Patent Publication Number: US-2023147382-A1

Title: System, vehicle, discharge method, and program

Description:
TECHNICAL FIELD 
     The present disclosure relates to a system, a vehicle, a discharge method, and a program. 
     The present application claims priority based on Japanese Patent Application No. 2020-067615 filed in Japan on Apr. 3, 2020, the contents of which are incorporated herein by reference. 
     BACKGROUND ART 
     A vehicle such as a hybrid electric vehicle is equipped with a battery that outputs a high voltage as an electric power source used for making the vehicle travel. In such a vehicle, a low voltage used in the vehicle may be generated from a high voltage output by the battery using a DC-DC converter power source. 
     PTL 1 discloses as a related technique an in-vehicle electric system that discharges electric charges from a smoothing capacitor when an abnormal situation occurs. 
     CITATION LIST 
     Patent Literature 
     
         
         [PTL 1] Japanese Unexamined Patent Application Publication No. 2015-100241 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, it is not desirable to come into contact with the smoothing capacitor when a high voltage electric charge is accumulated in the smoothing capacitor and a discharge passage of the electric charge has disappeared. Therefore, when the high voltage electric charge is accumulated in the smoothing capacitor and the discharge passage of the electric charge has disappeared, there is a demand for a technique capable of quickly discharging the electric charge, similar to the invention described in PTL 1. 
     The present disclosure aims to provide a system, a vehicle, a discharge method, and a program capable of solving the above problems. 
     Solution to Problem 
     In order to solve the above problems, a system according to the present disclosure includes: a power source that generates a first low voltage from a supplied high voltage; a capacitor that suppresses a fluctuation in the high voltage; and a first device that operates by using the first low voltage as an electric power source and that increases current consumption of the first device when supply of the high voltage to the power source is stopped. 
     A vehicle according to the present disclosure includes: the above-described system; a battery that outputs the high voltage; and a determination device that determines whether or not the supply of the high voltage to the power source is stopped, in which the first device increases the current consumption of the first device when the determination device determines that the supply of the high voltage to the power source is stopped. 
     A discharge method according to the present disclosure includes: causing a power source to generate a first low voltage from a supplied high voltage; causing a capacitor to suppress a fluctuation in the high voltage; and causing a first device to operate by using the first low voltage as an electric power source and to increase current consumption of the first device when supply of the high voltage to the power source is stopped. 
     A program according to the present disclosure for causing a computer of a system including a power source that generates a first low voltage from a supplied high voltage, a capacitor that suppresses fluctuations in the high voltage, and a first device that operates by using the first low voltage as an electric power source, to execute: increasing current consumption of the first device when supply of the high voltage to the power source is stopped. 
     Advantageous Effects of Invention 
     According to a system, a vehicle, a discharge method, and a program of an embodiment of the present disclosure, when a high voltage electric charge is accumulated in a capacitor and a discharge passage of the electric charge has disappeared, it is possible to quickly discharge the electric charge. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a diagram showing one example of a configuration of a vehicle according to an embodiment of the present disclosure. 
         FIG.  2    is a diagram showing one example of a configuration of an inverter according to the embodiment of the present disclosure. 
         FIG.  3    is a diagram showing a flow of a process of the vehicle according to one embodiment of the present disclosure. 
         FIG.  4    is a schematic block diagram showing a configuration of a computer according to at least one embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments 
     Hereinafter, embodiments will be described in detail with reference to the drawings. 
     (Configuration of Vehicle) 
     A vehicle  1  according to one embodiment of the present disclosure will be described. 
     The vehicle  1  is a hybrid electric vehicle or the like. As shown in  FIG.  1   , the vehicle  1  includes a battery  10 , a discharge determination device  20 , and an in-vehicle air conditioning system  30 . 
     The battery  10  is a battery that outputs a high voltage used for making the vehicle  1  travel. The output voltage of the battery  10  is supplied to the in-vehicle air conditioning system  30 . The output voltage of the battery  10  is, for example, 300 volts. 
     The discharge determination device  20  is a device that determines whether or not to output a discharge command to the in-vehicle air conditioning system  30  based on a state of the vehicle  1 . 
     For example, when the discharge determination device  20  determines that the vehicle  1  collided with an object, the discharge determination device  20  determines that the discharge command is output. Further, when the discharge determination device  20  determines that the vehicle  1  did not collide with the object, the discharge determination device  20  determines that the discharge command is not output. 
     Further, for example, when the discharge determination device  20  determines that a wiring between the battery  10  and the in-vehicle air conditioning system  30  is broken, the discharge determination device  20  determines that the discharge command is output. Further, when the discharge determination device  20  determines that a wiring between the battery  10  and the in-vehicle air conditioning system  30  is not broken, the discharge determination device  20  determines that the discharge command is not output. 
     When the discharge determination device  20  determines that the discharge command is output, the discharge determination device  20  outputs the discharge command to the in-vehicle air conditioning system  30 . Further, when the discharge determination device  20  determines that the discharge command is not output, the discharge determination device  20  does not output the discharge command to the in-vehicle air conditioning system  30 . 
     The in-vehicle air conditioning system  30  is a system that generates a low voltage from the high voltage output from the battery  10 . As shown in  FIG.  1   , the in-vehicle air conditioning system  30  includes a smoothing capacitor  301 , a motor  302 , an inverter  303 , a drive device  304 , a control device  305 , and a DC-DC power source  306 . 
     The smoothing capacitor  301  is a capacitor provided between a terminal of the battery  10  on a low voltage side and a terminal of the battery  10  on a high voltage side in order to suppress fluctuations in the output voltage of the battery  10 . When the battery  10  is connected to the smoothing capacitor  301 , the smoothing capacitor  301  is charged by the battery  10 . 
     The motor  302  is a motor used for an air conditioner in the vehicle  1 . The motor  302  operates according to a voltage received from the inverter  303 . The motor  302  is, for example, a compressor motor. 
     The inverter  303  is an inverter that operates at the high voltage output from the battery  10 . The inverter  303  drives the motor  302  according to a voltage received from the drive device  304 . 
     The drive device  304  is a device that operates at a first output voltage generated by the DC-DC power source  306 . The drive device  304  generates the voltage based on a voltage received from the control device  305 . The drive device  304  outputs the generated voltage to the inverter  303 . The drive device  304  is, for example, a driver integrated circuit (IC). 
     The control device  305  is a device that operates at a second output voltage generated by the DC-DC power source  306 . 
     The control device  305  generates the voltage for operating the motor  302  before receiving the discharge command from the discharge determination device  20 . The control device  305  outputs the generated voltage to the drive device  304 . 
     Further, when the control device  305  receives the discharge command from the discharge determination device  20 , the control device  305  increases current consumption of the control device  305  and outputs the voltage, which is used for increasing current consumption of the drive device  304 , to the drive device  304 . 
     Examples of a method of increasing the current consumption of the control device  305  include increasing a clock frequency when the control device  305  is a central processing unit (CPU), preparing a program for performing repetitive calculations in advance, executing the repetitive calculations when the discharge command is received, and the like. 
     Further, examples of a method of increasing the current consumption of the drive device  304  include outputting the voltage used for switching an insulated gate bipolar transistor (IGBT) at a high speed to the drive device  304  via the control device  305  when the drive device  304  is a driver IC configured with an IGBT, and the like. 
     For example, as shown in  FIG.  2   , when the inverter  303  includes switching elements  303   a ,  303   b ,  303   c ,  303   d ,  303   e , and  303   f , the control device  305  may switch only the IGBT that is related to the control of the switching elements  303   a ,  303   b , and  303   c  provided on the low voltage side of the switching elements  303   a  to  303   f  at a high speed and may fix the switching elements  303   d ,  303   e , and  303   f  in an OFF state regarding the IGBT that is related to the control of the switching elements  303   d ,  303   e , and  303   f . Alternatively, the control device  305  may switch only the IGBT that is related to the control of the switching elements  303   d ,  303   e , and  303   f  provided on the high voltage side of the switching elements  303   a  to  303   f  at a high speed and may fix the switching elements  303   a ,  303   b , and  303   c  in the OFF state regarding the IGBT that is related to the control of the switching elements  303   a ,  303   b , and  303   c.    
     As described above, when the current consumption of the control device  305  or the current consumption of the drive device  304  increases, the output current of the DC-DC power source  306  increases. Therefore, the current that flows from the smoothing capacitor  301  to the DC-DC power source  306  increases. That is, when a discharge command is received from the discharge determination device  20 , the in-vehicle air conditioning system  30  can discharge the electric charge, which is charged in the smoothing capacitor  301 , at a high speed by increasing the current consumption of the control device  305  or the current consumption of the drive device  304 . 
     The DC-DC power source  306  is a power source that generates a first output voltage and a second output voltage from the high voltage output from the battery  10 . For example, the first output voltage is 15 volts. Further, the second output voltage is 5 volts. 
     Next, the process of the vehicle  1  according to one embodiment of the present disclosure will be described. 
     The flow of the process of the vehicle  1  shown in  FIG.  3    will be described. 
     The discharge determination device  20  determines whether or not to output the discharge command to the in-vehicle air conditioning system  30  based on a state of the vehicle  1  (step S 1 ). 
     When the discharge determination device  20  determines that the discharge command is not output (NO in step S 1 ), the discharge determination device  20  returns the process to step S 1  without outputting the discharge command. 
     Further, when the discharge determination device  20  determines that the discharge command is output (YES in step S 1 ), the discharge determination device  20  outputs the discharge command to the in-vehicle air conditioning system  30  (step S 2 ). 
     The control device  305  receives the discharge command from the discharge determination device  20  (step S 3 ). When the control device  305  receives the discharge command, the control device  305  increases current consumption of the control device  305  and outputs the voltage, which is used for increasing current consumption of the drive device  304 , to the drive device  304  (step S 4 ). 
     As the current consumption of the control device  305  increases, the current that flows from the DC-DC power source  306  to the control device  305  increases. 
     The drive device  304  receives the voltage, which is used for increasing the current consumption, from the control device  305  (step S 5 ). When the drive device  304  receives the voltage, which is used for increasing the current consumption, the drive device  304  increases the current consumption according to the voltage (step S 6 ). 
     As the current consumption of the drive device  304  increases, the current that flows from the DC-DC power source  306  to the drive device  304  increases. 
     The above process is a process based on an electric signal, and the process is performed at a high speed. Therefore, the process of step S 4  and the process of step S 6  are processed substantially at the same time. That is, the current consumption of the control device  305  and the current consumption of the drive device  304  increase substantially at the same time. 
     The vehicle  1  according to one embodiment of the present disclosure has been described above. 
     In the in-vehicle air conditioning system  30  of the vehicle  1  according to one embodiment of the present disclosure, the DC-DC power source  306  (an example of a power source) generates a second output voltage (an example of a first low voltage) from the supplied high voltage. The smoothing capacitor  301  (an example of a capacitor) suppresses the fluctuations in the high voltage. The control device  305  (an example of a first device) is a device that operates by using the second output voltage as an electric power source and that increases the current consumption of the control device  305  when the supply of the high voltage to the DC-DC power source  306  is stopped. 
     By doing so, the current consumption of the control device  305  increases, and the current consumption of the DC-DC power source  306  also increases accordingly. When the supply of the high voltage to the DC-DC power source  306  is stopped, the current consumption of the DC-DC power source  306  is generated by the electric charge accumulated in the smoothing capacitor  301 . Therefore, when the supply of the high voltage to the DC-DC power source  306  is stopped, the electric charge that is accumulated in the smoothing capacitor  301  can be discharged at a high speed by increasing the current consumption of the control device  305 . That is, when the high voltage electric charge is accumulated in the capacitor and a discharge passage of the electric charge has disappeared, it is possible to quickly discharge the electric charge. 
     In the process according to the embodiment of the present disclosure, the order of the process may be changed within a range in which an appropriate process is performed. 
     Each of a storage unit and a storage device (including a register and a latch) in the embodiment of the present disclosure may be provided anywhere within a range in which appropriate information is transmitted and received. Further, each of the storage unit and the storage device may exist in a plurality of areas within a range in which appropriate information is transmitted and received and may store the data in a distributed manner. 
     Although the embodiment of the present disclosure has been described, the vehicle  1 , the discharge determination device  20 , the in-vehicle air conditioning system  30 , the control device  305 , and other control devices may have a computer system inside. The procedures of the above-mentioned processes are stored in a computer-readable recording medium in a form of a program, and the above-mentioned processes are performed by the computer reading and executing this program. A specific example of the computer is shown below. 
       FIG.  4    is a schematic block diagram showing a configuration of a computer according to at least one embodiment. 
     As shown in  FIG.  4   , the computer  5  includes a CPU  6 , a main memory  7 , a storage  8 , and an interface  9 . 
     For example, each of the above-mentioned vehicle  1 , the discharge determination device  20 , the in-vehicle air conditioning system  30 , the control device  305 , and other control devices is mounted on the computer  5 . An operation of each processing unit described above is stored in the storage  8  in the form of a program. The CPU  6  reads the program from the storage  8 , loads the program into the main memory  7 , and executes the above process according to the program. Further, the CPU  6  secures a storage area corresponding to each of the above-mentioned storage units in the main memory  7  according to the program. 
     Examples of the storage  8  include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, an optical magnetic disk, a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), a semiconductor memory, and the like. The storage  8  may be an internal medium directly connected to a bus in the computer  5  or may be an external medium connected to the computer  5  via an interface  9  or via a communication line. Further, when this program is distributed to the computer  5  by using the communication line, the computer  5 , in which the program is distributed, may load the program in the main memory  7  and execute the above process. In at least one embodiment, the storage  8  is a non-temporary tangible storage medium. 
     Further, the above program may implement some of the above-mentioned functions. Further, the program may be a file, a so-called difference file (difference program), that can implement the above-mentioned functions in combination with a program already recorded in a computer system. 
     Although some embodiments of the present disclosure have been described, these embodiments are examples and do not limit the scope of the invention. These embodiments may be subject to various additions, various omissions, various replacements, and various modifications without departing from the gist of the invention. 
     ADDITIONAL NOTES 
     The system ( 30 ), the vehicle ( 1 ), the discharge method, and the program described in each embodiment of the present disclosure are recognized as follows, for example. 
     (1) A system ( 30 ) according to a first aspect includes: a power source ( 306 ) that generates a first low voltage from a supplied high voltage; a capacitor ( 301 ) that suppresses fluctuations in the high voltage; and a first device ( 305 ) that operates by using the first low voltage as an electric power source and that increases current consumption of the first device when supply of the high voltage to the power source ( 306 ) is stopped. 
     The current consumption of the first device ( 305 ) increases, and the current consumption of the power source ( 306 ) also increases accordingly. When the supply of the high voltage to the power source ( 306 ) is stopped, the current consumption of the power source ( 306 ) is generated by an electric charge accumulated in the capacitor ( 301 ). Therefore, when the supply of the high voltage to the power source ( 306 ) is stopped, the electric charge that is accumulated in the capacitor ( 301 ) can be discharged at a high speed by increasing the current consumption of the first device ( 305 ). That is, with this system ( 30 ), when the high voltage electric charge is accumulated in the capacitor ( 301 ) and the discharge passage of the electric charge has disappeared, it is possible to quickly discharge the electric charge. 
     (2) The system ( 30 ) according to a second aspect may be the system ( 30 ) of (1) and may include: a second device ( 304 ) that operates by using a second low voltage as an electric power source, in which the power source ( 306 ) may generate the second low voltage from the high voltage, the first device ( 305 ) may output a voltage, which is used for increasing current consumption of the second device ( 304 ), to the second device ( 304 ) when the supply of the high voltage to the power source ( 306 ) is stopped, and the second device ( 304 ) may increase the current consumption of the second device ( 304 ) based on the voltage output from the first device ( 305 ). 
     With this system ( 30 ), the first device ( 305 ) can increase the current consumption, and the second device ( 304 ) can also increase the current consumption. Therefore, the system ( 30 ) according to the second aspect can discharge the electric charge of the capacitor ( 301 ) at a higher speed than the system ( 30 ) according to the first aspect. 
     (3) The system ( 30 ) according to a third aspect may be the system ( 30 ) of (2) and may include: a motor ( 302 ); and an inverter ( 303 ) that controls the motor ( 302 ) based on a voltage received from the second device ( 304 ). 
     With this system ( 30 ), even in the system ( 30 ) that drives the motor, when the high voltage electric charge is accumulated in the capacitor ( 301 ) and the discharge passage of the electric charge has disappeared, it is possible to quickly discharge the electric charge. 
     (4) The system ( 30 ) according to a fourth aspect may be the system ( 30 ) of (3), in which when the supply of the high voltage to the power source ( 306 ) is stopped, the second device ( 304 ) may set switching elements ( 303   d ,  303   e ,  303   f ) provided on a high voltage side of switching elements ( 303   a ,  303   b ,  303   c ,  303   d ,  303   e ,  303   f ) constituting the inverter ( 303 ) to an OFF state and cause only switching elements ( 303   a ,  303   b ,  303   c ) provided on a low voltage side of the switching elements ( 303   a ,  303   b ,  303   c ,  303   d ,  303   e ,  303   f ) to perform a switching operation, or may set the switching elements ( 303   a ,  303   b ,  303   c ) provided on the low voltage side of the switching elements ( 303   a ,  303   b ,  303   c ,  303   d ,  303   e ,  303   f ) constituting the inverter ( 303 ) to the OFF state and cause only the switching elements ( 303   d ,  303   e ,  303   f ) provided on the high voltage side of the switching elements ( 303   a ,  303   b ,  303   c ,  303   d ,  303   e ,  303   f ) to perform the switching operation. 
     With this system ( 30 ), even when the second device ( 304 ) increases the current consumption, the motor ( 302 ) is not rotated. Therefore, there is no adverse effect (for example, abnormal noise) associated with the rotation of the motor ( 302 ). 
     (5) A vehicle ( 1 ) according to a fifth aspect may include: the system ( 30 ) according to any one of (1) to (4); a battery ( 10 ) that outputs the high voltage; and a determination device ( 20 ) that determines whether or not the supply of the high voltage to the power source ( 306 ) is stopped, in which the first device ( 305 ) increases the current consumption of the first device ( 305 ) when the determination device ( 20 ) determines that the supply of the high voltage to the power source ( 306 ) is stopped. 
     With this vehicle ( 1 ), even in the system ( 30 ) provided in the vehicle ( 1 ), when the high voltage electric charge is accumulated in the capacitor ( 301 ) and the discharge passage of the electric charge has disappeared, it is possible to quickly discharge the electric charge. 
     (6) A discharge method according to a sixth aspect includes: causing a power source ( 306 ) to generate a first low voltage from a supplied high voltage; causing a capacitor ( 301 ) to suppress fluctuations in the high voltage; and causing a first device ( 305 ) to operate by using the first low voltage as an electric power source and to increase current consumption of the first device ( 305 ) when supply of the high voltage to the power source ( 306 ) is stopped. 
     With this discharge method, when the high voltage electric charge is accumulated in the capacitor ( 301 ) and the discharge passage of the electric charge has disappeared, it is possible to quickly discharge the electric charge. 
     (7) A program according to a seventh aspect for causing a computer ( 5 ), which has a system ( 30 ) including a power source ( 306 ) that generates a first low voltage from a supplied high voltage, a capacitor ( 301 ) that suppresses fluctuations in the high voltage, and a first device ( 305 ) that operates by using the first low voltage as an electric power source, to execute: increasing current consumption of the first device ( 305 ) when supply of the high voltage to the power source ( 306 ) is stopped. 
     With this program, when the high voltage electric charge is accumulated in the capacitor ( 301 ) and the discharge passage of the electric charge has disappeared, it is possible to quickly discharge the electric charge. 
     INDUSTRIAL APPLICABILITY 
     According to a system, a vehicle, a discharge method, and a program of an embodiment of the present disclosure, when a high voltage electric charge is accumulated in a capacitor and a discharge passage of the electric charge has disappeared, it is possible to quickly discharge the electric charge. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  Vehicle 
               5  Computer 
               6  CPU 
               7  Main memory 
               8  Storage 
               9  Interface 
               10  Battery 
               20  Discharge determination device 
               30  In-vehicle air conditioning system 
               301  Smoothing capacitor 
               302  Motor 
               303  Inverter 
               304  Drive device 
               305  Control device 
               306  DC-DC power source