Patent Publication Number: US-2017365889-A1

Title: Battery pack protecting system and method

Description:
TECHNICAL FIELD 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0081392 filed in the Korean Intellectual Property Office on Jun. 9, 2015, the entire contents of which are incorporated herein by reference. 
     The present invention relates to a system and a method of protecting a battery pack, and more particularly, to a system and a method of protecting a battery pack, which measure a gradient of one or more battery packs, determine whether the measurement value exceeds a predetermined threshold gradient value, and control an operation of a switch provided on a connection path between the one or more battery packs and an external power source based on a result of the determination, thereby blocking a path of a power source supplied to a battery pack and preventing an accident, such as leakage of an electrolyte of the battery cell and an electrical short of a high voltage and a high current when the battery pack is abnormally inclined. 
     BACKGROUND ART 
     A battery is called as a storage battery or a secondary cell, and means a device storing or outputting electric energy generated by a chemical reaction between an electrolyte and an electrode existing within the battery. 
     The battery has a characteristic in an easy application according to a product group, excellent preservability, a high energy density, and the like. Further, the battery attracts attention as a new energy source for improving an environmentally-friendly characteristic and energy efficiency in that a by-product according to the use of energy is not generated, as well as a primary advantage in that it is possible to decrease the use of fossil fuel. 
     Accordingly, the battery is universally applied to an electric vehicle (EV) or an energy storage system (ESS) driven by an electrical driving source, including a portable device. 
     Particularly, the electric vehicle is on the rise as an alternative in an era in which a pollution problem becomes serious day by day and oil price is high, and in Korea, various businesses have been pushed forward for an entrance to the four world powers in an electric vehicle field up to the year of 2020. 
     The electric vehicle is propelled while driving an electric motor by using electric energy accumulated in the battery as a power source, unlike an existing vehicle, which obtains driving energy while combusting fossil fuel. That is, the battery may be considered as a core factor determining travelling of the electric vehicle, and a speed and a driving distance of the electric vehicle. 
     Accordingly, there are suggested the apparatuses for stably operating and protecting a battery, and for example, Korean Patent Application Laid-Open No. 2010-0115513 relates to a battery saver system for a vehicle, and describes the configuration, in which a main power source is controlled by sensing a voltage of a battery, thereby protecting a battery used in a vehicle. 
     The related art is configured to protect the battery from an electrical problem, such as overcharging and overdischarging, but passes over an accident incurable by a physical change of the battery. 
     For example, when a vehicle driven by a battery receives large impact or is turned over by an accident, the internal battery may deviate from an existing fixed position and be inclined, and in this case, a high voltage and a high current may leak from the battery to cause a failure of a battery pack or cause electric shock to a human body riding inside the vehicle. 
     That is, the battery for a vehicle is inclined by physical impact by a primary accident of the vehicle, and thus, a secondary accident, such as an electrical short, leakage of electrolyte, and electric shock, may be incurred. 
     Here, the related art detects only an electrical problem of the battery, but has a problem in failing to detect a physical change of the battery. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Technical Problem 
     The present invention is conceived to solve the aforementioned problem, and an object of the present invention is to provide a system and a method of protecting a battery pack, which measure a gradient of a battery pack, determine whether the measurement value exceeds a predetermined threshold gradient value, and control an operation of a switch provided on a connection path between the battery pack and an external power source based on a result of the determination, thereby blocking a path of a power source supplied to a battery pack and preventing an accident, such as leakage of an electrolyte of the battery cell and an electrical short of a high voltage and a high current when the battery pack is abnormally inclined. 
     Further, an object of the present invention is to provide a system and a method of protecting a battery pack, which blocks a power source path to a battery pack and controls peripheral devices, such as a fan, a cooling valve, and a motor, to be operated to be off when the battery pack is inclined while exceeding a threshold gradient value, thereby preventing unnecessary driving of the peripheral devices and power consumption. 
     Technical Solution 
     An exemplary embodiment of the present invention provides a system for protecting a battery pack, including: one or more battery packs including a plurality of cells; a switch unit configured to open and close a connection path between the one or more battery packs and an external power source; a detecting unit configured to measure a physical gradient of the one or more battery packs; and a control unit configured to control an operation of the switch unit based on a measurement value of the detecting unit. 
     The switch unit may be formed of one or more of a field effect transistor FET and a relay. 
     The detecting unit may measure the gradient of the one or more battery packs by using a gradient measuring sensor at a predetermined time interval, and transmit the measurement value to the control unit. 
     The control unit may include: an algorithm, into which the measurement value received from the detecting unit is input, and from which a result value is output; and a driving driver configured to control an operation of the switch unit based on the result value of the algorithm. 
     The algorithm may include a command determining whether the measurement value exceeds a predetermined threshold gradient value. 
     When the measurement value exceeds the threshold gradient value, the algorithm may output a first result value, and when the measurement value does not exceed the threshold gradient value, the algorithm may output a second result value. 
     When the first result value is output from the algorithm, the driving driver may transmit an open operation signal to the switch unit, and when the second result value is output from the algorithm, the driving driver may transmit a close operation signal to the switch unit. 
     The driving driver may control an off operation of a separate peripheral device, and the separate peripheral device may be one of an air-cooling type fan and a water-cooling type cooling valve. 
     Another exemplary embodiment of the present invention provides a method of protecting a battery pack, including: measuring a physical gradient of the one or more battery packs formed of a plurality of cells; and controlling an operation of a switch provided on a connection path between the one or more battery packs and an external power source based on a measurement value of the measuring of the gradient. 
     The measuring of the gradient may include measuring the gradient of the one or more battery packs by using a gradient measuring sensor at a predetermined time interval, and controlling an operation of the switch based on the measurement value. 
     The controlling of the operation of the switch may include inputting the measurement value received from the measuring of the gradient to an algorithm and outputting a result value. 
     The algorithm may include a command determining whether the measurement value exceeds a predetermined threshold gradient value. 
     When the measurement value exceeds the threshold gradient value, the algorithm may output a first result value, and when the measurement value does not exceed the threshold gradient value, the algorithm may output a second result value. 
     The controlling of the operation of the switch may include controlling the switch to perform an open operation when the first result value is output from the algorithm, and controlling the switch to perform a close operation when the second result value is output from the algorithm. 
     Advantageous Effects 
     According to one aspect of the present invention, it is possible to provide the system and the method for protecting a battery pack, which measure a gradient of a battery pack, determine whether the measurement value exceeds a predetermined threshold gradient value, and control a switch provided on a connection path between the battery pack and an external power source to perform an open operation when the measurement value exceeds the threshold gradient value. 
     Accordingly, it is possible to block a supply of power to the battery pack, which is abnormally inclined by impact, an accident, and the like, and prevent an accident, such as a leakage of electrolyte of a battery cell, and an electrical short of a high voltage and a high current. 
     Further, it is possible to block a supply of power to the battery pack and control peripheral devices of the battery pack to be operated off, thereby preventing unnecessary driving of the peripheral devices and decreasing power consumption. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram schematically illustrating an electric vehicle, to which a system and a method of protecting a battery pack according to an exemplary embodiment of the present invention are applicable. 
         FIG. 2  is a diagram schematically illustrating a configuration of a system for protecting a battery pack according to an exemplary embodiment of the present invention. 
         FIG. 3  is a diagram schematically illustrating a circuit diagram of the system for protecting the battery pack according to the exemplary embodiment of the present invention. 
         FIG. 4  is a flowchart illustrating a method of protecting a battery pack according to an exemplary embodiment of the present invention. 
     
    
    
     BEST MODE 
     The present invention will be described in detail below with reference to the accompanying drawings. Herein, repeated descriptions and the detailed description of a publicly known function and configuration that may make the gist of the present invention unnecessarily ambiguous will be omitted. Exemplary embodiments of the present invention are provided so as to more completely explain the present invention to those skilled in the art. Accordingly, the shape, the size, etc., of elements in the figures may be exaggerated for more clear explanation. 
     Throughout the specification and the claims, unless explicitly described to the contrary, the word “include/comprise” and variations such as “includes/comprises” or “including/comprising” mean further including other constituent elements, not excluding the other constituent elements. 
     In addition, the term “ . . . unit” described in the specification means a unit for processing at least one function and operation and may be implemented by hardware components or software components and combinations thereof. 
       FIG. 1  is a diagram schematically illustrating an electric vehicle, to which a system and a method of protecting a battery pack according to an exemplary embodiment of the present invention are applicable. 
     However, it is noted that the system and the method of protecting the battery pack according to the exemplary embodiment of the present invention are applicable to various technical fields using a battery, in addition to an electric vehicle  1 . 
     Referring to  FIG. 1 , the electric vehicle  1  may include a battery  10 , a battery management system (BMS)  20 , an electronic control unit (ECU)  30 , an inverter  40 , and a motor  50 . 
     The battery  10  is an electric energy source providing driving force to the motor  50  and driving the electric vehicle  1 , and may be charged or discharged by the inverter  40  according to the driving of the motor  50  and/or an internal combustion engine (not illustrated). 
     Here, the kind of battery  10  is not particularly limited, and examples of the battery  10  may include a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel hydrogen battery, and a nickel zinc battery. 
     The BMS  20  may estimate a state of the battery  10  and control a charging/discharging current of the battery  10  by using information about the state, and further control an opening/closing operation of a contactor. 
     The ECU  30  is an electronic control device for controlling a state of the electric vehicle  1 . For example, the ECU  30  determines a torque level based on information about an accelerator, a brake, a speed, and the like, and controls an output of the motor  50  to correspond to torque information. 
     The inverter  40  makes the battery  10  be charged or discharged based on a control signal of the ECU  30 . 
     The motor  50  drives the electric vehicle  1  based on electric energy of the battery  10  and control information transmitted from the ECU  30 . 
     As described above, the electric vehicle  1  is propelled while driving the motor  50  with the electric energy received from the battery  10 , so that when a state of the battery  10  is abnormal, a failure and an accident of the electric vehicle  1  may be incurred. 
     Accordingly, it is important to detect a state of the battery  10 , appropriately control and protect the battery  10 , and stably operate the battery  10 , and hereinafter, the system and the method of protecting the battery pack according to the exemplary embodiment of the present invention will be described with reference to  FIGS. 2 to 4 . 
       FIG. 2  is a diagram schematically illustrating a configuration of the system for protecting the battery pack according to the exemplary embodiment of the present invention, and  FIG. 3  is a diagram schematically illustrating a circuit diagram of the system for protecting the battery pack according to the exemplary embodiment of the present invention. 
     Referring to  FIGS. 2 and 3 , the system  100  for protecting the battery pack according to the exemplary embodiment of the present invention may include a battery pack  110 , a switch unit  120 , a detecting unit  130 , and a control unit  140 . 
     However, the system  100  for protecting the battery pack illustrated in  FIGS. 2 and 3  is an exemplary embodiment, and constituent elements thereof are not limited to the exemplary embodiment illustrated in  FIGS. 2 and 3 , and some constituent elements may be added, changed, or removed as necessary. 
     Further, the present invention is described based on the protection of the battery pack  110  as an exemplary embodiment, but the battery pack  110  is a concept including both a battery cell and a battery module, so that it is noted that the present invention is capable of protecting a battery cell and a battery module, as well as the battery pack  110 . 
     The battery pack  110  includes a plurality of serially connected battery cells and battery modules, and one or more battery packs  110  are configured, and the battery pack  110  may serve to accumulate electric energy and supply the electric energy to an electric system. 
     As described above with reference to  FIG. 1 , the kind of battery forming the one or more battery packs  110  is not limited. 
     In this case, the one or more battery packs  110  are electrically connected with an external power source, and the switch unit  120  may be provided on a connection path. 
     Particularly, the switch unit  120  is installed between the one or more battery packs  110  and the external power source and is opened/closed according to the control signal of the control unit  140 , which is to be described below, and the one or more battery packs  110  and the external power source may be connected or blocked by the open/close operation of the switch unit  120 . 
     That is, when the switch unit  120  is operated to be opened, power supplied from the external power source is not transmitted to the one or more battery packs  110 , and in contrast to this, when the switch unit  120  is operated to be closed, power of the external power source may be applied to the one or more battery packs  110 . 
     The switch unit  120  is formed of one or more of a field effect transistor (FET) and a relay, and may be provided at an upper side and a lower side of the one or more battery packs  110 . 
     However, it is noted that as long as the switch unit  120  performs the aforementioned function, the kind of contactor configuring the switch unit  120  is not limited, and may be variously selected. 
     The detecting unit  130  may be provided at one side of an internal side or an external side of the one or more battery packs  110  to serve to measure a physical gradient of the battery pack  110 . 
     Referring to  FIG. 3 , it is illustrated that the single detecting unit  130  detects the one or more battery packs  110 , but the number of provided detecting unit  130  may correspond to the number of one or more battery packs  110  and the detecting unit  130  may also measure a gradient of each of the one or more battery packs  110 . 
     The detecting unit  130  includes a gradient measuring sensor therein as a measuring means, and measures a gradient of the one or more battery packs  110  at a predetermined time interval. For example, when a measurement time interval is set with two seconds, the detecting unit  130  may measure a gradient of the one or more battery packs  110  at a period of two seconds, and transmit the measurement value to the control unit  140  which is to be described below. 
     As described above, the configuration of measuring the gradient of the one or more battery packs  110  at the predetermined interval is for the purpose of rapidly responding to physical impact, which is applicable to the battery pack  110 , in advance, and further, for the purpose of securing reliability of the measurement value through a re-measurement after the measurement. 
     The control unit  140  may serve to control an operation of the switch unit  120  based on the measurement value of the gradient of the one or more battery packs  110  measured by the detecting unit  130 , and may be formed of a BMS itself, or may be included in the BMS. 
     Particularly, the control unit  140  may include an algorithm  141 , into which the measurement value received from the detecting unit  130  is input and from which a result value is output, and a driving driver  142  controlling an operation of the switch unit  120 . 
     In this case, a command determining the control of the operation of the switch unit  120  may be included in the algorithm  141 , and may be, for example, a command determining whether the measurement value of the gradient of the one or more battery packs  110  measured by the detecting unit  130  exceeds a predetermined threshold gradient value. 
     Here, the algorithm  141  may output a first or second result value as a result of the performance of the command. That is, when the measurement value of the detecting unit  130  exceeds the threshold gradient value, the algorithm  141  may output the first result value, and when the measurement value of the detecting unit  130  does not exceed the threshold gradient value, the algorithm  141  may output the second result value. 
     The driving driver  142  may generate an open or close operation signal of the switch unit  120  based on the result value of the algorithm  141 . 
     For example, the driving driver  142  may generate the open operation signal of the switch unit  120  for the first result value of the algorithm  141  and generate the close operation signal of the switch unit  120  for the second result value, and the generated signals may be transmitted to the switch unit  120 . 
     The switch unit  120  performs the open or close operation according to the operation signal received from the driving driver  142 , and blocks the supply of power to the one or more battery packs  110  during the open operation, thereby preventing various accidents incurable by the inclination of the battery pack  110 . In contrast to this, during the close operation, the supply of power to the one or more battery packs  110  may be maintained. 
     In the meantime, the driving driver  142  may control the operation of the switch unit  120 , and control peripheral external devices, such as an air-cooling type fan and a water-cooling type cooling valve, and circuit components of the one or more battery packs  110 . 
     Particularly, when the first result value is output from the algorithm  141 , the driving driver  142  may generate an off signal and transmit the generated off signal to the peripheral external device and the circuit component, and thus, when the one or more battery packs  110  are not driven, the driving driver  142  turns off the peripheral external device and the circuit component, of which the driving is not required, thereby preventing power consumption. 
       FIG. 4  is a flowchart illustrating a method of protecting a battery pack according to an exemplary embodiment of the present invention. 
     When the method of protecting the battery pack according to the exemplary embodiment of the present invention starts, first, the detecting unit measures a gradient of one or more battery packs by using the gradient measurement sensor at a predetermined time interval (S 410 ). 
     The measured measurement value of the gradient is transmitted to the control unit (S 420 ), and the control unit determines whether the measurement value exceeds a predetermined threshold gradient value of the battery pack through an algorithm (S 430 ). 
     In this case when the measurement value exceeds the threshold gradient value, the algorithm outputs a first result value (S 440 - 1 ), and in contrast to this, when the measurement value does not exceed the threshold gradient value, the algorithm outputs a second result value (S 440 - 1 ). 
     The driving driver of the control unit transmits an open operation signal corresponding to the first result value to the switch unit (S 450 - 1 ) and transmits a close operation signal corresponding to the second result value to the switch unit (S 450 - 2 ). 
     When the switch unit receives the open operation signal from the driving driver, the switch unit performs the open operation and blocks a connection path between the one or more battery packs and an external power source (S 460 - 1 ), and when the switch unit receives the close operation signal from the driving driver, the switch unit maintains the close operation and supplies power to the one or more battery packs (S 460 - 2 ). 
     In the forgoing, the specific exemplary embodiment of the present invention has been illustrated and described, but it is apparent to those skilled in the art that the technical spirit of the present invention is not limited by the accompanying drawings and the described contents, and may be modified in various forms without departing from the spirit of the present invention, and the modifications are considered to belong to the claims of the present invention without departing from the spirit of the present invention.