Charging control system for vehicle-mounted battery

Abstract

The invention provides a charging control system for a vehicle-mounted battery, which can suppress the depletion of a sub-battery in a parking state in a vehicle provided with a main battery and the sub-battery. The charging control system for the vehicle-mounted battery includes: a main battery that supplies power to a driving motor mounted on a vehicle; a sub-battery that can be charged by being supplied with power from the main battery; and a control unit that executes a first charging control for charging the sub-battery after a predetermined time has elapsed since the vehicle has reached a traveling function stop state, the control unit being configured to execute a second charging control for charging the sub-battery after a predetermined time has elapsed after the vehicle has reached a traveling function stop state. The control unit determines, on the basis of time information and position information of the vehicle, that the vehicle is in the driving function stop state within a predetermined time period and at a predetermined location set in advance, after a time shorter than the predetermined time has elapsed, that the vehicle is in the driving function stop state. Second charging control for starting charging of the sub-battery is performed.

Description

Technical Field

[0001] The present invention relates to a charging control system for a vehicle-mounted battery, and more particularly to a charging control system for a vehicle-mounted battery capable of charging a sub-battery by supplying electric power from a main battery to the sub-battery. Background Art

[0002] Electric vehicles such as electric cars and hybrid cars have a high-voltage main battery that supplies power to a driving motor and a sub-battery that supplies power to auxiliary equipment such as electrical equipment. The sub-battery is a battery that supplies power at a lower voltage than the main battery, and the main battery and the sub-battery are connected via an electrical circuit.

[0003] In a vehicle equipped with a main battery and a sub-battery, the charge level of the sub-battery decreases due to standby power during parking. For example, if a user leaves the vehicle in a parking lot at home for a long time, the charge level of the sub-battery decreases and the sub-battery is depleted, and there is a concern that the vehicle may not start normally when starting the vehicle. In order to prevent such battery depletion, in an electric vehicle, when the vehicle is parked for a long time, power is supplied from the main battery to the sub-battery to charge the sub-battery.

[0004] For example, Patent Document 1 describes a charging control device that operates a DCDC converter in an onboard electrical circuit that steps down the voltage of a main battery and supplies power to a sub-battery when a vehicle is in a parking state in which a driving function is stopped for a predetermined time, thereby charging the sub-battery. In this way, by charging the sub-battery in a long-term parking state, the sub-battery is prevented from being exhausted, and the power supply from the sub-battery can be maintained normally when the vehicle is started.

[0005] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2016-52869 Summary of the invention

[0006] Technical issues Generally, from the viewpoint of vehicle theft prevention, the charging of the sub-battery in the above-mentioned parked state is controlled so as to be interrupted when the user gets in the vehicle. Therefore, for example, when the user gets in to take out the goods in the parked vehicle, the charging may be interrupted even if it is not fully charged, and there is a concern that the sub-battery may be exhausted.

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a battery charging control system capable of preventing the sub-battery from being exhausted while the vehicle is parked in a vehicle including a main battery and a sub-battery.

[0008] Technical Solution In order to achieve the above-mentioned purpose, one embodiment of the present invention is characterized in that a charging control system for a vehicle-mounted battery comprises: a main battery, which supplies electric power to a driving motor mounted on a vehicle; a sub-battery, which is connected to the main battery via an electrical circuit and can be charged by the power supply from the main battery; and a control unit, which executes a first charging control for operating the electrical circuit to charge the sub-battery after a predetermined time set in advance has passed since the vehicle entered a driving function stop state. In the charging control system for the vehicle-mounted battery, when the control unit determines that the vehicle entered the driving function stop state within a predetermined time period and at a predetermined predetermined location based on time information and position information of the vehicle acquired by a position information acquisition unit, the control unit executes a second charging control for starting charging of the sub-battery after a time shorter than the predetermined time in the first charging control has passed.

[0009] Technical Effects According to the vehicle-mounted battery charge control system of the present invention, in a vehicle including a main battery and a sub-battery, it is possible to suppress depletion of the sub-battery while the vehicle is parked. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a block diagram showing a schematic configuration of a vehicle-mounted battery charging control system according to one embodiment of the present invention.

[0011] Figure 2 This is a block diagram showing a schematic configuration of a control mechanism in a charging control system.

[0012] Figure 3 This is a flowchart for explaining the operation of the charging control system.

[0013] Explanation of symbols 10. Charging control system for vehicle batteries 12 Main battery 14 Converter 15. DCDC Converter 16 batteries 17 Secondary battery sensor 18 Auxiliary Engine 20 Engine 22 Drive motor 30 Control device 34 Clock Department 36 Location information acquisition unit 38 Judgment Department 42 Start switch 44 Drive mode selector switch 46 Fuel level sensor DETAILED DESCRIPTION

[0014] Figure 1 1 is a block diagram showing a schematic configuration of a vehicle-mounted battery charging control system 10 according to an embodiment of the present invention. Figure 2 1 is a block diagram showing a simplified configuration of a control mechanism in a charging control system 10. The charging control system 10 is applied to a vehicle 1, for example, an electric vehicle such as an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and the vehicle 1 includes a high-voltage main battery 12 that supplies power to a drive motor 22 mounted on the vehicle 1, and a sub-battery 16 that supplies power to an auxiliary machine 18 such as an electrical device. In the charging control system 10, the main battery 12 and the sub-battery 16 are connected via an electrical circuit 11, and the sub-battery 16 is configured to be chargeable using power supplied from the main battery 12. In the present embodiment, as an example, an example of applying the charging control system 10 to a hybrid vehicle equipped with an engine 20 and a drive motor 22 as a drive source for driving the vehicle 1 is shown.

[0015] The vehicle 1 to which the charging control system 10 is applied includes a starter motor 21, an engine 20, a drive motor 22, and a transmission 24 as a power transmission path, and the transmission 24 is connected to a drive wheel 25. The charging control system 10 includes a main battery 12, an inverter 14, a DCDC converter 15, a sub-battery 16, a sub-battery sensor 17, and an auxiliary machine 18 connected via an electric circuit 11, and includes a control device 30 as a control unit that controls the operation of the vehicle 1. In addition, as Figure 2 As shown, the charging control system 10 includes an input unit 40 electrically connected to the control device 30, a start switch 42, a drive mode selection switch 44, a fuel amount sensor 46, and a passenger detection unit 48. Hereinafter, each component of the charging control system 10 will be described.

[0016] The starter motor 21 is a motor for starting the engine 20, and is driven by receiving power from the sub-battery 16. The output shaft of the starter motor 21 is connected to the crankshaft of the engine 20 via a gear, and is configured to transmit the power output from the starter motor 21 to the crankshaft of the engine 20. It should be noted that the starter motor 21 can also be driven by power supplied from the main battery 12 via the DCDC converter 15.

[0017] The engine 20 is an internal combustion engine that generates power using gasoline or the like as fuel, and outputs power for driving the drive wheels 25. The output shaft of the engine 20 is connected to the drive motor 22 and the transmission 24 via a torque converter or a clutch (not shown).

[0018] The driving motor 22 is a motor capable of outputting power for driving the driving wheel 25. For example, a multi-phase AC motor can be used as the driving motor 22. The transmission 24 changes the speed of the rotation input from the output shaft of the driving motor 22 at a predetermined speed ratio according to the driving state of the vehicle 1. As the transmission 24, for example, a continuously variable transmission (CVT (Continuously Variable Transmission)) that can change the speed ratio steplessly can be used. It should be noted that a stepped transmission that changes the meshing of a plurality of speed gears to change the speed ratio in stages can also be used in the transmission 24.

[0019] The driving motor 22 is connected to the main battery 12 via the inverter 14, and generates power by the power supplied from the main battery 21. The DC power discharged from the main battery 12 is converted into AC power by the inverter 14 and supplied to the driving motor 22. The driving motor 22 may also have the function of an engine that generates electricity using the rotational energy of the drive wheel 25. The AC power generated by the driving motor 22 can be converted into DC power by the inverter 14 and supplied to the main battery 12, thereby charging the main battery 12.

[0020] The main battery 12 is a battery for storing electric power supplied to the driving motor 22, and is a battery having a higher voltage (e.g., 100V) than the sub-battery 16. As the main battery 12, for example, a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery is used. The main battery 12 is connected to various devices in the vehicle 1 such as the sub-battery 16 and the auxiliary machine 18 via the DCDC converter 15, and the electric power stored in the main battery 12 can be stepped down by the DCDC converter 15 and supplied to the various devices.

[0021] The sub-battery 16 is a battery for storing electric power supplied to the starter motor 21 and the auxiliary machine 18, and is a battery having a voltage lower than that of the main battery 12 (e.g., 12V). As the sub-battery 16, for example, a secondary battery such as a lead storage battery or a lithium ion battery is used. The sub-battery 16 is connected to the auxiliary machine 18 and the starter motor 21, and the electric power stored in the sub-battery 16 is supplied to the auxiliary machine 18 and the starter motor 21. The auxiliary machine 18 includes various devices such as air conditioners and audio equipment.

[0022] The sub-battery sensor 17 detects various state quantities of the sub-battery 16 and outputs them to the control device 30. In the present embodiment, the sub-battery sensor 17 detects the voltage and degradation state (hereinafter also referred to as SOH (State Of Health)) of the sub-battery 16.

[0023] The input unit 40 allows the user to input information to the control device 30, and the input unit 40 is composed of a touch panel or the like. The user sets a predetermined place that becomes a reference for determination by the determination unit 38 in the charging control of the battery 16 described later through the input unit 40. The predetermined place is a predetermined place where the vehicle 1 is frequently parked, and for example, the user's home can be set. The position information of the place set by the input unit 40 is stored in the storage unit 32 of the control device 30.

[0024] The start switch 42 is a switch for starting a driving control system such as a powertrain system of the vehicle 1. For example, if a user presses the start switch 42 provided in the vehicle while stepping on the brake pedal, a signal indicating that it is turned on is sent to the control device 30, and the driving control system is started to control the vehicle 1 to a state in which the vehicle 1 can be driven (turned on). In addition, if a user presses the start switch 42 while stepping on the brake pedal when the vehicle 1 is in a state in which the vehicle 1 can be driven, a signal indicating that it is turned off is sent to the control device 30, and the driving control system is stopped, and the vehicle 1 is controlled to a state in which the driving function is stopped (turned off).

[0025] The drive mode selection switch 44 is a switch for switching the driving mode of the vehicle 1 between a normal mode that emphasizes passenger comfort and an energy-saving mode that emphasizes fuel efficiency and / or power consumption performance in a manner that increases the cruising distance compared to the normal mode. It should be noted that the mode that can be selected using the drive mode selection switch 44 is not limited to this, and may also be a power mode with an acceleration when the accelerator is operated increased compared to the normal mode.

[0026] The fuel amount sensor 46 detects the remaining amount of fuel of the engine 20 stored in the fuel tank and outputs the detection result to the control device 30. The passenger detection unit 48 detects whether a person is in the vehicle and outputs the result to the control device 30. The passenger detection unit 48 can be constituted by, for example, an in-vehicle camera.

[0027] The control device 30 is an electronic control unit having a calculation processing circuit for performing various calculation processes related to the driving control of the vehicle, a memory storing control programs and / or data, an input / output interface, etc. The control device 30 can control the driving of the engine 20 and / or the driving motor 22, for example, by controlling the converter 14 to adjust the amount of power exchanged between the driving motor 22 and the main battery 12, thereby controlling the number of revolutions and / or torque of the driving motor 22, or operating the starter motor 21 to start the engine 20, etc. In addition, the control device 30 can control the voltage of the main battery 12 by controlling the DCDC converter 15, thereby supplying it to each device. The control device 30 includes a storage unit 32, a clock unit 34, a position information acquisition unit 36, and a determination unit 38.

[0028] The storage unit 32 of the control device 30 stores various programs for executing information processing. In the present embodiment, when the vehicle 1 is in the driving function stop state, the storage unit 32 stores a charging control program for charging the sub-battery 16 by supplying power from the main battery 12. In the present embodiment, the charging control of the sub-battery 16 includes a first charging control and a second charging control. In the first charging control, after the vehicle 1 is in the driving function stop state, that is, the start switch 44 is turned off, the driving function stop state is maintained as it is, and the electric circuit 11 is operated to charge the sub-battery 16 by supplying power from the main battery 12. In the second charging control, after the vehicle 1 is in the driving function stop state, if a predetermined condition is satisfied, the charging of the sub-battery 16 is started after a time shorter than the predetermined time in the first charging control has passed.

[0029] It should be noted that, in the first charging control, the scheduled time for charging the sub-battery 16 is not limited to a fixed time, and may be set to change according to the state of degradation (SOH) of the sub-battery 16, for example, and specifically, may be set to shorten the scheduled time as the SOH value increases. In the second charging control, it may be preset to start charging after a time shorter than the scheduled time of the first charging control has passed according to a change in the scheduled time of the first charging control.

[0030] When the control device 30 detects that a person is in the vehicle cabin by the occupant detection unit 46 during the charging of the sub-battery 16 executed by the first charging control or the second charging control, the control device 30 stops the operation of the electric circuit 11 and stops the charging of the sub-battery 16. It should be noted that the operation and stop of the electric circuit 11 can be implemented by, for example, turning on / off a switch (not shown) provided between the main battery 12 and the sub-battery 16.

[0031] A predetermined threshold value that serves as a reference for switching between the first charging control and the second charging control is set in the storage unit 32. In the present embodiment, a fuel threshold value F is set as a threshold value of the fuel amount of the engine 20. th , a voltage threshold V which is a threshold of the voltage of the sub-battery 16 th , and an SOH threshold value H which is a threshold value of the state of degradation (SOH) of the sub-battery 16 th .

[0032] The clock unit 34 has a function of timing the moment. The position information acquisition unit 36 ​​is composed of, for example, a GPS receiver, and acquires the position information of the vehicle 1. When the start switch 42 is switched from the on state to the off state, the determination unit 38 determines whether the vehicle 1 is in a driving function stop state within a predetermined time period and at a predetermined predetermined place based on the time information of the clock unit 34 and the position information of the vehicle 1 acquired by the position information acquisition unit 36. Here, the predetermined time period can be set to a time period pre-set by the user through the input unit 40. In addition, alternatively, the control device 30 can also calculate the main time period for parking the vehicle 1 according to the user's use of the vehicle 1, and use the calculated parking time period as the predetermined time period. In addition, the predetermined predetermined place can be pre-set by the user through the input unit 40. The predetermined place is preferably a place where the user mainly parks the vehicle 1, for example, it can be set to the user's home.

[0033] Next, use Figure 3 The flowchart shown in FIG. 1 illustrates the charging control of the sub-battery 16 which is performed when the vehicle 1 is in the driving function stop state by the above-mentioned charging control system 10 .

[0034] When the control device 30 switches the vehicle 1 from the travelable state to the travel function stop state by switching the start switch 42 from the on state to the off state, the charging control program of the sub-battery 16 is started. The control device 30 acquires the time when the start switch 42 is switched to the off state through the clock unit 34, and acquires the position information of the vehicle 1 at that time through the position information acquisition unit 36. The determination unit 38 of the control device 30 determines whether the vehicle 1 is in the travel function stop state in a predetermined time period and at a predetermined place set in advance based on the acquired time information and the position information of the vehicle 1 (step S11).

[0035] When the determination unit 38 determines that the location where the vehicle 1 enters the travel function stop state is not the predetermined location or the time when the vehicle 1 enters the travel function stop state is outside the predetermined time period (step S11: No), the process moves to step S12, and the control device 30 executes the first charging control. In the first charging control, the sub-battery 16 is charged after a predetermined time set in advance has passed since the vehicle 1 enters the travel function stop state.

[0036] If the determination unit 38 determines that the location where the vehicle 1 enters the driving function stop state is a predetermined location and the time when the vehicle 1 enters the driving function stop state is within a predetermined time period (step S11: Yes), the process moves to step S13. Here, the predetermined location refers to a set location (point) and its vicinity. For example, if the user's home address is set, if the vehicle 1 enters the driving function stop state at the user's home and its vicinity, it is determined that the vehicle 1 enters the driving function stop state at the predetermined location.

[0037] In step S13, the determination unit 38 of the control device 30 determines whether the remaining fuel amount of the engine 20 is a predetermined threshold value F based on the output signal from the fuel amount sensor 46. th Next, it is determined based on the output signal from the drive mode selection switch 44 whether the energy-saving mode that increases the cruising distance compared to the cruising distance of the normal mode is selected as the travel mode.

[0038] In step S13, when the remaining fuel level exceeds a predetermined threshold value F th If it is determined that a driving mode other than the energy-saving mode is selected (step S13: Yes), the process moves to step S15, and the control device 30 executes the second charging control. In the second charging control, the sub-battery 16 is charged after a time shorter than the predetermined time set in advance in the first charging control has passed after the driving function is stopped.

[0039] In step S13, when the remaining fuel level reaches a predetermined threshold value F th When the driving mode is determined to be the energy-saving mode (step S13: No), it is determined whether the voltage of the sub-battery 16 is a predetermined threshold value V based on the output signal from the sub-battery sensor 17. th Next, it is determined whether the SOH of the sub-battery 16 is a predetermined threshold value H. th Next (step S14).

[0040] In step S14, when the voltage of the sub-battery 16 reaches a predetermined threshold value V th or the SOH of the sub-battery 16 is a predetermined threshold value H th In the following case (step S14: Yes), the process moves to step S15, and the control device 30 executes the second charging control. In step S14, when the voltage of the sub-battery 16 exceeds the predetermined threshold value V th and the SOH of the secondary battery 16 exceeds a predetermined threshold value H th In the case (step S14: No), the process proceeds to step S12, and control device 30 executes the first charging control.

[0041] It should be noted that the control device 30 Figure 3When the passenger detection unit 46 detects that a person is in the vehicle cabin while the sub-battery 16 charging control is being executed, the control is ended (END). Thereafter, when the passenger detection unit 46 detects that there is no passenger, the control returns to the start and the sub-battery 16 charging control is restarted.

[0042] In the above-mentioned vehicle-mounted battery charging control system 10, when the vehicle 1 is in a state where the driving function is stopped, that is, in a parking state, the charging control for charging the sub-battery 16 is selected from two modes: a first charging control in which charging starts after a predetermined time has passed since the vehicle was parked, or a second charging control in which charging starts after a time shorter than the predetermined time has passed. Generally, the user of the vehicle 1 often parks the vehicle 1 at a specific place and / or time period, such as parking the vehicle 1 in a parking lot at home at night. Therefore, for example, by setting the user's home as a predetermined place set in advance, and setting the time period when the vehicle is usually parked at home as the predetermined time period, when the user parks the vehicle 1 in the parking lot at home and during the usual time period, the sub-battery 16 can be charged at an earlier stage by selecting the second charging control, thereby suppressing the depletion of the sub-battery 16.

[0043] From the viewpoint of theft prevention of the vehicle 1, the charging of the sub-battery 16 during parking is controlled so that the charging is interrupted when the user gets in the vehicle. Therefore, in the conventional charging control, even when the user gets in the parked vehicle to take out the goods, for example, there is a case where charging is not started at the timing required for charging or charging is interrupted even if it is not sufficient, and there is a concern that the sub-battery 16 may be exhausted. In the charging control system 10 of the present embodiment, by selecting the second charging control, the sub-battery 16 can be charged with a margin at an early stage, so that the exhaustion of the sub-battery 16 during parking can be appropriately suppressed.

[0044] Furthermore, even when it is determined that the vehicle 1 is in the travel function stop state at a predetermined location within a predetermined time period, the vehicle 1 can be stopped by setting the fuel amount of the engine 20 to a predetermined threshold value F. th When the amount of fuel is low, the first charging control is selected to suppress the decrease in the power of the main battery 12 by supplying power from the main battery 12 to the sub-battery 16. If the power of the main battery 12 decreases, the frequency of starting the engine 20 increases during the next driving of the vehicle 1, and the fuel consumption deteriorates. In such a situation, by not implementing the second charging control but implementing the first charging control, the fuel consumption can be suppressed, or the noise caused by the use of the engine 20 can be suppressed to improve the comfort.

[0045] In addition, even if it is determined that the vehicle 1 is in a driving function stop state within a predetermined time period and at a predetermined location, the first charging control can be implemented while selecting an energy-saving mode, that is, a mode that emphasizes fuel consumption and / or power consumption, thereby suppressing the power consumption of the main battery 12 or suppressing the fuel consumption during subsequent driving.

[0046] In step S12, even if the fuel amount of the engine 20 reaches the predetermined threshold value F th If the energy-saving mode is selected, the sub-battery 16 may be exhausted if the voltage of the sub-battery 16 decreases or the sub-battery 16 deteriorates. For example, if the user of the vehicle 1 gives priority to the energy-saving mode and the first charging control is always selected, the waiting time until the sub-battery 16 is charged is long, and the sub-battery 16 is exhausted. Therefore, even if the fuel amount of the engine 20 is the predetermined threshold value F th When the voltage of the sub-battery 16 is below the predetermined threshold value V th or the SOH of the sub-battery 16 is a predetermined threshold value H th In the following case, the second charging control is executed to charge the sub-battery 16 at an early stage, thereby appropriately suppressing the depletion of the battery 16 .

[0047] It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the invention.

[0048] For example, when the charging control system 10 is mounted on an electric vehicle that does not mount the engine 20 , the determination based on the remaining fuel level of the engine 20 in step S13 is omitted.

[0049] In addition, the charging control system 10 may also be configured such that Figure 3 In step S11 of the flowchart shown in FIG. 1 , when the vehicle 1 is in the travel function stop state within a predetermined time period and at a predetermined location, the second charging control is executed without going through steps S13 and S14. Alternatively, the charging control system 10 may be configured such that, in step S13 following step S11, when the fuel amount of the engine 20 is a predetermined threshold value F th If the driving mode is the energy-saving mode, the first charging control is executed without going through step S14. In addition, the charging control system 10 may be configured such that, in step S13 following step S11, when the fuel amount of the engine 20 exceeds the predetermined threshold value F th And when the running mode is at least one of the modes other than the energy-saving mode, the second charging control is executed, and in other cases, the first charging control is executed or the process moves to step S14.

Claims

1. A charging control system for a vehicle battery, characterized in that: have: a main battery that supplies electric power to a driving motor mounted on the vehicle; a sub-battery connected to the main battery via an electrical circuit and capable of being charged by power supplied from the main battery; and a control unit for executing a first charging control for operating the electric circuit to charge the sub-battery after a predetermined time set in advance has elapsed since the vehicle entered the running function stop state, In the vehicle-mounted battery charging control system, When the control unit determines, based on the time information and the position information of the vehicle acquired by the position information acquisition unit, that the vehicle enters the driving function stop state within a predetermined time period and at a predetermined location that is set in advance, the control unit executes a second charging control for starting charging of the sub-battery after a time shorter than the predetermined time in the first charging control has passed.

2. The vehicle-mounted battery charging control system according to claim 1, characterized in that: The vehicle has an engine, When the control unit determines that the vehicle is in the driving function stopped state at the predetermined location within the predetermined time period, When the amount of fuel in the engine is equal to or less than a predetermined threshold, the first charging control is executed. When the amount of fuel of the engine exceeds the threshold value, the second charging control is executed.

3. The vehicle-mounted battery charging control system according to claim 2, characterized in that: The control unit executes the second charging control when it is determined that the vehicle enters the driving function stop state within the predetermined time period and at the predetermined location and the fuel amount of the engine is below the threshold value, and when the voltage of the sub-battery is below the predetermined threshold value or the degradation state of the sub-battery is below the predetermined threshold value.

4. The vehicle-mounted battery charging control system according to claim 1, characterized in that: When the control unit determines that the vehicle is in the driving function stopped state at the predetermined location within the predetermined time period, When the driving mode of the vehicle before entering the driving function stop state is an energy-saving mode in which a cruising distance is increased compared to a cruising distance in a normal mode, the first charging control is executed; When the travel mode is not the energy-saving mode, the second charging control is executed.

5. The vehicle-mounted battery charging control system according to claim 4, characterized in that: The control unit executes the second charging control when it is determined that the vehicle is in the driving function stop state at the predetermined location within the predetermined time period and the driving mode is the energy-saving mode, and when the voltage of the sub-battery is below a predetermined threshold value or the degradation state of the sub-battery is below a predetermined threshold value.

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