Patent Description:
In addition, various studies are being conducted to efficiently control the charging and discharging of a battery and reducing the risk of explosion of the battery. Patent Literature <NUM> discloses a battery pack capable of delaying damage, ignition and explosion caused by thermal runaway of a battery by operating a battery balancing circuit when a discharge switch provided to the battery pack malfunctions.

In Patent Literature <NUM>, since the battery is discharged by operating the balancing circuit, it is possible to temporarily prevent accidents caused by battery overcharge. However, since the battery is continuously used inside the battery pack, there is a problem that the same problem may recur again.

Further examples of background art can be found in <CIT>, <CIT>, <CIT>, and <CIT>.

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing an apparatus and method for detecting a defect of a battery pack, which may disconnect a battery cell at which a defect is detected inside a battery pack to remove a risk factor that may occur from the corresponding battery cell.

In accordance with the independent claim <NUM>, there is provided an apparatus for detecting a defect of a battery pack including at least one battery cell, comprising: a fuse having one end connected to a first terminal of the battery cell in series and the other end connected to an electrode terminal of the battery pack; a monitoring unit configured to measure at least one of voltage, current and temperature of the battery cell and determine whether the fuse is cut or not; a discharge line including a discharge resistor having one end connected to the first terminal of the battery cell in parallel, and a discharge switch having one end connected to a second terminal of the battery cell and the other end connected to the other end of the discharge resistor; and a control unit configured to receive a measurement result measured by the monitoring unit and a determination result on whether the fuse is cut is not, estimate a state of charge (SOC) of the battery cell based on the received measurement result, determine based on the received measurement result and the estimated SOC whether a state of the battery cell is a normal state or a defective state, and control an operation state of the discharge switch to a turn-on state or a turn-off state according to the determined state of the battery cell and the determination result on whether the fuse is cut or not.

The fuse may be configured to be cut when the operation state of the discharge switch is a turn-on state.

The control unit may be configured to determine that the state of the battery cell is a defective state and control the operation state of the discharge switch to a turn-on state, when the battery cell is determined based on the measurement result as being in at least one of an overcharge state and a high-temperature state higher than or equal to a threshold temperature.

In another aspect of the present disclosure, the apparatus for detecting a defect of a battery pack may further comprise a cooling unit connected on the discharge line in series and configured to be operated to lower the temperature of the battery cell while the operation state of the discharge switch is being controlled to a turn-on state by the control unit.

The control unit may be configured to control the operation state of the discharge switch to a turn-off state, when the fuse is cut and the SOC of the battery cell is lower than or equal to a preset lower limit value.

The control unit may be configured to control the operation state of the discharge switch to a turn-on state, when the SOC of the battery cell is higher than or equal to a preset upper limit value after the fuse is determined as being cut.

As also defined in the independent claim <NUM>, the apparatus for detecting a defect of a battery pack further comprises:.

The discharge resistor may be configured to have a resistance smaller than that of the cut-off resistor.

The control unit may be configured to control the operation state of the main switch to a turn-off state, when the state of the battery cell is determined as a defective state.

In still another aspect of the present disclosure, the apparatus for detecting a defect of a battery pack may further comprise an ammeter provided between one end of the discharge resistor and a line to which one end of the fuse and the first terminal of the battery cell are connected and configured to measure a current flowing in the discharge resistor.

The monitoring unit may be configured to determine that the fuse is cut, when the current value measured by the ammeter is higher than or equal to a predetermined threshold value.

The control unit may be configured to control the operation state of the main switch to a turn-on state, when the fuse is determined by the monitoring unit as being cut, even though the state of the battery cell is determined as a normal state.

In still another aspect of the present disclosure, the apparatus for detecting a defect of a battery pack may further comprise a fuse cutting module connected to the control unit and configured to cut the fuse by including at least one of a heating unit for generating heat, a current applying unit for applying a current to the fuse and a cutting unit for cutting the fuse when a cutting control signal is received from the control unit.

The control unit may be configured to output the cutting control signal, when the fuse is not cut and the state of the battery cell is determined as a defective state.

The battery pack may include a plurality of battery cells.

The fuse may be configured to be connected to the first terminal of a corresponding battery cell among the plurality of battery cells included in the battery pack.

The discharge line may be configured to be connected to each corresponding battery cell among the plurality of battery cells.

In still another aspect of the present disclosure, the apparatus for detecting a defect of a battery pack may further comprise a bypass switch connected to each corresponding battery cell among the plurality of battery cells in parallel and configured such that an operation state of the bypass switch is controlled to a turn-off state or a turn-on state by the control unit.

The control unit may be configured to select a battery cell, which is determined as in a defective state or as a fuse corresponding thereto is cut, among the plurality of battery cells as a target cell, control the operation state of the discharge switch included in the discharge line corresponding to the selected target cell to a turn-on state or a turn-off state according to the state of the selected target cell, and control the operation state of the bypass switch connected to the target cell in parallel to a turn-on state.

In still another aspect of the present disclosure, there is also provided a battery pack, comprising the apparatus for detecting a defect of a battery pack according to an aspect of the present disclosure.

In still another aspect of the present disclosure, there is also provided a method for detecting a defect of a battery pack, comprising: a measuring step of measuring at least one of voltage, current and temperature of a battery cell; a cutting determining step of determining whether a fuse is cut or not; a battery cell state determining step of determining a state of the battery cell as a normal state or a defective state based on the measurement result measured in the measuring step; and a discharge switch operation controlling step of controlling an operation state of a discharge switch to a turn-on state or a turn-off state according to the determined state of the battery cell and the determination result on whether the fuse is cut or not.

According to the present disclosure, there is an advantage that risk factors that may cause explosions can be eliminated by discharging the battery cell at which a defect is detected.

In addition, according to the present disclosure, there is an advantage that the recurrence of the risk factor can be prevented in advance by disconnecting the battery cell at which the defect is detected from the battery pack.

In addition, according to the present disclosure, since information on the battery cell disconnected from the battery pack since a defect is detected is provided, there is an advantage that the battery cell at which the defect is detected can be very easily identified and exchanged.

Furthermore, the term "control unit" described in the specification refers to a unit that processes at least one function or operation, and may be implemented by hardware, software, or a combination of hardware and software.

Hereinafter, a preferred embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

<FIG> is a diagram schematically showing an exemplary configuration of an apparatus for detecting a defect of a battery pack.

Referring to <FIG>, the apparatus for detecting a defect of a battery pack may include a fuse <NUM>, a monitoring unit <NUM>, a discharge line <NUM>, and a control unit <NUM>. Here, the battery pack may include at least one battery cell <NUM>. For example, if the battery pack includes a plurality of battery cells <NUM>, the plurality of battery cells <NUM> may be connected in series and/or in parallel. Hereinafter, a case in which one battery cell <NUM> is included in the battery pack will be described.

One end of the fuse <NUM> may be connected in series to a first terminal of the battery cell <NUM>. Here, the first terminal of the battery cell <NUM> may be a positive electrode terminal or a negative electrode terminal, and the second terminal may be a terminal having a polarity opposite to the first terminal. That is, one end of the fuse <NUM> may be connected to any one of a positive electrode terminal and a negative electrode terminal of the battery cell <NUM>. Hereinafter, for convenience of explanation, the first terminal of the battery cell <NUM> will be described as a positive electrode terminal, and the second terminal will be described as a negative electrode terminal. For example, in <FIG>, one end 20b of the fuse <NUM> may be connected to the positive electrode terminal of the battery cell <NUM>.

The other end of the fuse <NUM> may be configured to be connected to an electrode terminal of the battery pack. Here, the electrode terminal of the battery pack to which the other end of the fuse <NUM> is connected may be a terminal having the same polarity as the first terminal of the battery cell <NUM> to which one end of the fuse <NUM> is connected. For example, in <FIG>, one end 20b of the fuse <NUM> may be connected to the first terminal of the battery cell <NUM>, and the other end 20a of the fuse <NUM> may be connected to the positive electrode terminal (P+) of the battery pack.

The fuse <NUM> included in the apparatus for detecting a defect of a battery pack may be fused to cut its wiring when overcurrent flows, or may be cut when a certain level of heat is introduced thereto.

The monitoring unit <NUM> may measure at least one of voltage, current and temperature of the battery cell <NUM>.

For example, referring to <FIG>, the monitoring unit <NUM> may be connected to the battery cell <NUM> through a plurality of sensing lines SL1 and SL2. The monitoring unit <NUM> may measure the voltage of the battery cell <NUM> by measuring the voltage at both ends of the battery cell <NUM> through the plurality of sensing lines SL1 and SL2 and calculating the difference between the measured voltages at both ends of the battery cell <NUM>. In addition, the monitoring unit <NUM> may measure the temperature of the battery cell <NUM> through a temperature sensor attached to the battery cell <NUM>. In addition, although not shown in <FIG>, a sensing resistor is provided to the first terminal or the second terminal side of the battery cell <NUM>, and the monitoring unit <NUM> may measure the voltage at both ends of the sensing resistor. In addition, the monitoring unit <NUM> may measure the current output from the battery cell <NUM> or the current applied to the battery cell <NUM> by calculating the difference between the measured voltages at both ends of the sensing resistor.

In addition, the monitoring unit <NUM> may be configured to determine whether the fuse <NUM> is cut or not.

Here, the determination on whether the fuse <NUM> is cut or not may mean determining whether the fuse <NUM> is already cut or not. For example, the monitoring unit <NUM> may determine whether the fuse <NUM> is cut or not by measuring the voltage at both ends 20a and 20b of the fuse <NUM> and calculating a potential difference between both ends 20a and 20b of the fuse <NUM>. As another example, the monitoring unit <NUM> may determine whether the fuse <NUM> is cut or not by measuring the current flowing between the first terminal of the battery cell <NUM> and one end 20b of the fuse <NUM> or the current flowing between the other end 20a of the fuse <NUM> and the positive electrode terminal (P+) of the battery pack.

The discharge line <NUM> may be configured to include a discharge resistor <NUM> and a discharge switch <NUM>. Specifically, the discharge resistor <NUM> may be configured such that one end 32b is connected to the first terminal of the battery cell <NUM>. In addition, one end 31b of the discharge switch <NUM> may be connected to the second terminal of the battery cell <NUM>, and the other end 31a of the discharge switch <NUM> may be connected to the other end 32a of the discharge resistor <NUM>. Hereinafter, an example in which the discharge resistor <NUM> is one resistor will be described, but the discharge resistor <NUM> may also be a composite resistor in which a plurality of resistors are connected in series and/or in parallel.

For example, in <FIG>, the discharge line <NUM> may include the discharge resistor <NUM> and the discharge switch <NUM>, so that the discharge resistor <NUM> and the discharge switch <NUM> are connected in series with each other on the discharge line <NUM>. In addition, both ends of the discharge line <NUM> may be connected to both ends of the battery cell <NUM>, so that the discharge resistor <NUM> and the discharge switch <NUM> provided on the discharge line <NUM> are connected in parallel to the battery cell <NUM>.

In this configuration, if the fuse <NUM> is cut by overcurrent or heat and the operation state of the discharge switch <NUM> is shifted to a turn-on state, the battery cell <NUM> may be discharged through the discharge line <NUM>, particularly the discharge resistor <NUM> of the discharge line <NUM>.

The control unit <NUM> may receive a measurement result measured by the monitoring unit <NUM> and a determination result on whether the fuse <NUM> is cut or not. For example, the control unit <NUM> and the monitoring unit <NUM> may be connected in a wired and/or wireless manner, and the control unit <NUM> may receive the measurement result on at least one of the voltage, current and temperature of the battery cell <NUM> measured by the monitoring unit <NUM>. Also, the control unit <NUM> may receive the determination result on whether the fuse <NUM> is cut or not, determined by the monitoring unit <NUM>.

The control unit <NUM> may estimate a state of charge (SOC) of the battery cell <NUM> based on the received measurement result. For example, the control unit <NUM> may estimate the SOC of the battery cell <NUM> based on the received voltage of the battery cell <NUM>, and may also estimate the SOC of the battery cell <NUM> by integrating an amount of charging current applied to the battery cell <NUM> for a certain period of time.

The control unit <NUM> may determine the state of the battery cell <NUM> as a normal state or a defective state based on the received measurement result and the estimated SOC.

For example, if the estimated SOC of the battery cell <NUM> is higher than or equal to a preset upper limit value, the control unit <NUM> may determine the state of the battery cell <NUM> as a defective state. That is, if the battery cell <NUM> has an excessive SOC, the control unit <NUM> may determine the state of the battery cell <NUM> as a defective state.

Conversely, even when the estimated SOC of the battery cell <NUM> is lower than or equal to the preset lower limit value, the control unit <NUM> may determine the state of the battery cell <NUM> as a defective state. That is, if the battery cell <NUM> is in an overdischarge state, the control unit <NUM> may determine the state of the battery cell <NUM> as a defective state.

In addition, if the temperature of the battery cell <NUM> measured by the monitoring unit <NUM> is higher than or equal to a preset threshold temperature, the control unit <NUM> may determine the state of the battery cell <NUM> as a defective state. That is, if the battery cell <NUM> is in a high-temperature state beyond an appropriate level, the control unit <NUM> may determine the state of the battery cell <NUM> as a defective state.

The control unit <NUM> may be configured to control the operation state of the discharge switch <NUM> to a turn-on state or a turn-off state according to the determined state of the battery cell <NUM> and the determination result on whether the fuse <NUM> is cut or not.

For example, if the state of the battery cell <NUM> is determined as a normal state, the control unit <NUM> may maintain the operation state of the discharge switch <NUM> as a turn-off state. Conversely, if the state of the battery cell <NUM> is determined to be a defective state, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-on state or a turn-off state.

Preferably, when the battery cell <NUM> is in a defective state, the control unit <NUM> may first determine whether the SOC of the battery cell <NUM> is in a dangerous level. For example, if the SOC of battery cell <NUM> is <NUM>% or above, the control unit <NUM> may determine that the SOC of the battery cell <NUM> is in a dangerous level.

If the SOC of battery cell <NUM> is determined as being in a dangerous level, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-on state. If the state of the battery cell <NUM> is a defective state but the SOC of the battery cell <NUM> does not reach the dangerous level, the control unit <NUM> may control or maintain the operation state of the discharge switch <NUM> as a turn-off state. That is, when the state of the battery cell <NUM> is an overdischarge state, even though the state of the battery cell <NUM> is a defective state, the operation state of the discharge switch <NUM> may be controlled or maintained as a turn-off state.

For example, in <FIG>, if the operation state of the discharge switch <NUM> is controlled to a turn-on state by the control unit <NUM>, the battery cell <NUM> may be electrically connected with the discharge switch <NUM> and the discharge resistor <NUM> provided on the discharge line <NUM>. Thus, the battery cell <NUM> may be discharged.

Since the apparatus for detecting a defect of a battery pack according to an example of the present disclosure determines whether the battery cell <NUM> is in a defective state based on the voltage and temperature of the battery cell <NUM>, it has an advantage that a defect of the battery pack including the corresponding battery cell <NUM> is detected.

In addition, since the apparatus for detecting a defect of a battery pack according to an example of the present disclosure discharges the battery cell <NUM> in a defective state through the discharge line <NUM>, energy (remaining capacity) in the battery cell <NUM> may be consumed. In this case, since the energy in the battery cell <NUM> is lowered, there is an advantage that unexpected accidents such as ignition or explosion may be prevented.

The control unit <NUM> may be implemented in hardware by using at least one of ASICs (Application specific integrated circuits), DSPs (Digital signal processors), DSPDs (Digital signal processing devices), PLDs (Programmable logic devices), FPGAs (Field programmable gate arrays), microprocessors, and electrical units for performing other functions. The control unit <NUM> may include a memory. The memory stores data, commands and software required for overall operations of the apparatus, and may include at least one type of storage media selected from a flash memory type, hard disk type, an SSD type (Solid State Disk type), an SDD type (Silicon Disk Drive type), Multimedia card micro type, RAM (Random access memory), SRAM (Static random access memory), ROM (Read-only memory), EEPROM (Electrically erasable programmable) and PROM (Programmable read-only memory).

The fuse <NUM> may be configured to be cut when the operation state of the discharge switch <NUM> is a turn-on state.

As described above, the fuse <NUM> may be cut by heat introduced thereto. If the operation state of the discharge switch <NUM> is a turn-on state, the battery cell <NUM> may be discharged through the discharge line <NUM>. While discharging the battery cell <NUM> through the discharge line <NUM>, the current output from the battery cell <NUM> passes through the discharge resistor <NUM>, and heat may be generated at the discharge resistor <NUM>. In addition, the heat generated from the discharge resistor <NUM> may be introduced to the fuse <NUM>. To this end, the discharge resistor <NUM> may be positioned adjacent to the fuse <NUM> so that enough heat to fuse the fuse <NUM> is applied to the fuse <NUM>. Therefore, if the operation state of the discharge switch <NUM> is a turn-on state, the fuse <NUM> may be cut by the heat generated from the discharge resistor <NUM>.

The control unit <NUM> may determine the state of the battery cell <NUM> as a defective state, if the battery cell <NUM> is determined as being in at least one of an excessive SOC state and a high-temperature state over a threshold temperature based on the measured measurement result.

For example, since the electrolyte contained in the battery cell <NUM> is sensitive to heat, if a strong current flows in the battery cell <NUM> or the battery cell <NUM> is exposed to a high temperature environment, a chemical reaction may occur in the battery cell <NUM> according to the movement of electrons and gas or heat may be generated. The generated gas or heat may cause a swelling phenomenon in which the battery cell <NUM> swells, or ignition or explosion may occur.

In addition, if the battery cell <NUM> is in an excessive SOC state, a lithium plating phenomenon in which lithium is deposited may occur, degradation of the battery cell <NUM> is accelerated, and ignition or explosion may occur.

Accordingly, the control unit <NUM> may be configured to control the operation state of the discharge switch <NUM> to a turn-on state if the battery cell <NUM> is in an excessive SOC state and/or a high-temperature state.

If the apparatus for detecting a defect of a battery pack according to an example of the present disclosure is used, when the fuse <NUM> is not cut by external factors, the fuse <NUM> may be cut in the process of discharging the battery cell <NUM> through the discharge line <NUM>. Therefore, the configuration required for cutting the fuse <NUM> and discharging the battery cell <NUM> may be simplified, and the time required therefor may be reduced.

In addition, if the battery cell <NUM> is in an excessive SOC state and/or a high-temperature state, the apparatus for detecting a defect of a battery pack according to an example of the present disclosure consumes the remaining capacity inside the battery cell <NUM>, thereby lowering the internal energy of the battery cell <NUM> and thus preventing accidents such as ignition or explosion.

The apparatus for detecting a defect of a battery pack according to an example of the present disclosure may further include a cooling unit for lowering the temperature of the battery cell <NUM>.

The cooling unit is connected in series on the discharge line <NUM>, and may be operated by the control unit <NUM> while the operation state of the discharge switch <NUM> is controlled to a turn-on state, thereby lowering the temperature of the battery cell <NUM>.

Referring to <FIG>, if the operation state of the discharge switch <NUM> is controlled as a turn-on state so that the battery cell <NUM> is discharged through the discharge line <NUM>, heat may be generated by a chemical reaction inside the battery cell <NUM>. Also, heat may be generated while a current is passing through the discharge resistor <NUM>. Thus, there is a risk that the temperature of the battery cell <NUM> is further increased by heat and resistance heat caused by a chemical reaction generated during the discharge process. Therefore, in order to prevent an accident that may occur due to the increase in temperature of the battery cell <NUM>, the cooling unit may be provided.

For example, the cooling unit may be configured using a fan. The fan is connected in series on the discharge line <NUM>, and if the operation state of the discharge switch <NUM> is controlled to a turn-on state, the fan may be operated by receiving a current from the battery cell <NUM>. In this case, the battery cell <NUM> may be cooled and discharged simultaneously.

As another example, the cooling unit may be configured using a thermoelectric element. The thermoelectric element is provided to the discharge line <NUM> and may receive a current from the battery cell <NUM>. As the current is applied to both terminals of the thermoelectric element, the terminal at which an endothermic reaction occurs may contact the battery cell <NUM>. In this case, the battery cell <NUM> may be cooled and discharged simultaneously.

In the above, the fan and the thermoelectric element have been described as examples of the cooling unit, but any cooling unit capable of lowering the temperature of the battery cell <NUM> may be used without limitation.

That is, since the apparatus for detecting a defect of a battery pack may include the cooling unit provided on the discharge line <NUM>, it is possible to simultaneously discharge and cool the battery cell <NUM>. Therefore, since the remaining capacity and temperature of the battery cell <NUM> may be simultaneously lowered, there is an advantage that the state of the battery cell <NUM> may come to a stable state more quickly.

The control unit <NUM> may be configured to control the operation state of the discharge switch <NUM> to a turn-off state, if the fuse <NUM> is cut and the SOC of the battery cell <NUM> is lower than or equal to the preset lower limit value. Here, the preset lower limit value is a reference value for determining whether the battery cell <NUM> is overdischarged, and may be stored in a memory of the control unit <NUM> or the like in advance.

In general, the overdischarge state means a state in which the SOC of the battery cell <NUM> is lowered to the preset lower limit value or below, and if the battery cell <NUM> is overdischarged, various problems may occur. For example, if the battery cell <NUM> is overdischarged, a separator may be damaged by lithium precipitation, which may cause ignition and explosion. Accordingly, when the battery cell <NUM> is in an overdischarge state, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-off state, so that the battery cell <NUM> is not discharged through the discharge line <NUM>.

For example, it is assumed that the preset lower limit value is set to <NUM>%. The control unit <NUM> may continuously estimate the SOC of the battery cell <NUM>. If the estimated SOC of the battery cell <NUM> is lower than or equal to <NUM>%, the control unit <NUM> may control or maintain the operation state of the discharge switch <NUM> as a turn-off state to prevent the battery cell <NUM> from being overcharged.

Meanwhile, if the fuse <NUM> is not cut even though the battery cell <NUM> is determined as in an overdischarge state, the control unit <NUM> may cut the fuse <NUM> by controlling the operation state of the discharge switch <NUM> to a turn-on state. In addition, the control unit <NUM> may prevent the battery cell <NUM> from being discharged by controlling the operation state of the discharge switch <NUM> to a turn-off state.

That is, since the apparatus for detecting a defect of a battery pack may cut the fuse <NUM> connected to the battery cell <NUM> in a defective state and may lower the SOC thereof, there is an advantage that secondary accidents caused by the battery cell <NUM> in a defective state can be prevented in advance.

The control unit <NUM> may be configured to control the operation state of the discharge switch <NUM> to a turn-on state, if the SOC of the battery cell <NUM> is greater than or equal to the preset upper limit value after the fuse <NUM> is determined as being cut.

For example, it is assumed that the preset upper limit value is set to <NUM>%. If the SOC of the battery cell <NUM> is <NUM>% or above, the control unit <NUM> may determine that the energy of the battery cell <NUM> is in a dangerous level. The control unit <NUM> may discharge the battery cell <NUM> by controlling the operation state of the discharge switch <NUM> to a turn-on state in order to lower the energy of the battery cell <NUM>. During the discharging process, the monitoring unit <NUM> may continuously measure the voltage of the battery cell <NUM>, and the control unit <NUM> may estimate the SOC of the battery cell <NUM> based on the measurement result measured by the monitoring unit <NUM>. When the SOC of the battery cell <NUM> is lowered to the preset lower limit value or below, the control unit <NUM> may control the discharge switch <NUM> to a turn-off state to prevent an accident caused by overdischarge of the battery cell <NUM>.

When the operation state of the discharge switch <NUM> is controlled to a turn-on state, the battery cell <NUM> and the discharge line <NUM> are electrically connected, and the current output from the battery cell <NUM> may be consumed by the discharge resistor <NUM>. In addition, if the SOC of the battery cell <NUM> is lowered to the preset lower limit value or below, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-off state.

The apparatus for detecting a defect of a battery pack may continuously estimate the SOC of the battery cell <NUM> even in the process of discharging the battery cell <NUM> through the discharge line <NUM> to prevent the battery cell <NUM> from being overdischarged. In this case, an unexpected accident caused by overdischarge of the battery cell <NUM> can be prevented in advance.

Hereinafter, the apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure will be described with reference to <FIG> is a diagram schematically showing another exemplary configuration of the apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure. In describing the apparatus for detecting a defect of a battery pack as shown in <FIG>, the features identical to those of the apparatus for detecting a defect of a battery pack as shown in <FIG> will not be described in detail, and only features different therefrom will be described in detail.

Referring to <FIG>, the apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure may further include a main switch <NUM> and a cut-off resistor <NUM>.

The main switch <NUM> may be provided on a large current path through which the charging/discharging current of the battery pack flows. In particular, one end 40b of the main switch <NUM> may be connected to the other end 20a of the fuse <NUM>, and the other end 40a of the main switch <NUM> may be connected to the electrode terminal of the battery pack. Preferably, one end 40b of the main switch <NUM> may be connected in series to the other end 20a of the fuse <NUM>, and the other end 40a of the main switch <NUM> may be connected in series to the positive electrode terminal (P+) of the battery pack. That is, the main switch <NUM> may be provided on a large current path between the fuse <NUM> and the electrode terminal of the battery pack.

For example, as shown in <FIG>, it is assumed that the other end 40a of the main switch <NUM> is connected to the positive electrode terminal (P+) of the battery pack. If the operation state of the main switch <NUM> is a turn-off state, the fuse <NUM> and the positive electrode terminal (P+) of the battery pack may be disconnected. Conversely, if the operation state of the main switch <NUM> is a turn-on state, the fuse <NUM> and the positive electrode terminal (P+) of the battery pack may be electrically connected. Therefore, depending on the operation state of the main switch <NUM>, the positive electrode terminal of battery cell <NUM> and the positive electrode terminal (P+) of the battery pack may be connected or disconnected.

One end 33b of the cut-off resistor <NUM> may be connected between the fuse <NUM> and the main switch <NUM>, and the other end 33a of the cut-off resistor <NUM> may be connected between the discharge resistor <NUM> and the discharge switch <NUM>. That is, one end 33b of the cut-off resistor <NUM> may be connected on a line to which the other end 20a of the fuse <NUM> and one end 40b of the main switch <NUM> are connected, and the other end 33a of the cut-off resistor <NUM> may be connected on a line to which the other end 32a of the discharge resistor <NUM> and the other end 31a of the discharge switch <NUM> are connected.

Referring to <FIG>, the cut-off resistor <NUM> may be connected between the other end 20a of the fuse <NUM> and the other end 32a of the discharge resistor <NUM>.

Preferably, the resistance of the cut-off resistor <NUM> may be greater than the resistance of the discharge resistor <NUM>. For example, if the operation state of the main switch <NUM> is a turn-off state and the operation state of the discharge switch <NUM> is a turn-on state, the current flowing from the positive electrode terminal of the battery cell <NUM> may not pass through the cut-off resistor <NUM> but may be applied to the negative electrode terminal of the battery cell <NUM> through the discharge resistor <NUM>.

According to this configuration, by allowing a current to flow through the discharge resistor <NUM>, it is possible not only to discharge the battery cell <NUM> but also to cut the fuse <NUM> by the heat generated by the current flowing through the discharge resistor <NUM>.

The resistance of the cut-off resistor <NUM> may be greater than the internal resistance of the discharge switch <NUM>. For example, if the operation state of the discharge switch <NUM> is a turn-on state, the current output from the battery cell <NUM> may pass through the discharge resistor <NUM>. After that, the current passing through the discharge resistor <NUM> may pass through the discharge switch <NUM> and be applied to the second terminal of the battery cell <NUM>. Therefore, if the operation state of the discharge switch <NUM> is a turn-on state, the battery cell <NUM> can be effectively discharged.

According to this configuration, even if the fuse <NUM> is cut and the operation state of the main switch <NUM> is a turn-on state, the current output from the battery cell <NUM> may not flow to the electrode terminal of the battery pack but may flow toward the discharge switch <NUM>. Therefore, there is an advantage that the operation state of the main switch <NUM> does not necessarily need to be controlled to a turn-off state.

The apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure may disconnect the electrode terminal of the battery pack and the battery cell <NUM> through the main switch <NUM>, so there is an advantage that the apparatus may flexibly cope with the state of the battery cell <NUM>.

In addition, the apparatus for detecting a defect of a battery pack may control the path of current through the cut-off resistor <NUM>. Therefore, it is possible to prevent the current from being consumed while passing through the resistor, thereby increasing the charging and discharging efficiency.

Meanwhile, the discharge resistor <NUM> may be configured to have a resistance greater than the internal resistance of the fuse <NUM>.

For example, the case where the fuse <NUM> is not cut and the operation state of the main switch <NUM> is a turn-on state will be described. The current output from the battery cell <NUM> may flow into the fuse <NUM>, which has a smaller resistance than the discharge resistor <NUM>. Therefore, the current output from the battery cell <NUM> may not flow to the path where the discharge resistor <NUM> is located, but flow to the large current path of the battery pack, namely toward the positive electrode terminal (P+) of the battery pack.

Conversely, in a situation where a charging current is applied from the positive electrode terminal (P+) of the battery pack, due to the cut-off resistor <NUM> and the discharge resistor <NUM>, the charging current may be applied to the battery cell <NUM> through the fuse <NUM>.

Also, the resistance of the discharge resistor <NUM> may be smaller than the resistance of the cut-off resistor <NUM>.

For example, it is assumed that the operation state of the main switch <NUM> is a turn-off state and the operation state of the discharge switch <NUM> is a turn-on state. In this case, as described above, the battery cell <NUM> and the discharge line <NUM> may be connected so that the battery cell <NUM> is discharged. Since the resistance of the discharge resistor <NUM> is smaller than the resistance of the cut-off resistor <NUM>, the current output from the battery cell <NUM> may not flow to the cut-off resistor <NUM> but may pass through the discharge resistor <NUM>. Also, the current passing through the discharge resistor <NUM> may be applied to the second terminal of the battery cell <NUM> through the discharge switch <NUM>. In addition, the heat generated by the discharge resistor <NUM> may be applied to the fuse <NUM>. Therefore, if the operation state of the discharge switch <NUM> is a turn-on state, the fuse <NUM> may be cut by the heat generated from the discharge resistor <NUM>.

If the apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure is used, the fuse <NUM> may be cut in the process of discharging the battery cell <NUM> through the discharge line <NUM>. Accordingly, the configuration required for cutting the fuse <NUM> and discharging the battery cell <NUM> may be simplified, and the time required therefor may be reduced.

The control unit <NUM> may be configured to control the operation state of the main switch <NUM> to a turn-off state, if the state of the battery cell <NUM> is determined as a defective state.

First, the case where the fuse <NUM> is cut will be described. The control unit <NUM> may determine the state of the battery cell <NUM> as a normal state or a defective state based on the measurement result measured by the monitoring unit <NUM>. If the battery cell <NUM> is in a defective state, the control unit <NUM> first controls the operation state of the main switch <NUM> to a turn-off state, thereby disconnecting the battery cell <NUM> in a defective state and the electrode terminal of the battery pack. After that, the control unit <NUM> may control the operation state of the discharge switch <NUM> based on the SOC and/or temperature of the battery cell <NUM>. For example, if the SOC of the battery cell <NUM> is lower than or equal to the preset lower limit value, the control unit <NUM> may maintain the operation state of the discharge switch <NUM> as a turn-off state. Conversely, if the SOC of the battery cell <NUM> is higher than or equal to the preset upper limit value, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-on state to discharge the battery cell <NUM>.

Next, the case in which the fuse <NUM> is not cut but the state of the battery cell <NUM> is determined as a defective state will be described. If the battery cell <NUM> is in a defective state, the control unit <NUM> first controls the operation state of the main switch <NUM> to a turn-off state, thereby disconnecting the battery cell <NUM> in a defective state and the electrode terminal of the battery pack. In addition, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-on state, thereby cutting the fuse <NUM> by the resistance heat generated from the discharge resistor <NUM>. After the fuse <NUM> is cut, the control unit <NUM> may estimate the SOC of the battery cell <NUM> again. If the estimated SOC is lower than or equal to the preset lower limit value, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-off state to prevent the battery cell <NUM> from being overdischarged.

Therefore, the apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure may disconnect the battery cell <NUM> in a defective state from an external device through the main switch <NUM>. Accordingly, there is an advantage that the battery cell <NUM> in a defective state may be prevented from being connected to an external device and thus being charged or discharged.

In addition, the apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure first disconnects the battery cell <NUM> from an external device and then takes flexible measures according to the state of the battery cell <NUM>, so there is an advantage of preventing secondary accidents such as ignition and/or explosion caused by the battery cell <NUM>.

The apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure may further include an ammeter <NUM> provided on the discharge line <NUM> and configured to measure a current applied to the discharge resistor <NUM>.

For example, referring to <FIG>, the ammeter <NUM> may be provided between one end 32b of the discharge resistor <NUM> and a line to which one end 20b of the fuse <NUM> and the first terminal of the battery cell <NUM> are connected and configured to measure a current applied to the discharge resistor <NUM>. Alternatively, the ammeter <NUM> may be provided between the discharge resistor <NUM> and a line to which the cut-off resistor <NUM> and the discharge switch <NUM> are connected and configured to measure a current applied to the discharge resistor <NUM>.

The monitoring unit <NUM> may be configured to determine that the fuse <NUM> is cut, if a current value for the current measured by the ammeter <NUM> is greater than or equal to a predetermined threshold value.

Referring to <FIG>, if the fuse <NUM> is cut, the current output from the battery cell <NUM> may be applied to the discharge resistor <NUM>. Therefore, if the current measured by the ammeter <NUM> is greater than or equal to the predetermined threshold value set in advance based on the current output from the battery cell <NUM>, the monitoring unit <NUM> may determine that the fuse <NUM> is cut.

For example, in a discharge situation where the main switch <NUM> and the discharge switch <NUM> are controlled in a turn-on state, if the fuse <NUM> is not cut, current may substantially not flow through the discharge resistor <NUM>. If it is measured that a current greater than <NUM>, for example 1A or above, flows through the ammeter, it may be regarded that the fuse <NUM> is cut and the current output from the battery cell <NUM> is applied to the discharge resistor <NUM>. Therefore, in this case, the monitoring unit <NUM> may determine that the fuse <NUM> is cut, based on the current value measured by the ammeter <NUM>.

If it is determined that the fuse <NUM> is cut by the monitoring unit <NUM>, the control unit <NUM> may be configured to discharge the battery cell <NUM> by controlling the operation state of the discharge switch <NUM> to a turn-on state. At this time, since the resistance of the cut-off resistor <NUM> is greater than the internal resistance of the discharge switch <NUM>, the current passing through the discharge resistor <NUM> may be applied to the discharge switch <NUM>, not to the main switch <NUM>.

The apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure has an advantage of quickly determining whether the fuse <NUM> is cut or not.

The control unit <NUM> be configured to control the operation state of the main switch <NUM> to a turn-on state, if it is determined that the battery cell <NUM> is in a normal state but the fuse <NUM> is disconnected by the monitoring unit <NUM>.

Preferably, if it is determined that the fuse <NUM> is cut, the control unit <NUM> may be configured to control (change or maintain) the operation state of the discharge switch <NUM> to a turn-off state according to the state of the battery cell <NUM>.

For example, the fuse <NUM> may be cut due to external factors such as an overcurrent introduced from the outside or an impact applied to the battery pack. In this case, if the state of battery cell <NUM> is a normal state, it may not be desirable to discharge the battery cell <NUM> through the discharge line <NUM>.

In order to cope with such an exceptional situation, if it is determined that the fuse <NUM> is cut, the control unit <NUM> may first determine whether the state of the battery cell <NUM> is a normal state or a defective state.

For example, if the state of battery cell <NUM> is a normal state, the control unit <NUM> may not control the discharge switch <NUM> to a turn-on state to discharge the battery cell <NUM> but control the main switch <NUM> to a turn-on state to connect the battery cell <NUM> to the electrode terminal of the battery pack.

As another example, if the state of battery cell <NUM> is a defective state due to overdischarge, the control unit <NUM> may maintain the operation state of the discharge switch <NUM> as a turn-off state.

As another example, if the state of battery cell <NUM> is an overcharge state and/or a high-temperature state, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-on state. Specifically, if the state of battery cell <NUM> is a defective state due to overcharge and/or high temperature, the control unit <NUM> may determine whether the SOC of the battery cell <NUM> is in a dangerous level. As in the previous example, if the SOC of the battery cell <NUM> is <NUM>% or above, the control unit <NUM> may determine that the SOC of the battery cell <NUM> is in a dangerous level. If the SOC of the battery cell <NUM> is in a dangerous level, the control unit <NUM> may discharge the battery cell <NUM> by controlling the operation state of the discharge switch <NUM> to a turn-on state.

That is, the apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure may additionally check the state of the battery cell <NUM> in an exceptional situation, for example when the fuse <NUM> is cut by an external factor. Accordingly, it may be prevented that the battery cell <NUM> in a normal state is determined as in a defective state due to an exception situation. In addition, there is an advantage that the battery cell <NUM> may be more flexibly handled in an exceptional situation.

<FIG> are diagrams schematically showing still another exemplary configuration of the apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure. Hereinafter, various embodiments for actively cutting the fuse <NUM> will be described with reference to <FIG>.

Referring to <FIG>, the apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure may further include a fuse cutting module <NUM> configured to cut the fuse <NUM>. That is, <FIG> may be regarded as diagrams for illustrating an embodiment in which the fuse cutting module <NUM> is further included in the apparatus for detecting a defect of a battery pack as shown in <FIG>.

The fuse cutting module <NUM> is connected to the control unit <NUM>, and may be configured to include at least one of a heating unit <NUM> configured to generate heat if a cutting control signal is received from the control unit <NUM>, a current applying unit <NUM> configured to apply a current to the fuse <NUM>, and a cutting unit <NUM> configured to cut the fuse <NUM>, in order to cut the fuse <NUM>. Here, the cutting control signal is a signal that the control unit <NUM> sends to the fuse cutting module <NUM> to cut the fuse <NUM>.

For example, referring to <FIG>, the fuse cutting module <NUM> may include a heating unit <NUM>. The heating unit <NUM> may be operated if the fuse cutting module <NUM> receives a cutting control signal from the control unit <NUM>. In this case, the heating unit <NUM> of the fuse cutting module <NUM> is fixed at a position very close to the fuse <NUM>, and the fuse <NUM> may be melted and cut by the heat generated by the heating unit <NUM>.

As another example, referring to <FIG>, the fuse cutting module <NUM> may include a current applying unit <NUM>. In this case, the fuse cutting module <NUM> may be connected to one end 20b and the other end 20a of the fuse <NUM>, respectively. If the fuse cutting module receives a cutting control signal from the control unit <NUM>, the current applying unit <NUM> may apply a current to the fuse <NUM> to cut the fuse <NUM>. The current applying unit <NUM> of the fuse cutting module <NUM> may receive power from a separate power source provided therein, an external power source, or the battery cell <NUM>.

As another example, referring to <FIG>, the fuse <NUM> may be placed on the fuse cutting module <NUM> and fixedly coupled thereto. The fuse cutting module <NUM> may include a cutting unit <NUM> to cut the body, one end 20b or the other end 20a of the fuse <NUM> when receiving a cutting control signal.

For example, a terminal of the fuse <NUM> may be inserted into a groove provided at the cutting unit <NUM>. If the fuse cutting module <NUM> receives a cutting control command from the control unit <NUM>, the size of the groove of the cutting unit into which the terminal of the fuse <NUM> is inserted is reduced, so the terminal of the fuse <NUM> may be cut.

As another example, the cutting unit <NUM> may be configured to have a plate-like structure for cutting the terminal or body of the fuse <NUM>. The cutting unit <NUM> is configured to be movable inside the fuse cutting module <NUM>. Thus, if the fuse cutting module <NUM> receives a cutting control command from the control unit <NUM>, the cutting unit <NUM> may be moved to cut the terminal or body of the fuse <NUM>.

Preferably, the control unit <NUM> may be configured to output the cutting control signal, if the fuse <NUM> is not cut and the state of the battery cell <NUM> is determined as a defective state.

For example, if the fuse <NUM> is cut by an external impact or overcurrent introduced from the outside, the control unit <NUM> may not output a cutting control signal. In addition, even when the battery cell <NUM> is in a normal state, the control unit <NUM> may not output a cutting control signal.

Accordingly, the control unit <NUM> may output a cutting control signal to the fuse cutting module <NUM> only when the fuse <NUM> is not cut and the battery cell <NUM> is in a defective state.

That is, the apparatus for detecting a defect of a battery pack according to an embodiment of the present disclosure may directly cut the fuse <NUM> through the fuse cutting module <NUM>, so there is an advantage of securely disconnecting the connection between the battery cell <NUM> in a defective state and the electrode terminal of the battery pack. Accordingly, various problems caused when the battery cell <NUM> in a defective state is connected to the outside may be prevented in advance.

<FIG> is a diagram schematically showing an exemplary configuration of an apparatus for detecting a defect of a battery pack according to another embodiment of the present disclosure.

The battery pack may include a plurality of battery cells 10A and 10B. For example, the plurality of battery cells 10A and 10B may be connected in series and/or in parallel. Hereinafter, for convenience of description, an embodiment of a battery pack in which the first battery cell 10A and the second battery cell 10B are connected in series will be described.

The fuse 20A and 20B may be provided in plural, and the plurality of fuses 20A and 20B may be configured to correspond to the plurality of battery cells 10A and 10B included in the battery pack, respectively. In addition, each of the fuses 20A and 20B may be configured to be connected to one side of the corresponding battery cell 10A and 10B, such as the first terminal thereof.

That is, the first fuse 20A may correspond to the first battery cell 10A, and the second fuse 20B may correspond to the second battery cell 10B. For example, in the embodiment of <FIG>, one end 20Ab of the first fuse 20A may be connected to the first terminal of the first battery cell 10A. The other end 20Ba of the second fuse 20B may be connected to the second terminal of the first battery cell 10A, and the one end 20Bb of the second fuse 20B may be connected to the first terminal of the second battery cell 10B. The other end 20Aa of the first fuse 20A may be connected to the positive electrode terminal (P+) of the battery pack, and the second terminal of the second battery cell 10B may be connected to the negative electrode terminal (P-) of the battery pack.

The discharge line 30A and 30B may be provided in plural, and the plurality of discharge lines 30A and 30B may be configured to correspond to the plurality of battery cells 10A and 10B, respectively. In addition, the discharge lines 30A and 30B respectively includes discharge resistors 32A and 32B and discharge switches 31A and 31B, and may be configured to be connected in parallel to the corresponding battery cells 10A and 10B, respectively.

For example, in the embodiment of <FIG>, the first discharge line 30A may correspond to the first battery cell 10A, and the second discharge line 30B may correspond to the second battery cell 10B. Specifically, the first discharge line 30A may include a first discharge resistor 32A and a first discharge switch 31A, and the second discharge line 30B may include a second discharge resistor 32B and a second discharge switch 31B. Here, if a current is applied to the first discharge line 30A, the first fuse 20A may be cut by the heat generated from the first discharge line 30A. Likewise, if a current is applied to the second discharge line 30B, the second fuse 20B may be cut by the heat generated in the second discharge line 30B.

One end 32Ab of the first discharge resistor 32a may be connected to a line connecting the first fuse 20A and the first terminal of the first battery cell 10A, and the other end 32Aa of the first discharge resistor 32a may be connected to the other end 31Aa of the first discharge switch 31A. One end 31Ab of the first discharge switch 31A may be connected to a line connecting the second terminal of the first battery cell 10A and the other end 20Ba of the second fuse 20B. Specifically, one end 32Ab of the first discharge resistor 32a may be connected to a line connecting one end 20Ab of the first fuse 20A and the first terminal of the first battery cell 10A. One end 31Ab of the first discharge switch 31A may be connected to a line connecting the second terminal of the first battery cell 10A and the other end 20Ba of the second fuse 20B.

One end 32Bb of the second discharge resistor 32B may be connected to a line connecting the first terminal of the second battery cell 10B and one end 20Bb of the second fuse 20B, and the other end 32Ba of the second discharge resistor 32B may be connected to the other end 31Ba of the second discharge switch 31B. One end 31Bb of the second discharge switch 31B may be connected to a line connecting the second terminal of the second battery cell 10B and the negative electrode terminal (P-) of the battery pack. Specifically, one end of the second discharge resistor 32B may be connected to a line connecting one end 20Bb of the second fuse 20B and the first terminal of the second battery cell 10B.

The apparatus for detecting a defect of a battery pack according to another embodiment of the present disclosure may further include bypass switches 60A and 60B.

Referring to <FIG>, the bypass switch 60A and 60B may be provided in plural, and the plurality of bypass switches 60A and 60B may be configured to correspond to the plurality of battery cells 10A and 10B, respectively. In addition, each of the bypass switches 60A and 60B may be connected in parallel to each of the corresponding battery cells 10A and 10B. That is, the first bypass switch 60A may be connected in parallel to the first battery cell 10A, and the second bypass switch 60B may be connected in parallel to the second battery cell 10B. At this time, it may be regarded that the bypass line on which each of the bypass switches 60A and 60B is installed is configured to be connected in parallel to each of the discharge lines 30A and 30B. Moreover, the bypass line in which each of the bypass switches 60A and 60B is installed may be configured to bypass all of the battery cells 10A and 10B and the fuses 20A and 20B.

In addition, the bypass switches 60A and 60B may be configured such that the operation state thereof is controlled to a turn-off state or a turn-on state by the control unit <NUM>. In a general situation, the operation state of the bypass switches 60A and 60B may be a turn-off state, similar to the operation state of the discharge switches 31A and 31B. After that, if the connection between the corresponding battery cells 10A and 10B and the battery pack is disconnected, the operation state of the bypass switches 60A and 60B may be controlled to a turn-on state.

For example, in the embodiment of <FIG>, it is assumed that the first fuse 20A is cut off, the first battery cell 10A is in a defective state, and the second battery cell 10B is in a normal state. In this case, the connection between the positive electrode terminal (P+) of the battery pack to the first battery cell 10A and the second battery cell 10B may be disconnected. Therefore, in order to connect the second battery cell 10B in a normal state to the positive electrode terminal (P+) of the battery pack, the control unit <NUM> may control the operation state of the first bypass switch 60A to a turn-on state. The first terminal of the second battery cell 10B may be connected to the positive electrode terminal (P+) of the battery pack through the second fuse 20B and the first bypass switch 60A, and the second terminal of the second battery cell 10B may be connected to the negative electrode terminal (P-) of the battery pack.

That is, since the apparatus for detecting a defect of a battery pack according to another embodiment of the present disclosure further includes a plurality of bypass switches 60A and 60B, it is possible to selectively disconnect the connection between the battery cell in a defective state among the plurality of battery cells 10A and 10B and the electrode terminal of the battery pack. Therefore, the battery pack may be used longer, and it is possible to prevent the battery pack being entirely unusable due to a defect in some battery cells.

The control unit <NUM> may select a battery cell, which is determined as in a defective state or as a fuse 20A and 20B corresponding thereto is cut, among the plurality of battery cells 10A and 10B as a target cell.

Here, the monitoring unit <NUM> may measure at least one of voltage, current and temperature of each of the plurality of battery cells 10A and 10B through the sensing lines respectively connected to the plurality of battery cells 10A and 10B. In addition, the monitoring unit <NUM> may determine whether the fuses 20A and 20B respectively corresponding to the plurality of battery cells 10A and 10B are cut or not.

For example, seeing the embodiment shown in <FIG>, the monitoring unit <NUM> may monitor the first battery cell 10A through the first sensing line SL1 and the second sensing line SL2. In addition, the monitoring unit <NUM> may monitor the second battery cell 10B through the third sensing line SL3 and the fourth sensing line SL4. As in the former embodiment, if the second fuse 20B is cut and the operation state of the second bypass switch 60B is controlled to a turn-on state, the current output from the second battery cell 10B is not applied to the second sensing line SL2, so the voltage or the like of the second battery cell 10B may not be measured through the second sensing line SL2 and the fourth sensing line SL4. Accordingly, the monitoring unit <NUM> may monitor the corresponding battery cells 10A and 10B through the sensing lines provided at both ends of each of the battery cells 10A and 10B.

The control unit <NUM> may control the operation state of the discharge switch included in the discharge line corresponding to the selected target cell to a turn-on state or a turn-off state according to the state of the selected target cell.

For example, if the target cell is in an overcharged defective state, the control unit <NUM> may control the operation state of the discharge switch corresponding to the target cell to a turn-on state.

Seeing the embodiment shown in <FIG>, if the first fuse 20A is cut and the first battery cell 10A is selected as a target cell, the control unit <NUM> may determine the state of the first battery cell 10A. If it is determined that the state of the first battery cell 10A is a defective state, the control unit <NUM> may control the operation state of the first discharge switch 31A to a turn-on state.

The control unit <NUM> may be configured to control the operation state of the bypass switch connected in parallel to the target cell to a turn-on state.

As in the former embodiment, if the operation state of the first discharge switch 31A is controlled to a turn-on state, the control unit <NUM> may control the operation state of the first bypass switch 60A to a turn-on state in order to connect the positive electrode terminal (P+) of the battery pack and the second battery cell 10B.

The apparatus for detecting a defect of a battery pack according to another embodiment of the present disclosure has an advantage of allowing the battery pack to be used longer by selectively disconnecting the battery pack and the target cell. In addition, there is an advantage that secondary accidents caused by the target cell in a defective state can be prevented in advance.

<FIG> is a diagram schematically showing another exemplary configuration of the apparatus for detecting a defect of a battery pack according to another embodiment of the present disclosure.

The apparatus for detecting a defect of a battery pack according to another embodiment of the present disclosure may further include a plurality of fuse cutting modules 300A and 300B respectively corresponding to the plurality of fuses 20A and 20B.

For example, in the embodiment shown in <FIG>, the apparatus for detecting a defect of a battery pack may further include a first fuse 20A cutting unit 300A corresponding to the first fuse 20A and a second fuse 20B cutting unit 300B corresponding to the second fuse 20B. Both the first fuse 20B cutting unit 300A and the second fuse 20B cutting unit 300B are connected to the control unit <NUM> and may receive a cutting control command from the control unit <NUM>. Only the fuse cutting module receiving the cutting control command from the control unit <NUM> may be operated to cut the corresponding fuse.

<FIG> is a diagram schematically showing a method for detecting a defect of a battery pack according to still another embodiment of the present disclosure. The method for detecting a defect of a battery pack according to still another embodiment of the present disclosure may be performed by the apparatus for detecting a defect of a battery pack as described above.

Referring to <FIG>, the method for detecting defects of the battery pack according to still another embodiment of the present disclosure may include a measuring step (S <NUM>), a cutting determining step (S200), a battery cell state determining step (S300), and a discharge switch operation controlling step (S400).

The measuring step (S100) is a step of measuring at least one of voltage, current and temperature of the battery cell <NUM>, and may be performed by the monitoring unit <NUM>.

The monitoring unit <NUM> may monitor the battery cell <NUM> by measuring the voltage, current and temperature for each battery cell <NUM>.

The cutting determining step (S200) is a step of determining whether the fuse <NUM> is cut or not, and may be performed by the monitoring unit <NUM>, similar to the measuring step (S100).

For example, the monitoring unit <NUM> may determine whether the fuse <NUM> is cut or not by measuring the voltage at both ends of the fuse <NUM>, or may determine whether the fuse <NUM> is cut or not based on the current measured by a voltmeter as in the embodiment of <FIG>.

The battery cell state determining step (S300) is a step of determining the state of the battery cell <NUM> as a normal state or a defective state based on the measurement result measured in the measuring step (S100), and may be performed by the control unit <NUM>.

The control unit <NUM> may receive the measurement result from the monitoring unit <NUM>. In addition, the control unit <NUM> may estimate the SOC of the battery cell <NUM> based on the received measurement result.

The control unit <NUM> may determine the state of the battery cell <NUM> as a defective state if the estimated SOC of the battery cell <NUM> is lower than or equal to the preset lower limit value or greater than or equal to the preset upper limit value. In addition, the control unit <NUM> may determine the state of the battery cell <NUM> as a defective state if the temperature of the battery cell <NUM> in the measurement results received from the monitoring unit <NUM> is higher than or equal to a predetermined threshold temperature.

The discharge switch operation controlling step (S400) is a step of controlling the operation state of the discharge switch <NUM> to a turn-on state or a turn-off state according to the determined state of the battery cell <NUM> and the determination result on whether the fuse <NUM> is cut, and may be performed by the control unit <NUM>.

If the fuse <NUM> is already cut, the control unit <NUM> may control the operation state of the discharge switch <NUM> according to the state of the battery cell <NUM>. For example, if the battery cell <NUM> is overcharged and the state of the battery cell <NUM> is determined as a defective state, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-on state in order to lower the energy in the battery cell <NUM>. As another example, if the battery cell <NUM> is overdischarged and the state of the battery cell <NUM> is determined as a defective state, the control unit <NUM> may maintain the operation state of the discharge switch <NUM> as a turn-off state so that the battery cell <NUM> is not discharged any longer.

As another example, if the temperature of battery cell <NUM> rises to a proper temperature or above and the state of the battery cell <NUM> is determined as a defective state, the control unit <NUM> may maintain the operation state of the discharge switch <NUM> as a turn-off state and lower the temperature of the battery cell <NUM>. In addition, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-on state to operate the cooling unit provided on the discharge line <NUM> so that the temperature of the battery cell <NUM> is lowered.

Even when the fuse <NUM> is not cut, the control unit <NUM> may control the operation state of the discharge switch <NUM> according to the state of the battery cell <NUM>.

For example, if the battery cell <NUM> is overcharged and the state of the battery cell <NUM> is determined as a defective state, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-on state in order to lower the energy in the battery cell <NUM> while cutting the fuse <NUM>. In this case, the fuse <NUM> may be cut by the heat generated by the discharge resistor <NUM> provided on the discharge line <NUM>.

As another example, if the battery cell <NUM> is overdischarged and the state of the battery cell <NUM> is determined as a defective state, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-on state to cut the fuse <NUM>, and then control the operation state of the discharge switch <NUM> to a turn-off state so that the battery cell <NUM> is not discharged any longer.

As another example, if the battery cell <NUM> is overdischarged and the state of the battery cell <NUM> is determined as a defective state, the control unit <NUM> may maintain the operation state of the discharge switch <NUM> as a turn-off state so that the battery cell <NUM> is not discharged any longer, and then output a cutting control command to the fuse cutting module <NUM>. The fuse <NUM> may be cut by the fuse cutting module <NUM> receiving the cutting control command.

As still another example, if the temperature of battery cell <NUM> rises and the state of the battery cell <NUM> is determined as a defective state, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-on state to cut the fuse <NUM>. After that, the control unit <NUM> may control the operation state of the discharge switch <NUM> to a turn-off state to lower the temperature of the battery cell <NUM>, or maintain the operation state of the discharge switch <NUM> as a turn-on state to operate the cooling unit provided on the discharge line <NUM> so that the temperature of the battery cell <NUM> is lowered.

A battery pack according to an embodiment of the present disclosure may include the apparatus for detecting a defect of a battery pack according to the present disclosure described above. For example, as shown in <FIG>, the battery pack may include the battery cell <NUM> and the apparatus for detecting a defect of a battery pack. In addition, the battery pack according to the present disclosure may include electronic equipment (including a BMS, a relay, a fuse <NUM>, and the like) and a pack case, in addition to the apparatus for detecting a defect of a battery pack.

Claim 1:
An apparatus for detecting a defect of a battery pack including at least one battery cell (<NUM>), comprising:
a fuse (<NUM>) having one end connected to a first terminal of the battery cell (<NUM>) in series and the other end configured to be connected to an electrode terminal of the battery pack;
a monitoring unit (<NUM>) configured to measure at least one of voltage, current and temperature of the battery cell (<NUM>) and determine whether the fuse (<NUM>) is cut or not;
a discharge line (<NUM>) including a discharge resistor (<NUM>) having one end configured to be connected to the first terminal of the battery cell (<NUM>) in parallel, and a discharge switch (<NUM>) having one end configured to be connected to a second terminal of the battery cell (<NUM>) and the other end connected to the other end of the discharge resistor (<NUM>); and
a control unit (<NUM>) configured to receive a measurement result measured by the monitoring unit (<NUM>) and a determination result on whether the fuse (<NUM>) is cut is not, estimate a state of charge (SOC) of the battery cell (<NUM>) based on the received measurement result, determine based on the received measurement result and the estimated SOC whether a state of the battery cell (<NUM>) is a normal state or a defective state, and control an operation state of the discharge switch (<NUM>) to a turn-on state or a turn-off state according to the determined state of the battery cell (<NUM>) and the determination result on whether the fuse (<NUM>) is cut or not,
the apparatus for detecting a defect of a battery pack being characterized in that it further comprises:
a main switch (<NUM>) having one end connected to the other end of the fuse (<NUM>) and the other end configured to be connected to the electrode terminal of the battery pack; and
a cut-off resistor (<NUM>) having one end connected between the fuse (<NUM>) and the main switch (<NUM>) and the other end connected between the discharge resistor (<NUM>) and the discharge switch (<NUM>).