Patent Publication Number: US-2022212567-A1

Title: Heating Pad Control Apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2020/013499 filed Oct. 5, 2020, published in Korean, which claims priority from Korean Patent Application No. 10-2019-0125481 filed Oct. 10, 2019, all of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a heating pad control apparatus, and more particularly, to a heating pad control apparatus for controlling an operating state of a heating pad provided to a battery pack. 
     BACKGROUND ART 
     Recently, the demand for portable electronic products such as notebook computers, video cameras and portable telephones has increased sharply, and electric vehicles, energy storage batteries, robots, satellites and the like have been developed in earnest. Accordingly, high-performance batteries allowing repeated charging and discharging are being actively studied. 
     Batteries commercially available at present include nickel-cadmium batteries, nickel hydrogen batteries, nickel-zinc batteries, lithium batteries and the like. Among them, the lithium batteries are in the limelight since they have almost no memory effect compared to nickel-based batteries and also have very low self-discharging rate and high energy density. 
     Meanwhile, in general, since a battery and a battery pack including the battery have a sealed structure, they have a risk of a fire or explosion accident due to heat generated inside. Therefore, for safe use of the battery pack, when the temperature of the battery pack reaches a certain level or higher, it is necessary to lower the temperature of the battery pack by eliminating the heat generation factor. 
     Patent Literature 1 discloses an integrated active fuse module for shorting a fuse by sensing a voltage value conducted to a battery and a temperature of heat emitted through the battery, and a method for preventing overvoltage through the same. 
     However, since Patent Literature 1 discloses a configuration for shorting a disposable fuse, there is a problem that the battery pack cannot be reused. That is, Patent Literature 1 discloses a configuration for cutting the fuse of the battery pack when reaching a temperature at which the battery pack cannot be reused, and there is a problem in that it is impossible to solve the heat generation factor itself that increases the temperature of the battery pack.
     (Patent Literature 1) KR 10-2018-0116625 A   

     SUMMARY 
     Technical Problem 
     The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a heating pad control apparatus capable of preventing a battery pack from maintaining a high-temperature state by controlling an operating state of a heating pad based on the temperature of the battery pack and the current flowing through the battery pack. 
     These and other objects and advantages of the present disclosure may be understood from the following detailed description and will become more fully apparent from the exemplary embodiments of the present disclosure. Also, it will be easily understood that the objects and advantages of the present disclosure may be realized by the means shown in the appended claims and combinations thereof. 
     Technical Solution 
     In one aspect of the present disclosure, there is provided a heating pad control apparatus connected to a battery pack. 
     The heating pad control apparatus according to an aspect of the present disclosure may comprise a sensor configured to measure a temperature of the battery pack and output a measured temperature signal corresponding to the measured temperature of the battery pack; a processor configured to output a reference temperature signal corresponding to a preset reference temperature; and a heating control circuit configured to receive the measured temperature signal from the sensor, receive the reference temperature signal from the processor, and output a control signal for controlling an operating state of a heating relay, wherein the heating relay is disposed on a heating line to generate heat on a main charging and discharging line when a current flows in the heating line, wherein the operating state of the heating relay is configured to control the current flowing in the heating line and is based on both-end voltages of a main relay disposed between a positive electrode terminal of a battery module of the battery pack and a positive electrode terminal of the battery pack on a main charging and discharging, the measured temperature signal and the reference temperature signal to control the operating state of a heating pad disposed on the heating line. 
     In response to a turn-on control signal being output from the heating control circuit, the operating state of the heating relay may be configured to change to a turn-on state so that the main charging and discharging line and the heating pad are connected. 
     In response to an operating state of the main relay and the operating state of the heating relay are controlled to a turn-on state, the heating pad may be configured to receive a current output from the battery module. 
     The heating control circuit may include a first comparator configured to receive a first end voltage and a second end voltage of the main relay, respectively, and output a voltage comparison signal corresponding to a difference between the first end voltage and the second end voltage of the main relay; a second comparator configured to output a temperature comparison signal corresponding to a result obtained by comparing sizes of the received measured temperature signal and the received reference temperature signal; and a control signal output circuit configured to receive the voltage comparison signal and the temperature comparison signal and output a control signal corresponding to values of the voltage comparison signal and the temperature comparison signal. 
     The first comparator may be configured to output a first voltage comparison signal in response to the difference between the first and second end voltages being smaller than a predetermined size, and the first comparator may be configured to output a second voltage comparison signal in response to the difference between the first and second end voltages being greater than or equal to the predetermined size. 
     The second comparator may be configured to output a first temperature comparison signal in response to the value corresponding to the measured temperature signal being greater than or equal to a value corresponding to the reference temperature signal, and the second comparator may be configured to output a second temperature comparison signal in response to the value corresponding to the measured temperature signal being smaller than the value corresponding to the reference temperature signal. 
     In response to the first voltage comparison signal being received from the first comparator and the first temperature comparison signal being received from the second comparator, the control signal output circuit may be configured to output a turn-off control signal for changing the operating state of the heating relay to a turn-off state. 
     The processor may be configured to receive the measured temperature signal from the sensor and control the operating state of the heating relay based on a result obtained by comparing the measured temperature measured by the sensor and the set reference temperature. 
     A battery pack according to another aspect of the present disclosure may comprise the heating pad control apparatus according to an aspect of the present disclosure. 
     A vehicle according to still another aspect of the present disclosure may comprise the heating pad control apparatus according to an aspect of the present disclosure. 
     Advantageous Effects 
     According to an aspect of the present disclosure, there is an advantage in that the temperature of the battery pack may be prevented from rising above a certain level. Accordingly, since the temperature of the battery pack is maintained at a certain level, damage to the elements provided in the battery pack is reduced, and the use efficiency of the battery pack may be improved. 
     In addition, according to an aspect of the present disclosure, since the temperature of the battery pack is prevented from rising above a reference temperature by using the heating control unit and the processor, there is an advantage in that the risk of an accident caused by the increase of the temperature of the battery pack is remarkably reduced. 
     The effects of the present disclosure are not limited to the above, and other effects not mentioned herein will be clearly understood by those skilled in the art from the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate a preferred embodiment of the present disclosure and together with the foregoing disclosure, serve to provide further understanding of the technical features of the present disclosure, and thus, the present disclosure is not construed as being limited to the drawing. 
         FIG. 1  is a diagram showing an exemplary configuration of a battery pack including a heating pad control apparatus according to an embodiment of the present disclosure. 
         FIG. 2  is a diagram schematically showing the heating pad control apparatus according to an embodiment of the present disclosure. 
         FIG. 3  is a diagram showing a first example of the current flowing in the battery pack. 
         FIG. 4  is a diagram showing an exemplary configuration in which a load is connected to the battery pack including the heating pad control apparatus according to an embodiment of the present disclosure. 
         FIG. 5  is a diagram showing a second example of the current flowing in the battery pack. 
         FIG. 6  is a diagram showing another exemplary configuration of the battery pack including the heating pad control apparatus according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     It should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. 
     Therefore, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the scope of the disclosure. 
     Additionally, in describing the present disclosure, when it is deemed that a detailed description of relevant known elements or functions renders the key subject matter of the present disclosure ambiguous, the detailed description is omitted herein. 
     The terms including the ordinal number such as “first”, “second” and the like, may be used to distinguish one element from another among various elements, but not intended to limit the elements by the terms. 
     Throughout the specification, when a portion is referred to as “comprising” or “including” any element, it means that the portion may include other elements further, without excluding other elements, unless specifically stated otherwise. 
     Furthermore, the term “processor” 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. 
     In addition, throughout the specification, when a portion is referred to as being “connected” to another portion, it is not limited to the case that they are “directly connected”, but it also includes the case where they are “indirectly connected” with another element being interposed between them. 
     Hereinafter, a preferred embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a diagram showing an exemplary configuration of a battery pack  1  including a heating pad control apparatus  100  according to an embodiment of the present disclosure. 
     Referring to  FIG. 1 , the battery pack  1  may include a battery module  10 , a main relay  20 , a heating pad  30 , a heating relay  40 , and a heating pad control apparatus  100 . 
     Here, the battery module  10  may be at least one battery cell connected in series and/or in parallel. In addition, the battery cell refers to one independent cell that has a negative electrode terminal and a positive electrode terminal and is physically separable. For example, one pouch-type lithium polymer cell may be regarded as the battery cell. 
     Specifically, the battery pack  1  may include a main relay  20  disposed between a positive electrode terminal of the battery module  10  and a positive electrode terminal P+ of the battery pack  1  on a main charging and discharging line ML. For example, referring to  FIG. 1 , the main charging and discharging line ML may be a large current path that connects the positive electrode terminal P+ of the battery pack  1 , the battery module  10  and a negative electrode terminal P− of the battery pack  1 . The main relay  20  may be connected to the main charging and discharging line ML so that one end thereof is connected to the battery module  10  and the other end thereof is connected to the positive electrode terminal P+ of the battery pack  1 . 
     The heating pad  30  may be disposed on a heating line HL connected to the main charging and discharging line ML and configured to generate heat when a current is applied thereto. For example, referring to  FIG. 1 , the heating line HL may be connected to the positive electrode terminal P+ and the negative electrode terminal P− of the battery pack  1  in parallel. 
     In addition, the heating relay  40  for controlling the flow of current flowing through the heating line HL according to an operating state may be provided on the heating line HL. For example, referring to  FIG. 1 , if the operating state of the heating relay  40  is controlled to a turn-on state, the current flowing through the main charging and discharging line ML may be applied to the heating pad  30 . As another example, if the operating state of the heating relay  40  is controlled to a turn-off state, the current may not be applied to the heating pad  30 . 
     The heating pad control apparatus  100  according to an embodiment of the present disclosure may be connected to the battery pack  1  and configured to control an operating state of the heating pad  30  provided in the battery pack  1 . 
       FIG. 2  is a diagram schematically showing the heating pad control apparatus  100  according to an embodiment of the present disclosure. 
     Referring to  FIG. 2 , the heating pad control apparatus  100  according to an embodiment of the present disclosure may include a measuring unit  110 , a processor  120 , and a heating control unit  130 . 
     The measuring unit  110  may be configured to measure a temperature of the battery pack  1 . 
     For example, the measuring unit  110  may include a general temperature sensor to measure the temperature of the battery pack  1 . In addition, referring to  FIG. 1 , the measuring unit  110  may be connected to the battery module  10  to measure the temperature of the battery module  10 . 
     The measuring unit  110  may be configured to output a measured temperature signal corresponding to the measured temperature of the battery pack  1 . 
     Specifically, the measuring unit  110  may convert the measured temperature of the battery pack  1  into a digital signal. In addition, the measuring unit  110  may output the converted digital signal through a line connected to an output terminal. 
     For example, in the embodiment of  FIG. 1 , the measured temperature signal corresponding to the temperature of the battery pack  1  measured by the measuring unit  110  may be output through a third line L 3 . 
     The processor  120  may be configured to output a reference temperature signal corresponding to a preset reference temperature. 
     Here, the preset reference temperature may mean an upper limit temperature in a preset normal temperature range for the battery pack  1 . That is, the preset reference temperature may be a critical temperature at which the battery pack  1  may operate normally. 
     Specifically, the processor  120  may generate a reference temperature signal indicating the preset reference temperature and output the generated reference temperature signal. 
     For example, in the embodiment of  FIG. 1 , the reference temperature signal generated by the processor  120  may be output through a fourth line L 4 . 
     The heating control unit  130  may be configured to receive the measured temperature signal from the measuring unit  110 . In addition, the heating control unit  130  may be configured to receive the reference temperature signal from the processor  120 . 
     Specifically, the heating control unit  130  may be connected to the measuring unit  110  and the processor  120 , respectively. For example, referring to  FIG. 1 , the heating control unit  130  may be connected to the measuring unit  110  through the third line L 3  and connected to the processor  120  through the fourth line L 4 . 
     In addition, the heating control unit  130  may receive the measured temperature signal from the measuring unit  110  through the third line L 3  and receive the reference temperature signal from the processor  120  through the fourth line L 4 . 
     The heating control unit  130  be configured to control the operating state of the heating pad  30  by outputting a control signal for controlling the operating state of the heating relay  40  based on both-end voltages of the main relay  20 , the measured temperature signal and the reference temperature signal. 
     Specifically, the heating control unit  130  may output a control signal for controlling the operating state of the heating relay  40  based on the both-end voltages of the main relay  20  disposed on the main charging and discharging line ML of the battery pack  1 , the measured temperature signal received from the measuring unit  110 , and the reference temperature signal received from the processor  120 . 
     Here, the control signal output from the heating control unit  130  may be a signal that controls the operating state of the heating relay  40  to a turn-on state or a turn-off state. That is, if the heating relay  40  receives the control signal output from the heating control unit  130 , the operating state of the heating relay  40  may be changed to a turn-on state or a turn-off state. 
     In addition, by controlling the operating state of the heating relay  40 , the operating state of the heating pad  30  may be controlled. 
     For example, in the embodiment of  FIG. 1 , if the operating state of the heating relay  40  is a turn-on state and a current flows through the main charging and discharging line ML, a current is applied to the heating pad  30  so that the heating pad  30  may be operated. That is, the heating pad  30  may generate heat. 
     As another example, if the operating state of the heating relay  40  is a turn-off state, the heating pad  30  may not operate regardless of whether a current flows through the main charging and discharging line ML. Therefore, if the operating state of the heating relay  40  is controlled to a turn-off state, the temperature of the battery pack  1  may gradually decrease because the heating pad  30  is not operated. 
     That is, the heating pad control apparatus  100  according to an embodiment of the present disclosure may control the operating state of the heating pad  30  based on the state of the battery pack  1  (for example, the both-end voltages of the main relay  20  and the temperature of the battery pack  1 ). 
     Therefore, since the temperature of the battery pack  1  is maintained at a certain level, it is possible to prevent internal components of the battery pack  1  from being exposed to high temperature. In particular, it is possible to prevent that the temperature of the battery pack  1  is maintained above a reference temperature to damage lines, relays or resistors inside the battery pack  1  due to high temperature. In addition, since the temperature of the battery module  10  may be prevented from rising by the temperature of the battery pack  1 , accidents such as explosion of the battery module  10  may be prevented. 
     Meanwhile, the processor  120  provided to the heating pad control apparatus  100  may optionally include a processor  120  known in the art, an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a register, a communication modem, a data processing device, and the like in order to execute various control logics performed in the present disclosure. In addition, when the control logic is implemented in software, the processor  120  may be implemented as a set of program modules. In this case, the program module may be stored in a memory and executed by the processor  120 . The memory may be provided in or out of the processor  120  and may be connected to the processor  120  through various well-known means. 
     The heating relay  40  may be configured to connect the main charging and discharging line ML and the heating pad  30  by changing the operating state to a turn-on state, if a turn-on control signal is output from the heating control unit  130 . 
     Referring to  FIG. 1 , one end of the heating line HL may be connected between the positive electrode terminal P+ of the battery pack  1  and the other end of the main relay  20 . That is, one end of the heating line HL may be connected to a second node N 2  between the positive electrode terminal P+ of the battery pack  1  and the other end of the main relay  20 . In addition, the other end of the heating line HL may be connected between the negative electrode terminal P− of the battery pack  1  and the negative electrode terminal of the battery module  10 . Accordingly, the heating line HL may be connected in parallel with the battery module  10  to the main charging and discharging line ML of the battery pack  1 . 
     In addition, the heating pad  30  and the heating relay  40  may be connected in series to the heating line HL. 
     For example, referring to  FIG. 1 , one end of the heating relay  40  may be connected to the positive electrode terminal P+ of the battery pack  1  on the heating line HL, and one end of the heating pad  30  and the other end of the heating relay  40  may be directly connected. In addition, the other end of the heating pad  30  may be connected to the negative electrode terminal P− of the battery pack  1  on the heating line HL. 
     Therefore, if the operating state of the heating relay  40  is controlled to a turn-on state, the main charging and discharging line ML and the heating pad  30  may be electrically connected. 
     In addition, the heating pad  30  may be configured to receive the current output from the battery module  10 , if the operating states of the main relay  20  and the heating relay  40  are controlled to a turn-on state. 
     Here, the operating state of the main relay  20  may be controlled by the processor  120 . For example, in the embodiment of  FIG. 1 , the processor  120  may be electrically connected to the main relay  20  through a ninth line L 9 . In addition, the processor  120  may control the operating state of the main relay  20  to a turn-on state or a turn-off state by outputting a signal for controlling the operating state of the main relay  20  through the ninth line L 9 . 
       FIG. 3  is a diagram showing a first example of the current flowing in the battery pack  1 . In  FIG. 3 , arrows indicate the direction in which the current output from the battery module  10  flows. 
     Referring to  FIG. 3 , if the operating states of the main relay  20  and the heating relay  40  are controlled to a turn-on state, a closed circuit may be formed through the battery module  10 , the main relay  20 , the heating relay  40  and the heating pad  30 . 
     That is, the current output from the battery module  10  may be applied to the heating pad  30  through the main relay  20  and the heating relay  40 . In this case, the heating pad  30  to which the current is applied may generate heat and increase the temperature of the battery pack  1 . 
     Referring to  FIGS. 1 and 3 , the heating control unit  130  may include a first comparator  131 , a second comparator  132 , and a control signal output unit  133 . 
     The first comparator  131  may be configured to receive one end voltage and the other end voltage of the main relay  20 , respectively. 
     Specifically, the first comparator  131  may have two input terminals. The first input terminal of the first comparator  131  may be connected to a node between one end of the main relay  20  and the battery module  10  to receive one end voltage of the main relay  20 . In addition, the second input terminal of the first comparator  131  may be connected to a node between the other end of the main relay  20  and the positive electrode terminal P+ of the battery pack  1  to receive the other end voltage of the main relay  20 . 
     For example, in the embodiment of  FIG. 1 , the first comparator  131  may be connected to a first node N 1  through the second line L 2 . In addition, the first comparator  131  may receive one end voltage of the main relay  20  through the second line L 2 . In addition, the first comparator  131  may be connected to the second node N 2  through the first line L 1 . In addition, the first comparator  131  may receive the other end voltage of the main relay  20  through the first line L 1 . 
     The first comparator  131  may be configured to output a voltage comparison signal corresponding to a difference between the received both-end voltages of the main relay  20 . That is, the first comparator  131  may have one output terminal. 
     For example, in the embodiment of  FIG. 1 , the output terminal of the first comparator  131  may be connected to a fifth line L 5 . Accordingly, the first comparator  131  may output the voltage comparison signal corresponding to the difference between one end voltage and the other end voltage of the main relay  20  through the fifth line L 5 . Here, the output voltage comparison signal may be input to the control signal output unit  133  through the fifth line L 5 . 
     The second comparator  132  may be configured to output a temperature comparison signal corresponding to a result obtained by comparing sizes of the received measured temperature signal and the received reference temperature signal. 
     Specifically, like the first comparator  131 , the second comparator  132  may have two input terminals. The first input terminal of the second comparator  132  may be connected to the measuring unit  110  to receive the measured temperature signal from the measuring unit  110 . In addition, the second input terminal of the second comparator  132  may be connected to the processor  120  to receive the reference temperature signal from the processor  120 . 
     For example, in the embodiment of  FIG. 1 , the second comparator  132  may be connected to the measuring unit  110  through the third line L 3 . The second comparator  132  may receive the measured temperature signal output from the measuring unit  110  through the third line L 3 . In addition, the second comparator  132  may be connected to the processor  120  through the fourth line L 4 . The second comparator  132  may receive the reference temperature signal output from the processor  120  through the fourth line L 4 . 
     In addition, the second comparator  132  may output the temperature comparison signal corresponding to the result obtained by comparing the sizes of the received measured temperature signal and the received reference temperature signal through a sixth line L 6 . Preferably, the second comparator  132  may have one output terminal. 
     For example, in the embodiment of  FIG. 1 , the output terminal of the second comparator  132  may be connected to the sixth line L 6 . Accordingly, the second comparator  132  may output the temperature comparison signal through the sixth line L 6 . Here, the output temperature comparison signal may be input to the control signal output unit  133  through the sixth line L 6 . 
     The control signal output unit  133  may be configured to receive the voltage comparison signal and the temperature comparison signal and output a control signal corresponding to values of the voltage comparison signal and the temperature comparison signal. 
     The control signal output unit  133  may have two input terminals. The voltage comparison signal output from the first comparator  131  may be input to the first input terminal of the control signal output unit  133 . In addition, the temperature comparison signal output from the second comparator  132  may be input to the second input terminal of the control signal output unit  133 . 
     For example, in the embodiment of  FIG. 1 , to the control signal output unit  133 , the voltage comparison signal may be input through the fifth line L 5  and the temperature comparison signal may be input through the sixth line L 6 . 
     In addition, the control signal output unit  133  may have an output terminal. The control signal output unit  133  may output a control signal for the heating relay  40  through the output terminal. 
     For example, in the embodiment of  FIG. 1 , a seventh line L 7  may be connected to the output terminal of the control signal output unit  133 . In addition, the seventh line L 7  may be connected to the heating relay  40 . Accordingly, the control signal output from the control signal output unit  133  may be transmitted to the heating relay  40  through the seventh line L 7 , so that the operating state of the heating relay may be controlled to an operating state corresponding to the control signal. 
     The first comparator  131 , the second comparator  132  and the control signal output unit  133  may be configured to output a signal corresponding to an input signal without separate control of the processor  120 . That is, the first comparator  131  may output a voltage comparison signal corresponding to the received both-end voltages of the main relay  20  even if there is no control of the processor  120 . Also, the second comparator  132  may output a temperature comparison signal corresponding to a result obtained by comparing the sizes of the received measured temperature signal and the received reference temperature signal even if there is no control of the processor  120 . In addition, the control signal output unit  133  may output a control signal corresponding to a level of the received voltage comparison signal and the received temperature comparison signal even if there is no control of the processor  120 . Therefore, even if there is no separate control by the processor  120 , the operating state of the heating pad  30  may be automatically controlled according to the state of the battery pack  1 , thereby preventing the temperature of the battery pack  1  from rising above a certain level in advance. 
     Hereinafter, a problem of the battery pack  1  in which the heating control unit  130  is not provided and the operating state of the heating relay  40  is controlled by the processor  120  will be described. It is assumed that the operating states of the main relay  20  and the heating relay  40  of the battery pack  1  are a turn-on state and a problem occurs in software of the processor  120  or a connection between the processor  120  and the heating relay  40 . In this case, since the current output from the battery module  10  is continuously applied to the heating pad  30 , the temperature of the battery pack  1  rises continuously, and an accident such as explosion of the battery pack  1  may occur. 
     Meanwhile, even if a problem occurs in software of the processor  120  or a connection between the processor  120  and the heating relay  40 , the battery pack  1  including the heating pad control apparatus  100  according to an embodiment of the present disclosure may control the operating state of the heating relay  40  by the heating control unit  130 . That is, since the heating control unit  130  is configured to output a signal corresponding to an applied signal even if there is no control of the processor  120 , the operating state of the heating pad  30  may be controlled even if the above problem occurs. 
     Therefore, there is an advantage in that the temperature of the battery pack  1  may be prevented from rising above a certain level by the heating pad control apparatus  100  according to an embodiment of the present disclosure. In addition, since the temperature of the battery pack  1  is maintained at a certain level, damage to elements provided in the battery pack  1  may be reduced, and the use efficiency of the battery pack  1  may be improved. 
     The first comparator  131  may be configured to output a first voltage comparison signal if the difference between the both-end voltages is smaller than a predetermined size. In addition, the first comparator  131  may be configured to output a second voltage comparison signal if the difference between the both-end voltages is greater than or equal to the predetermined size. 
     Here, the predetermined size may be set equal to the voltage of the battery module  10 . Preferably, the predetermined size may be set smaller than the voltage of the battery module  10  in consideration of the voltage of the battery module  10  and the internal resistance of the main relay  20 . However, hereinafter, for convenience of description, it will be described that the predetermined size is set equal to the voltage of the battery module  10  without considering the internal resistance of the main relay  20 . 
     For example, it is assumed that the voltage of the battery module  10  is 10 [V] and the predetermined size is set to 10 [V]. If one end voltage of the main relay  20  is 10 [V] and the other end voltage thereof is 9.9 [V], the difference between the both-end voltages of the main relay  20  is 0.1 [V]. That is, since the difference (0.1 [V]) between the both-end voltages of the main relay  20  is smaller than the predetermined size (10 [V]), the first comparator  131  may output the first voltage comparison signal. 
     As another example, if one end voltage of the main relay  20  is 10 [V] and the other end voltage thereof is 0 [V], the difference (10 [V]) between the both-end voltages of the main relay  20  is equal to the predetermined size (10 [V]), so the first comparator  131  may output the second voltage comparison signal. 
     As still another example, if one end voltage of the main relay  20  is 10 [V] and the other end voltage thereof is 7 [V], the difference (3[V]) between the both-end voltages of the main relay  20  is smaller than the predetermined size (10 [V]), so the first comparator  131  may output the first voltage comparison signal. This case will be described with reference to  FIGS. 4 and 5 . 
       FIG. 4  is a diagram showing an exemplary configuration in which a load  2  is connected to the battery pack  1  including the heating pad control apparatus  100  according to an embodiment of the present disclosure.  FIG. 5  is a diagram showing a second example of the current flowing in the battery pack  1 . In  FIG. 5 , arrows indicate the direction in which the current output from the load  2  flows. 
     Referring to  FIGS. 4 and 5 , even if the operating state of the main relay  20  is a turn-off state, if the battery pack  1  and the load  2  are connected, the voltage of the load  2  may be applied to the second node N 2 . In addition, in this case, if the operating state of the heating relay  40  is a turn-on state, a closed circuit may be formed by the load  2 , the heating relay  40  and the heating pad  30 , so that the current output from the load  2  may be applied to the heating pad  30 . Therefore, the heating pad  30  may generate heat by the current output from the load  2 . 
     In addition, for example, a smoothing capacitor for maintaining a constant voltage level may be further included in the battery pack  1 . In the capacitor, a voltage corresponding to the battery module  10  may be stored. That is, if the operating state of the main relay  20  is changed to a turn-off state to release the connection between the battery module  10  and the capacitor, the current stored in the capacitor may be emitted. In this case, if the operating state of the heating relay  40  is controlled only based on the operating state of the main relay  20 , there is a problem that the heating pad  30  may generate heat by the current output from the capacitor. 
     Meanwhile, the first comparator  131  may not output a corresponding voltage comparison signal in consideration of only the operating state of the main relay  20 , but may output a corresponding voltage comparison signal in consideration of a difference between the both-end voltages of the main relay  20 . That is, in the case where the heating pad  30  receives the current from the battery module  10  and in the case where the heating pad  30  receives the current from other than the battery module  10 , the operating state of the heating relay  40  may be controlled in the same manner. 
     Therefore, since the heating pad control apparatus  100  according to an embodiment of the present disclosure considers the difference between the both-end voltages of the main relay  20 , there is an advantage in that the heating pad  30  is prevented from unexpectedly generating heat by the current applied from not only the battery module  10  but also other than the battery module  10 . 
     The second comparator  132  may be configured to output the first temperature comparison signal if a value corresponding to the measured temperature signal is greater than or equal to a value corresponding to the reference temperature signal. In addition, the second comparator  132  may be configured to output the second temperature comparison signal if the value corresponding to the measured temperature signal is smaller than the value corresponding to the reference temperature signal. 
     Here, the value corresponding to the reference temperature signal may be an upper limit temperature in a normal temperature range of the battery pack  1 . For example, the upper limit temperature of the normal temperature range of the battery pack  1  may be set to 60° C. Accordingly, the reference temperature signal may be a signal corresponding to 60° C., and the value corresponding to the reference temperature signal may be 60° C. 
     That is, the second comparator  132  may be configured to output the first temperature comparison signal if the temperature of the battery pack  1  actually measured by the measuring unit  110  is higher than the preset upper limit temperature of the battery pack  1 . Conversely, the second comparator  132  may be configured to output the second temperature comparison signal if the measured temperature of the battery pack  1  is lower than the preset upper limit temperature of the battery pack  1 . 
     If the first voltage comparison signal is received from the first comparator  131  and the first temperature comparison signal is from the second comparator  132 , the control signal output unit  133  may be configured to output a turn-off control signal for changing the operating state of the heating relay  40  to a turn-off state. 
     Specifically, the control signal output unit  133  may receive the first voltage comparison signal in the case where a current is applied to the heating pad  30 . In this case, the heating pad  30  may receive a current from the battery module  10  or a voltage source other than the battery module  10 . In addition, the control signal output unit  133  may receive the first temperature comparison signal in the case where the measured temperature of the battery pack  1  is greater than or equal to the reference temperature. Therefore, if the temperature of the battery pack  1  is higher than or equal to the preset upper limit temperature and a current is applied to the heating pad  30 , the control signal output unit  133  may output the turn-off control signal that changes the operating state of the heating relay  40  to a turn-off state. 
     For example, referring to  FIG. 1 , the control signal output unit  133  may output the turn-off control signal through a seventh line L 7 . The output turn-off control signal may be transmitted to the heating relay  40  through the seventh line L 7 . 
     The control signal output from the control signal output unit  133  will be described with reference to Table 1 below. 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Voltage 
                 Temperature 
                   
               
               
                 comparison signal 
                 comparison signal 
                 Control signal 
               
               
                   
               
             
            
               
                 First voltage 
                 First temperature 
                 Turn-off control signal 
               
               
                 comparison signal 
                 comparison signal 
               
               
                 First voltage 
                 Second temperature 
                 Turn-on control signal 
               
               
                 comparison signal 
                 comparison signal 
               
               
                 Second voltage 
                 First temperature 
                 Turn-on control signal 
               
               
                 comparison signal 
                 comparison signal 
               
               
                 Second voltage 
                 Second temperature 
                 Turn-on control signal 
               
               
                 comparison signal 
                 comparison signal 
               
               
                   
               
            
           
         
       
     
     Table 1 is a table showing the control signal output according to the voltage comparison signal and the temperature comparison signal received by the control signal output unit  133 . 
     Referring to Table 1, the control signal output unit  133  may output the turn-off control signal only when the first voltage comparison signal is received from the first comparator  131  and the first temperature comparison signal is received from the second comparator  132 . That is, only in this case, the operating state of the heating relay  40  may be controlled to a turn-off state by the control signal output from the control signal output unit  133 . 
     For example, the control signal output unit  133  may be configured as a NAND (Negative-AND) gate element. Here, the NAND gate is a logic circuit that emits a false output when all inputs are true. That is, in terms of a logic circuit, the first voltage comparison signal and the first temperature comparison signal may be true, and the second voltage comparison signal and the second temperature comparison signal may be false. Also, the turn-off control signal may be false, and the turn-on control signal may be true. 
     If the temperature of the battery pack  1  is higher than or equal to the reference temperature and the heating pad  30  receives a current from the battery module  10  or another voltage source, the heating pad control apparatus  100  according to an embodiment of the present disclosure may block the current applied to the heating pad  30 , even without separate control by the processor  120 . 
     Accordingly, the heating pad control apparatus  100  has an advantage of preventing the temperature of the battery pack  1  from rising above a certain level by blocking the current applied to the heating pad  30  as long as a predetermined condition is satisfied. 
     The processor  120  may be configured to receive the measured temperature signal from the measuring unit  110 . 
     The measured temperature signal output from the measuring unit  110  may be input to the processor  120  as well as the second comparator  132 . 
     For example, referring to  FIG. 1 , the measuring unit  110  may be connected to the processor  120  through the third line L 3 . That is, the third line L 3  may include a unit line connecting the measuring unit  110  and the processor  120  and a unit line connecting the measuring unit  110  and the second comparator  132 . Therefore, the processor  120  may receive the measured temperature signal from the measuring unit  110  through the third line L 3 . 
     The processor  120  may be configured to control the operating state of the heating relay  40  based on a result obtained by comparing the measured temperature measured by the measuring unit  110  with the set reference temperature. 
     Specifically, the operating state of the heating relay  40  may be controlled not only by the heating control unit  130  but also by the processor  120 . That is, the heating control unit  130  and the processor  120  may control the operating state of the heating pad  30  by controlling the operating state of the heating relay  40  in a complementary relationship with each other. Accordingly, as the heating control unit  130  and the processor  120  control the operating state of the heating pad  30 , the high-temperature state of the battery pack  1  may be effectively prevented from continuing. 
     For example, in the embodiment of  FIG. 1 , the processor  120  may receive the measured temperature signal from the measuring unit  110  through the third line L 3  and determine the temperature of the battery pack  1  measured by the measuring unit  110  by reading the received measured temperature signal. In addition, the processor  120  may compare the determined temperature of the battery pack  1  with the preset reference temperature and output a signal for controlling the operating state of the heating relay  40  through an eighth line L 8 . Here, if the determined temperature of the battery pack  1  is equal to or higher than the preset reference temperature, the processor  120  may output a signal for controlling the operating state of the heating relay  40  to a turn-off state through the eighth line L 8 . Conversely, if the determined temperature of the battery pack  1  is lower than the preset reference temperature, the processor  120  may output a signal for controlling the operating state of the heating relay  40  to a turn-on state through the eighth line L 8 . 
     Therefore, the heating pad control apparatus  100  according to an embodiment of the present disclosure prevents the temperature of the battery pack  1  from rising above the reference temperature doubly by using the heating control unit  130  and the processor  120 , thus has an advantage of remarkably reducing the risk of accidents caused by the temperature rise of the battery pack  1 . 
     A specific configuration of the heating relay  40  will be described with reference to  FIG. 6 . 
       FIG. 6  is a diagram showing another exemplary configuration of the battery pack  1  including the heating pad control apparatus  100  according to an embodiment of the present disclosure. 
     Referring to  FIG. 6 , the heating relay  40  may include a first relay  41 , a second relay  42 , an inductor  43 , a third relay  44 , and a voltage source  45 . 
     For example, the first relay  41  and the second relay  42  may be a metal-oxide-semiconductor field effect transistor (MOSFET). In addition, the third relay  44  may include a contact point and an ion piece. That is, the ion piece moves by a magnetic force generated when a current flows through the inductor  43 . Also, if the ion piece comes into contact with the contact point, the operating state of the third relay  44  may be a turn-on state. 
     The first relay  41  may be connected to the control signal output unit  133  through the seventh line L 7 , and the second relay  42  may be connected to the processor  120  through the eighth line L 8 . However, the connection relationship among the first relay  41 , the second relay  42 , the control signal output unit  133  and the processor  120  is not limited to that shown in the drawing, and the first relay  41  may also be connected to the processor  120 , and the second relay  42  may be connected to the control signal output unit  133 . That is, the first relay  41  may be connected to any one of the control signal output unit  133  and the processor  120 , and the second relay  42  may be connected to any one of the control signal output unit  133  and the processor  120 , which is not connected to the first relay  41 . Hereinafter, as illustrated in  FIG. 6 , it will be described that the first relay  41  is connected to the control signal output unit  133  and the second relay  42  is connected to the processor  120 . 
     The first relay  41  may receive the control signal from a control signal output unit  133  through the seventh line L 7 , and the operating state of the first relay  41  may be changed to correspond to the received control signal. In addition, the second relay  42  may receive a signal from the processor  120  through the eighth line L 8 , and the operating state of the second relay  42  may be changed to correspond to the received signal. 
     That is, the operating state of the first relay  41  may be changed by the heating control unit  130  according to the state of the battery pack  1 , without being controlled by the processor  120 . 
     For example, it is assumed that the heating relay  40  does not include the first relay  41  and that the processor  120  and the second relay  42  are disconnected due to damage of the eighth line L 8  when the operating state of the second relay  42  is a turn-on state. In this case, since a current may flow through the heating line HL, the current may be continuously applied to the heating pad  30 . In addition, if the load  2  is connected as shown in  FIG. 5 , even if the operating state of the main relay  20  is controlled to a turn-off state by the processor  120 , the current may be applied to the heating pad  30  through the load  2 . Thus, the heating pad  30  continuously generates heat, and the temperature of the battery pack  1  may rise above the reference temperature. That is, when only the second relay  42  is provided, there is a problem that the battery pack  1  may be damaged due to a defect in the connection between the processor  120  and the second relay  42  or in the processor  120  itself. 
     Meanwhile, even when both the first relay  41  and the second relay  42  are provided in the heating relay  40  as in the present disclosure, it is assumed that the processor  120  and the second relay  42  is disconnected due to the damage of the eighth line L 8 . In this case, if a current flows through the heating line HL, a voltage difference between the first node N 1  and the second node N 2  may be smaller than a predetermined size. Accordingly, the first comparator  131  may output the first voltage comparison signal, which is a true value, to the control signal output unit  133  through the fifth line L 5 . In addition, if the temperature of the battery pack  1  is equal to or higher than the reference temperature, the second comparator  132  may output the first temperature comparison signal, which is a true value, to the control signal output unit  133  through the sixth line L 6 . Referring to Table 1, the control signal output unit  133  receiving the first voltage comparison signal and the first temperature comparison signal may output the turn-off control signal through the seventh line L 7 . In this case, the operating state of the first relay  41  is changed to a turn-off state, and the current applied to the heating pad  30  may be blocked. 
     Conversely, if the control signal output unit  133  does not normally output the control signal according to Table 1 since a defect occurs in the heating control unit  130 , the processor  120  may control the operating state of the second relay  42  to prevent the battery pack  1  from maintaining a high-temperature state. 
     Therefore, the heating pad control apparatus  100  according to an embodiment of the present disclosure has an advantage of effectively preventing the battery pack  1  from maintaining a high-temperature state by including both the processor  120  and the heating control unit  130 , which are complementary with each other. 
     The heating pad control apparatus  100  according to the present disclosure may be provided in the battery pack  1 . That is, battery pack  1  according to the present disclosure may include the heating pad control apparatus  100  described above and at least one battery cell. In addition, the battery pack  1  may further include electrical equipment (a relay, a fuse, etc.) and a case. 
     In addition, the heating pad control apparatus  100  according to the present disclosure may be provided in a vehicle. Preferably, the heating pad control apparatus  100  according to the present disclosure may be provided in an electric vehicle. More preferably, the battery pack  1  including the heating pad control apparatus  100  according to the present disclosure may be provided in an electric vehicle. Therefore, the heating pad control apparatus  100  may minimize damage to internal components of the vehicle by preventing the battery pack  1  from maintaining a high-temperature state. 
     The embodiments of the present disclosure described above may not be implemented only through an apparatus and method, but may be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present disclosure or a recording medium on which the program is recorded. The program or recording medium may be easily implemented by those skilled in the art from the above description of the embodiments. 
     The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description. 
     In addition, since the present disclosure described above can be substituted, modified and changed in various ways by those skilled in the art without departing from the technical idea of the present disclosure, the present disclosure is not limited by the embodiments described above and the accompanying drawings, and all or some of the embodiments may be selectively combined to enable various modifications. 
     EXPLANATION OF REFERENCE SIGNS 
     
         
         
           
               1 : battery pack 
               2 : load 
               10 : battery module 
               20 : main relay 
               30 : heating pad 
               40 : heating relay 
               41 : first relay 
               42 : second relay 
               43 : inductor 
               44 : fourth relay 
               45 : voltage source 
               100 : heating pad control apparatus 
               110 : measuring unit 
               120 : processor 
               130 : heating control unit 
               131 : first comparator 
               132 : second comparator 
               133 : control signal output unit