JP2019170080A - Power conversion device - Google Patents

Abstract

To provide a power conversion device that prevents overcharge of an on-vehicle battery to suppress an occurrence of abnormality during charging.SOLUTION: Provided is a battery support device 10 to be connected to an on-vehicle battery E1 that supplies power to a starter 101, in which a control unit 12 acquires a battery voltage of the on-vehicle battery E1. The control unit 12 stores a threshold voltage set on the basis of the acquired battery voltage of the on-vehicle battery E1 at engine stop in a storage unit 122. Upon detection of startup of the starter 101, the control unit 12 controls switching of an AC-DC converter 11 so as to output a voltage up to the threshold voltage stored in the storage unit 122.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power conversion device connected to an in-vehicle battery that supplies power to a starter.

  If the engine cannot be started due to insufficient charging of the vehicle-mounted battery, electric power may be supplied from the outside in order to assist the engine start. For example, Patent Literature 1 discloses a vehicle start control device that recognizes a charging state of a main battery that supplies power to a motor that generates driving force of the vehicle and charges the main battery from a commercial AC power source. . By charging the main battery, power can be supplied to each device connected to the main battery, and the engine can be started. As a result, the vehicle can be run.

JP 2011-244649 A

  By the way, the vehicle-mounted battery is generally a lead storage battery. A lead storage battery generates hydrogen gas by electrolysis of water during charging. For this reason, as described in Patent Document 1, when a large current is supplied to a lead battery when charging a vehicle-mounted battery from a commercial AC power supply, a large amount of gas may be generated.

  This invention is made | formed in view of such a situation, and it aims at providing the power converter device which prevents the overcharge of a vehicle-mounted battery and suppresses the abnormality generation at the time of charge.

  In order to solve the above-described problem, the power conversion device according to the first invention of the present application includes a power output unit connected so as to be able to supply power to the in-vehicle battery and the starter, and voltage information for acquiring battery voltage information regarding the battery voltage of the in-vehicle battery. An acquisition unit, a setting unit that sets a threshold voltage based on battery voltage information acquired by the voltage information acquisition unit before starting the starter, and a storage unit that stores information on the threshold voltage set by the setting unit And a start detection unit that detects start of the starter, and when the start detection unit detects start of the starter, an output voltage controlled to a voltage having the threshold voltage as an upper limit is output from the power output unit. A first output control unit.

  A power conversion device according to a second invention of the present application includes a power output unit connected to an in-vehicle battery and an in-vehicle accessory so as to be able to supply power, a voltage information acquisition unit that acquires battery voltage information related to a battery voltage of the in-vehicle battery, and the in-vehicle unit Before starting power consumption by the accessory, a setting unit that sets a threshold voltage based on the battery voltage information acquired by the voltage information acquisition unit, a storage unit that stores information on the threshold voltage set by the setting unit, A first output control unit that outputs an output voltage controlled to a voltage value with the threshold voltage as an upper limit after the power supply to the in-vehicle battery is completed, from the power output unit;

  A power conversion device according to a third aspect of the present invention includes a power output unit connected to a vehicle battery and a starter so as to be able to supply power, a voltage information acquisition unit that acquires battery voltage information relating to a battery voltage of the vehicle battery, and the vehicle battery A storage unit that stores a threshold voltage, a start detection unit that detects the start of the starter, and a voltage that has the threshold voltage as an upper limit when the start detection unit detects the start of the starter. A first output control unit that outputs an output voltage controlled to a value from the power output unit.

  4th invention of this application is the power converter device from 1st invention to 3rd invention, Comprising: The said 1st output control part outputs the fixed voltage which makes the said threshold voltage an upper limit.

  5th invention of this application is the power converter device from 1st invention to 4th invention, Comprising: The said 1st output control stops the output of a voltage based on the information which the said voltage information acquisition part acquires.

  6th invention of this application is a power converter device of 5th invention, Comprising: Said 1st output control is the said output voltage after the voltage value of the said battery voltage reaches the said threshold voltage after the output operation of the said output voltage. Stop the output of.

  A seventh invention of the present application is the power conversion device according to the fifth invention, wherein the first output control stops the output of the output voltage based on the change amount of the battery voltage after the output operation of the output voltage. .

  An eighth invention of the present application is the power conversion device according to the first invention to the fourth invention, wherein the first output control is based on a predetermined time lapse state after the start of power supply to the in-vehicle battery. The voltage output is set to a voltage for fully charging the in-vehicle battery.

  A ninth invention of the present application is the power conversion device according to the first to eighth inventions, wherein a second output control unit that outputs a constant voltage with the threshold voltage as an upper limit before starting the starter, Prepare.

  A tenth aspect of the present invention is the power conversion device according to the first to eighth aspects of the present invention, in which an output voltage controlled to a voltage value with the threshold voltage as an upper limit is started from the power output unit before the starter is started. A second output control unit for outputting.

  An eleventh invention of the present application is the power conversion device according to the ninth invention or the tenth invention, comprising a full charge unit that fully charges the in-vehicle battery, wherein the second output control unit is the full charge unit. The voltage based on the battery voltage of the said vehicle-mounted battery after being fully charged by is output.

  A twelfth invention of the present application is the power conversion device according to the first invention to the eleventh invention, which is connected to an AC power supply, and the first output control unit includes an AC-DC converter.

  A thirteenth invention of the present application is the power conversion device according to the first to eleventh inventions, comprising an input voltage detector connected to an external charger and detecting an input voltage from the external charger, When the input voltage detected by the input voltage detection unit is equal to or lower than the threshold voltage, the first output control unit outputs the input voltage and the input voltage detected by the input voltage detection unit When the input voltage is higher than the threshold voltage, the second control for stepping down and outputting the input voltage is executed.

  A fourteenth aspect of the present invention is the power conversion device of the thirteenth aspect, wherein the first output control unit includes a step-down circuit provided between the in-vehicle battery and the external charger. In the first control, The switch included in the step-down circuit is always turned on, and in the second control, the switch is switched and the step-down circuit is operated.

  A fifteenth aspect of the present invention is the power conversion device according to the thirteenth or fourteenth aspect of the present invention, comprising an external charger charging unit that charges the external charger with an alternator that charges the in-vehicle battery.

  A sixteenth aspect of the present invention is the power conversion device according to the fifteenth aspect of the present invention, wherein the external charger charging unit is a diode having an anode connected to the in-vehicle battery and a cathode connected to the external charger.

  A seventeenth aspect of the invention is a power conversion device connected between an in-vehicle battery that supplies power to a starter and an external charger, a switch connected between the in-vehicle battery and the external charger, A start detection unit that detects a start; and an output control unit that turns on the switch for a predetermined time when the start detection unit detects the start of the starter.

  An eighteenth aspect of the invention is a power conversion device of the seventeenth aspect of the invention, comprising a diode connected in parallel with the switch, having an anode connected to the in-vehicle battery, and a cathode connected to the external charger.

  According to the present invention, it is possible to assist the output of the in-vehicle battery when starting the starter. At this time, overcharging of the in-vehicle battery is prevented by setting the threshold voltage of the upper limit value of the output voltage of the power conversion device. For this reason, generation | occurrence | production of abnormality at the time of charge of a vehicle-mounted battery can be suppressed.

It is a figure which shows the use condition of a battery auxiliary device. It is a figure which shows the equivalent circuit of FIG. It is a figure which shows the flowchart of the process which a control part performs. It is a graph which shows the battery voltage of a vehicle-mounted battery, and the output current of a battery auxiliary device. It is a figure which shows the flowchart of the process which the control part of Embodiment 2 performs. It is a graph which shows the battery voltage of a vehicle-mounted battery, and the output current of a battery auxiliary device. It is a graph which shows the battery voltage of a vehicle-mounted battery, and the output current of a battery auxiliary device. It is a graph which shows the battery voltage of a vehicle-mounted battery in the case of fully charging a vehicle-mounted battery, and the output current of a battery auxiliary device. It is a figure which shows the equivalent circuit of the battery auxiliary device of Embodiment 5. It is a figure which shows the flowchart of the process which the control part of Embodiment 5 performs. It is a figure which shows the equivalent circuit of the battery auxiliary device of Embodiment 6. It is a figure which shows the flowchart of the process which the control part of Embodiment 6 performs. It is a figure which shows the use condition of the battery auxiliary device of Embodiment 7.

<1. Embodiment 1>
Embodiment 1 of the battery auxiliary device of the present invention will be described below. The battery auxiliary device is a device that is connected to the in-vehicle battery and the starter and assists the engine start of the vehicle. The battery auxiliary device is an example of the “power conversion device” in the present invention.

<1.1. Battery auxiliary device usage status>
FIG. 1 is a diagram illustrating a usage state of the battery auxiliary device 10.

  The in-vehicle battery E1 shown in FIG. 1 is a lead storage battery mounted on a vehicle. The in-vehicle battery E1 may be an “open type” lead storage battery or a “sealed” lead storage battery. A starter 101 is connected to the in-vehicle battery E1. The starter 101 is an electric motor for starting the engine. When the ignition key 102 is turned on, the starter 101 is supplied with power from the in-vehicle battery E1 and starts.

  Note that accessories such as a lamp (not shown) and devices such as a security system are connected to the in-vehicle battery E1. These devices are supplied with power from the in-vehicle battery E1 even when the ignition key 102 is not turned on.

  The battery auxiliary device 10 is connected to the in-vehicle battery E1. The battery auxiliary device 10 may be disposed inside the vehicle or may be disposed outside the vehicle. The battery auxiliary device 10 has a power plug 10A. The power plug 10A is connected to a household power source, for example. The battery auxiliary device 10 converts the input AC voltage into a DC voltage and outputs it to the in-vehicle battery E1.

  When the ignition key 102 is turned on, a large current flows from the in-vehicle battery E1 to the starter 101, and the battery voltage of the in-vehicle battery E1 rapidly decreases. The battery auxiliary device 10 outputs a current to the starter 101 to start the starter 101 in order to assist the output of the in-vehicle battery E1 when the battery voltage rapidly decreases. That is, the battery auxiliary device 10 is a device for assisting engine start, which assists the vehicle-mounted battery E1 to start the engine.

<1.2. Configuration of Battery Auxiliary Device>
FIG. 2 is a diagram showing an equivalent circuit of FIG.

  The battery auxiliary device 10 has a pair of battery connection ports P11 and P12 and a pair of power supply connection ports P13 and P14. The battery connection ports P11 and P12 are connected to the in-vehicle battery E1. The power connection ports P13 and P14 are connected to the AC power supply Va. The AC power source Va is a household power source to which the power plug 10A of FIG. 1 is connected.

  The battery auxiliary device 10 has an AC-DC converter 11. The AC-DC converter 11 is a power output unit connected to the in-vehicle battery E1 and the starter 101 so as to be able to supply power. The input of the AC-DC converter 11 is connected to the power connection ports P13 and P14. The output of the AC-DC converter 11 is connected to battery connection ports P11 and P12. The AC-DC converter 11 converts the AC voltage input from the battery connection ports P11 and P12 into a DC voltage. The converted DC voltage is output from the power supply connection ports P13 and P14.

  An output current detector 14 and an output voltage detector 15 are provided on the output side of the AC-DC converter 11. The output current detection unit 14 is means for detecting the output current Io of the AC-DC converter 11. The output voltage detector 15 is means for detecting the output voltage Vo of the AC-DC converter 11.

  The battery auxiliary device 10 includes a control unit 12. The control unit 12 includes a processor 121 and a storage unit 122. The storage unit 122 includes a ROM and a RAM. The storage unit 122 stores a computer program and data for operating the battery auxiliary device 10. The data includes a threshold current I1 described later. The processor 121 reads and executes the computer program and data stored in the storage unit 122. The processor 121 functions as a “voltage information acquisition unit”, “setting unit”, “starting detection unit”, and “first output control unit” of the present invention by executing a computer program.

  The processor 121 acquires the output current Io of the AC-DC converter 11 from the detection result of the output current detection unit 14. Further, the processor 121 acquires the output voltage Vo of the AC-DC converter 11 from the detection result of the output voltage detection unit 15. The processor 121 performs switching control of the AC-DC converter 11 so that the output current Io becomes a predetermined current and the output voltage Vo becomes a predetermined voltage.

  Moreover, the processor 121 acquires the battery voltage Vc of the vehicle-mounted battery E1. In this example, the on-vehicle battery E1 is connected to a voltage detection unit 103 that detects the battery voltage Vc. The voltage detection unit 103 is, for example, a voltage dividing resistor circuit. The processor 121 acquires the detection result of the voltage detection unit 103, and acquires the battery voltage Vc of the in-vehicle battery E1. In the present embodiment, the voltage detection unit 103 is provided independently of the battery auxiliary device 10. Then, the battery auxiliary device 10 acquires the detection result of the voltage detection unit 103. In this case, the voltage detection unit 103 provided for use in other control can be used. However, the battery auxiliary device 10 may include the voltage detection unit 103.

<1.3. Operation of Battery Auxiliary Device>
Below, the process which the processor 121 performs is demonstrated in detail using a flowchart and a graph.

  FIG. 3 is a diagram illustrating a flowchart of processing executed by the processor 121. FIG. 4 is a graph showing the battery voltage Vc of the in-vehicle battery E1 and the output current of the battery auxiliary device 10. The output current of the battery auxiliary device 10 is also the output current Io of the AC-DC converter 11. In FIG. 4, the graph of the battery voltage Vc is indicated by a solid line, and the graph of the output current Io is indicated by a broken line.

  The processor 121 determines whether or not the engine is stopped (step S1). For example, the processor 121 may acquire and determine the driving state of the engine from the outside, or may determine from the charging state of the in-vehicle battery E1 charged from the alternator (generator). If the engine is not stopped (step S1: NO), the in-vehicle battery E1 is charged from the alternator, and the engine auxiliary assistance by the battery auxiliary device 10 is unnecessary, and thus this process is terminated.

  When the engine is stopped (step S1: YES), that is, before starting the starter 101, the processor 121 acquires the battery voltage Vc of the in-vehicle battery E1 from the detection result of the voltage detection unit 103 (step S2). . The acquisition timing of the battery voltage Vc (timing (1) in FIG. 4) is not particularly limited as long as it is before the starter 101 is started. For example, the timing (1) in FIG. 4 may be immediately after the battery auxiliary device 10 is connected to the in-vehicle battery E1. The processor 121 sets the acquired battery voltage Vc as the threshold voltage V1, and stores it in the storage unit 122 (step S3).

  The processor 121 determines whether or not the starter 101 has been started (step S4). For example, the processor 121 continues to acquire the battery voltage Vc from the voltage detection unit 103. A large current flows when the starter 101 is started. For this reason, as shown in the timing (2) of FIG. 4, the battery voltage Vc of the vehicle-mounted battery E1 rapidly decreases. The processor 121 detects the start of the starter 101 by detecting the sudden decrease in the battery voltage Vc. When detecting the battery voltage Vc that rapidly decreases, it may be detected that the battery voltage Vc is not zero in order to detect disconnection or the like.

  When the starter 101 has not been started (step S4: NO), the processor 121 executes the process of step S4 again. When starting of the starter 101 is detected (step S4: YES), the processor 121 drives the AC-DC converter 11 and performs power feeding control (step S5). In this power supply control, the processor 121 acquires the output current Io and the output voltage Vo. Then, the processor 121 performs switching control of the AC-DC converter 11 so that the output voltage Vo = the threshold voltage V1 and the output current Io ≦ the threshold current I1.

  The threshold current I1 is a limit value for overcurrent protection of the battery auxiliary device 10 stored in the storage unit 122 in advance. The threshold current I1 is appropriately set according to the performance of the battery auxiliary device 10.

  As shown in FIG. 4, at the timing (2) at which the starter 101 is started, the battery voltage Vc rapidly decreases from the threshold voltage V1. When the battery voltage Vc rapidly decreases and the threshold voltage V1 is output from the battery auxiliary device 10, in addition to the current flowing from the in-vehicle battery E1 to the starter 101, the current also flows from the battery auxiliary device 10. . As a result, a sufficient current flows through the starter 101 and the engine can be started.

  In this power supply control, the processor 121 outputs the threshold voltage V1 from the AC-DC converter 11 at a constant level. The threshold voltage V1 is the battery voltage Vc before the starter 101 is started. That is, a voltage higher than the battery voltage before the starter 101 is started is not applied to the in-vehicle battery E1. Thereby, the overcharge of the vehicle-mounted battery E1 can be prevented. And generation | occurrence | production of the gas which arises in the vehicle-mounted battery E1 which is a lead storage battery can be suppressed by preventing overcharge.

  Further, in the power supply control, the upper limit of the output current Io is set as the threshold current I1. That is, no current larger than the threshold current I1 flows through the battery auxiliary device 10. Thereby, the overcurrent protection of the battery auxiliary device 10 can be performed.

  In step S5, the processor 121 only needs to perform switching control of the AC-DC converter 11 in a range where the upper limit of the output voltage Vo does not exceed the threshold voltage V1. At least when the starter 101 is started, there may be a voltage difference in which current flows from the battery auxiliary device 10 to the in-vehicle battery E1. Similarly, the processor 121 may control the AC-DC converter 11 in a range in which the upper limit of the output current Io does not exceed the threshold current I1 so that overcurrent protection of the battery auxiliary device 10 can be performed.

  The processor 121 determines whether or not the battery voltage Vc of the in-vehicle battery E1 has reached the threshold voltage V1 (step S6). The output current Io of the battery auxiliary device 10 decreases as the battery voltage Vc of the in-vehicle battery E1 increases. Then, at the timing (3) in FIG. 4, the output current Io becomes almost zero. For this reason, when the battery voltage Vc of the vehicle-mounted battery E1 becomes the threshold voltage V1 (step S6: YES), the processor 121 stops the control of the AC-DC converter 11 and stops the power feeding control (step S7). ). When the battery voltage Vc does not exceed the threshold voltage V1 (step S6: NO), the processor 121 executes the process of step S6 again.

  After timing (2) in FIG. 4, when starter 101 is driven and the engine is started, power generation by an alternator (not shown) is started. When the voltage of the in-vehicle battery E1 is lowered, charging is started by the power generation of the alternator. In this example, the battery voltage Vc after the timing (3) is higher than the threshold voltage V1 by being charged by the alternator.

  As described above, in the present embodiment, the starter 101 is started and the battery auxiliary device 10 outputs the threshold voltage V1 to start the engine start assist for the in-vehicle battery E1. Thereby, driving of the starter 101 can be assisted. Further, since the threshold voltage V1 is the battery voltage Vc of the in-vehicle battery E1 before the starter 101 is started, overcharge of the in-vehicle battery E1 can be prevented. For this reason, generation | occurrence | production of the gas in the vehicle-mounted battery E1 can be suppressed.

  When the in-vehicle battery E1 is an open-type lead storage battery, there is a risk of leakage from the in-vehicle battery E1 if a large amount of gas is generated during charging. Moreover, when the vehicle-mounted battery E1 is a sealed lead-acid battery, there is no escape place for the generated gas, and the vehicle-mounted battery E1 may burst. The battery auxiliary device 10 of the present embodiment can suppress the generation of gas by preventing overcharge regardless of the open type and the sealed type by setting the output voltage to the threshold voltage V1, and the in-vehicle battery E1 Can be avoided.

  The threshold voltage V1 is the battery voltage Vc of the in-vehicle battery E1 acquired when the engine is stopped, but is not limited to this. When the type of the in-vehicle battery E1 is known, the threshold voltage V1 may be set based on the specification of the in-vehicle battery E1. For example, the threshold voltage V1 may be a voltage determined by the specifications of the onboard battery E1 and capable of suppressing gas generation.

<2. Second Embodiment>
The second embodiment described below is different from the first embodiment in that power supply is started from the battery auxiliary device 10 before the starter 101 is started. Since the configuration of the battery auxiliary device 10 is the same as that of the first embodiment, the description thereof is omitted.

  FIG. 5 is a diagram illustrating a flowchart of processing executed by the processor 121 according to the second embodiment. FIG. 6 is a graph showing the battery voltage Vc of the in-vehicle battery E1 and the output current Io of the battery auxiliary device 10. In FIG. 6, the graph of the battery voltage Vc is indicated by a solid line, and the graph of the output current Io is indicated by a broken line. In the second embodiment, the control unit 12 is an example of the “second output control unit” in the present invention.

  The processor 121 determines whether or not the engine is stopped (step S11). If the engine is not stopped (step S11: NO), the vehicle-mounted battery E1 does not require engine start assistance by the battery auxiliary device 10, and thus this process is terminated. When the engine is stopped (step S11: YES), the processor 121 acquires the battery voltage Vc at the timing (1) shown in FIG. 6 (step S12). And the control part 12 sets the acquired battery voltage Vc to the threshold voltage V1, and memorize | stores it in the memory | storage part 122 (step S13).

  The processor 121 drives the AC-DC converter 11 and performs first power supply control (step S14). The timing for starting the first power supply control (timing (4) in FIG. 6) is not particularly limited as long as it is before the starter 101 is started. For example, it may be started immediately after obtaining the battery voltage Vc, or may be started when the vehicle door is opened or closed. Or you may start by a user's instruction | indication. In the first power supply control, the processor 121 acquires the output current Io and the output voltage Vo, and switches the AC-DC converter 11 so that the output voltage Vo = the threshold voltage V1 and the output current Io ≦ the threshold current I2. Control.

  The threshold current I2 is a limit value for overcurrent protection of the in-vehicle battery E1 and the battery auxiliary device 10. The threshold current I2 is stored in the storage unit 122 in advance. The threshold current I2 is appropriately set according to the performance of the in-vehicle battery E1 and the battery auxiliary device 10.

  As described above, even when the engine is stopped, a current flows from the in-vehicle battery E1 to the accessory device. For this reason, the battery voltage Vc of the vehicle-mounted battery E1 becomes somewhat low. When the threshold voltage V1 is output from the battery auxiliary device 10, when the battery voltage Vc of the in-vehicle battery E1 becomes lower than the threshold voltage V1, a current flows from the battery auxiliary device 10 to the in-vehicle battery E1. Thereby, the vehicle-mounted battery E1 is charged.

  Moreover, the battery voltage Vc of the vehicle-mounted battery E1 is maintained at the threshold voltage V1 by the first power supply control. The output voltage Vo of the battery auxiliary device 10 is the threshold voltage V1. That is, power is supplied from the in-vehicle battery E1 and the battery auxiliary device 10 to the accessory devices connected to the in-vehicle battery E1. As a result, the burden on the in-vehicle battery E1 when the engine is stopped is reduced.

  The processor 121 determines whether or not the starter 101 has been started (step S15). When the starter 101 has not been started (step S15: NO), the processor 121 executes the process of step S15 again. When starting of the starter 101 is detected (step S15: YES), the processor 121 shifts from the first power supply control to the second power supply control (step S16). The second power supply control is the same as the power supply control of the first embodiment. That is, the control unit 12 performs switching control of the AC-DC converter 11 so that the output voltage Vo = the threshold voltage V1 and the output current Io ≦ the threshold current I1.

  The processor 121 determines whether or not the battery voltage Vc of the in-vehicle battery E1 has reached the threshold voltage V1 (step S17). When the battery voltage Vc of the in-vehicle battery E1 becomes the threshold voltage V1 (step S17: YES), the processor 121 stops the control of the AC-DC converter 11 and stops the second power feeding control (step S18). . When the battery voltage Vc does not exceed the threshold voltage V1 (step S17: NO), the processor 121 executes the process of step S17 again.

  As described above, in the present embodiment, engine start assistance can be performed by the battery assist device 10 as in the first embodiment. Moreover, the overcharge of the vehicle-mounted battery E1 can be prevented and the generation of gas in the vehicle-mounted battery E1 can be suppressed. Furthermore, by performing the first power supply control before starting the starter 101, it is possible to prevent the battery from running up while preventing overcharging. Moreover, the burden of the vehicle-mounted battery E1 is reduced.

<3. Embodiment 3>
In the first and second embodiments, the threshold voltage V1 is the battery voltage Vc of the in-vehicle battery E1 acquired when the engine is stopped. In contrast, in the third embodiment, the threshold voltage V1 is a voltage obtained by providing an offset to the battery voltage Vc of the in-vehicle battery E1 acquired when the engine is stopped. That is, the battery auxiliary device 10 outputs a voltage higher than the battery voltage Vc when the engine is stopped when the engine is started.

  The flowchart of the process executed by the processor 121 in the third embodiment is almost the same as that in the second embodiment, and will be described below with reference to the flowchart in FIG.

  FIG. 7 is a graph showing the battery voltage Vc of the in-vehicle battery E1 and the output current Io of the battery auxiliary device 10. In FIG. 7, the graph of the battery voltage Vc is indicated by a solid line, and the graph of the output current Io is indicated by a broken line.

  When the processor 121 acquires the battery voltage Vc at the timing (1) (step S12 in FIG. 5), the processor 121 stores a voltage obtained by providing an offset to the battery voltage Vc in the storage unit 122 as the threshold voltage V1. In FIG. 7, the battery voltage Vc acquired when the engine is stopped before the engine auxiliary assistance by the battery auxiliary device 10 is represented by Va. That is, the threshold voltage V1 is a voltage obtained by providing an offset to the battery voltage Va. This offset value is set according to the specifications of the in-vehicle battery E1. For example, the offset value is set in a range in which the threshold voltage V1 does not exceed the voltage when the vehicle-mounted battery E1 is fully charged.

  The processor 121 starts the first power supply control at timing (4) (step S14 in FIG. 5). In the first power supply control of the third embodiment, the processor 121 performs switching control of the AC-DC converter 11 so that the output voltage Vo = the threshold voltage V1 and the output current Io = the threshold current I2. The threshold voltage V1 is larger than the battery voltage Va. Therefore, when the first power supply control is started, a current starts to flow from the battery auxiliary device 10 to the in-vehicle battery E1, and charging of the in-vehicle battery E1 is started. At this time, as shown in FIG. 7, the battery voltage Vc rises with the threshold voltage V1 as the upper limit.

  Then, when detecting the start of the starter 101, the processor 121 starts the second power feeding control (step S16 in FIG. 5). As in the second embodiment, the second power supply control of the third embodiment performs switching control of the AC-DC converter 11 so that the output voltage Vo = the threshold voltage V1 and the output current Io ≦ the threshold current I1.

  As described above, in the third embodiment, the engine starting drive can be performed by the battery auxiliary device 10. Moreover, the overcharge of the vehicle-mounted battery E1 can be prevented and the generation of gas in the vehicle-mounted battery E1 can be suppressed. Furthermore, by performing the first power supply control before starting the starter 101, it is possible to prevent the battery from running up while preventing overcharging. Further, the burden on the in-vehicle battery E1 when the engine is stopped is reduced.

  In addition, by setting the threshold voltage V1 higher than the battery voltage Va, even if the battery voltage Va is reduced to a voltage that may cause the battery to be discharged due to discharge at the time of engine stop, before the starter 101 is started. Can be charged. As a result, the possibility that the starter 101 will not start can be suppressed.

  In the third embodiment, the first power supply control and the second power supply control are performed as in the second embodiment. However, as in the first embodiment, the first power supply control before starting the starter 101 is not performed. May be.

<4. Embodiment 4>
The fourth embodiment is different from the first to third embodiments in that the in-vehicle battery E1 is once fully charged when the engine is stopped. Below, before the 1st electric power feeding control demonstrated in Embodiment 2, 3, the vehicle-mounted battery E1 is fully charged. In the fourth embodiment, the control unit 12 is an example of the “full charge unit” in the present invention.

  FIG. 8 is a graph showing the battery voltage Vc of the in-vehicle battery E1 and the output current Io of the battery auxiliary device 10 when the in-vehicle battery E1 is fully charged. In FIG. 8, the graph of the battery voltage Vc is indicated by a solid line, and the graph of the output current Io is indicated by a broken line.

  The processor 121 controls the AC-DC converter 11 so that a known voltage V2 for fully charging the vehicle-mounted battery E1 is output and a current equal to or smaller than the threshold current I1 is output. As shown in FIG. 8, when the voltage V2 is output at timing (5), charging of the in-vehicle battery E1 is started. When the in-vehicle battery E1 approaches full charge, the output current Io of the AC-DC converter 11 gradually decreases and becomes almost zero (timing (6)). At this timing (6), the control unit 12 temporarily stops the control of the AC-DC converter 11.

  The battery voltage Vc of the in-vehicle battery E1 that is fully charged is represented by a voltage V3. The control unit 12 acquires the voltage V3 and controls the AC-DC converter 11 so that the voltage V3 is output at timing (4). The voltage V3 may be an offset corrected voltage. Thereby, after timing (4), the voltage V3 of the battery voltage Vc of the in-vehicle battery E1 is maintained. As a result, as in the second and third embodiments, the battery is prevented from rising and the burden on the in-vehicle battery E1 is reduced.

<5. Embodiment 5>
In the first to fourth embodiments, a household power source is connected to the power connection ports P13 and P14. In contrast, in the fifth embodiment, an external battery is connected to the power connection ports P13 and P14.

<5.1. Configuration of Battery Auxiliary Device>
FIG. 9 is a diagram illustrating an equivalent circuit of the battery auxiliary device 20 according to the fifth embodiment.

  The battery auxiliary device 20 includes a step-down converter 21. The input of the step-down converter 21 is connected to the power supply connection ports P13 and P14. The output of the step-down converter 21 is connected to battery connection ports P11 and P12. The step-down converter 21 includes a capacitor C1, an inductor L1, a diode D1, and a switch SW1. Step-down converter 21 steps down the DC voltage input from battery connection ports P11 and P12. The step-down converter 21 is an example of the “power output unit” in the present invention.

  Further, the battery auxiliary device 20 includes a diode D2 connected in parallel to the switch SW1. The cathode of the diode D2 is connected to the power supply connection ports P13 and P14. The anode of the diode D2 is connected to the battery connection ports P11 and P12.

  An output current detection unit 14 and an output voltage detection unit 15 are provided on the output side of the step-down converter 21. Further, an input voltage detection unit 26 is provided on the input side of the step-down converter 21. The input voltage detection unit 26 is means for detecting the input voltage Vi of the step-down converter 21.

  The control unit 12 included in the battery auxiliary device 20 executes the processing shown in FIG. 10 by executing the computer program stored in the storage unit 122.

<5.2. Operation of Battery Auxiliary Device>
FIG. 10 is a flowchart illustrating processing executed by the processor 121 according to the fifth embodiment. Note that the processor 121 turns off the switch SW1 of the step-down converter 21 before executing the processing of FIG.

  The processor 121 determines whether or not the engine is stopped (step S21). When the engine is not stopped (step S21: NO), the in-vehicle battery E1 is charged from the alternator, and the engine auxiliary assistance by the battery auxiliary device 10 is unnecessary, and thus this process is terminated.

  At this time, the switch SW1 of the step-down converter 21 is off. A diode D1 is connected in parallel to the switch SW1. For this reason, a current flows from the alternator to the external battery (external charger) E2. That is, during the engine start, the external battery E2 is charged by the alternator.

  When the engine is stopped (step S21: YES), the processor 121 acquires the battery voltage Vc (step S22). Then, the processor 121 sets the acquired battery voltage Vc to the threshold voltage V1, and stores it in the storage unit 122 (step S23).

  The processor 121 determines whether or not the starter 101 has been started (step S24). When the starter 101 has not been started (step S24: NO), the processor 121 executes the process of step S24 again. When starting of the starter 101 is detected (step S24: YES), the processor 121 acquires the input voltage Vi from the detection result of the input voltage detection unit 26 (step S25). Then, the processor 121 determines whether or not the input voltage Vi is higher than the threshold voltage V1 (step S26).

  When the input voltage Vi is higher than the threshold voltage V1 (step S26: YES), the processor 121 executes the second control for driving the step-down converter 21 (step S27). The control unit 12 controls the step-down converter 21 to step down the input voltage Vi to the threshold voltage V1. By reducing the input voltage Vi to the threshold voltage V1, it is possible to prevent a large current from flowing through the in-vehicle battery E1.

  When the input voltage Vi is not higher than the threshold voltage V1 (step S26: NO), the processor 121 executes first control for turning on the switch SW1 of the step-down converter 21 (step S28). When the starter 101 starts, since the switch SW1 is on, a current flows from the external battery E2 and the in-vehicle battery E1 to the starter 101. When the engine is started, charging from the alternator is started for the in-vehicle battery E1.

  The processor 121 determines whether or not the battery voltage Vc of the in-vehicle battery E1 has reached the threshold voltage V1 (step S29). When the battery voltage Vc of the in-vehicle battery E1 becomes the threshold voltage V1 (step S29: YES), the processor 121 turns off the switch SW1 of the step-down converter 21 (step S30). Thereby, the current supply from the external battery E2 is stopped. When the battery voltage Vc does not exceed the threshold voltage V1 (step S29: NO), the processor 121 executes the process of step S29 again.

  Thus, even if the external battery E2 is connected to the battery auxiliary device 20, driving of the starter 101 can be assisted. Moreover, the overcharge of the vehicle-mounted battery E1 can be prevented and the generation of gas in the vehicle-mounted battery E1 can be suppressed. Further, since the external battery E2 is charged from the alternator after the engine is started, it is possible to avoid the possibility that the battery voltage of the external battery E2 is lowered and the starter 101 cannot be assisted.

<6. Embodiment 6>
In the first to fifth embodiments, the battery voltage Vc of the in-vehicle battery E1 is acquired, and output control of the battery auxiliary device is performed based on the acquired battery voltage Vc. On the other hand, the sixth embodiment is different from the first to fifth embodiments in that the output control of the battery auxiliary device is performed with time regardless of the battery voltage Vc.

<6.1. Configuration of Battery Auxiliary Device>
FIG. 11 is a diagram illustrating an equivalent circuit of the battery auxiliary device 30 according to the sixth embodiment.

  An external battery E2 is connected to the power supply connection ports P13 and P14 of the battery auxiliary device 30. The battery connection ports P11 and P12 are connected to the in-vehicle battery E1.

  The battery auxiliary device 30 includes a switch SW2. The switch SW2 is connected between the power supply connection port P13 and the battery connection port P11. The battery auxiliary device 30 has a diode D3 connected in parallel to the switch SW2. The cathode of the diode D3 is connected to the power supply connection port P13. The anode of the diode D3 is connected to the battery connection port P11. The switch SW2 is an example of the “power output unit” in the present invention.

  The processor 121 included in the battery auxiliary device 30 performs on / off control of the switch SW2 with time. The processor 121 turns on the switch SW2 for a predetermined time when assisting engine start. The processor 121 turns off the switch SW2 while engine start assistance is not performed. The processor 121 is an example of the “output control unit” in the present invention.

<6.2. Operation of Battery Auxiliary Device>
FIG. 12 is a diagram illustrating a flowchart of processing executed by the processor 121 according to the sixth embodiment. The processor 121 turns off the switch SW2 before executing the process of FIG.

  The processor 121 determines whether or not the engine is stopped (step S41). When the engine is not stopped (step S41: NO), the in-vehicle battery E1 is charged from the alternator, and the engine auxiliary assistance by the battery auxiliary device 10 is unnecessary, and thus this process is terminated.

  At this time, the switch SW2 is off. A diode D3 is connected in parallel to the switch SW2. For this reason, a current flows from the alternator to the external battery E2. That is, during the engine start, the external battery E2 is charged by the alternator.

  When the engine is stopped (step S41: YES), the processor 121 determines whether or not the starter 101 is detected to be started (step S42). When the starter 101 has not been started (step S42: NO), the processor 121 executes the process of step S42 again. When the start of the starter 101 is detected (step S42: YES), the processor 121 turns on the switch SW2 (step S43).

  The processor 121 determines whether or not a predetermined time has elapsed since the switch SW2 was turned on (step S44). If the certain time has not elapsed (step S44: NO), the processor 121 executes step S44 again. When the predetermined time has elapsed (step S44: YES), the processor 121 turns off the switch SW2 (step S45).

  The time for turning on the switch SW2 is determined in advance. However, it may be determined that the engine has started when battery voltage Vc ≧ threshold voltage V1, and switch SW2 may be turned off.

  Thus, even if the external battery E2 is connected to the battery auxiliary device 30, the driving of the starter 101 can be assisted. Overcharging of the in-vehicle battery E1 can be prevented, and generation of gas in the in-vehicle battery E1 can be suppressed. Further, since the external battery E2 is charged from the alternator after the engine is started, it is possible to avoid the possibility that the battery voltage of the external battery E2 is lowered and the starter 101 cannot be assisted. Further, by controlling the time of the switch SW2, it is possible to avoid complication of processing.

  In addition, when the voltage of the external battery E2 is confirmed and the switch SW2 is turned on, it may be detected from the potential difference whether or not a current may flow from the in-vehicle battery E1 to the external battery E2.

<7. Embodiment 7>
FIG. 13 is a diagram illustrating a usage state of the battery auxiliary device 10 according to the seventh embodiment. In FIG. 13, an accessory device 110 connected to the battery auxiliary device 10 is illustrated. The battery auxiliary device 10 is connected to the in-vehicle battery E1 and the accessory device 110 so that power can be supplied. The accessory device 110 is, for example, a lamp or a security system.

  Even when the engine is stopped, current is supplied from the in-vehicle battery E1 to devices such as accessories. For this reason, the battery voltage Vc of the vehicle-mounted battery E1 slightly decreases. And if an engine stop period is long, the battery voltage Vc of the vehicle-mounted battery E1 will continue to fall. On the other hand, if a voltage of a certain level or higher is continuously applied to the in-vehicle battery E1 in order to prevent the battery from running out, it may be deteriorated due to overcharging.

  The processor 121 of the battery auxiliary device 10 of the present embodiment performs switching control on the AC-DC converter 11 so that the output voltage Vo = the threshold voltage V1 is always satisfied. As a result, the battery can be prevented from running up without overcharging the in-vehicle battery E1. In addition, when performing engine start assistance, the voltage of the battery auxiliary device 10 and the in-vehicle battery E1 is substantially equal, and the output current from the battery auxiliary device 10 flows to the starter 101. Therefore, when starting the starter 101, engine start assistance is performed. It can be performed.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment. About the detailed structure of a battery auxiliary | assistant apparatus, you may differ from each figure of this application. Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

10, 20, 30: Battery auxiliary device 10A: Power plug 11: AC-DC converter 12: Control unit 121: Processor 122: Storage unit 14: Output current detection unit 15: Output voltage detection unit 21: Step-down converter 26: Input voltage Detection unit 101: Starter 102: Ignition key 103: Voltage detection unit C1: Capacitors D1, D2, D3: Diode E1: In-vehicle battery E2: External battery P11, P12: Battery connection port P13, P14: Power supply connection port SW1, SW2: Switch V1: AC power supply

Claims (18)

A power output unit connected to be able to supply power to the vehicle battery and the starter;
A voltage information acquisition unit for acquiring battery voltage information related to a battery voltage of the in-vehicle battery;
Before starting the starter, a setting unit that sets a threshold voltage based on battery voltage information acquired by the voltage information acquisition unit;
A storage unit for storing information on the threshold voltage set by the setting unit;
A start detector for detecting start of the starter;
When the start detection unit detects the start of the starter, a first output control unit that outputs from the power output unit an output voltage controlled to a voltage with the threshold voltage as an upper limit;
A power conversion device comprising: A power output unit connected to be able to supply power to the vehicle battery and the vehicle accessory;
A voltage information acquisition unit for acquiring battery voltage information related to a battery voltage of the in-vehicle battery;
Before the start of power consumption by the in-vehicle accessory, a setting unit that sets a threshold voltage based on the battery voltage information acquired by the voltage information acquisition unit;
A storage unit for storing information on the threshold voltage set by the setting unit;
A first output control unit that outputs an output voltage controlled to a voltage value with the threshold voltage as an upper limit after the power supply to the in-vehicle battery is completed;
A power conversion device comprising: A power output unit connected to be able to supply power to the vehicle battery and the starter;
A voltage information acquisition unit for acquiring battery voltage information related to a battery voltage of the in-vehicle battery;
A storage unit configured to store a threshold voltage set based on the specifications of the in-vehicle battery;
A start detector for detecting start of the starter;
When the start detection unit detects the start of the starter, a first output control unit that outputs an output voltage controlled to a voltage value with the threshold voltage as an upper limit from the power output unit;
A power conversion device comprising: It is a power converter device as described in any one of Claim 1- Claim 3, Comprising:
The first output control unit outputs a constant voltage with the threshold voltage as an upper limit,
Power conversion device. A power conversion device according to any one of claims 1 to 4, wherein
The first output control stops output of voltage based on information acquired by the voltage information acquisition unit.
Power conversion device. The power conversion device according to claim 5,
In the first output control, after the output operation of the output voltage, the output of the output voltage is stopped after the voltage value of the battery voltage reaches the threshold voltage.
Power conversion device. The power conversion device according to claim 5,
In the first output control, after the output operation of the output voltage, the output of the output voltage is stopped based on the amount of change in the battery voltage.
Power conversion device. A power conversion device according to any one of claims 1 to 4, wherein
The first output control sets the output of the output voltage to a voltage for fully charging the in-vehicle battery based on a predetermined time lapse state after the start of power supply to the in-vehicle battery.
Power conversion device. The power conversion device according to any one of claims 1 to 8,
A second output control unit that outputs a constant voltage with the threshold voltage as an upper limit before starting the starter;
A power conversion device comprising: The power conversion device according to any one of claims 1 to 8,
A second output control unit that outputs an output voltage controlled to a voltage value with the threshold voltage as an upper limit before starting the starter from the power output unit;
A power conversion device comprising: The power conversion device according to claim 9 or 10, wherein
A fully charged portion for fully charging the in-vehicle battery,
With
The second output controller is
Output a voltage based on the battery voltage of the in-vehicle battery after being fully charged by the full charge unit,
Power conversion device. It is a power converter device as described in any one of Claim 1- Claim 11, Comprising:
Connected to AC power supply,
The first output control unit includes an AC-DC converter.
Power conversion device. It is a power converter device as described in any one of Claim 1- Claim 11, Comprising:
An external charger is connected,
An input voltage detector for detecting an input voltage from the external charger;
With
The first output control unit includes:
A first control that outputs the input voltage when the input voltage detected by the input voltage detector is equal to or lower than the threshold voltage;
A second control for stepping down and outputting the input voltage when the input voltage detected by the input voltage detector is higher than the threshold voltage;
Run the
Power conversion device. The power conversion device according to claim 13,
The first output control unit includes:
A step-down circuit provided between the in-vehicle battery and the external charger; in the first control, a switch included in the step-down circuit is always turned on; in the second control, the switch is switched; Operate the step-down circuit,
Power conversion device. The power conversion device according to claim 13 or 14,
By an alternator that charges the in-vehicle battery, an external charger charging unit that charges the external charger,
A power conversion device comprising: The power conversion device according to claim 15,
The external charger charging unit is a diode having an anode connected to the in-vehicle battery and a cathode connected to the external charger.
Power conversion device. A power conversion device connected between an in-vehicle battery that supplies power to a starter and an external charger,
A switch connected between the in-vehicle battery and the external charger;
A start detector for detecting start of the starter;
An output control unit that turns on the switch for a predetermined time when the start detection unit detects the start of the starter;
A power conversion device comprising: The power conversion device according to claim 17,
A diode connected in parallel with the switch, an anode connected to the vehicle battery, and a cathode connected to the external charger;
A power conversion device comprising:

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