Battery monitoring system and method

Abstract

The present invention provides a battery monitoring system and method. The battery monitoring system and method, according to a preferred embodiment of the present invention, may comprise a redundant circuit unit, which has a switching module provided between a battery and an input / output end, determines whether overcharging and over-discharging occurs by using a current flowing through the battery, determines overvoltage and undervoltage states by using an overall voltage of the battery, and controls on / off of the switching module when an abnormal state occurs in the battery, and thus, even if a failure occurs in an MCU and the like primarily responsible for the on / off control of the switching module, the redundant circuit unit can reliably block the supply of overcharge power to the battery, the over-discharging of the battery, and the like.

Description

Battery Monitoring System and Method

[0001] The present invention relates to a battery monitoring system and method, and more specifically, to a monitoring system and method for a lithium battery having a plurality of cells.

[0002] With the recent rapid proliferation of electric vehicles, interest in high-voltage batteries, a core component of electric vehicles, is also increasing. High-voltage batteries for electric vehicles typically consist of multiple battery cells, and recently, there has been a trend toward using lithium batteries instead of the previously used lead-acid batteries. However, lithium batteries have problems such as fires occurring during overvoltage and overcharging, and issues such as a rapid reduction in battery lifespan during undervoltage and over-discharge.

[0003] To prevent such problems from occurring, monitoring systems that monitor the battery's condition and cut off power input to and output from the battery are being developed recently.

[0004] In conventional battery monitoring systems, status diagnosis and fault diagnosis are periodically performed on multiple battery cells constituting a lithium battery through a Battery Monitoring Integrated Circuit (BMIC) and an MCU.

[0005] In this case, typical cell failure states include overcharging, over-discharging, overvoltage, and undervoltage. However, when the BMIC and MCU enter a Reset or Fail state, they are unable to diagnose the condition of the lithium battery. In particular, if the lithium battery is continuously exposed to an overcharge state, it is exposed to the possibility of thermal runaway, increasing the risk of fire, and if it is continuously exposed to undervoltage and over-discharge states, the lifespan of the lithium battery is significantly reduced.

[0006] The problem that the present invention aims to solve is to provide a battery monitoring system and method equipped with a redundant circuit capable of monitoring battery problems and blocking the supply of charging power to the battery and the discharge of the battery, even when functional failures of the BMIC and MCU included in the conventional battery monitoring system occur or when the system is in a reset state.

[0007] A redundant battery monitoring system according to a preferred embodiment of the present invention for solving the above-mentioned problem comprises: a switching module connected between an input / output terminal to which a charger and a load are sequentially connected and a battery; a redundant circuit unit that checks whether the battery is over-discharged or over-charged using the current flowing through the battery, and checks the overvoltage and undervoltage of the battery using the total voltage of the battery to output a first state signal; and a control circuit unit that measures the state of battery cells included in the battery to generate a second state signal, and turns the switching module on / off using the first state signal and the second state signal.

[0008] Additionally, the redundancy circuit unit determines whether over-discharge and over-charge occur by comparing the voltage generated using the current flowing through the shunt resistor connected in series with the battery with a reference voltage, and if it is determined that over-discharge and over-charge have not occurred, it outputs a logic value HIGH as a first state signal to the control circuit unit, and if it is determined that over-discharge or over-charge has occurred, it outputs a logic value LOW as a first state signal to the control circuit unit, and the control circuit unit can turn off the switching module if it is determined that over-discharge or over-charge has occurred in either the first state signal or the second state signal.

[0009] Additionally, the redundancy circuit comprises: a bidirectional amplifier that receives a voltage generated by the current flowing through the shunt resistor and outputs a voltage corresponding to the charging current or the discharging current; a first comparator that receives the output voltage of the bidirectional amplifier at a + input terminal and receives an overcharge reference voltage at a - input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; and a second comparator that receives the output voltage of the bidirectional amplifier at a - input terminal and receives an overdischarge reference voltage at a + input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal. It may include an AND gate that receives the output values ​​of the first comparator and the second comparator, respectively, performs an AND operation on the input logic values, and outputs the result to the control circuit as the first state signal.

[0010] In addition, the redundancy circuit unit determines whether the battery is overvoltage or undervoltage by comparing the total voltage of the battery with a reference voltage, and if it is determined that no overvoltage or undervoltage has occurred, outputs a logic value HIGH as a first state signal to the control circuit unit, and if it is determined that overvoltage or undervoltage has occurred, outputs a logic value LOW as a first state signal to the control circuit unit, and the control circuit unit can turn off the switching module if it is determined that either the first state signal or the second state signal has overvoltage or undervoltage.

[0011] Additionally, the redundancy circuit may include: a third comparator that receives the total voltage of the battery at the + input terminal and receives a low voltage reference voltage at the - input terminal, outputs a logic value HIGH if the input voltage of the + input terminal is greater than the input voltage of the - input terminal, and outputs a logic value LOW if the input voltage of the + input terminal is less than the input voltage of the - input terminal; a fourth comparator that receives the total voltage of the battery at the - input terminal and receives an overvoltage reference voltage at the + input terminal, outputs a logic value HIGH if the input voltage of the + input terminal is greater than the input voltage of the - input terminal, and outputs a logic value LOW if the input voltage of the + input terminal is less than the input voltage of the - input terminal; and an AND gate that receives the output values ​​of the third comparator and the fourth comparator, respectively, performs an AND operation on the input logic values, and outputs them to the control circuit as a first state signal.

[0012] In addition, the redundancy circuit outputs a logic value LOW as the first state signal if it corresponds to at least one of over-discharge, over-charge, overvoltage, or undervoltage of the battery, and outputs a logic value HIGH as the first state signal if it does not correspond to any of them, and the control circuit performs an AND operation on the first state signal and the second state signal, and turns on the switching module if the result of the AND operation is HIGH, and turns off the switching module if the result of the AND operation is LOW.

[0013] Additionally, the redundancy circuit comprises: a bidirectional amplifier that receives a voltage generated by the current flowing through the shunt resistor and outputs a voltage corresponding to the charging current or the discharging current; a first comparator that receives the output voltage of the bidirectional amplifier at a + input terminal and receives an overcharge reference voltage at a - input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; and a second comparator that receives the output voltage of the bidirectional amplifier at a - input terminal and receives an overdischarge reference voltage at a + input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal. It may include: a third comparator that receives the total voltage of the battery at the + input terminal and receives a low voltage reference voltage at the - input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; a fourth comparator that receives the total voltage of the battery at the - input terminal and receives an overvoltage reference voltage at the + input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; and an AND gate that receives the output values ​​of the first comparator, the second comparator, the third comparator, and the fourth comparator, respectively, performs an AND operation on the input logic values, and outputs the result to the control circuit as the first state signal.

[0014] Additionally, the control circuit may include: a BMIC that measures the state of each battery cell included in the battery; an MCU that generates and outputs a second state signal that controls the switching module on / off according to the state of the battery cells input from the BMIC; an AND gate that performs an AND operation on the first state signal and the second state signal and outputs the result; and a switching driver that turns the switching module on / off by outputting the signal output from the AND gate to the switching module.

[0015] Meanwhile, a battery monitoring method performed in a battery monitoring system according to a preferred embodiment of the present invention for solving the above-mentioned problem comprises: the battery monitoring system including a switching module, a redundancy circuit, and a control circuit connected between an input / output terminal to which a charger and a load are connected and a battery; (a) a step in which the switching module is turned on so that current flows between the input / output terminal and the battery; (b) a step in which the control circuit measures the total voltage of the battery and measures the state of battery cells included in the battery to generate a second state signal that controls the on / off of the switching module; (c) a step in which the redundancy circuit checks whether the battery is over-discharged and over-charged using the current flowing through the battery, and checks the overvoltage and undervoltage of the battery using the total voltage of the battery to output a first state signal to the control circuit; and (d) a step in which the control circuit turns the switching module on / off using the first state signal and the second state signal.

[0016] Additionally, in step (b) above, the control circuit outputs a logic value HIGH as the second state signal when the state of the battery cells is normal, and outputs a logic value LOW as the second state signal when the state of the battery cells is abnormal; in step (c) above, the redundancy circuit outputs a logic value LOW as the first state signal if it corresponds to at least one of over-discharge, over-charge, overvoltage, or undervoltage of the battery, and outputs a logic value HIGH as the first state signal if it does not correspond to any of them; and in step (d) above, the control circuit performs an AND operation on the first state signal and the second state signal, and turns on the switching module if the result of the AND operation is HIGH, and turns off the switching module if the result of the AND operation is LOW.

[0017] A battery monitoring system and method according to a preferred embodiment of the present invention includes a switching module installed between the battery and an input / output terminal, a redundant circuit that determines whether overcharging and over-discharging occur using the current flowing through the battery, determines overvoltage and undervoltage conditions using the total voltage of the battery, and controls the on / off of the switching module when an abnormal condition occurs in the battery, thereby enabling reliable overcharging power supply to the battery and over-discharging of the battery by means of the redundant circuit, even in the event of a failure of an MCU or the like that mainly responsible for the on / off control of the switching module.

[0018] FIG. 1 is a drawing illustrating the overall configuration of a battery monitoring system according to a preferred embodiment of the present invention.

[0019] FIG. 2 is a diagram illustrating a configuration for determining overcharging and over-discharging among a battery monitoring system according to a preferred embodiment of the present invention.

[0020] FIG. 3 is a diagram illustrating a configuration for determining high voltage and low voltage among a battery monitoring system according to a preferred embodiment of the present invention.

[0021] FIG. 4 is a flowchart illustrating a battery monitoring method according to a preferred embodiment of the present invention.

[0022] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0023] Hereinafter, the aforementioned objects, features, and advantages of the present invention will become more apparent from the following detailed description in conjunction with the accompanying drawings. However, as the present invention is subject to various modifications and may have various embodiments, specific embodiments are illustrated in the drawings and described in detail below.

[0024] Throughout the specification, identical reference numbers indicate identical components in principle. Additionally, components with identical functions within the scope of the same concept appearing in the drawings of each embodiment are described using the same reference numeral.

[0025] When a part of a specification is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Furthermore, terms such as "...part" or "module" as used in the specification refer to a unit that processes at least one function or operation, and this may be implemented in hardware or software, or as a combination of hardware and software.

[0026] If it is determined that a detailed description of known functions or configurations related to the present invention may unnecessarily obscure the essence of the present invention, such detailed description is omitted. Additionally, numbers used in the description of this specification (e.g., 1st, 2nd, etc.) are merely identification symbols to distinguish one component from another.

[0027]

[0028] FIG. 1 is a drawing illustrating the overall configuration of a battery monitoring system according to a preferred embodiment of the present invention, FIG. 2 is a drawing illustrating the configuration for determining overcharging and over-discharging among the battery monitoring system according to a preferred embodiment of the present invention, and FIG. 3 is a drawing illustrating the configuration for determining overvoltage and undervoltage among the battery monitoring system according to a preferred embodiment of the present invention.

[0029] Hereinafter, a battery monitoring system according to a preferred embodiment of the present invention will be described with reference to FIGS. 1 to 3. The battery monitoring system includes a switching module (700), a control circuit unit (100), and a redundancy circuit unit (200).

[0030] First, the switching module (700) is connected between the battery (300) and the input / output terminal (800), to which the charging device (600) and the load (500) are alternately connected, and is turned ON or OFF according to a control signal input from the control circuit unit (100) to power the input / output terminal (800) and the battery (300) or to disconnect the power.

[0031] The switching module (700) includes one or more switches, and the switches may be implemented as semiconductor switches or relay switches, etc. However, in a preferred embodiment of the present invention, the switching module (700) is implemented as two FET semiconductor switches connected to each other, but is not limited thereto.

[0032] The redundancy circuit unit (200) checks whether the battery (300) is over-discharged and over-charged using the current flowing through the battery (300), and checks for overvoltage and undervoltage of the battery (300) using the total voltage (Vout1) of the battery (300), generates a first state signal indicating a normal state or abnormal state of the battery, and outputs the first state signal to the control circuit unit (100).

[0033] If the first state signal corresponds to at least one of over-discharge, over-charge, overvoltage, or undervoltage of the battery (300), a logic value LOW is output to the control circuit (100) as the first state signal, and if it does not correspond to any of them (i.e., if the battery (300) is in a normal state), a logic value HIGH is output to the control circuit (100) as the first state signal.

[0034] The control circuit (100) measures the state of the battery cells included in the battery (300) and generates a second state signal indicating the normal state or abnormal state of the battery (300). Using the first state signal and the second state signal, the switching module (700) is kept ON while the battery (300) is in a normal state, and the switching module (700) is turned OFF when the battery (300) is in an abnormal state (over-discharge, over-charge, overvoltage, undervoltage, etc.).

[0035] Specifically, the control circuit section (100) includes a DC / DC converter (160), an MCU (120), a BMIC (110), a first AND gate (130), and a switching driver (140).

[0036] The DC / DC converter (160) receives the voltage applied to the input / output terminal (800), steps down or steps up to a preset voltage, and provides a driving voltage to components such as the MCU (120) and BMIC (110).

[0037] The BMIC (Battery Management Integrated Circuit) (110) measures the state of the battery cells and provides it to the MCU (120). The BMIC (110) measures the voltage, current, temperature, etc. of each battery cell and performs balancing to reduce the voltage difference between cells connected in series.

[0038] The MCU (120) receives the measurement status of the battery cells from the BMIC (110) and, accordingly, generates a second state signal that indicates the state of the switching module (700) and controls the on / off state, and outputs it to the first AND gate (130). At this time, the second state signal may be a logic value HIGH (normal state) or LOW (abnormal state).

[0039] Specifically, the MCU (120) receives the voltage applied to the battery cells from the BMIC (110), calculates the total voltage (Vout1) of the battery (300), and checks whether the entire battery (300) is currently in an overvoltage state or an undervoltage state.

[0040] Additionally, the MCU (120) checks whether overcharging or over-discharging is currently occurring by using measurement information regarding the current flowing through each battery cell. For reference, the current flowing from the input / output terminal (800) to the battery (300) becomes the charging current, and the current flowing from the battery (300) to the input / output terminal (800) becomes the discharging current. If the charging current or the discharging current exceeds a preset reference value, the MCU (120) can determine that the state of the battery (300) is in an overcharging or over-discharging state.

[0041] When the battery (300) is in a normal state, the MCU (120) generates a second state signal with a logic value of HIGH to allow the battery (300) and the input / output terminal (800) to communicate with each other and outputs it to the first AND gate (130), and when the battery (300) is determined to be in an abnormal state (over-discharge, over-charge, overvoltage, undervoltage, etc.), it generates a second state signal with a logic value of LOW to electrically disconnect the battery (300) and the input / output terminal (800) from each other and outputs it to the first AND gate (130).

[0042] The first AND gate (130) performs an AND operation on the first state signal input from the redundancy circuit (200) and the second state signal input from the MCU (120), and outputs the result to the switching driver (140). The first state signal and the second state signal both have a HIGH value while the battery (300) is in a normal state, and the switching driver (140) performs an AND operation and outputs the HIGH value to the switching module (700) to turn on the switching module (700) so that the input / output terminal (800) and the battery (300) are connected to each other.

[0043] In contrast, when the battery (300) is in an abnormal state, both the first state signal and the second state signal have a LOW value, and the first AND gate (130) outputs a LOW value to the switching driver (140) through an AND operation of the first state signal and the second state signal, and the switching driver (140) turns off the switching module (700) so that the switching module (700) electrically disconnects the input / output terminal (800) and the battery (300) from each other.

[0044] At this time, if the BMIC (110) or MCU (120) does not operate normally and the second state signal is not input to the first AND gate (130), or even if the battery (300) is actually in an abnormal state but a HIGH signal indicating a normal state is input to the first AND gate (130) as the second state signal, the first state signal, which is a logic value LOW indicating an abnormal state, is input from the redundancy circuit (200) which determined that the battery (300) is in an abnormal state. Therefore, the first AND gate (130) outputs a logic value LOW as the result of an AND operation due to the first state signal to the switching driver (140), and the switching driver (140) electrically disconnects the input / output terminal (800) and the battery (300) by turning off the switches included in the switching module (700).

[0045] Meanwhile, the redundancy circuit section (200) is configured to include a bidirectional amplifier (230), a first comparator (211), a second comparator (212), a third comparator (213), a fourth comparator (214), and a second AND gate (220).

[0046] First, a shunt resistor (400) is installed between the battery (300) and ground, and the voltage across the shunt resistor (400) is input to a bidirectional amplifier (230). In a preferred embodiment of the present invention, the shunt resistor (400) is set to 1 m ohm, but the setting value may vary depending on the embodiment. (See FIG. 2)

[0047] The bidirectional amplifier (230) receives a voltage generated by the current flowing through the shunt resistor (400) and outputs a voltage (Vout2) corresponding to the charging current or the discharging current. In a preferred embodiment of the present invention, the ground terminal of the shunt resistor (400) is connected to the + input terminal of the bidirectional amplifier (230), and the node connecting the shunt resistor (400) and the battery (300) is connected to the - input terminal of the bidirectional amplifier (230).

[0048] The bidirectional amplifier (230) outputs an output voltage (Vout2) corresponding to the input voltage to the first comparator (211) and the second comparator (212) according to a predefined gain. In a preferred embodiment of the present invention, the bidirectional amplifier (230) uses a gain of 25v / v and a REF voltage of 2v.

[0049] For example, when a charging current of 10A flows from the shunt resistor (400) toward ground, a voltage of - (1m ohm * 10A) = -0.01V is applied to the bidirectional amplifier (230). Then, the bidirectional amplifier (230) outputs a voltage value of -0.01V * 25V / v + 2V (ref) = 1.75V to the first comparator (211) and the second comparator (212).

[0050] In the same way, when a discharge current of 10A flows from ground toward the shunt resistor (400), a voltage of + (1m ohm * 10A) = +0.01V is applied to the bidirectional amplifier (230). Then, the bidirectional amplifier (230) outputs a voltage value of +0.01V * 25V / v + 2V (ref) = 2.25V to the first comparator (211) and the second comparator (212).

[0051] As described above, the first comparator (211) and the second comparator (212) can determine whether the battery (300) is charging or discharging based on the voltage value input from the bidirectional amplifier (230), and can determine the magnitude of the charging current and the discharging current.

[0052] Meanwhile, the first comparator (211) receives the output voltage of the bidirectional amplifier (230) at the + input terminal and receives the overcharge reference voltage at the - input terminal. In a preferred embodiment of the present invention, the Vcc voltage 5V is distributed by resistors R5 and R6 and applied to the - input terminal as the overcharge reference voltage, and the voltage output from the bidirectional amplifier (230) is input directly to the + input terminal.

[0053] The first comparator (211) outputs a logic value HIGH if the input voltage of the + input terminal is greater than the input voltage of the - input terminal, and outputs a logic value LOW to the second AND gate (220) if the input voltage of the + input terminal is less than the input voltage of the - input terminal, thereby outputting whether the current battery (300) is in an overcharged state.

[0054] For example, assuming that the reference value of the overcharge current is 10A and that an overcharge occurs when a charging current greater than 10A flows, the bidirectional amplifier (230) outputs 1.75V to the first comparator (211) and the second comparator (212) when the charging current is 10A, and outputs a voltage lower than 1.75V when the charging current becomes greater than 10A. In this case, the values ​​of the divider resistor R5 and the resistor R6 are set so that Vcc (5V) is divided by the divider resistor R5 and the resistor R6, and 1.75V is applied to the - input terminal of the first comparator (211).

[0055] Here, while the charging current is less than 10A, a voltage value higher than 1.75V is applied to the + input terminal of the first comparator (211), so the first comparator (211) outputs a logic value HIGH to the second AND gate (220). As charging progresses and the charging current becomes greater than 10A, resulting in an overcharged state, a voltage value lower than 1.75V is applied to the + input terminal of the first comparator (211), so the logic value output from the first comparator (211) changes from HIGH to LOW and is input to the second AND gate (220). The LOW value input to the second AND gate (220) makes the output value of the first AND gate (130) LOW, which in turn turns off the switches of the switching module (700) through the switching driver (140).

[0056] Meanwhile, the second comparator (212) receives the output voltage of the bidirectional amplifier (230) at the - input terminal and the over-discharge reference voltage at the + input terminal, and outputs a logic value HIGH to the second AND gate (220) if the input voltage of the + input terminal is greater than the input voltage of the - input terminal, and outputs a logic value LOW to the second AND gate (220) if the input voltage of the + input terminal is less than the input voltage of the - input terminal, thereby outputting whether the current battery (300) is in an over-discharge state.

[0057] Specifically, the second comparator (212) outputs a logic value HIGH if the input voltage of the + input terminal is greater than the input voltage of the - input terminal, and outputs a logic value LOW to the second AND gate (220) if the input voltage of the + input terminal is less than the input voltage of the - input terminal, thereby outputting whether the current battery (300) is in an over-discharged state.

[0058] For example, assuming the reference value of the over-discharge current is 10A, the bidirectional amplifier (230) outputs 2.25V to the first comparator (211) and the second comparator (212) when the discharge current is 10A, and outputs a voltage higher than 2.25V when the discharge current becomes greater than 10A. In this case, Vcc (5V) is divided by the divider resistor R3 and the resistor R4, and the values ​​of the divider resistor R3 and the resistor R4 are set so that the over-discharge reference voltage of 2.25V is applied to the + input terminal of the second comparator (212).

[0059] Here, while the discharge current is less than 10A, a voltage value lower than 2.25V is applied to the - input terminal of the second comparator (212), so the second comparator (212) outputs a logic value HIGH to the second AND gate (220). As the discharge progresses and the discharge current becomes greater than 10A, resulting in an over-discharge state, a voltage value higher than 2.25V is applied to the - input terminal of the second comparator (212), so the logic value output from the second comparator (212) changes from HIGH to LOW and is input to the second AND gate (220). The LOW value input to the second AND gate (220) makes the output value of the first AND gate (130) LOW, which in turn turns off the switches of the switching module (700) through the switching driver (140).

[0060] Meanwhile, referring to FIG. 3, the + input terminal of the third comparator (213) is connected to a node between the battery (300) and the switching module (700) to receive the total voltage (Vout1) of the battery (300) at the + input terminal and a low voltage reference voltage at the - input terminal. As long as the input voltage of the + input terminal is maintained at a higher value than the input voltage of the - input terminal, a logic value HIGH is output to the second AND gate (220), and when the input voltage of the + input terminal becomes lower than the input voltage of the - input terminal, a logic value LOW is output to the second AND gate (220), thereby outputting whether the battery (300) is in a low voltage state. In a preferred embodiment of the present invention, the third comparator (213) is designed to output a LOW signal when the total voltage (Vout1) drops to less than 30V, but the specific reference voltage value may be changed according to the embodiment.

[0061] The operation method of the third comparator (213) is the same as that of the first comparator (211), except that the voltage value input to the + input terminal is not the voltage (Vout2) output from the bidirectional amplifier (230) but the total voltage (Vout1) of the battery (300), so a detailed explanation is omitted.

[0062] The - input terminal of the fourth comparator (214) is connected to a node between the battery (300) and the switching module (700) to receive the total voltage (Vout1) of the battery (300) at the - input terminal and the overvoltage reference voltage at the + input terminal. While the input voltage of the + input terminal is greater than the input voltage of the - input terminal, a logic value HIGH is output to the second AND gate (220), and when the input voltage of the + input terminal becomes smaller than the input voltage of the - input terminal, a logic value LOW is output to the second AND gate (220), thereby outputting whether the battery (300) is in an overvoltage state. The fourth comparator (214) is designed to output a LOW signal when the total voltage (Vout1) rises above 54V, but the specific reference voltage value may be changed according to the embodiment.

[0063] The operation method of the fourth comparator (214) is the same as that of the second comparator (212), except that the voltage value input to the input terminal is not the voltage (Vout2) output from the bidirectional amplifier (230) but the total voltage (Vout1) of the battery (300), so a detailed explanation is omitted.

[0064] The second AND gate (220) receives the output values ​​of the first comparator (211), the second comparator (212), the third comparator (213), and the fourth comparator (214), respectively, performs an AND operation on the input logic values, and outputs the result to the control circuit (100) as a first state signal.

[0065] Accordingly, assuming that one of overcharging, over-discharging, overvoltage, or undervoltage occurs in the battery (300) and the other three are in a normal state, any one of the first comparator (211) to the fourth comparator (214) outputs a logic value LOW to the second AND gate (220), and the other comparators output a logic value HIGH, and since the second AND gate (220) includes a LOW value among the input values, it outputs a LOW value to the first AND gate (130).

[0066] Here, if all four inputs are HIGH, the second AND gate (220) outputs a HIGH value as a first state signal to the first AND gate (130), and the first AND gate (130) outputs a logic value identical to the second state signal input from the MCU (120) to the switching driver (140).

[0067] In contrast, if any of the four inputs input from the first comparator (211) to the fourth comparator (214) is a LOW value, the second AND gate (220) outputs the LOW value as a first state signal to the first AND gate (130), and the first AND gate (130) outputs the LOW value to the switching driver (140) regardless of the second state signal input from the MCU (120), thereby turning off the switching module (700) and electrically disconnecting the input / output terminal (800) from the battery (300).

[0068]

[0069] FIG. 4 is a flowchart illustrating a battery monitoring method according to a preferred embodiment of the present invention. Hereinafter, the battery monitoring method will be described with further reference to FIG. 4.

[0070] However, since the battery monitoring method of the present invention is performed in the battery monitoring system described with reference to FIGS. 1 to 3, its function is identical. Therefore, to avoid duplication of description, the following will briefly examine the overall flow of the battery monitoring method according to a preferred embodiment of the present invention.

[0071] When the battery monitoring system of the present invention is operated, the MCU (120) turns on the switches included in the switching module (700), and power is supplied between the input / output terminal (800) and the battery (300) (S410). Then, a charging current is supplied to the battery (300) from the charging device (600) connected to the input / output terminal (800), or a discharge current is output from the battery (300) to the load (500) connected to the input / output terminal (800).

[0072] After that, the BMIC (110) measures the state of the battery cells included in the battery (300), and the MCU (120) checks the state of the battery cells through the information input from the BMIC (110), while measuring the total voltage of the battery (300) (S420), and generates a second state signal to control the ON / OFF of the switching module (700) (S430).

[0073] At the same time as the above-mentioned step S430 is performed, the redundancy circuit unit (200) checks whether the battery (300) is over-discharged and over-charged using the current flowing through the battery (300), checks for overvoltage and undervoltage of the battery (300) using the total voltage of the battery (300), generates a first state signal, and outputs the first state signal to the control circuit unit (100) (S440).

[0074] The control circuit (100) performs on / off control of the switching module (700) using the first state signal and the second state signal (S450).

[0075]

[0076] The battery monitoring method according to the preferred embodiment of the present invention described so far can be implemented as a computer program that is implemented as computer-executable instructions and stored in a non-transient storage medium.

[0077] Storage media include all types of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable storage media include ROM, RAM, CD-ROM, and optical data storage devices. Additionally, computer-readable storage media are distributed across networked computer systems, allowing computer-readable code to be stored and executed in a distributed manner.

[0078] The present invention has been described above with reference to its preferred embodiments. Those skilled in the art will understand that the present invention may be embodied in modified forms without departing from the essential characteristics of the invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the invention is defined by the claims, not by the foregoing description, and all variations within the scope of the claims should be interpreted as being included in the invention.

Claims

1. As a redundant battery monitoring system, A switching module connected between an input / output terminal, to which a charger and a load are sequentially connected, and a battery; A redundant circuit unit that checks whether the battery is over-discharged or over-charged using the current flowing through the battery, and checks for overvoltage and undervoltage of the battery using the total voltage of the battery, and outputs a first state signal; and A redundant battery monitoring system characterized by including a control circuit that measures the state of battery cells included in the battery to generate a second state signal, and uses the first state signal and the second state signal to turn the switching module on / off.

2. In claim 1, the redundancy circuit The voltage generated using the current flowing through the shunt resistor connected in series with the battery is compared with a reference voltage to determine whether over-discharge and over-charge have occurred, respectively; if it is determined that over-discharge and over-charge have not occurred, a logic value HIGH is output to the control circuit as the first state signal, and if it is determined that over-discharge or over-charge has occurred, a logic value LOW is output to the control circuit as the first state signal. A redundant battery monitoring system characterized by the control circuit turning off the switching module if it is determined that over-discharge or over-charge has occurred in either the first state signal or the second state signal.

3. In Clause 2, the redundancy circuit A bidirectional amplifier that receives a voltage generated by the current flowing through the shunt resistor and outputs a voltage corresponding to the charging current or the discharging current; A first comparator that receives the output voltage of the above bidirectional amplifier at the + input terminal and the overcharge reference voltage at the - input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; A second comparator that receives the output voltage of the above-mentioned bidirectional amplifier at the - input terminal and receives an over-discharge reference voltage at the + input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; and A redundant battery monitoring system characterized by including an AND gate that receives the output values ​​of the first comparator and the second comparator, respectively, performs an AND operation on the input logic values, and outputs the result to the control circuit as the first state signal.

4. In claim 1, the redundancy circuit The total voltage of the battery is compared with a reference voltage to determine whether the battery is overvoltage or undervoltage, respectively; if it is determined that no overvoltage or undervoltage has occurred, a logic value HIGH is output to the control circuit as the first state signal, and if it is determined that overvoltage or undervoltage has occurred, a logic value LOW is output to the control circuit as the first state signal. A redundant battery monitoring system characterized by the control circuit turning off the switching module if it is determined that either the first state signal or the second state signal has an overvoltage or undervoltage.

5. In claim 4, the redundancy circuit A third comparator that receives the total voltage of the above battery at the + input terminal and receives a low voltage reference voltage at the - input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; A fourth comparator that receives the total voltage of the battery at the - input terminal and an overvoltage reference voltage at the + input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; and A redundant battery monitoring system characterized by including an AND gate that receives the output values ​​of the third comparator and the fourth comparator, respectively, performs an AND operation on the input logic values, and outputs the result to the control circuit as the first state signal.

6. In Paragraph 1, The above redundancy circuit outputs a logic value LOW as the first state signal if it corresponds to at least one of over-discharge, over-charge, overvoltage, or undervoltage of the battery, and outputs a logic value HIGH as the first state signal if it does not correspond to any of them. A redundant battery monitoring system characterized by the control circuit performing an AND operation on the first state signal and the second state signal, turning on the switching module when the result of the AND operation is HIGH, and turning off the switching module when the result of the AND operation is LOW.

7. In claim 1, the redundancy circuit A bidirectional amplifier that receives a voltage generated by the current flowing through the shunt resistor and outputs a voltage corresponding to the charging current or the discharging current; A first comparator that receives the output voltage of the above bidirectional amplifier at the + input terminal and the overcharge reference voltage at the - input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; A second comparator that receives the output voltage of the above bidirectional amplifier at the - input terminal and the over-discharge reference voltage at the + input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; A third comparator that receives the total voltage of the above battery at the + input terminal and receives a low voltage reference voltage at the - input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; A fourth comparator that receives the total voltage of the battery at the - input terminal and an overvoltage reference voltage at the + input terminal, outputs a logic value HIGH if the input voltage at the + input terminal is greater than the input voltage at the - input terminal, and outputs a logic value LOW if the input voltage at the + input terminal is less than the input voltage at the - input terminal; and A redundant battery monitoring system characterized by including an AND gate that receives the output values ​​of the first comparator, the second comparator, the third comparator, and the fourth comparator, respectively, performs an AND operation on the input logic values, and outputs the result to the control circuit as the first state signal.

8. In claim 1, the control circuit part BMIC that measures the state of each battery cell included in the battery; An MCU that generates and outputs the second state signal for controlling the switching module on / off according to the state of the battery cells input from the BMIC; An AND gate that performs an AND operation on the first state signal and the second state signal and outputs the result; and A redundant battery monitoring system characterized by including a switching driver that turns the switching module on / off by outputting a signal output from the AND gate to the switching module.

9. A battery monitoring method performed in a battery monitoring system, The above battery monitoring system includes a switching module, a redundancy circuit, and a control circuit connected between the battery and an input / output terminal to which a charger and a load are connected, and a redundancy circuit. (a) A step in which the switching module is turned on so that current flows between the input / output terminal and the battery; (b) a step in which the control circuit measures the total voltage of the battery and measures the state of the battery cells included in the battery to generate a second state signal that controls the on / off of the switching module; (c) a step in which the redundancy circuit unit checks whether the battery is over-discharged and over-charged using the current flowing through the battery, and checks for overvoltage and undervoltage of the battery using the total voltage of the battery, and outputs a first state signal to the control circuit unit; and (d) A battery monitoring method characterized by including the step of turning the switching module on / off using the first state signal and the second state signal.

10. In Paragraph 9, In step (b) above, the control circuit outputs a logic value HIGH as the second state signal when the state of the battery cells is normal, and outputs a logic value LOW as the second state signal when the state of the battery cells is abnormal, In step (c) above, the redundancy circuit outputs a logic value LOW as the first state signal if it corresponds to at least one of over-discharge, over-charge, overvoltage, or undervoltage of the battery, and outputs a logic value HIGH as the first state signal if it does not correspond to any of them. A battery monitoring method characterized in that, in step (d) above, the control circuit performs an AND operation on the first state signal and the second state signal, and turns on the switching module when the result of the AND operation is HIGH, and turns off the switching module when the result of the AND operation is LOW.

Images