Battery management device and method

Abstract

The present invention provides a battery management device and method comprising: a battery monitoring IC (BMIC) for diagnosing a battery condition; a first over-voltage detection unit for comparing a battery voltage with a first reference voltage to generate a first detection signal; a second over-voltage detection unit for comparing the battery voltage with a second reference voltage different from the first reference voltage to generate a second detection signal; and a microcontrol unit (MCU) for controlling the battery based on a diagnostic signal from the battery management integrated circuit (BMIC) and diagnosing an abnormality within the device based on the first detection signal and the second detection signal.

Description

Technical Field

[0001] The present invention relates to a battery management device (BMS: Battery management system), and more particularly, to a battery management device and method capable of preventing diagnostic failures due to measurement errors in a battery management integrated circuit (BMIC: battery monitoring Integrated Circuit) and a micro control unit (MCU: Micro Control Unit) of the battery management device. Further, when applying an overvoltage detection integrated circuit (IC) for preventing this, there may be an error (error) in the diagnosis of a conventional overvoltage detection IC, and the present invention relates to a battery management device and method for preventing a diagnostic error of the conventional overvoltage detection IC.

Background Art

[0002] A rechargeable secondary battery, that is, a battery, is widely used as an energy source for mobile devices such as smartphones. Moreover, the battery is also used as an energy source for environment-friendly vehicles such as electric vehicles and hybrid electric vehicles, which are presented as a measure for solving air pollution caused by gasoline vehicles and diesel vehicles using fossil fuels. The types of applications using batteries are very diverse, and in the future, it is expected that batteries will be applied to more fields and products than at present.

[0003] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium-ion batteries, etc. Among them, lithium-ion batteries are attracting attention because they have almost no memory effect compared to nickel-based batteries, so they can be charged and discharged freely, have a very low self-discharge rate, and have a high energy density. In addition, since lithium-ion batteries can be made small and lightweight, they are used as a power source for mobile devices, and their use range has expanded to the power source of electric vehicles, attracting attention as a next-generation energy storage medium.

[0004] For electrical and electronic devices that use a battery as a power source, a battery management device (Battery management system; BMS) or the like must be provided to control the operation of the battery. The BMS monitors the state of the battery such as temperature, voltage, and current, and based on the monitored state of the battery, performs battery balancing and estimation of the state of charge (SOC) to control charging or discharging. Such a BMS may include a battery management integrated circuit (BMIC: battery monitoring IC) for monitoring the state of the battery and generating a diagnostic signal, and a microcontroller unit (Micro Controller Unit; MCU) for controlling the battery according to the state of the battery. At this time, the BMIC and the MCU are connected by a predetermined communication line to input and output data or signals. That is, the BMIC generates a diagnostic signal from state information such as voltage, current, and temperature measured for the battery and delivers it to the MCU. Further, the MCU can input a diagnostic signal from the BMIC, determine the state of the battery, and control the battery based on the determination result according to the state of the battery.

[0005] On the other hand, the battery management device may not be able to diagnose, for example, overvoltage of the battery due to measurement errors of the MCU or BMIC. In order to keep the battery in a safety state under such circumstances, an overvoltage detection unit is provided. The overvoltage detection unit receives the voltage monitoring result of the battery and detects whether the voltage of the battery is an overvoltage exceeding the set voltage. At this time, the overvoltage detection unit can be provided singly within the battery management device. That is, conventionally, an overvoltage detection unit is provided singly within the BMS to detect whether the voltage monitoring result of the battery is an overvoltage exceeding the set voltage, and the MCU is used to keep the battery in a safe state.

[0006] However, according to the conventional technology that determines overvoltage using a single overvoltage detection unit, there is a risk of false detection due to a failure of the overvoltage detection unit or a failure of the peripheral circuit of the overvoltage detection unit. That is, there is a risk of problems such as the overvoltage detection unit itself failing or the overvoltage detection unit being unable to properly detect overvoltage due to a failure of the peripheral circuit of the overvoltage detection unit. Thus, if the overvoltage cannot be properly detected due to a failure of a single overvoltage detection unit, the battery cannot be controlled, and as a result, there is a high risk of the problem that the battery becomes unusable.

[0007] As related prior art, the following documents can be cited.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present invention provides a battery management device and method capable of preventing false detection of overvoltage.

[0010] The present invention provides a battery management device and method capable of preventing false detection of overvoltage by detecting the voltage of a battery with at least two overvoltage detection units having different reference voltages.

Means for Solving the Problems

[0011] A battery management device according to one aspect of the present invention includes a battery management integrated circuit (BMIC) that diagnoses the state of a battery, a first overvoltage detection unit that compares the voltage of the battery with a first reference voltage to generate a first detection signal, a second overvoltage detection unit that compares the voltage of the battery with a second reference voltage different from the first reference voltage to generate a second detection signal, and a microcontroller unit (MCU) that controls the battery based on a diagnosis signal from the battery management integrated circuit (BMIC) and diagnoses an abnormality in the device based on the first and second detection signals.

[0012] The first reference voltage is lower than the second reference voltage.

[0013] The first overvoltage detection unit generates the first detection signal if the voltage of the battery is higher than the first reference voltage, and the second overvoltage detection unit generates the second detection signal if the voltage of the battery is higher than the second reference voltage.

[0014] If the second detection signal does not occur, the microcontroller unit (MCU) determines that the battery management integrated circuit (BMIC), the first overvoltage detection unit, the second overvoltage detection unit, and their peripheral circuits are operating normally.

[0015] When the second detection signal occurs, the microcontroller unit (MCU) compares the maximum voltage of the battery with the second reference voltage.

[0016] If the maximum voltage of the battery is higher than the second reference voltage, the microcontroller unit (MCU) determines that the second overvoltage detection unit is operating normally. If the maximum voltage of the battery is lower than the second reference voltage, the microcontroller unit (MCU) determines that there is a measurement error in the voltage of the battery in the battery management integrated circuit (BMIC) or the microcontroller unit (MCU) or that an abnormality has occurred in the second overvoltage detection unit.

[0017] When the second detection signal is generated, the micro control unit (MCU) determines an error in at least one of the first overvoltage detection unit and the second overvoltage detection unit based on the first detection signal.

[0018] If the second detection signal is generated and the first detection signal is generated, it is determined that the second overvoltage detection unit operates normally.

[0019] If the second detection signal is generated and the first detection signal is not generated, it is determined that at least one of the first overvoltage detection unit and the second overvoltage detection unit operates abnormally.

[0020] A battery management method according to another aspect of the present invention includes a process of measuring the state of a battery, a process of comparing a measured voltage value of the battery with a first reference voltage of a first overvoltage detection unit and a second reference voltage of a second overvoltage detection unit, respectively, a process of determining whether a second detection signal is generated from the second overvoltage detection unit when the second reference voltage is higher than the measured voltage of the battery, a process of determining that it is a normal operation if the second detection signal is not generated, a process of comparing the maximum voltage of the battery with the second reference voltage if the second detection signal is generated, a process of determining that the second overvoltage detection unit operates normally if the maximum voltage of the battery is higher than the second reference voltage, and a process of determining that there is an error in the voltage measurement of the battery or an abnormality occurs in the second overvoltage detection unit if the maximum voltage of the battery is lower than the second reference voltage.

[0021] The first reference voltage is lower than the second reference voltage.

[0022] The battery management method further includes a process of determining whether the voltage of the battery is the same as when the first detection signal was generated when the second detection signal is generated, a process of determining that the second overvoltage detection unit operates normally when the first detection signal is generated, and a process of determining that at least one of the first and second overvoltage detection units operates abnormally when the first detection signal is not generated.

Effect of the Invention

[0023] The battery management device according to an embodiment of the present invention includes a first overvoltage detection unit and a second overvoltage detection unit having different first reference voltages and second reference voltages between a BMCI and an MCU. The first overvoltage detection unit and the second overvoltage detection unit compare the measured voltage of the battery with the first reference voltage and the second reference voltage, respectively, and output a first detection signal and a second detection signal to the MCU. The MCU can diagnose abnormalities in the BMIC, the first overvoltage detection unit, the second overvoltage detection unit, and their peripheral circuits using the first detection signal and the second detection signal. That is, when the second detection signal is generated, the MCU can diagnose a measurement error of the BMIC or the MCU by comparing the voltage of the battery input from the BMIC with the second reference voltage. Further, when the second detection signal is generated, the MCU can diagnose an error in at least one of the first overvoltage detection unit and the second overvoltage detection unit according to the presence or absence of the first detection signal.

[0024] Therefore, the present invention can prevent problems of false detection due to failures of the overvoltage detection unit or failures of peripheral circuits of the overvoltage detection unit compared to the prior art. That is, by using two overvoltage detection units having different reference voltages, it is possible to prevent problems such as the overvoltage detection unit itself failing or the overvoltage detection unit being unable to properly detect overvoltage due to a failure of a peripheral circuit of the overvoltage detection unit.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0026] Hereinafter, embodiments of the present invention will be described in more detail based on the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be embodied in various different forms. The following embodiments are provided only to make the disclosure of the present invention complete and to fully inform those with ordinary knowledge of the scope of the invention.

[0027] FIG. 1 is a block diagram for explaining the configuration of a battery device according to an embodiment of the present invention. That is, FIG. 1 is a block diagram of a battery device including a battery and a battery management device. Further, FIG. 2 is a block diagram for explaining the configuration of the MCU of a battery management system according to an embodiment of the present invention.

[0028] Referring to FIG. 1, a battery device according to an embodiment of the present invention includes a battery 100 including a plurality of rechargeable battery cells, a monitoring unit 200 for monitoring the state of the battery 100, a battery management integrated circuit (BMIC: battery monitoring IC) 300 for diagnosing the state of the battery 100 based on the monitoring result of the battery 100, a first overvoltage detection unit 400 having a first reference voltage and comparing the voltage of the battery 100 from the monitoring unit 200 with the first reference voltage, a second overvoltage detection unit 500 having a second reference voltage different from the first reference voltage and comparing the voltage of the battery 100 from the monitoring unit 200 with the second reference voltage, and an MCU 600 for communicating signals with the BMIC 300, receiving detection signals from the first overvoltage detection unit 400 and the second overvoltage detection unit 500, and controlling the battery 100 according to the state of the battery 100. Here, the monitoring unit 200, the BMIC 300, the first overvoltage detection unit 400 and the second overvoltage detection unit 500, and the MCU 600 form a battery management device. The battery device including such a battery and battery management device according to the present invention will be described in more detail for each component as follows.

[0029] 1. Battery

[0030] The battery 100 is an electrical energy source that provides energy to a power-consuming device to drive the power-consuming device. Here, the power-consuming device can cover mobile devices such as smartphones and transportation means such as electric scooters, electric vehicles, and hybrid electric vehicles. The battery 100 may include at least one battery pack. At this time, each of the at least one battery pack may include a plurality of battery modules, and the battery module may include a plurality of rechargeable battery cells. That is, the battery 100 may include a plurality of battery cells, and the plurality of battery cells may be bundled in a predetermined unit to form a battery module, or a plurality of battery modules may form one battery pack. On the other hand, the plurality of battery cells can be connected in series and / or in parallel by various methods so as to match the specification of the power-consuming device. Needless to say, a plurality of battery packs each including a plurality of battery cells can also be connected in series and / or in parallel. Here, the type of the battery cell is not particularly limited, and for example, it may be composed of a lithium-ion battery, a lithium polymer battery, a nickel-cadmium battery, a nickel-metal hydride battery, a nickel-zinc battery, or the like.

[0031] 2. Monitoring Unit

[0032] The monitoring unit 200 may be provided to monitor the state of the battery 100. For example, the monitoring unit 200 can measure the current, voltage, temperature, etc. of the battery 100. Further, the monitoring unit 200 can measure the states of the battery pack, battery module, and battery cell. That is, the monitoring unit 200 can also measure the state of each of the plurality of battery cells, the state of the battery module formed by bundling the plurality of battery cells, and the state of the battery pack formed by bundling the plurality of battery modules. For this purpose, the monitoring unit 200 may include a plurality of sensors. That is, the monitoring unit 200 may include at least one current sensor, at least one voltage sensor, and at least one temperature sensor. The current sensor, the voltage sensor, and the temperature sensor can periodically measure the current, voltage, and temperature of the battery 100 and provide the measurement results to the BMIC 300. The measurement results can be provided to the BMIC 300 as an analog signal or a digital signal. Here, the current sensor can generate a signal corresponding to the magnitude of the charging current. Needless to say, the current sensor can measure not only the charging current but also the magnitude of the discharging current. For this purpose, the current sensor may be disposed, for example, on the charge and discharge path, which is the path through which the charge and discharge current flows in the battery 100. On the other hand, the current sensor according to the present invention may include a shunt resistor. Further, the voltage sensor generates a signal corresponding to the voltage applied between the positive and negative electrodes of the battery 100. As an example, the voltage sensor may include a differential amplification circuit that outputs a voltage signal corresponding to the voltage difference between the positive terminal and the negative terminal of the battery 100. And, as an example, the temperature sensor may be a thermocouple used for temperature measurement. The temperature sensor generates a signal corresponding to the temperature of the battery 100. Further, in addition to the temperature sensor that measures the temperature of the battery 100, the temperature sensor may further include an external temperature sensor that measures the external temperature at which the heat of the battery 100 is dissipated.The external temperature sensor may be composed of the same sensors as the temperature sensor and generates a signal corresponding to the external temperature. On the other hand, the monitoring unit 200 is connected to the first overvoltage detection unit 400 and the second overvoltage detection unit 500 and can provide the voltage measurement results to the first overvoltage detection unit 400 and the second overvoltage detection unit 500. That is, the voltage of the battery 100 measured by the voltage sensor is provided to the first overvoltage detection unit 400 and the second overvoltage detection unit 500 and can be used for detecting the overvoltage of the first overvoltage detection unit 400 and the second overvoltage detection unit 500.

[0033] 3.BMIC

[0034] The BMIC300 receives the state signal of the battery measured by the monitoring unit 200, generates a diagnostic signal from the measured state information, and delivers it to the MCU600. For example, the BMIC300 can compare the voltage of the battery measured from the monitoring unit 200 with a set voltage range and generate a diagnostic signal based on the comparison result. To give a specific example, when the voltage of the battery is set to 3V to 4.5V, the BMIC300 compares the voltage of the battery with the set voltage range and can generate diagnostic signals at different levels for the case of an abnormal voltage outside the set voltage range and the case of a normal voltage, and deliver them to the MCU600. Also in the case of current, it is possible to determine whether it is within the set current range or outside the set current range, determine an abnormal current, and generate a diagnostic signal based on it. The BMIC300 and the MCU600 can be connected via a predetermined communication line. Therefore, the diagnostic signal can be delivered from the output terminal of the BMIC300 to the input terminal of the MCU600 via the communication line. On the other hand, the BMIC300 can control the battery 100 based on the control signal transmitted from the MCU600. For example, the BMIC300 can discharge the cell to be balanced among a plurality of battery cells via a cell balancing circuit based on the cell balancing signal transmitted from the MCU600. For this purpose, the BMIC300 can generate a plurality of switching signals based on the cell balancing signal of the MCU600. At this time, switches may be connected to the plurality of battery cells, and each of the switching signals can control the switching operation of the corresponding switch. If a switching signal at the on level is supplied to the corresponding switch, the switch turns on and the battery cell discharges. In this way, the BMIC300 and the MCU600 can be connected by a communication line to input and output predetermined data or signals. That is, a communication unit may be provided that includes an output unit for outputting a state signal such as the diagnostic signal of the BMIC300 to the MCU600 via the communication line, and an input unit for inputting a signal such as a cell balancing signal from the BMIC300 via the communication line.

[0035] 4. First overvoltage detection unit

[0036] The first overvoltage detection unit 400 is connected to the monitoring unit 200 and receives the voltage measurement value of the battery 100 from the monitoring unit 200. That is, the first overvoltage detection unit 400 receives the voltage measurement value of the battery 100 from the voltage sensor of the monitoring unit 200. The first overvoltage detection unit 400 has a first reference voltage and compares the voltage of the battery 100 with the first reference voltage. Here, the first reference voltage of the first overvoltage detection unit 400 can be set to a lower fault level than the second reference voltage of the second overvoltage detection unit 500. Therefore, the first overvoltage detection unit 400 serves to confirm whether the second overvoltage detection unit 500 has detected the voltage of the battery 100 in a normal state. On the other hand, the first overvoltage detection unit 400 outputs first detection signals of different levels based on the comparison result between the first reference voltage and the voltage of the battery 100. For example, if the voltage of the battery 100 is lower than the first reference voltage, the first overvoltage detection unit 400 outputs a low-level first detection signal, and if the voltage of the battery 100 is higher than the first reference voltage, the first overvoltage detection unit 400 outputs a high-level first detection signal. The first detection signal from the first overvoltage detection unit 400 is delivered to the MCU 600. Such a first overvoltage detection unit 400 may be provided in case overvoltage detection becomes impossible due to a diagnostic error of the BMIC 300.

[0037] 5. Second overvoltage detection unit

[0038] The second overvoltage detection unit 500 is connected to the monitoring unit 200 and receives the voltage measurement value of the battery 100 from the monitoring unit 200. That is, the second overvoltage detection unit 500 receives the voltage measurement value of the battery 100 from the voltage sensor of the monitoring unit 200 at the same time as the first overvoltage detection unit 400. The second overvoltage detection unit 500 has a second reference voltage and compares the voltage of the battery 100 with the second reference voltage. Here, the second reference voltage of the second overvoltage detection unit 500 can be set to a fail level higher than the first reference voltage of the first overvoltage detection unit 400. That is, the second overvoltage detection unit 500 has a reference voltage for actually entering a safe state. On the other hand, the second overvoltage detection unit 500 outputs second detection signals of different levels based on the comparison result between the second reference voltage and the voltage of the battery 100. For example, if the voltage of the battery 100 is lower than the second reference voltage, the second overvoltage detection unit 500 outputs a second detection signal of a low level, and if the voltage of the battery 100 is higher than the second reference voltage, the second overvoltage detection unit 500 outputs a second detection signal of a high level. The second detection signal from the second overvoltage detection unit 500 is delivered to the MCU 600. Such a second overvoltage detection unit 500 can be provided together with the first overvoltage detection unit 400 according to the present invention in case the overvoltage cannot be detected due to a diagnostic error of the BMIC 300.

[0039] 6.MCU

[0040] The MCU 600 can monitor the state of the battery 100 by receiving a diagnostic signal from the BMIC 300 and control the battery 100 according to the state of the battery 100. For example, if an abnormal diagnostic signal of the battery voltage or current is input from the BMIC 300, the MCU 600 can stop the operation of the battery using functions such as turning off communication. For this purpose, the MCU 600 may include an abnormal diagnosis unit 610. That is, based on the abnormal diagnostic signal generated when the voltage of the battery 100 is out of the set voltage range or the current of the battery 100 is out of the set current range, the abnormal diagnosis unit 610 of the MCU 600 can stop the operation of the battery 100. Also, the MCU 600 can control the operations of the battery such as charging and discharging or cell balancing based on the diagnostic signal of the BMIC 300. For this purpose, the MCU 600 may include a battery control unit 620. That is, when the voltage of the battery is within the set voltage range or the current of the battery is within the set current range, based on the normal diagnostic signal, the battery control unit 620 of the MCU 600 can stop the operation of the battery. At this time, the MCU 600 can control the charging of the battery when the voltage or current of the battery is low through the battery control unit 620, and can control the discharging of the battery when the voltage or current is stable. Also, the MCU 600 can control cell balancing through the battery control unit 620 when at least one battery cell is higher than the set voltage or current. For cell balancing, the MCU 600 can output a balancing control signal to the BMIC 300 and control cell balancing through the BMIC 300. For such operations, the MCU 600 can be connected to the BMIC 300 by a predetermined communication line. That is, the MCU 600 may be provided with a communication unit including an input unit for inputting state signals such as diagnostic signals from the BMIC 300 via a communication line and an output unit TX for outputting signals such as cell balancing signals to the BMIC 300 via a communication line.

[0041] In addition, the MCU 600 according to the present invention receives not only the voltage of the battery 100 diagnosed by the BMIC 300, but also the first detection signal and the second detection signal from the first overvoltage detection unit 400 and the second overvoltage detection unit 500, respectively. That is, the MCU 600 may include a first detection signal input unit 630 and a second detection signal input unit 640 for receiving the first detection signal and the second detection signal from the first overvoltage detection unit 400 and the second overvoltage detection unit 500, respectively. The MCU 600 can diagnose abnormalities in the BMIC 300, the first overvoltage detection unit 400, the second overvoltage detection unit 500, and their peripheral circuits using the first detection signal and the second detection signal. For this purpose, the MCU 600 may include a comparison and determination unit 650. When the first detection signal and the second detection signal from the first overvoltage detection unit 400 and the second overvoltage detection unit 500 are input, the comparison and determination unit 650 compares the respective first reference voltage and second reference voltage of the first overvoltage detection unit 400 and the second overvoltage detection unit 500 with the voltage of the battery to diagnose abnormalities in the BMIC 300, the first overvoltage detection unit 400, the second overvoltage detection unit 500, and their peripheral circuits. That is, when the second detection signal is generated from the second overvoltage detection unit 500, that is, when the second detection signal is input at a high level, the MCU 600 compares the voltage of the battery 100 input from the BMIC 300 via the abnormality diagnosis unit 610 with the second reference voltage of the second overvoltage detection unit 500 to diagnose a measurement error in the BMIC 300 or the MCU 600. Further, when the second detection signal is input at a high level from the second overvoltage detection unit 500, the MCU 600 can diagnose an error in at least one of the first overvoltage detection unit 400 and the second overvoltage detection unit 500 based on the first detection signal from the first overvoltage detection unit 400. That is, if the second detection signal is not generated, that is, if the second detection signal is input at a low level, the MCU 600 determines that the BMIC 300, the first overvoltage detection unit 400, the second overvoltage detection unit 500, the MCU 600, and their peripheral circuits are operating normally, and if the second detection signal is input at a high level, a diagnosis operation is performed.If we explain in more detail the driving method based on the diagnostic operation of such an MCU 600, it is as follows. When the second detection signal from the second overvoltage detection unit 500 is input at a high level, the MCU 600 compares the maximum voltage (cell max voltage) of the battery 100 from the BMIC 300 with the second reference voltage of the second overvoltage detection unit 500. If the maximum voltage of the battery 100 is higher than the second reference voltage, it is determined that the second overvoltage detection unit 500 is operating normally. However, if the second detection signal from the second overvoltage detection unit 500 is input at a high level and the maximum voltage of the battery 100 is lower than the second reference voltage, the MCU 600 can determine that there is an error in the voltage measurement of the battery 100 or an abnormality has occurred in the second overvoltage detection unit 500. That is, if the maximum voltage of the battery 100 is lower than the second reference voltage, it can be determined that the voltage of the battery is erroneously measured due to an error in the BMIC 300 or the MCU 600, etc., or the second detection signal is erroneously output from the second overvoltage detection unit 500 due to an abnormality in the second overvoltage detection unit 500 or its peripheral circuit.

[0042] Also, when the second detection signal from the second overvoltage detection unit 500 is input at a high level and the first detection signal from the first overvoltage detection unit 400 is input at a high level, since the first reference voltage is lower than the second reference voltage, the MCU 600 can determine that the second overvoltage detection unit 500 is operating normally. However, when the second detection signal from the second overvoltage detection unit 500 is input at a high level and the first detection signal from the first overvoltage detection unit 400 is input at a low level, it can be determined that at least one of the first overvoltage detection unit 400 and the second overvoltage detection unit 500 is operating abnormally. That is, it can be determined that an abnormality has occurred in the overvoltage detection unit.

[0043] As described above, the battery device according to an embodiment of the present invention includes a first overvoltage detection unit 400 and a second overvoltage detection unit 500 between the BMIC 300 and the MCU 600. That is, the present invention is provided with one additional overvoltage detection unit compared to the prior art. Here, the first overvoltage detection unit 400 and the second overvoltage detection unit 500 have a first reference voltage and a second reference voltage that are different from each other, and the first reference voltage has a value lower than the second reference voltage. The first and second overvoltage detection units 400 and 500 compare the voltage of the battery 100 measured by the monitoring unit 200 with the first reference voltage and the second reference voltage, respectively, and output a first detection signal and a second detection signal, respectively. The first overvoltage detection unit 400 and the second overvoltage detection unit 500 generate a first detection signal and a second detection signal, respectively, and supply them to the MCU 600 if the voltage of the battery is greater than the first reference voltage and the second reference voltage, respectively. The MCU 600 can diagnose abnormalities in the BMIC 300, the first overvoltage detection unit 400, the second overvoltage detection unit 500, and their peripheral circuits using the first detection signal and the second detection signal. That is, when the second detection signal is generated from the second overvoltage detection unit 500, the MCU 600 compares the voltage of the battery 100 input from the BMIC 300 with the second reference voltage of the second overvoltage detection unit 500, and can diagnose a measurement error in the BMIC 300 or the MCU 600. Further, when the second detection signal is input at a high level from the second overvoltage detection unit 500, the MCU 600 can diagnose an error in at least one of the first overvoltage detection unit 400 and the second overvoltage detection unit 500 based on the first detection signal from the first overvoltage detection unit 400. That is, if the second detection signal is not generated, that is, if the second detection signal is input at a low level, the MCU 600 determines that the BMIC 300, the first overvoltage detection unit 400, the second overvoltage detection unit 500, the MCU 600, and their peripheral circuits are operating normally, and if the second detection signal is input at a high level, the MCU 600 performs a diagnostic operation.

[0044] Therefore, the present invention can prevent problems of false detection due to a failure of the overvoltage detection unit or a failure of the peripheral circuit of the overvoltage detection unit compared with the prior art. That is, by using two overvoltage detection units having different reference voltages, it is possible to prevent problems such as the overvoltage detection unit itself failing or the overvoltage detection unit being unable to properly detect an overvoltage due to a failure of the peripheral circuit of the overvoltage detection unit.

[0045] FIG. 3 is a flowchart for explaining an operation method of a battery device according to an embodiment of the present invention.

[0046] Referring to FIG. 3, the operation method of the battery device according to an embodiment of the present invention includes a process of measuring the state of the battery 100 (S110), a process of comparing the measured voltage value of the battery 100 with a first reference voltage Vref1 and a second reference voltage Vref2 respectively (S120), a process of determining whether the second reference voltage Vref2 is higher than the measured voltage of the battery and a second detection signal is generated (S130), a process of determining that it is a normal operation if the second detection signal is not generated (S140), a process of comparing the maximum voltage Vmax of the battery 100 with the second reference voltage Vref2 if the second detection signal is generated (S150), a process of determining that the second overvoltage detection unit 500 operates normally if the maximum voltage Vmax of the battery 100 is higher than the second reference voltage Vref2 (S160), a process of determining that there is an error in the voltage measurement of the battery 100 or an abnormality occurs in the second overvoltage detection unit 500 if the maximum voltage of the battery 100 is lower than the second reference voltage (S170), a process of determining whether the first detection signal is generated if the second detection signal is generated (S180), a process of determining that the second overvoltage detection unit 500 operates normally if the first detection signal is generated (S190), and a process of determining that at least one of the first overvoltage detection unit and the second overvoltage detection unit operates abnormally if the first detection signal is not generated (S200). Here, S150 and S180 may be performed simultaneously or sequentially. When S150 and S180 are performed sequentially, S150 may be performed first and S180 may be performed later, or conversely, S180 may be performed first and then S150 may be performed subsequently.

[0047] If the operation method of the battery device according to an embodiment of the present invention is described in more detail for each process, it is as follows.

[0048] S110: The monitoring unit 200 monitors the state of the battery 100. For example, the monitoring unit 200 can measure the current, voltage, temperature, etc. of the battery 100. At this time, the monitoring unit 200 can measure the states of the battery pack, battery module, and battery cell. For this purpose, the monitoring unit 200 may include at least one current sensor, at least one voltage sensor, and at least one temperature sensor. The current sensor, voltage sensor, and temperature sensor can periodically measure the current, voltage, and temperature of the battery 100 and provide the measurement results to the BMIC 300. Here, the current sensor can generate a signal corresponding to the magnitude of the charging current. Needless to say, the current sensor can measure not only the charging current but also the magnitude of the discharging current. Also, the voltage sensor generates a signal corresponding to the voltage applied between the positive and negative electrodes of the battery 100. As an example, the voltage sensor may include a differential amplifier circuit that outputs a voltage signal corresponding to the voltage difference between the positive terminal and the negative terminal of the battery 100. And the temperature sensor may be, for example, a thermocouple used for temperature measurement. The temperature sensor generates a signal corresponding to the temperature of the battery 100. Also, the monitoring unit 200 is connected to the first overvoltage detection unit 400 and the second overvoltage detection unit 500 and can provide the voltage measurement results to the first overvoltage detection unit 400 and the second overvoltage detection unit 500. That is, the voltage of the battery 100 measured by the voltage sensor is provided to the first overvoltage detection unit 400 and the second overvoltage detection unit 500 and can be used for overvoltage detection by the first overvoltage detection unit 400 and the second overvoltage detection unit 500.

[0049] On the one hand, the BMIC300 receives the state signal of the battery measured in the monitoring unit 200, generates a diagnostic signal from the measured state information, and delivers it to the MCU600. For example, the BMIC300 can compare the voltage of the battery measured from the monitoring unit 200 with a set voltage range and generate a diagnostic signal based on the comparison result. Taking a specific example, when the voltage of the battery is set to 3V to 4.5V, the BMIC300 can compare the voltage of the battery with the set voltage range and generate diagnostic signals at different levels in the case of abnormal voltage outside the set voltage range and the case of normal voltage, and deliver them to the MCU600. In the case of current, it is also possible to determine whether it is within the set current range or outside the set current range to determine abnormal current and generate a diagnostic signal based on it. The BMIC300 and the MCU600 can be connected via a predetermined communication line. Therefore, the diagnostic signal can be delivered from the output end of the BMIC300 to the input end of the MCU600 via the communication line.

[0050] S120: The voltage measurement value of the battery 100 by the monitoring unit 200 is compared with the first reference voltage Vref1 and the second reference voltage Vref2 of the first overvoltage detection unit 400 and the second overvoltage detection unit 500, respectively. For this purpose, the first overvoltage detection unit 400 and the second overvoltage detection unit 500 each have the first reference voltage Vref1 and the second reference voltage Vref2, and receive the voltage measurement value of the battery 100 from the monitoring unit 200, respectively. Then, the first overvoltage detection unit 400 and the second overvoltage detection unit 500 compare the voltage of the battery 100 with the first reference voltage and the second reference voltage, respectively. Here, the first reference voltage of the first overvoltage detection unit 400 can be set to a lower fault level than the second reference voltage of the second overvoltage detection unit 500, and the second reference voltage can be set to a higher fail level than the first reference voltage. On the other hand, the first overvoltage detection unit 400 and the second overvoltage detection unit 500 output first and second detection signals of different levels based on the comparison results between the first reference voltage and the second reference voltage and the voltage of the battery 100, respectively. For example, if the voltage of the battery 100 is lower than the first reference voltage, the first overvoltage detection unit 400 outputs a low-level first detection signal, and if the voltage of the battery 100 is higher than the first reference voltage, the first overvoltage detection unit 400 outputs a high-level first detection signal. Also, if the voltage of the battery 100 is lower than the second reference voltage, the second overvoltage detection unit 500 outputs a low-level second detection signal, and if the voltage of the battery 100 is higher than the second reference voltage, the second overvoltage detection unit 500 outputs a high-level second detection signal. That is, when the voltage of the battery is higher than the first reference voltage and the second reference voltage, the first overvoltage detection unit 400 and the second overvoltage detection unit 500 generate the first detection signal and the second detection signal, respectively. The first detection signal and the second detection signal from the first overvoltage detection unit 400 and the second overvoltage detection unit 500 are delivered to the MCU600, respectively.

[0051] S130: The MCU 600 determines whether a second detection signal is input from the second overvoltage detection unit 500. That is, if the voltage of the battery 100 is higher than the second reference voltage and the second overvoltage detection unit 500 generates and outputs a second detection signal at a high level to the MCU 600, the MCU 600 determines whether the second detection signal is input at a high level.

[0052] S140: If no second detection signal is input from the second overvoltage detection unit 500, that is, if the voltage of the battery 100 is lower than the second reference voltage and a low-level second detection signal is input, the MCU 600 determines that it is operating normally. That is, in such a case, the MCU 600 can determine that the BMIC 300, the first overvoltage detection unit 400, the second overvoltage detection unit 500, the MCU 600, and its peripheral circuits are operating normally.

[0053] S150: If it is determined that a second detection signal is input from the second overvoltage detection unit 500, the MCU 600 compares the maximum voltage Vmax of the battery 100 from the BMIC 300 with the second reference voltage Vref2 of the second overvoltage detection unit 500.

[0054] S160: If the maximum voltage of the battery 100 is higher than the second reference voltage, it is determined that the second overvoltage detection unit 500 is operating normally.

[0055] S170: However, if the second detection signal from the second overvoltage detection unit 500 is input at a high level and the maximum voltage of the battery 100 is lower than the second reference voltage, the MCU 600 can determine that there is an error in the voltage measurement of the battery 100 or an abnormality has occurred in the second overvoltage detection unit 500. That is, if the maximum voltage of the battery 100 from the BMIC 300 is lower than the second reference voltage, it may be the case that the battery voltage is erroneously measured due to an error in the BMIC 300 or the MCU 600, or the second detection signal is erroneously output from the second overvoltage detection unit 500 due to an abnormality in the second overvoltage detection unit 500 or its peripheral circuits.

[0056] S180: Also, when the second detection signal is input at a high level from the second overvoltage detection unit 500, the MCU 600 determines whether the first detection signal is input at a high level from the first overvoltage detection unit 400.

[0057] S190: When the first detection signal is input at a high level together with the second detection signal, it can be determined that the second overvoltage detection unit 500 is operating normally.

[0058] S200: However, when the second detection signal is input at a high level from the second overvoltage detection unit 500 and the first detection signal is input at a low level from the first overvoltage detection unit 400, it can be determined that at least one of the first overvoltage detection unit 400 and the second overvoltage detection unit 500 is operating abnormally. That is, it can be determined that an abnormality has occurred in the overvoltage detection unit.

[0059] The technical idea of the present invention as described above has been specifically described based on the above embodiment, but it should be noted that the above embodiment is for the purpose of explanation and not for limitation. Those skilled in the technical field of the present invention can understand that various embodiments can be implemented within the scope of the technical idea of the present invention.

[0060] The names of the reference numerals of the respective components used in the present invention are as follows.

Explanation of Reference Numerals

[0061] 100: Battery 200: Monitoring Unit 300: BMIC 400: First Overvoltage Detection Unit 500: Second Overvoltage Detection Unit 600: MCU

Claims

**Claim 1**: A monitoring unit that periodically measures the voltage of a battery and provides the measurement result to a battery management integrated circuit (BMIC), a first overvoltage detection unit, and a second overvoltage detection unit; A battery management integrated circuit (BMIC) that compares the voltage of the battery measured by the monitoring unit with a set voltage range, generates diagnostic signals at different levels for abnormal voltages outside the set voltage range and normal voltages, and delivers them to a microcontroller unit (MCU); A first overvoltage detection unit and a second overvoltage detection unit that receive the measurement result of the battery voltage from the monitoring unit in case the detection of overvoltage becomes impossible due to a diagnostic error of the battery management integrated circuit (BMIC) that generates the diagnostic signal, and generate a first detection signal and a second detection signal respectively; A microcontroller unit (MCU) that controls the battery based on the diagnostic signal from the battery management integrated circuit (BMIC) and diagnoses abnormalities of the battery management integrated circuit (BMIC), the first overvoltage detection unit, and the second overvoltage detection unit based on whether the first detection signal and the second detection signal are at a high level or a low level. The first overvoltage detection unit compares the voltage of the battery with a first reference voltage and generates first detection signals at different levels based on the comparison result. The second overvoltage detection unit compares the voltage of the battery with a second reference voltage higher than the first reference voltage and generates second detection signals at different levels based on the comparison result. A battery management device. **Claim 2** If the voltage of the battery is higher than the first reference voltage, the first overvoltage detection unit outputs the first detection signal at a high level. If the voltage of the battery is higher than the second reference voltage, the second overvoltage detection unit outputs the second detection signal at a high level. The battery management device according to claim 1. **Claim 3** If the second detection signal does not occur, the microcontroller unit (MCU) determines that the battery management integrated circuit (BMIC), the first overvoltage detection unit, the second overvoltage detection unit, and the peripheral circuits are operating normally. The battery management device according to claim 2. **Claim 4** The battery management device according to claim 2, wherein when the second detection signal is generated, the micro control unit (MCU) compares the maximum voltage of the battery, which is the maximum voltage of the battery measured periodically by the monitoring unit, with the second reference voltage.

5. If the maximum voltage of the battery is higher than the second reference voltage, the micro control unit (MCU) determines that the second overvoltage detection unit is operating normally. If the maximum voltage of the battery is lower than the second reference voltage, the battery management device according to claim 4 determines that there is a measurement error in the voltage of the battery in the battery management integrated circuit (BMIC) or the micro control unit (MCU) or an abnormality has occurred in the second overvoltage detection unit.

6. The battery management device according to claim 4, wherein when the second detection signal is generated, the micro control unit (MCU) determines an error in at least one of the first overvoltage detection unit and the second overvoltage detection unit based on the first detection signal.

7. The battery management device according to claim 6, wherein if the second detection signal is generated and the first detection signal is generated, it is determined that the second overvoltage detection unit is operating normally.

8. The battery management device according to claim 7, wherein if the second detection signal is generated and the first detection signal is not generated, it is determined that at least one of the first overvoltage detection unit and the second overvoltage detection unit has malfunctioned.

9. The process of periodically measuring the voltage of the battery; The process of comparing the measured voltage value of the battery with the first reference voltage of the first overvoltage detection unit and the second reference voltage of the second overvoltage detection unit respectively; The process of determining whether a second detection signal is generated from the second overvoltage detection unit when the measured voltage value of the battery is higher than the second reference voltage; The process of determining that the battery is operating normally if the second detection signal is not generated; The process of comparing the maximum voltage of the battery, which is the maximum voltage of the battery measured periodically, with the second reference voltage if the second detection signal is generated; The process of determining that the second overvoltage detection unit has operated normally if the maximum voltage of the battery is higher than the second reference voltage. If the maximum voltage of the battery is lower than the second reference voltage, a process of determining that there is an error in the voltage measurement of the battery or an abnormality has occurred in the second overvoltage detection unit, and a battery management method including the process.

10. The battery management method according to claim 9, wherein the first reference voltage is lower than the second reference voltage.

11. A process of determining whether the second detection signal is generated and whether the voltage of the battery is higher than the first reference voltage and the first detection signal is generated; When the first detection signal is generated, a process of determining that the second overvoltage detection unit is operating normally; The battery management method according to claim 9 or claim 10, further including a process of determining that at least one of the first overvoltage detection unit and the second overvoltage detection unit has malfunctioned when the first detection signal is not generated.

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