Device and method for measuring current of battery device

Abstract

In a battery management system, a first operational amplifier outputs a first output voltage by amplifying a difference between a voltage of a first terminal of a shunt resistor and a voltage of a second terminal of the shunt resistor on the basis of a first gain, and a second operational amplifier outputs a second output voltage by amplifying the difference between the voltage of the first terminal of the shunt resistor and the voltage of the second terminal of the shunt resistor on the basis of a second gain that is lower than the first gain. A comparison circuit outputs a selection signal by comparing the first output voltage to one or more reference voltages, and a multiplexer selects one of the first output voltage and the second output voltage on the basis of the selection signal and outputs the selected output voltage as a measurement voltage corresponding to a current flowing through the shunt resistor.

Description

Current measuring device and method for battery device

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0173609 filed November 28, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] The disclosure relates to a current measuring device and method for a battery device.

[0004] Electric or hybrid vehicles are vehicles that generate power by driving a motor primarily using a battery as a power source, and active research is being conducted on them as an alternative capable of solving the pollution and energy problems associated with internal combustion engine vehicles. In addition, batteries are used in various external devices other than vehicles.

[0005] A shunt current sensor can be used to measure the current of a battery. The shunt current sensor can measure the voltage across the shunt resistor in the current path using an operational amplifier. In this case, the gain of the operational amplifier can be set considering the current range. However, as various outputs are required from the battery, a wide range of currents may be output from the battery. Therefore, if the gain of the operational amplifier is set low to account for high current ranges, the output voltage of the operational amplifier may drop at low current ranges, making it susceptible to noise. Conversely, if the gain is set high to account for low current ranges, there is a problem in that the output voltage of the operational amplifier becomes too high at high current ranges.

[0006] Some embodiments may provide a current measuring device and method capable of measuring a range of currents in a battery device.

[0007] According to some embodiments, a battery management system for a battery device may be provided, comprising a battery module and a shunt resistor through which current flows in the battery module. The battery management system may include a first operational amplifier that amplifies the difference between the voltage at a first terminal of the shunt resistor and the voltage at a second terminal of the shunt resistor based on a first gain to output a first output voltage; a second operational amplifier that amplifies the difference between the voltage at the first terminal of the shunt resistor and the voltage at the second terminal of the shunt resistor based on a second gain lower than the first gain to output a second output voltage; a comparison circuit that compares the first output voltage with one or more reference voltages to output a selection signal; and a multiplexer that selects one of the first output voltage and the second output voltage based on the selection signal and outputs it as a measurement voltage corresponding to the current flowing through the shunt resistor.

[0008] A battery device according to some embodiment may include a battery module, a shunt resistor through which current flows in the battery module, a current measuring device that generates a first output voltage corresponding to the current flowing through the shunt resistor based on a first gain, generates a second output voltage corresponding to the current flowing through the shunt resistor based on a second gain different from the first gain, and selects one output voltage among a plurality of output voltages including the first output voltage and the second output voltage as a measurement voltage based on the first output voltage, and a processor that determines the current flowing through the shunt resistor based on the measurement voltage of the current measuring device.

[0009] A current measurement method for a battery device according to some embodiment may include the steps of: receiving a voltage between a first terminal and a second terminal of a shunt resistor formed in a current-flowing path of a battery module; generating a first output voltage by amplifying the voltage between the first terminal and the second terminal based on a first gain; generating a second output voltage by amplifying the voltage between the first terminal and the second terminal based on a second gain different from the first gain; and measuring the current flowing through the resistor based on the second output voltage when the first output voltage satisfies a predetermined condition.

[0010] FIG. 1 is a block diagram of a battery device according to some embodiment.

[0011] FIG. 2 is a drawing showing a current measuring device of a battery device according to a certain embodiment.

[0012] FIG. 3 is a diagram showing an operational amplifier circuit of a current measuring device according to a certain embodiment.

[0013] FIG. 4 is a diagram showing a comparison circuit of a current measuring device according to a certain embodiment.

[0014] FIG. 5 is a drawing showing a multiplexer of a current measuring device according to a certain embodiment.

[0015] FIG. 6 is a flowchart illustrating a current measurement method of a battery device according to some embodiment.

[0016] Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are denoted by similar reference numerals.

[0017] When it is stated that a component is "connected" to another component, it should be understood that it may be directly connected to that other component, or that there may be other components in between. On the other hand, when it is stated that a component is "directly connected" to another component, it should be understood that there are no other components in between.

[0018] Expressions written in the singular in the description below may be interpreted as singular or plural unless explicit expressions such as "one" or "singular" are used.

[0019] In the flowchart described with reference to the drawing, the order of operations may be changed, multiple operations may be merged or some operations may be divided, and specific operations may not be performed.

[0020] FIG. 1 is a block diagram of a battery device according to some embodiment.

[0021] Referring to FIG. 1, the battery device (100) has a structure that can be electrically connected to an external device through a positive link terminal (DC(+)) and a negative link terminal (DC(-)). In some embodiments, when the external device is a load, the battery device (100) can be discharged by operating as a power source that supplies power to the load. When the external device is a charger, the battery device (100) can be charged by receiving external power through the charger. In some embodiments, the external device operating as a load may be, for example, an electronic device, a means of transportation, or an energy storage system (ESS), and the means of transportation may be, for example, a vehicle such as an electric vehicle, a hybrid vehicle, or smart mobility.

[0022] The battery device (100) may include a battery module (110), a positive switch (121), a negative switch (122), a battery monitoring circuit (130), a current measuring device (140), and a processor (150). In some embodiments, the battery device (100) may include a battery management system, and the battery management system may include a battery monitoring circuit (130), a current measuring device (140), and a processor (150). The battery device (100) may be a battery pack.

[0023] A battery module (110) may include a plurality of battery cells (not shown) connected in series. In some embodiments, the battery cells may be rechargeable batteries. In some embodiments, a plurality of battery modules (110) may be connected in series or in parallel to supply desired power. A battery module (110) may be connected to a link terminal (DC(+), DC(-)) of a battery device (100) through a positive switch (121) and a negative switch (122).

[0024] A positive switch (121) may be connected between the positive terminal of the battery module (110) and the positive link terminal (DC(+)) of the battery device (100). A negative switch (122) may be connected between the negative terminal of the battery module (110) and the negative link terminal (DC(-)) of the battery device (100). The switches (121, 122) may be controlled by a processor (150) to control the connection between the battery module (110) and the external device (10). In some embodiments, the switches (121, 122) may each include a contactor including a relay. In some embodiments, the switches (121, 122) may each include an electrical switch such as a transistor. In some embodiments, the battery device (100) may further include a driving circuit (not shown) that drives the switches (121, 122) in response to a control signal from the processor (150). When the positive switch (121) and the negative switch (122) are closed, power can be supplied from the battery module (110) to the external device (10) or from the external device (10) to the battery module (110).

[0025] A battery monitoring circuit (130) is connected to a battery module (110) and is connected to each of a plurality of battery cells included in the battery module (110) to monitor the state of the battery cells (e.g., cell voltage) and / or the state of the battery module (110) (e.g., voltage, temperature and / or charge capacity of the battery module (110). In some embodiments, the battery monitoring circuit (130) may include a battery monitoring IC (BMIC) provided as an integrated circuit (IC).

[0026] A current measuring device (140) is connected to a resistor (141) installed in the path through which current flows in the battery module (110), and can measure the current flowing in the battery module (110) based on the voltage across the resistor (141). The current measuring device (140) may be called a current sensor, and the resistor (141) may be called a shunt resistor. In some embodiments, as shown in FIG. 1, the current measuring device (140) can measure the current flowing in the battery module (110) based on the voltage across the resistor (141) connected between the negative terminal of the battery module (110) and the negative link terminal (DC(-)) of the battery device (or one terminal of the negative switch (122). In some embodiments, the current measuring device (140) can measure the current flowing through the battery module (110) based on the voltage across a resistor (not shown) connected between the positive terminal of the battery module (110) and the positive link terminal (DC(+)) of the battery device (or one terminal of the positive switch (121).

[0027] The processor (150) can control the positive switch (121) and the negative switch (122). The processor (150) can electrically connect the battery device (100) and the external device (10) by closing the positive switch (121) and the negative switch (122). The processor (150) can electrically disconnect the battery device (100) and the external device (10) by opening the positive switch (121) and / or the negative switch (122). The processor (150) can receive information about the cell voltage and temperature measured from the battery monitoring circuit (130) and information about the current measured from the current measuring device (140). In some embodiments, the processor (150) may be a processing circuitry, for example, a microcontroller unit (MCU).

[0028] FIG. 2 is a drawing showing a current measuring device of a battery device according to a certain embodiment.

[0029] Referring to FIG. 2, a current measuring device (200) may be connected to a resistor (20) of a battery device. In some embodiments, the resistor (20) may be formed in a path through which current flows from a battery module (e.g., 110 in FIG. 1). In some embodiments, the resistor (20) may be connected between the negative terminal of the battery module (110) and the negative link terminal of the battery device (e.g., DC(-) in FIG. 1) (or one terminal of a negative switch (e.g., 122 in FIG. 1). In some embodiments, the resistor (20) may be connected between the positive terminal of the battery module (110) and the positive link terminal of the battery device (e.g., DC(+) in FIG. 1) (or one terminal of a positive switch (e.g., 121 in FIG. 1).

[0030] The current measuring device (200) may include an operational amplifier circuit (210), a comparison circuit (220), and a multiplexer (230).

[0031] The operational amplifier circuit (210) is connected to both terminals (N1, N2) of the resistor (20) and can receive the voltage of both terminals (N1, N2) as input. Multiple gains may be set in the operational amplifier circuit (210). In some embodiments, the multiple gains may include a first gain (or high gain) and a second gain (or low gain) that is lower than the first gain. The first gain may be used to measure the current in a low current range, and the second gain may be used to measure the current in a high current range. The operational amplifier circuit (210) can amplify the difference between the voltage of the first terminal (N1) and the voltage of the second terminal (N2) of the resistor (20) based on each of the multiple gains, and output multiple output voltages (VL, VH) amplified by each of the multiple gains. The voltage amplified in the operational amplifier circuit (210) may be given as a voltage obtained by multiplying the difference between the voltage at the first terminal (N1) and the voltage at the second terminal (N2) of the resistor (20) by each gain, for example. In some embodiments, the operational amplifier circuit (210) may output a first output voltage (VL) amplified based on a first gain to the difference between the voltage at the first terminal (N1) and the voltage at the second terminal (N2) of the resistor (20), and a second output voltage (VH) amplified based on a second gain to the difference between the voltage at the first terminal (N1) and the voltage at the second terminal (N2) of the resistor (20).

[0032] The comparison circuit (220) can output a selection signal (S1) indicating an output voltage to be selected from a plurality of output voltages (VL, VH) based on the magnitude of the current flowing through the resistor (20). In some embodiments, the comparison circuit (220) can determine the magnitude of the current flowing through the resistor (20) based on at least one output voltage among the plurality of output voltages of the operational amplifier circuit (210). That is, the comparison circuit (220) can output a selection signal (S1) based on the magnitude of at least one output voltage (e.g., a first output voltage (VL)) among the plurality of output voltages of the operational amplifier circuit (210). In some embodiments, the comparison circuit (220) can output a selection signal (S1) having a predetermined level when the magnitude of the first output voltage (VL) is higher than a first threshold voltage or lower than a second threshold voltage. When the current flowing through the resistor (20) belongs to the high current range, the first output voltage (VL) may be higher than the first threshold voltage or lower than the second threshold voltage, so the comparison circuit (220) can output a selection signal (S1) having a predetermined level.

[0033] The multiplexer (230) receives a plurality of output voltages (VL, VH) from the operational amplifier circuit (210) and can output one of the plurality of output voltages (VL, VH) as a measurement voltage (Vm) based on a selection signal (S1). In some embodiments, the multiplexer (230) can select an output voltage (Vm) among the plurality of output voltages (VL, VH) based on the level of the selection signal (S1). In some embodiments, the multiplexer (230) can select a first output voltage (VL) and output the first output voltage (VL) as a measurement voltage (Vm) when the selection signal (S1) does not have a predetermined level, and switch modes to select a second output voltage (VH) and output the second output voltage (VH) as a measurement voltage (Vm) when the selection signal (S1) has a predetermined level. The multiplexer (230) can switch between a mode for measuring current in a low current range and a mode for measuring current in a high current range in response to a selection signal (S1). The selection signal (S1) can be a mode switching signal.

[0034] The processor (240) can receive the output voltage output from the multiplexer (230) and determine the measured current. In some embodiments, the processor (240) can additionally receive a selection signal (S1). The processor (240) can determine the gain used in the current measuring device (200) based on the level of the selection signal (S1) and calculate the measured current based on the determined gain and the output voltage input from the multiplexer (230).

[0035] As explained above, the current measuring device (200) can measure the current using a high gain when the current flowing through the resistor (20) falls within a low current range, and measure the current using a low gain when the current flowing through the resistor (20) falls within a high current range. Thus, the problem of the output voltage of the current measuring device (200) being susceptible to noise or becoming too high can be resolved.

[0036] FIG. 3 is a diagram showing an operational amplifier circuit of a current measuring device according to a certain embodiment.

[0037] Referring to FIG. 3, the operational amplifier circuit (300) may include operational amplifiers (310, 320). In some embodiments, the operational amplifier circuit (300) may further include resistors (R1, R2, R3, R4, R5, R6, R7, R8).

[0038] The operational amplifier (310) has a positive input terminal, a negative input terminal, and an output terminal (OUT1), and the operational amplifier (320) may have a positive input terminal, a negative input terminal, and an output terminal (OUT2).

[0039] The negative input terminal of the operational amplifier (310, 320) can be connected to one terminal (or first terminal) (N1) of the resistor (30) to receive the voltage (V1) of the first terminal of the resistor (20). The positive input terminal of the operational amplifier (310, 320) can be connected to another terminal (or second terminal) (N2) of the resistor (30) to receive the voltage (V2) of the second terminal of the resistor (30). The operational amplifier (310) can be configured to have a first gain, and the operational amplifier (320) can be configured to have a second gain lower than the first gain. Then, the operational amplifier (310) can be used to measure the current in a low current range, and the operational amplifier (320) can be used to measure the current in a high current range. The operational amplifier (310) can output a first output voltage (VL) amplified based on a first gain of the voltage (V2-V1) between the two terminals (N1, N2) of the resistor (30) to an output terminal (OUT1), and the operational amplifier (320) can output a second output voltage (VH) amplified based on a second gain of the voltage (V2-V1) between the two terminals (N1, N2) of the resistor (30) to an output terminal (OUT2).

[0040] In some embodiments, the operational amplifier (310) may be connected in the form of a differential amplifier to have a first gain, and the operational amplifier (320) may be connected in the form of a differential amplifier to have a second gain. A resistor (R1) may be connected between the negative input terminal of the operational amplifier (310) and the first terminal (N1) of the resistor (30), a resistor (R2) may be connected between the negative input terminal of the operational amplifier (310) and the output terminal (OUT1) of the operational amplifier (310), a resistor (R3) may be connected between the positive input terminal of the operational amplifier (310) and the second terminal (N2) of the resistor (30), and a resistor (R4) may be connected between the positive input terminal of the operational amplifier (310) and a power supply (Vs1) that provides a predetermined voltage (Vs). Likewise, a resistor (R5) may be connected between the negative input terminal of the operational amplifier (320) and the first terminal (N1) of the resistor (30), a resistor (R6) may be connected between the negative input terminal of the operational amplifier (320) and the output terminal (OUT2) of the operational amplifier (320), a resistor (R7) may be connected between the positive input terminal of the operational amplifier (320) and the second terminal (N2) of the resistor (30), and a resistor (R8) may be connected between the positive input terminal of the operational amplifier (320) and a power supply (Vs2) that provides a predetermined voltage (Vs).

[0041] In some embodiments, the ratio of the resistance values ​​of resistors (R1, R2) (R2 / R1) and the ratio of the resistance values ​​of resistors (R3, R4) (R4 / R3) may be set to be the same. For example, the resistance values ​​of resistors (R1, R3) may be the same, and the resistance values ​​of resistors (R2, R4) may be the same. In some embodiments, the ratio of the resistance values ​​of resistors (R5, R6) (R6 / R5) and the ratio of the resistance values ​​of resistors (R7, R8) (R8 / R7) may be set to be the same. For example, the resistance values ​​of resistors (R5, R7) may be the same, and the resistance values ​​of resistors (R6, R8) may be the same. In this case, the output voltages (VL, VH) of the operational amplifiers (310, 320) may be given as Equations 1 and 2, respectively. Therefore, the gain (or first gain) of the operational amplifier (310) is given as R2 / R1, and the gain (or second gain) of the operational amplifier (320) can be given as R6 / R5.

[0042]

[0043]

[0044] In some embodiments, a predetermined voltage (Vs) may be set such that the output voltage (VL, VH) of the operational amplifiers (310, 320) has a positive value. For example, assume that the size of the resistor (R2) is 1 mΩ, the low current range is in the range of -20 A to 20 A, the high current range is in the range of -100 A to 100 A, the first gain (R2 / R1) is 100, and the second gain (R6 / R5) is 20. In this case, the predetermined voltage may be set to, for example, 2.5 V. Then, in the low current range, the first operational amplifier (310) can output an output voltage (VL) between 0.5 V and 4.5 V, and in the high current range, the second operational amplifier (320) can also output an output voltage (VH) between 0.5 V and 4.5 V.

[0045] FIG. 4 is a diagram showing a comparison circuit of a current measuring device according to a certain embodiment.

[0046] Referring to FIG. 4, the comparison circuit (400) may include comparators (410, 420).

[0047] The comparator (410) can compare the output voltage of one of the operational amplifiers included in the operational amplifier circuit with a reference voltage (or a first reference voltage) (Vref1). In some embodiments, the comparator (410) can receive the output voltage (VL) of the operational amplifier having a high gain among the operational amplifiers (e.g., 310 in FIG. 3). In some embodiments, the comparator (410) may have a positive input terminal for receiving the output voltage (VL) of the operational amplifier (310) and a negative input terminal for receiving the reference voltage (Vref1). The comparator (410) can compare the output voltage (VL) of the operational amplifier (310) with the reference voltage (Vref1) and output an output signal (C1) according to the comparison result to the output terminal. When the output voltage (VL) of the operational amplifier (310) is higher than the reference voltage (Vref1), the comparator (410) can output an output signal (C1) having a predetermined level. A predetermined level can be a high level, for example, as a logical level.

[0048] The comparator (420) can compare the output voltage of one of the operational amplifiers included in the operational amplifier circuit with a reference voltage (or a second reference voltage) (Vref2). The second reference voltage (Vref2) may be a voltage lower than the first reference voltage (Vref1). In some embodiments, the comparator (420) may receive the output voltage (VL) of the operational amplifier having a high gain among the operational amplifiers (e.g., 310 in FIG. 3). In some embodiments, the comparator (420) may have a negative input terminal for receiving the output voltage (VL) of the operational amplifier (310) and a positive input terminal for receiving the reference voltage (Vref2). The comparator (420) may compare the output voltage (VL) of the operational amplifier (310) with the reference voltage (Vref2) and output an output signal (C2) according to the comparison result to the output terminal. The comparator (420) can output an output signal (C2) having a predetermined level when the output voltage (VL) of the operational amplifier (310) is lower than the reference voltage (Vref2). The predetermined level may be, for example, a high level in logic level.

[0049] The comparison circuit (400) can output an output signal having a predetermined level (e.g., a high level) among the output signal (C1) of the comparator (410) and the output signal (C2) of the comparator (420) as a final output signal (i.e., a selection signal) (S1) at the output terminal (OUT). In some embodiments, to output an output signal having a predetermined level among the output signal (C1) of the comparator (410) and the output signal (C2) of the comparator (420) as a selection signal (S1), the comparison circuit (400) may further include diodes (D1, D2). The anode of diode (D1) may be connected to the output terminal of the comparator (410), and the anode of diode (D2) may be connected to the output terminal of the comparator (420). The cathode of diode (D1) and the cathode of diode (D2) may be connected to the output terminal (OUT) of the comparison circuit (400).

[0050] For example, the first reference voltage (Vref1) may be 4.5V and the second reference voltage (Vref2) may be 0.5V. In this case, referring to the example described above, when the current flowing through the resistor (e.g., 20 in FIG. 2) is greater than 20A, the output voltage (VL) of the operational amplifier (e.g., 310 in FIG. 3) becomes higher than 4.5V, so the comparator (410) can output an output signal (C1) having a predetermined level. Accordingly, the comparison circuit (400) outputs a selection signal (S1) having a predetermined level, and the multiplexer (e.g., 230 in FIG. 2) can output an output voltage (VH) of an operational amplifier (e.g., 320 in FIG. 3) having a low gain in response to the selection signal (S1). In addition, when the current flowing through the resistor (20) is less than -20A, the output voltage (VL) of the operational amplifier (310) becomes lower than 0.5V, so the comparator (420) can output an output signal (C2) having a predetermined level. Accordingly, the comparison circuit (400) outputs a selection signal (S1) having a predetermined level, and the multiplexer (230) can output an output voltage (VH) of the operational amplifier (320) having a low gain in response to the selection signal (S1). In this way, when the current falls into a high current range outside the range of -20A to 20A, the current can be measured through the operational amplifier (320) having a low gain.

[0051] FIG. 5 is a drawing showing a multiplexer of a current measuring device according to a certain embodiment.

[0052] Referring to FIG. 5, the multiplexer (500) may have a plurality of input terminals (IN1, IN2) that each receive the output voltages of a plurality of operational amplifiers included in the operational amplifier circuit, and an output terminal (OUT) that outputs a selected output voltage in response to a selection signal (S1) among the plurality of output voltages. Additionally, the multiplexer (500) may have a selection terminal (SE) that receives the selection signal (S1). In some embodiments, the input terminal (IN1) may receive the output voltage (VL) of an operational amplifier having high gain (e.g., 310 in FIG. 3), and the input terminal (IN2) may receive the output voltage (VH) of an operational amplifier having low gain (e.g., 320 in FIG. 3).

[0053] The multiplexer (500) may include a plurality of switches (510, 520). Switch (510) may be connected between an input terminal (IN1) and an output terminal (OUT), and switch (520) may be connected between an input terminal (IN2) and an output terminal (OUT). In some embodiments, the multiplexer (500) may further include a driver (530) that drives the switches (510, 520). The driver (530) may drive the switches (510, 520) in response to a selection signal (S1). In some embodiments, when the selection signal (S1) has a predetermined level (e.g., a high level), the driver (530) outputs a control signal to close the switch (520) and open the switch (510), and the multiplexer (500) may output an output voltage (VH) as a measurement voltage (Vm). When the selection signal (S1) does not have a predetermined level, the driver (530) outputs a control signal to open the switch (510) and close the switch (520), and the multiplexer (500) can output the output voltage (VL) as the measurement voltage (Vm).

[0054] FIG. 6 is a flowchart illustrating a current measurement method of a battery device according to some embodiment.

[0055] Referring to FIG. 6, a current measuring device can receive the voltage across the terminals of a shunt resistor (e.g., 141 in FIG. 1) formed in the path through which current flows from a battery module (e.g., 110 in FIG. 1) (S610). The current measuring device can generate a first output voltage corresponding to the current flowing through the resistor (141) by amplifying the voltage across the terminals of the resistor (141) based on a high gain (or a first gain) (S620). In some embodiments, the current measuring device can generate the first output voltage by amplifying the voltage across the terminals of the resistor (141) using a first operational amplifier having a high gain (S620). The current measuring device can generate a second output voltage corresponding to the current flowing through the resistor (141) by amplifying the voltage across the terminals of the resistor (141) based on a low gain (or a second gain) (S630). In some embodiments, the current measuring device may use a second operational amplifier with low gain to amplify the voltage across the ends of the resistor (141) to generate a second output voltage (S630).

[0056] When the first output voltage satisfies a predetermined condition (S640: Yes), the current measuring device may provide a second output voltage to a processor (e.g., 150 in FIG. 1) (S650). In some embodiments, the predetermined condition may include a condition in which the first output voltage is higher than a first reference voltage or lower than a second reference voltage. The second reference voltage may be a voltage lower than the first reference voltage.

[0057] While the current measuring device measures the current flowing through the resistor (141) based on the first output voltage, if the first output voltage satisfies a predetermined condition, the current flowing through the resistor (141) can be measured based on the first output voltage. In some embodiments, the current measuring device may provide a selection signal (or mode change signal) to the processor (150) indicating a mode for measuring current with a low-gain operational amplifier (or a mode for measuring current in a high-current range) (S650). If the output voltage of the high-gain operational amplifier does not satisfy a predetermined condition (S640: No), the current measuring device may provide the first output voltage of the high-gain operational amplifier to the processor (150) (S660). In some embodiments, the current measuring device may provide a selection signal (or mode change signal) to the processor (150) indicating a mode for measuring current with a high-gain operational amplifier (or a mode for measuring current in a low-current range) (S660).

[0058] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

Claims

1. A battery management system for a battery device comprising a battery module and a shunt resistor through which current flows of the battery module, wherein A first operational amplifier that amplifies the difference between the voltage at the first terminal of the shunt resistor and the voltage at the second terminal of the shunt resistor based on a first gain to output a first output voltage, A second operational amplifier that outputs a second output voltage by amplifying the difference between the voltage at the first terminal of the shunt resistor and the voltage at the second terminal of the shunt resistor based on a second gain lower than the first gain, A comparison circuit that outputs a selection signal by comparing the first output voltage with one or more reference voltages, and A multiplexer that selects one of the first output voltage and the second output voltage based on the above selection signal, and outputs the selected output voltage as a measured voltage corresponding to the current flowing through the shunt resistor. A battery management system including 2. In Paragraph 1, A battery management system further comprising a processor that receives the selection signal and the measurement voltage, and determines the current flowing through the shunt resistor based on the selection signal and the measurement voltage.

3. In Paragraph 2, The above processor is, When the above selection signal has a predetermined level, the current flowing through the shunt resistor is determined based on the second gain and the measured voltage, and If the above selection signal does not have the above predetermined level, the current flowing through the shunt resistor is determined based on the above first gain and the above measured voltage. Battery management system.

4. In Paragraph 1, The above one or more reference voltages include a first reference voltage and a second reference voltage lower than the first reference voltage, and The above comparison circuit is A first comparator that compares the first output voltage and the first reference voltage, and outputs a first output signal having a predetermined level as the selection signal in response to the first output voltage which is higher than the first reference voltage, and A second comparator that compares the first output voltage with the second reference voltage and outputs a second output signal having the predetermined level as the selection signal in response to the first output voltage being lower than the second reference voltage. A battery management system including 5. In Paragraph 4, A first diode having its anode connected to the output terminal of the first comparator, and It further includes a second diode whose anode is connected to the output terminal of the second comparator, and The cathode of the first diode and the cathode of the second diode are connected to the output terminal of the comparison circuit where the selection signal is output. Battery management system.

6. In Paragraph 1, The above multiplexer A first switch connected between a first input terminal and an output terminal to which the first output voltage is input, A second switch connected between a second input terminal to which the second output voltage is input and the output terminal, and A driver that drives the first switch and the second switch in response to the above selection signal A battery management system including 7. In Paragraph 1, A battery management system in which the first operational amplifier and the second operational amplifier are each connected in the form of a differential amplifier.

8. In Paragraph 1, A first resistor connected between the first terminal of the shunt resistor and the negative input terminal of the first operational amplifier, A second resistor connected between the negative input terminal of the first operational amplifier and the output terminal of the first operational amplifier, A third resistor connected between the second terminal of the shunt resistor and the positive input terminal of the first operational amplifier, A fourth resistor connected between the positive input terminal of the first operational amplifier and a power supply supplying a predetermined voltage, A fifth resistor connected between the first terminal of the shunt resistor and the negative input terminal of the second operational amplifier, A sixth resistor connected between the negative input terminal of the second operational amplifier and the output terminal of the second operational amplifier, A seventh resistor connected between the second terminal of the above shunt resistor and the positive input terminal of the above second operational amplifier, and An eighth resistor connected between the positive input terminal of the second operational amplifier and the power supply supplying the predetermined voltage. A battery management system that further includes 9. In Paragraph 8, The ratio of the resistance values ​​of the first resistor and the second resistor is the same as the ratio of the resistance values ​​of the third resistor and the fourth resistor, and The ratio of the resistance values ​​of the fifth resistor and the sixth resistor is the same as the ratio of the resistance values ​​of the seventh resistor and the eighth resistor. Battery management system.

10. Battery module, The shunt resistor through which current flows in the above battery module, A current measuring device that generates a first output voltage corresponding to a current flowing through a shunt resistor based on a first gain, generates a second output voltage corresponding to a current flowing through a shunt resistor based on a second gain different from the first gain, and selects one output voltage among a plurality of output voltages including the first output voltage and the second output voltage as a measurement voltage based on the first output voltage, and A processor that determines the current flowing through the shunt resistor based on the measured voltage of the current measuring device. A battery device including 11. In Paragraph 10, The above current measuring device An operational amplifier circuit that generates a first output voltage corresponding to the current flowing through the shunt resistor based on the first gain, and generates a second output voltage corresponding to the current flowing through the shunt resistor based on the second gain, A comparison circuit that generates a selection signal based on the result of comparing the first output voltage with one or more reference voltages, and A multiplexer that selects one of the plurality of output voltages as the measurement voltage based on the above selection signal A battery device including 12. In Paragraph 11, A battery device in which the second gain is lower than the first gain.

13. In Paragraph 11, The above operational amplifier circuit is A first operational amplifier that generates the first output voltage by amplifying the difference between the voltage at the first terminal of the shunt resistor and the voltage at the second terminal of the shunt resistor based on the first gain, and A second operational amplifier that generates the second output voltage by amplifying the difference between the voltage at the first terminal of the shunt resistor and the voltage at the second terminal of the shunt resistor based on the second gain. A battery device including 14. In Paragraph 11, The above one or more reference voltages include a first reference voltage and a second reference voltage lower than the first reference voltage, and The above comparison circuit is A first comparator that compares the first output voltage and the first reference voltage, and outputs a first output signal having a predetermined level as the selection signal in response to the first output voltage which is higher than the first reference voltage, and A second comparator that compares the first output voltage with the second reference voltage and outputs a second output signal having the predetermined level as the selection signal in response to the first output voltage being lower than the second reference voltage. A battery device including 15. In Paragraph 11, The above multiplexer When the above selection signal has a predetermined level, the second output voltage is selected as the output voltage, and If the above selection signal does not have the above predetermined level, the first output voltage is selected as the output voltage. Battery device.

16. In Paragraph 11, A battery device, wherein the processor receives the selection signal and the measurement voltage, and determines the current flowing through the shunt resistor based on the selection signal and the measurement voltage.

17. As a method for measuring the current of a battery device, A step of receiving the voltage of the first and second terminals of a shunt resistor formed in the current flow path of the battery module, A step of generating a first output voltage by amplifying the voltage between the first terminal and the second terminal based on the first gain, A step of generating a second output voltage by amplifying the voltage between the first terminal and the second terminal based on the first gain and a second gain different from the first gain, and When the first output voltage satisfies a predetermined condition, the step of measuring the current flowing through the resistor based on the second output voltage A power measurement method including 18. In Paragraph 17, A current measurement method further comprising the step of measuring the current flowing through the resistor based on the first output voltage when the first output voltage does not satisfy the predetermined condition.

19. In Paragraph 17, The above predetermined conditions include a condition in which the first output voltage is higher than the first reference voltage or lower than the second reference voltage, and The second reference voltage is lower than the first reference voltage Current measurement method.

Images