltage of the shunt resistor 332 with a gain of 100 mV/A.

The central MCU 320 can convert the analog current measured by the current measurement unit 330 into digital current and monitor the battery pack voltage, current, and temperature.

The central MCU 320 can monitor both battery pack current and voltage. At this time, the current can be collected through the battery current measuring unit 330, and the battery pack voltage can be obtained by adding up all battery module voltages. The battery module voltage is transmitted from the local MCU 250 to the central MCU 320 through serial communication, but the local MCU 250 and the central MCU 320 have different voltage levels. Therefore, the level shifter 314 can be used to ensure stable communication between two MCUs with different voltage levels.

As described above, the modular battery management system according to an embodiment of the present invention can provide high compatibility by distinguishing between a local management unit and a central management unit and modularizing the local management unit, thereby providing high compatibility with the cells of the battery. Even if the structure changes, there is no need to manufacture a new BMS.

The modular battery management system according to an embodiment of the present invention can increase the lifespan of the battery module by accurately measuring the cell voltage of each of a plurality of battery cells in a battery pack composed of a plurality of battery modules and performing cell balancing. You can.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those skilled in the art will recognize that various modifications and other equivalent embodiments are possible therefrom. You will understand.

Therefore, the true technical protection scope of the present invention should be determined by the scope of the patent claims below.

100: battery rack
110: battery module
200: Local management unit
210: Voltage monitoring unit
220: Temperature monitoring unit
230: Battery monitoring unit
240: interface unit
250: Local MCU
300: Central management unit
310: Department of Communications
320: Central MCU
330: Current measuring unit

Claims (9)

A battery pack consisting of a plurality of battery modules with a plurality of battery cells connected to each other;
a plurality of local management units each connected to the plurality of battery modules and monitoring the voltage and temperature of each battery module; and
A central management unit electrically connected to the plurality of local management units and monitoring the voltage and temperature of the battery pack using the voltage and temperature of the battery module transmitted from each local management unit,
The local management unit is,
It includes a voltage monitoring unit that measures the analog cell voltage of each battery cell included in the battery module,
The voltage monitoring unit,
a discharge switch unit that measures the analog cell voltage of each battery cell and performs voltage balancing of the battery cells; and
It includes a filtering unit that filters transient voltage generated when the switching element of the discharge switch unit operates,
The filtering unit includes a resistor and a shunt capacitor,
The discharge switch unit,
A switching element that is turned on or off according to a balancing control signal from the battery monitoring unit;
A discharge resistor connected to the switching element and the corresponding battery cell; and
A modular battery management system comprising a Zener diode that removes noise generated during the on/off operation of the switching element and maintains a voltage between the source and gate of the switching element.
According to paragraph 1,
The local management unit is,
A temperature monitoring unit that measures the temperature of the battery module;
a battery monitoring unit that receives analog cell voltage and battery module temperature from the voltage monitoring unit and the temperature monitoring unit, and converts the received analog cell voltage and battery module temperature into digital cell voltage and battery module temperature; and
Further comprising a local MCU (main control unit) that calculates a battery module voltage by adding the digital cell voltages of all battery cells included in the battery module, and transmits the battery module voltage and battery module temperature to the central management unit. Features a modular battery management system.
delete According to paragraph 1,
The discharge switch unit,
When the switching element is turned on, the discharge resistor is connected in parallel to the battery cell to discharge the battery cell to perform voltage balancing,
When the switching element is turned off, the discharge resistor is not connected to the battery cell and the battery cell operates normally.
According to paragraph 2,
The temperature monitoring unit,
a thermistor that measures the temperature of the battery module; and
A modular battery management system comprising a first buffer that maintains the output signal of the thermistor or amplifies the output signal of the thermistor.
According to paragraph 2,
The battery monitoring unit,
The voltage difference between two adjacent battery cells is measured and compared with a preset threshold, and if overvoltage or undervoltage occurs as a result of the comparison, a balancing control signal to perform a voltage balancing operation of the battery cell is transmitted to the discharge switch unit of the voltage monitoring unit. A modular battery management system characterized in that.
According to paragraph 1,
The central management unit is,
a communication unit for communication with the local management unit;
a current measuring unit connected between the battery pack and the load to measure an analog current charged or discharged in the battery pack; and
A central MCU that converts the analog current measured by the current measurement unit into a digital current and calculates the voltage of the battery pack by summing the voltages of the battery modules received from a plurality of local management units through the communication unit. Features a modular battery management system.
In clause 7,
The Department of Communications,
SCI (Serial Communication Interface) signal line; and
A modular battery management system comprising a level shifter that adjusts the voltage level between the local management unit and the central management unit.
In clause 7,
The current measuring unit,
a shunt resistor connected between the battery pack and the load; and
A modular battery management system comprising an operational amplifier that amplifies the voltage measured across the shunt resistor.