Battery pack

A battery pack may include: a plurality of cell stacks; a plurality of monitoring circuits configured to detect voltages of a plurality of cells included in a corresponding cell stack among the cell stacks; a plurality of current measurement circuits configured to measure current consumption of a corresponding monitoring circuit among the monitoring circuits; a plurality of current adjustment circuits configured to adjust a discharge current of a corresponding cell stack among the cell stacks; and a battery controller configured to receive a current consumption measurement result of the monitoring circuits from the current measurement circuits, to calculate current consumption deviation between the monitoring circuits based on the current consumption measurement result of the monitoring circuits, and to control the current adjustment circuits based on the current consumption deviation.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a National Phase Patent Application of International Patent Application Number PCT/KR2017/011603, filed on Oct. 19, 2017, which claims priority of Korean Patent Application No. 10-2016-0175833, filed Dec. 21, 2016. The entire contents of both of which are incorporated herein by reference.

TECHNICAL FIELD

An exemplary embodiment relates to a battery pack.

BACKGROUND ART

Recently, according to strengthening of environmental regulations including CO2regulations, interest in environmentally-friendly vehicles has been increasing. Accordingly, vehicle companies have been actively researching and developing pure electrical vehicles and hydrogen vehicles as well as hybrid and plug-in hybrid vehicles.

A high-voltage battery for storing electrical energy obtained from various energy sources is applied to the environmentally-friendly vehicles. The high-voltage battery needs to supply high-voltage electrical energy of 200 V to 800 V to an inverter to drive a driving motor of the vehicle. To this end, the high-voltage battery is configured to include a plurality of battery modules connected in series with each other.

A battery management system (BMS) for managing a high-voltage battery is mounted in a vehicle to which the high-voltage battery is applied. A cell balancing function which compensates a voltage deviation between cells constituting a battery module by monitoring the voltage of each of the cells is one of the main functions of the battery management system. The battery management system includes a monitoring circuit for monitoring a cell voltage for each battery module for cell balancing.

For efficient use of high-voltage batteries, it is also important to maintain battery balancing as well as cell balancing. A deviation of current consumption of a monitoring circuit for monitoring the cell voltage may cause a voltage imbalance between the battery modules. That is, since the monitoring circuit uses the entire voltage of the corresponding battery module for power, a deviation of current consumption between monitoring circuits may cause a voltage imbalance between the corresponding battery modules.

DISCLOSURE

Technical Problem

Exemplary embodiments have been made in an effort to provide a battery pack that minimizes a deviation of current consumption between monitoring circuits to minimize an imbalance between battery modules.

Technical Solution

An exemplary embodiment of the present invention provides a battery pack including: a plurality of cell stacks; a plurality of monitoring circuits configured to detect voltages of a plurality of cells included in a corresponding cell stack among the cell stacks; a plurality of current measurement circuits configured to measure current consumption of a corresponding monitoring circuit among the monitoring circuits; a plurality of current adjustment circuits configured to adjust a discharge current of a corresponding cell stack among the cell stacks; and a battery controller configured to receive a current consumption measurement result of the monitoring circuits from the current measurement circuits, to calculate current consumption deviation between the monitoring circuits based on the current consumption measurement result of the monitoring circuits, and to control the current adjustment circuits based on the current consumption deviation.

The battery pack may further include a plurality of current detection resistors respectively connected between the cell stacks and the monitoring circuits, and each of the measurement circuits may measure a current flowing through a corresponding current detection resistor among the current detection resistors and may output the measured current as a measured value of the current consumption.

Each of the monitoring circuits may include a voltage detection integrated circuit, and each of the current detection resistors may be connected between a corresponding one of the cell stacks and a power terminal of the voltage detection integrated circuit.

The current measurement circuits may be disposed within the voltage detection integrated circuit of a corresponding monitoring circuit among the monitoring circuits.

The current adjustment circuits may be disposed within the voltage detection integrated circuit of a corresponding monitoring circuit among the monitoring circuits.

The battery pack may further include a plurality of short-circuit switches respectively connected between the cell stacks and the monitoring circuits, and each of the short-circuit switches may be connected in parallel with a corresponding one of the current detection resistors.

The battery controller may control the short-circuit switches to be turned off during a period for measuring current consumption by using the current measurement circuits.

The battery controller may control the short-circuit switches to be turned on during a period for detecting cell voltages by using the monitoring circuits.

Each of current detection resistors may be connected between a negative terminal of a lowest potential cell among a plurality of cells included in a corresponding cell stack of the cell stacks and a ground terminal of a corresponding monitoring circuit of the monitoring circuits.

Each of the current adjustment circuits may include a plurality of resistors connected between opposite ends of a corresponding cell stack of the cell stacks, and a plurality of switches connected to corresponding resistors of the resistors to block or conduct current flows of the corresponding resistors.

The battery controller may adjust a discharge current of a corresponding cell stack of the cell stacks by adjusting a number of switches that are turned on among the switches.

Each of the current adjustment circuits may include a plurality of balancing resistors connected between a corresponding cell stack of the cell stacks and a corresponding monitoring circuit of the monitoring circuits, and a plurality of switches connected to corresponding balancing resistors of the balancing resistors to block or conduct current flows of the corresponding balancing resistors.

The battery controller may receive a cell voltage detection result for each of the cell stacks through the monitoring circuits, and may control cell balancing of each of the cell stacks by controlling the switches based on the cell voltage detection results.

The battery controller may turn on the switches included in a corresponding current adjustment circuit among the current adjustment circuits for a monitoring circuit having relatively small current consumption among the monitoring circuits.

The battery controller may control a turn-on duty of the switches included in each of the current adjustment circuits to adjust a current consumption amount of the current adjustment circuits.

An exemplary embodiment of the present invention provides a battery pack including: a cell stack configured to include a plurality of cells; a voltage detection integrated circuit electrically connected to the cells to detect cell voltages of the cells; a current measurement resistor connected between one of opposite ends of the cell stack and a power terminal of the voltage detection integrated circuit; a short-circuit switch connected in parallel with the current measuring resistor; a current measurement circuit configured to measure a current flowing in the current measurement resistor; a current adjustment circuit connected between opposite ends of the cell stack to adjust a discharge current of the cell stack; and a battery controller configured to control turn-on of the short-circuit switch, to receive a current measurement result from the current measurement circuit in a state where the short-circuit switch is turned off, and to control the current adjustment circuit based on the current measurement result.

Advantageous Effects

According to the exemplary embodiments, it is possible to minimize a deviation of current consumption between monitoring circuits to minimize imbalance between battery modules.

MODE FOR INVENTION

To clearly describe the exemplary embodiments, parts that are irrelevant to the description are omitted, and like numerals refer to like or similar constituent elements throughout the specification. Therefore, the reference numbers of the constituent elements used in a previous drawing may be used in a subsequent drawing.

Further, since sizes and thicknesses of constituent members shown in the accompanying drawings are arbitrarily given for better understanding and ease of description, the exemplary embodiments are not limited to the illustrated sizes and thicknesses. In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity.

A case of electrically connecting two constituent elements includes not only a case of directly connecting the constituent elements but also a case of connecting the constituent elements via another constituent element therebetween. The constituent element therebetween may include a switch, a resistor, a capacitor, and the like. In describing exemplary embodiments, an expression of connection indicates electrical connection unless explicitly described to be direct connection.

Hereinafter, a battery management system (BMS) according to exemplary embodiments and a battery pack including the same will be described in detail with reference to the drawings.

FIG. 1schematically illustrates a battery pack according to a first exemplary embodiment.FIG. 2schematically illustrates a battery module according to the first exemplary embodiment.FIG. 3,FIG. 4, andFIG. 5schematically illustrate battery modules according to second, third, and fourth exemplary embodiments, respectively.

Referring toFIG. 1, a battery pack100according to the first embodiment may include a plurality of battery modules101, a battery controller102, and a battery cut-off circuit103. Although a case where the battery pack100includes three battery modules101connected in series with each other is illustrated inFIG. 1as an example, the present invention is not limited thereto, and a number of the battery modules101included in the battery pack100may be changed depending on an exemplary embodiment.

Each of the battery modules101includes a cell stack110and a voltage detection integrated circuit (IC)120. Each of the battery modules101may further include a monitoring circuit130such as a temperature sensor in addition to the voltage detection IC120.

Each cell stack110may include a plurality of cells111electrically connected to each other. Although a case where one cell stack includes a plurality of cells111connected in series with each other is illustrated inFIG. 1as an example, the present invention is not limited thereto. According to another exemplary embodiment, a plurality of cells connected in parallel constitute a cell group, and a plurality of cell groups may be connected in series to constitute one cell stack.

The voltage detection IC120is a monitoring circuit for monitoring a voltage of the corresponding cell stack110. The voltage detection IC120may perform a function of detecting a cell voltage of each of the cells111included in the corresponding cell stack110. In addition, the voltage detection IC120may perform a function of detecting a total voltage of the corresponding cell stack110. To this end, the voltage detection IC120may include a voltage detection circuit (not illustrated) for voltage detection. In this document, the voltage detection IC may include an analog front end (AFE) IC having a cell voltage detection function, a cell voltage monitoring (CVM) IC, and the like.

The voltage detection IC120may control cell balancing of the corresponding cell stack110. The cell balancing is a function of equalizing the cell voltages between the cells111included in one cell stack110. The battery module101includes balancing resistors (not illustrated) connected to each of the cells that constitute the cell stack110for cell balancing. The cell balancing of the battery module101may be controlled by conducting or blocking bypass currents of the respective balancing resistors by cell balancing switches (not illustrated) disposed inside the voltage detection IC120.

The voltage detection IC120may be connected to a corresponding cell stack110through power terminals VCC and GND, to receive an operation power from the cell stack110. The power terminals VCC and GND of the voltage detection IC120are electrically connected to corresponding terminals of opposite ends of the cell stack110. For example, the power terminal VCC may be connected to a positive terminal of a highest potential cell among the cells included in the corresponding cell stack110, and the ground power terminal GND may be connected to a negative terminal of a lowest potential cell among the cells included in the corresponding cell stack110.

Each battery module101may include a current measurement resistor R1for current measurement. The current measurement resistor R1may be disposed on a path through which a current supplied from the cell stack110to the voltage detection IC120and the monitoring circuit130flows. For example, the current measurement resistor R1may be disposed on a current path between the negative terminal of the lowest potential cell among the cells included in the corresponding cell stack110and ground terminals of the voltage detection IC120and the monitoring circuit130. In this case, the current measurement resistor R1may be electrically connected between a negative power terminal of the voltage detection IC120, i.e., the ground terminal GND, and the negative terminal of the lowest potential cell among the plurality of cells included in the corresponding cell stack110.

The voltage detection IC120may measure current consumption of the corresponding battery module101, and may adjust the current consumption of the corresponding battery module101under the control of the battery controller102.

Referring toFIG. 2, the voltage detection IC120may include a current measurement circuit.

The current measurement circuit may include a current monitoring circuit121and an analog-to-digital converter (ADC)122.

The current monitoring circuit121is electrically connected to opposite ends of the current measurement resistor R1through current measurement terminals IS0and IS1to measure a current flowing through the current measurement resistor R1.

A voltage between the opposite ends of the current measurement resistor R1is proportional to the current flowing in the current measurement resistor R1. Therefore, the current monitoring circuit121may output a corresponding voltage value of the current flowing through the current measurement resistor R1as a measured value. Since the current measurement resistor R1is disposed on a path through which a current bypassing the monitoring circuit (the voltage detecting IC120and the monitoring circuit130) flows, the measured value of the current monitoring circuit121may be a value corresponding to a current consumed in the detection IC120and the monitoring circuit130.

The ADC122converts a measurement result of the current monitoring circuit121into a digital value and outputs it.

The voltage detection IC120may further include a current adjustment circuit125.

The current regulating circuit125may adjust the current consumption of the voltage detection IC120by increasing or decreasing a current path between the power terminals VCC and GND of the voltage detection IC120.

The current adjustment circuit125may include a plurality of current adjustment resistors R11, R12, R13, and R14that are connected in parallel between the power terminals VCC and GND of the voltage detection IC120. The current adjustment circuit125also includes a plurality of switches S11, S12, S13, and S14connected between the current adjustment resistors R11, R12, R13, and R14and a power terminal (e.g., a ground terminal GND). The switches S11, S12, S13, and S14are used for conducting or blocking the connection between the corresponding resistors R11, R12, R13, and R14and the power terminal (e.g., ground terminal GND). Each of the switches S11, S12, S13, and S14is turned on/off by the control of the battery controller102.

As a number of switches turned on in the switches S11, S12, S13, and S14increases, a number of resistors connected in parallel between the power terminals VCC and GND of the voltage detection IC120increases. Therefore, the current path between the power terminals VCC and GND may be increased or decreased by the turn-on/turn-off control of the switches S11, S12, S13, and S14, thereby adjusting the current consumption in the voltage detection IC120. As the current consumed by the voltage detection IC120is adjusted, a discharge current of the cell stack110may be correspondingly adjusted.

Although a case where four current adjustment resistors are connected in parallel between the power terminals VCC and GND of the voltage detection IC120is illustrated inFIG. 2as an example, the present invention is not limited thereto, and a number of the current adjustment resistors connected in parallel between the power terminals VCC and GND of the voltage detection IC120may be changed.

The voltage detection IC120may include a register123and a transceiver124for communicating with the battery controller102.

The register123may record an output value of the ADC122to transfer it to the battery controller102through the transceiver124.

In addition, when control information of the switches S11, S12, S13, and S14constituting the current adjustment circuit125is received from the battery controller102through the transceiver124, the register123may control the turn-on/turn-off of the switches S11, S12, S13, and S14based on the received control information.

Referring again toFIG. 1, the transceiver124of each voltage detecting IC120may communicate with another voltage detecting IC by a daisy chain method, and may communicate with the battery controller102through a daisy chain interface.

The battery controller102constitutes a battery management system (BMS) of the battery pack100together with the monitoring circuit (the voltage detection IC120and the monitoring circuit130) of each battery module101.

The battery controller102may receive a cell voltage detection result from each voltage detection IC120to control cell balancing of each battery module101based on the result. In addition, the battery controller102may receive a total voltage of the corresponding cell stack110from each voltage detection IC120to control balancing between the battery modules101based on the total voltage.

The battery controller102may control the battery cut-off circuit103for controlling charge/discharge of the battery pack100based on a cell voltage detection result of each voltage detection IC120.

The battery controller receives a current consumption measurement result of the corresponding battery101, i.e., a current consumption measurement result of the monitoring circuit including the voltage detection IC120from each voltage detection IC120to calculate a current consumption deviation between the battery modules101(a current consumption deviation between the monitoring circuits) based on the received result.

The battery controller102may control the current adjustment circuit125of each voltage detection IC120based on the current consumption deviation between the battery modules101, so as to eliminate a current consumption imbalance between the battery modules101. For example, the battery controller102may control the current adjustment circuit125in the corresponding voltage detection IC120to increase current consumption for the battery module101with relatively small current consumption.

Although a case where the current measurement resistor R1is connected to the negative electrode of the lowest potential cell among the cells included in the corresponding cell stack110is illustrated inFIG. 1andFIG. 2as an example, the present invention is not limited thereto. For example, referring toFIG. 3, the current measurement resistor R1may be connected to the positive electrode of the highest potential cell among the cells included in the corresponding cell stack110. In this case, the current measurement resistor R1may be electrically connected between the positive power terminal VCC of the voltage detection IC120and the positive terminal of the highest potential cell among the cells included in the corresponding cell stack110, to be disposed on a path through which a current outputted from the cell stack110is supplied to the monitoring circuit (the voltage detection IC120and the monitoring circuit130).

Although a case where the current measuring circuit is disposed inside each voltage detection IC is illustrated inFIG. 1andFIG. 2, the present invention is not limited thereto. According to another exemplary embodiment, at least a portion of the current measurement circuit may be disposed outside the voltage detection IC120. For example, referring toFIG. 4, the current monitoring circuit121of the current measurement circuit may be disposed outside the voltage detecting IC120. In this case, the current monitoring circuit121may measure a voltage between opposite ends of the current measurement resistor R1to correspond to the current flowing in the current measurement resistor R1to transfer it to the ADC122in the voltage detection IC120. In addition, for example, both the current monitoring circuit121and the ADC122may be disposed outside the voltage detection IC120. In this case, the measurement result of the current measurement circuit may be directly transferred to the battery controller102without passing through the voltage detection IC120.

In the meantime, when the current measurement resistor R1is connected to the negative electrode of the lowest potential cell among the cells included in the corresponding cell stack110, a reference potential of the voltage detection IC120may be varied, thereby affecting the voltage detection result of the voltage detection IC. Therefore, as illustrated inFIG. 5, the battery module101may further include a short-circuit switch S15for controlling the connection between the current measurement resistor R1and the cell stack110. Referring toFIG. 5, the short-circuit switch S15is connected in parallel with the current measurement resistor R1between the power terminal GND of the voltage detection IC120and the cell stack110. The short-circuit switch S15is turned on or off depending on a control command of the battery controller102transferred through the voltage detecting IC120. The battery controller102turns on the short-circuit switch S15to short-circuit opposite ends of the current measurement resistor R1so as to enable stable voltage detection during a period during which no current consumption is measured or a voltage detection period. When the current consumption needs to be measured, the battery controller102turns off the short-circuit switch S15so that a consumption current flows through the current measurement resistor R1.

Although a case where a separate current adjustment circuit is provided inside the voltage detection IC120to adjust the current consumption of the battery module is illustrated inFIG. 1toFIG. 5, the present invention is not limited thereto.

According to another exemplary embodiment, a battery balancing circuit of each battery module may be used to eliminate the current deviation between battery modules.

FIG. 6illustrates a schematic view of a battery pack according to a fifth exemplary embodiment, showing a case where current consumption of the battery module is adjusted by using a cell balancing circuit.FIG. 7schematically illustrates a battery module according to the fifth exemplary embodiment. Hereinafter, the same or similar constituent elements as those of the above-described battery pack100among constituent elements of the battery pack200will not be described in detail.

Referring toFIG. 6, a battery pack200according to the fifth embodiment may include a plurality of battery modules201, a battery controller202, and a battery cut-off circuit203.

Each of the battery modules201includes a cell stack210, a plurality of balancing resistors Rb, and a voltage detection IC220. Each of the battery modules201may further include a monitoring circuit230such as a temperature sensor in addition to the voltage detection IC220.

Each cell stack210may include a plurality of cells211electrically connected to each other.

The balancing resistors Rb may be connected between the corresponding cell and the voltage detection IC220to serve to discharge the corresponding cells.

The voltage detection IC220may serve to detect a cell voltage of each of the cells211included in the corresponding cell stack210, and a total voltage of the corresponding cell stack210through a voltage detection circuit (not illustrated).

The voltage detection IC220may control cell balancing between the cells211included in the corresponding cell stack210. The voltage detecting IC220may control the cell balancing of the corresponding cell stack210by conducting or blocking a current flowing through the corresponding balancing resistors Rb.

The voltage detection IC220is connected to the corresponding cell stack210through power terminals VCC and GND, to receive operation power from the cell stack210. The power terminal VCC of the voltage detection IC220may be connected to a positive terminal of a highest potential cell among the cells included in the corresponding cell stack210, and the power terminal GND may be connected to a negative terminal of a lowest potential cell among the cells included in the corresponding cell stack210.

Each battery module201may include a current measurement resistor R2for current measurement. The current measurement resistor R2may be disposed on a path through which a current supplied from the cell stack210to the monitoring circuit (the voltage detection IC220and the monitoring circuit230) flows. For example, the current measurement resistor R2may be disposed on a current path that is connected between the negative terminal of the lowest potential cell among the cells included in the corresponding cell stack210and ground terminals of the monitoring circuit (the voltage detection IC220and the monitoring circuit230). In this case, the current measurement resistor R2, as illustrated inFIG. 6, may be electrically between a negative power terminal of the voltage detection IC220, i.e., the ground terminal GND, and the negative terminal of the lowest potential cell among the plurality of cells included in the corresponding cell stack210. However, the present invention is not limited thereto, and the current measurement resistor R2may be electrically connected between the positive power terminal VCC of the voltage detection IC220and the positive terminal of a highest potential cell among the cells included in the corresponding cell stack210.

The voltage detection IC220may measure current consumption of the corresponding battery module201, and may adjust the current consumption of the corresponding battery module201under the control of the battery controller202.

Referring toFIG. 7, the voltage detection IC220may include a current measurement circuit. The current measurement circuit may include a current monitoring circuit221and an ADC222.

The current monitoring circuit221is electrically connected to opposite ends of the current measurement resistor R2through current measurement terminals IS0and IS1to measure a current flowing through the current measurement resistor R2. Since the current measurement resistor R2is disposed on a path through which a current bypassing the monitoring circuit (the voltage detecting IC220and the monitoring circuit230) flows, the measured value of the current monitoring circuit221may be a value corresponding to a current consumed in the detection IC220and the monitoring circuit230.

The ADC222converts a measurement result of the current monitoring circuit221into a digital value and outputs it.

The voltage detection IC220may include a plurality of cell balancing switches S2. Each of cell balancing switches S2may be connected between opposite ends of a corresponding cell to block or conduct a current path through the corresponding balancing resistor Rb under the control of the battery controller202.

The battery balancing switches S2and the balancing resistors Rb may also be used as a current control circuit for controlling the current consumption of the battery module201under the control of the battery controller202. When the cell balancing switches S2are turned on, the current path between the cell stack210and the voltage detection IC220increases, which increases the current consumption of the battery module201, resulting in an increase in a discharge current of the cell stack210. Therefore, unlike in the battery pack100ofFIG. 1, the current consumption of the battery module201may be adjusted by using the cell balancing switches S2and the balancing resistors Rb without providing a separate current adjustment circuit.

The voltage detection IC220may include a register223and a transceiver224for communicating with the battery controller202.

The register223may record an output value of the ADC222to transfer it to the battery controller202through the transceiver224.

In addition, when control information of the cell balancing switches S2constituting a current adjustment circuit is received from the battery controller202through the transceiver224, the register223may control the turn-on/turn-off of the cell balancing switches S2based on the received control information.

Referring toFIG. 6again, the battery controller202may receive a cell voltage detection result from each voltage detection IC220to control cell balancing of each battery module201by controlling the cell balancing switches S2based on the result. In addition, the battery controller202may receive a total voltage of the corresponding cell stack210from the voltage detection IC220to control balancing between the battery modules201based on the total voltage.

The battery controller202may control the battery cut-off circuit203for controlling charge/discharge of the battery pack200based on a cell voltage detection result of each voltage detection IC220.

The battery controller202may receive a current consumption measurement value of the corresponding battery module201from each voltage detection IC220to calculate a consumption current deviation between the battery modules201based on the measured consumption current values. The battery controller202may control the cell balancing switches S2based on the current consumption deviation between the battery modules201, so as to eliminate current consumption imbalance between the battery modules201. For example, the battery controller202may conduct a current path of the corresponding balancing resistors Rb to increase current consumption for the battery module201with relatively small current consumption.

The battery controller202may adjust current consumption by simultaneously turning on all the corresponding cell balancing switches S2for the battery module201requiring current consumption adjustment in order to minimize an influence of current consumption adjustment using the balancing resistors Rb on cell balancing. The battery controller202may adjust current consumption of each battery module201by calculating a discharge amount of each battery module201based on a current consumption deviation between the battery modules201and controlling turn-on duty of the cell balancing switches S2included in each battery module201based on the calculated discharge amount.

The battery pack200having the above-described structure may prevent balance collapse between the battery modules201by measuring the current consumption of the battery modules201and controlling the current consumption between the battery modules201to be equalized based on the measured current consumption. In addition, the current consumption may be equalized without any additional cost since the current consumption between the battery modules201is equalized by using the balancing resistors Rb and the cell balancing switches S2without a separate current adjustment circuit.

According to another exemplary embodiment, each battery module may include a separate current control circuit provided outside the voltage detection IC, thereby eliminating current consumption deviation between the battery modules.

FIG. 8illustrates a schematic view of a battery pack according to a sixth exemplary embodiment, showing a case where current consumption of the battery module is adjusted by using a separate current adjustment circuit provided outside a voltage detection IC.FIG. 9schematically illustrates a battery module according to the sixth exemplary embodiment. Hereinafter, the same or similar constituent elements as those of the battery pack100according to the aforementioned first exemplary embodiment among constituent elements of a battery pack300according to the sixth exemplary embodiment will not be described in detail.

Referring toFIG. 8, the battery pack300according to the sixth embodiment may include a plurality of battery modules301, a battery controller302, and a battery cut-off circuit303.

Each of the battery modules301includes a cell stack310, a voltage detection IC320, and a current adjustment circuit340. Each of the battery modules301may further include a monitoring circuit330such as a temperature sensor in addition to the voltage detection IC320.

Each cell stack310may include a plurality of cells311electrically connected to each other.

The voltage detection IC320may serve to detect a cell voltage of each of the cells311included in the corresponding cell stack310and a total voltage of the corresponding cell stack310through a voltage detection circuit (not illustrated).

The voltage detection IC320may control cell balancing between the cells311included in the corresponding cell stack310. The voltage detection IC320may control cell balancing by conducting or blocking a bypass current of the balancing resistor (not illustrated) connected to each of the cells311.

The voltage detection IC320is connected to the cell stack310through power terminals VCC and GND, to receive operation power from the cell stack310.

Each battery module301may include a current measurement resistor R2for current measurement. The current measurement resistor R3may be disposed on a path through which a current supplied from the cell stack310to the voltage detection IC320and the monitoring circuit330flows. For example, the current measurement resistor R3may be disposed on a current path that is connected between the negative terminal of the lowest potential cell among the cells included in the corresponding cell stack310and ground terminals of the voltage detection IC320and the monitoring circuit330. In this case, the current measurement resistor R3, as illustrated inFIG. 8, may be electrically connected between a negative power terminal of the voltage detection IC320, i.e., the ground terminal GND, and the negative terminal of the lowest potential cell among the plurality of cells included in the corresponding cell stack310. However, the present invention is not limited thereto, and the current measurement resistor R3may be electrically connected between the positive power terminal VCC of the voltage detection IC320and the positive terminal of a highest potential cell among the cells included in the corresponding cell stack310.

The voltage detection IC320may measure current consumption of the corresponding battery module301.

Referring toFIG. 9, the voltage detection IC320may include a current measurement circuit. The current measurement circuit may include a current monitoring circuit321and an ADC322.

The current monitoring circuit321is electrically connected to opposite ends of the current measurement resistor R3through current measurement terminals IS0and IS1to measure a current flowing through the current measurement resistor R3. Since the current measurement resistor R3is disposed on a path through which a current bypassing the monitoring circuit (the voltage detecting IC320and the monitoring circuit330) flows, the measured value of the current monitoring circuit321may be a value corresponding to a current consumed in the detection IC320and the monitoring circuit330.

The ADC322converts a measurement result of the current monitoring circuit321into a digital value and outputs it.

The voltage detection IC320may include a register323and a transceiver324for communicating with the battery controller302.

The register323may record an output value of the ADC322to transfer it to the battery controller302through the transceiver324.

In addition, when control information of the switches S31, S32, S33, and S34constituting the current adjustment circuit340is received from the battery controller302through the transceiver324, the register323may control the turn-on/turn-off of the switches S31, S32, S33, and S34based on the received control information.

The current adjustment circuit340may serve to adjust the current consumption of the corresponding battery module301under the control of the battery controller302.

The current adjustment circuit340may include a plurality of current adjustment resistors R31, R32, R33, and R34connected in parallel between the power terminals VCC and GND of the corresponding cell stack310. The current adjustment circuit340may further include a plurality of switches S31, S32, S33, and S34connected between the respective current adjustment resistors R31, R32, R33, and R34and the corresponding cell stack310. The switches S31, S32, S33, and S34are used for conducting or blocking a current path of the corresponding resistors R31, R32, R33, and R34. Each of the switches S31, S32, S33, and S34is controlled to be turned on/off by a control command of the battery controller302transferred through the voltage detection IC320.

As the plurality of switches S31, S32, S33, and S34are turned on or off, a current discharged by the current adjustment circuit340may be reduced, and thus a current consumed by the current adjustment circuit340may be adjusted.

Referring toFIG. 8again, the battery controller302may receive a cell voltage detection result from each voltage detection IC320to control cell balancing of the corresponding cell stack310based on the result310. In addition, the battery controller302may receive a total voltage of the corresponding cell stack310from the voltage detection IC320to control balancing between the cell stacks310based on the total voltage.

The battery controller302may control the battery cut-off circuit303for controlling charge/discharge of the battery pack300based on a cell voltage detection result of each voltage detection IC320.

The battery controller302may receive a current consumption measurement value of the corresponding battery module301from each voltage detection IC320to control the current adjustment circuit340based on the measured consumption current values such that current a consumption imbalance between the battery modules301is eliminated.

For example, the battery controller302may increase or decrease a current path inside the corresponding current adjustment circuit340to adjust the current consumption for the battery module301requiring adjustment of the current consumption. As a number of switches that are turned on among the switches S31, S32, S33, and S34of the current adjusting circuit340increases, a number of resistors connected to the corresponding cell stack310increases. As a result, a current path of the current adjusting circuit340through which a current discharged from the cell stack310flows increases, and thus the current consumption of the battery module301also increases.

In addition, for example, the battery controller302may adjust a discharge time of the corresponding current adjustment circuit340to adjust the current consumption for the battery module301requiring adjustment of the current consumption. In this case, the battery controller302calculates the discharge amount of each battery module301on the basis of the current consumption deviation between the battery modules301. Turn-on times of the switches S31, S32, S33, and S34constituting the current adjustment circuit340may be adjusted based on the calculated discharge amount to eliminate the current consumption imbalance between the battery modules301.

Although a case where the current measurement resistors are used for measuring the current consumption of the battery modules is illustrated as an example in the aforementioned exemplary embodiments, the present invention is not limited thereto, and the current measurement circuit used to measure the current consumption of the battery modules may be replaced by another circuit capable of current detection.

According to the aforementioned exemplary embodiments, the battery management system may prevent balance collapse between the battery modules by measuring the current consumption of the battery modules and controlling the current consumption between the battery modules to be equalized based on the measured current consumption.

While exemplary embodiments of the present invention have been particularly shown and described with reference to the accompanying drawings, the specific terms used herein are only for the purpose of describing the invention and are not intended to define the meanings thereof or be limiting of the scope of the invention set forth in the claims. Therefore, those skilled in the art will understand that various modifications and other equivalent embodiments of the present invention are possible. Consequently, the true technical protective scope of the present invention must be determined based on the technical spirit of the appended claims.

DESCRIPTION OF SYMBOLS

100,200,300: battery pack

101,201,301: battery module

102,202,302: battery controller

110,210,310: cell stack

120,220,320: voltage detection IC

121,221,321: current monitoring circuit

125,340: current adjustment circuit

130,230,330: monitoring circuit