Vehicle-mounted power supply device

Abstract

An in-vehicle power supply device (10) is used in an in-vehicle power supply system (100). An in-vehicle power supply system (100) is provided with a battery (20), a power path (21) to which power from the battery (20) is supplied, and a capacitor (22) connected to the power path (21). An in-vehicle power supply device (10) is provided with a mechanical system main relay (first SMR (51)), a parallel circuit (53), and a second relay (56). A system main relay (first SMR (51)) is provided in the power path (21) on the battery (20) side of the capacitor (22). The parallel circuit (53) configures a structure in which the first relay (54) and the resistor unit (55) are connected in series, and is provided in parallel with a system main relay (first SMR (51)). The second relay (56) is provided in parallel with the resistor unit (55).

Description

Technical Field

[0001] The present disclosure relates to a vehicle-mounted power supply device. Background Art

[0002] Patent document 1 discloses a power supply device for a vehicle. The power supply device includes a contactor and a pre-charging circuit. The contactor switches the power supply from the driving battery to the load on and off. The pre-charging circuit is connected in parallel with the contactor to pre-charge the capacitor. The pre-charging circuit includes a pre-charging resistor for limiting the pre-charging current and a pre-charging switch connected in series with the pre-charging resistor.

[0003] Prior art literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2009-89535 Summary of the invention

[0005] Problems to be solved by the invention

[0006] In this technology, when precharging a capacitor, it takes time for the capacitor voltage to reach the target voltage due to current limitation by the precharging resistor. However, depending on the situation, it is sometimes desirable to complete the precharging of the capacitor more quickly.

[0007] An object of the present disclosure is to provide a technology that enables precharging via a resistor unit and that can more quickly complete precharging of a capacitor while suppressing damage to a system main relay.

[0008] Means for solving problems

[0009] The vehicle-mounted power supply device disclosed in the present invention is used for a vehicle-mounted power supply system, which includes: a battery; a power path to which power based on the battery is supplied; and a capacitor connected to the power path.

[0010] The above-mentioned vehicle-mounted power supply device comprises:

[0011] a mechanical system main relay provided in the power path at a position closer to the battery than the capacitor;

[0012] A parallel circuit, which is a structure in which the first relay and the resistor are connected in series, is provided in parallel with the system main relay; and

[0013] The second relay is provided in parallel with the resistor.

[0014] Effects of the Invention

[0015] The technology disclosed in the present invention can perform precharging via the resistor unit, and can more quickly complete precharging of the capacitor while suppressing damage to the system main relay. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a block diagram of an in-vehicle power supply system including the in-vehicle power supply device according to the first embodiment.

[0017] Figure 2 This is a flowchart showing the flow of processing performed by the vehicle-mounted power supply device according to the first embodiment.

[0018] Figure 3 It is an explanatory diagram illustrating the temporal change of the voltage of a capacitor. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present disclosure are listed and illustrated.

[0020] [1] An in-vehicle power supply device for use in an in-vehicle power supply system, the in-vehicle power supply system comprising: a battery; a power path to which power based on the battery is supplied; and a capacitor connected to the power path.

[0021] The above-mentioned vehicle-mounted power supply device comprises:

[0022] a mechanical system main relay provided in the power path at a position closer to the battery than the capacitor;

[0023] A parallel circuit, which is a structure in which the first relay and the resistor are connected in series, is provided in parallel with the system main relay; and

[0024] The second relay is provided in parallel with the resistor.

[0025] The vehicle-mounted power supply device can pre-charge the capacitor via the resistor when the system main relay and the second relay are in the disconnected state and the first relay is in the connected state. Furthermore, the vehicle-mounted power supply device can bypass the resistor and pre-charge the capacitor more rapidly when the system main relay is in the disconnected state and the first relay and the second relay are in the connected state. Therefore, the vehicle-mounted power supply device can pre-charge via the resistor and can complete the pre-charging of the capacitor more rapidly while suppressing damage to the system main relay.

[0026] [2] The vehicle-mounted power supply device according to [1], wherein:

[0027] The vehicle-mounted power supply device includes a control unit that controls the system main relay, the first relay, and the second relay.

[0028] The control unit performs a first control of controlling the system main relay and the second relay to be in an OFF state and controlling the first relay to be in an ON state when a start condition for starting charge and discharge of the storage battery is satisfied,

[0029] When the first switching condition is satisfied during the execution of the first control, a second control is executed to control the system main relay to be in an OFF state and the first relay and the second relay to be in an ON state.

[0030] When a second switching condition is satisfied during execution of the second control, a third control is executed to control the first relay and the second relay to be in an OFF state and to control the system main relay to be in an ON state.

[0031] The vehicle-mounted power supply device switches to the second control after the voltage of the capacitor is increased to a certain extent by the first control, thereby avoiding the inrush current flowing in the first relay and switching to a more rapid pre-charging. As a result, the vehicle-mounted power supply device can complete the pre-charging of the capacitor more quickly while suppressing damage to the system main relay.

[0032] [3] The vehicle-mounted power supply device according to [2], wherein:

[0033] The second relay is a semiconductor relay.

[0034] In the above-mentioned vehicle-mounted power supply device, the second relay is a contactless semiconductor relay, and therefore it is possible to avoid damage to the second relay when switching from the first control to the second control.

[0035] [4] The vehicle-mounted power supply device according to [2] or [3], wherein:

[0036] The first switching condition is that a potential difference between both ends of the system main relay or a value of a current flowing in the parallel circuit becomes equal to or less than a threshold value.

[0037] The vehicle-mounted power supply device switches to the second control after the potential difference between the two ends of the system main relay or the value of the current flowing in the parallel circuit becomes less than the threshold value. Therefore, the vehicle-mounted power supply device can accurately determine the upper limit value of the current flowing through the second relay in the second control. Therefore, the vehicle-mounted power supply device can easily use a component suitable for the rated current of the second relay as a component of the second relay.

[0038] [5] The vehicle-mounted power supply device according to [2] or [3], wherein:

[0039] The first switching condition is that a first time has passed since the start of the first control.

[0040] The above-mentioned in-vehicle power supply device switches to the second control after a first time has elapsed since the start of the first control. That is to say, the above-mentioned in-vehicle power supply device switches to the second control after raising the voltage of the capacitor to a certain extent by the first control. Therefore, the above-mentioned in-vehicle power supply device can accurately determine the upper limit value of the current flowing through the second relay to a certain extent with a simple structure. Therefore, it is easy for the above-mentioned in-vehicle power supply device to adopt components suitable for the rated current of the second relay as the components constituting the second relay.

[0041] 〔6〕According to the in-vehicle power supply device described in 〔5〕, wherein,

[0042] The above-mentioned second switching condition is that a second time shorter than the first time has elapsed since the start of the above-mentioned second control.

[0043] It is easy for the above-mentioned in-vehicle power supply device to ensure a relatively long first time, and thus it is easy to increase the voltage of the capacitor when switching to the second control. Therefore, it is easy for the above-mentioned in-vehicle power supply device to adopt components with a lower rated current as the components constituting the second relay.

[0044] 〔7〕According to the in-vehicle power supply device described in 〔2〕 or 〔3〕, wherein,

[0045] The above-mentioned first switching condition is that the voltage of the above-mentioned capacitor becomes equal to or higher than the threshold voltage.

[0046] The above-mentioned in-vehicle power supply device switches to the second control after the voltage of the capacitor becomes equal to or higher than the threshold voltage. That is to say, the above-mentioned in-vehicle power supply device switches to the second control after the difference between the voltage of the battery and the voltage of the capacitor becomes smaller to a certain extent. Therefore, the above-mentioned in-vehicle power supply device can accurately determine the upper limit value of the current flowing through the second relay to a certain extent. Therefore, it is easy for the above-mentioned in-vehicle power supply device to adopt components suitable for the rated current of the second relay as the components constituting the second relay.

[0047] <First Embodiment>

[0048] 1. Structure of the in-vehicle power supply system 100

[0049] In Figure 1 the in-vehicle power supply system 100 equipped with the in-vehicle power supply device 10 is shown. The vehicle equipped with the in-vehicle power supply system 100 can be an electric vehicle, a fuel cell vehicle (FCV), or a hybrid vehicle. In addition to the in-vehicle power supply device 10, the in-vehicle power supply system 100 further includes a battery 20, a power path 21, and a capacitor 22.

[0050] The battery 20 may be a lithium-ion battery, a lead-acid battery, or other batteries.

[0051] The power path 21 is an electrical path for supplying power based on the battery 20. The power path 21 has a positive-side power line 30 and a negative-side power line 31. The positive-side terminal of the battery 20 is electrically connected to the positive-side power line 30. The negative-side terminal of the battery 20 is electrically connected to the negative-side power line 31. The negative-side power line 31 is electrically connected to the ground. The output voltage of the battery 20 is applied to the power path 21 (more specifically, the positive-side power line 30). In addition, in this specification, voltage refers to a potential difference based on the ground potential, and refers to a potential difference based on the negative-side power line 31.

[0052] The capacitor 22 is electrically connected to the power path 21. The capacitor 22 is provided between the positive-side power line 30 and the negative-side power line 31. One end of the capacitor 22 is electrically connected to the positive-side power line 30. The other end of the capacitor 22 is electrically connected to the negative-side power line 31. Power from the battery 20 is supplied to the capacitor 22 via the power path 21. The capacitor 22 smoothes the voltage from the battery 20.

[0053] In the present embodiment, the capacitor 22 is configured as a part of the driving unit 40 provided in the vehicle-mounted power supply system 100. The driving unit 40 includes an inverter 41 and a motor 42 in addition to the capacitor 22. The capacitor 22 is provided on the battery 20 side relative to the inverter 41. The capacitor 22 smoothes the voltage based on the battery 20 and supplies it to the inverter 41. The inverter 41 is electrically connected to the power path 21. The inverter 41 generates an AC voltage (for example, a three-phase AC) based on a DC voltage based on the voltage supplied from the battery 20, and supplies it to the motor 42. The motor 42 is, for example, a main system motor. The motor 42 is a device that rotates based on the power supplied from the battery 20 and applies a rotational force to the wheels of the vehicle.

[0054] The vehicle-mounted power supply device 10 is used in a vehicle-mounted power supply system 100. The vehicle-mounted power supply device 10 includes a first system main relay 51 (hereinafter referred to as “first SMR51”) and a second system main relay 52 (hereinafter referred to as “second SMR52”).

[0055] The first SMR51 is equivalent to an example of a "system main relay". The first SMR51 is provided in the power path 21 at a position closer to the battery 20 than the capacitor 22. The first SMR51 is provided on the positive-side power line 30. One end of the first SMR51 is electrically connected to the terminal on the positive side of the battery 20, and is short-circuited with the terminal on the positive side of the battery 20. The other end of the first SMR51 is electrically connected to one end of the capacitor 22, and is short-circuited with one end of the capacitor 22. In the present embodiment, the first SMR51 is a mechanical relay. The first SMR51 includes contacts 51A, 51B, and 51C. The first SMR51 includes: fixed contacts 51A, 51B, a movable contact 51C, and a coil 51D that actuates the movable contact 51C. When the coil 51D is energized, the first SMR51 makes the movable contact 51C contact the fixed contacts 51A and 51B, and becomes an on state. When coil 51D is not energized, first SMR 51 separates movable contact 51C from fixed contacts 51A and 51B to be in an OFF state.

[0056] The second SMR52 is provided on the power path 21 closer to the battery 20 than the capacitor 22. The second SMR52 is provided on the negative-side power line 31. One end of the second SMR52 is electrically connected to the terminal on the negative side of the battery 20, and is short-circuited with the terminal on the negative side of the battery 20. The other end of the second SMR52 is electrically connected to the other end of the capacitor 22, and is short-circuited with the other end of the capacitor 22. In the present embodiment, the second SMR52 is a mechanical relay. The second SMR52 includes contacts 52A, 52B, and 52C. The second SMR52 includes: fixed contacts 52A, 52B, a movable contact 52C, and a coil 52D that actuates the movable contact 52C. When the coil 52D is energized, the second SMR52 makes the movable contact 52C contact the fixed contacts 52A and 52B, and becomes an on state. When coil 52D is not energized, second SMR 52 separates movable contact 52C from fixed contacts 52A and 52B to be in an OFF state.

[0057] The positive-side power line 30 includes a first positive-side power line 32 provided on the battery 20 side relative to the first SMR 51 and a second positive-side power line 33 provided on the opposite side of the first SMR 51 from the battery 20 side. The negative-side power line 31 includes a first negative-side power line 34 provided on the battery 20 side relative to the second SMR 52 and a second negative-side power line 35 provided on the opposite side of the second SMR 52 from the battery 20 side.

[0058] The vehicle-mounted power supply device 10 includes a parallel circuit 53. The parallel circuit 53 is provided in parallel with the first SMR 51. One end of the parallel circuit 53 is electrically connected to the first positive-side power line 32 and short-circuited to the first positive-side power line 32. The other end of the parallel circuit 53 is electrically connected to the second positive-side power line 33 and short-circuited to the second positive-side power line 33. The parallel circuit 53 is configured to connect the first relay 54 and the resistor 55 in series.

[0059] In the present embodiment, the first relay 54 is a mechanical relay. The first relay 54 includes contacts 54A, 54B, and 54C. The first relay 54 includes fixed contacts 54A and 54B, a movable contact 54C, and a coil 54D for actuating the movable contact 54C. When the coil 54D is energized, the first relay 54 makes the movable contact 54C contact the fixed contacts 54A and 54B, and becomes an on state. In addition, when the coil 54D is not energized, the first relay 54 separates the movable contact 54C from the fixed contacts 54A and 54B, and becomes an off state.

[0060] The resistor portion 55 is formed of, for example, a well-known resistor.

[0061] The vehicle-mounted power supply device 10 includes a second relay 56. The second relay 56 is arranged in parallel with the resistor section 55. In the present embodiment, the second relay 56 is a semiconductor relay. In the present embodiment, the second relay 56 is an N-channel MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor). The second relay 56 has an input section 56A (a gate in the present embodiment). The second relay 56 is turned on when an on signal (a high level signal in the present embodiment) is provided to the input section 56A, and is turned off when an off signal (a low level signal in the present embodiment) is provided to the input section 56A. The drain 56B of the second relay 56 is electrically connected to the end of the first positive side power line 32 in the resistor section 55, and is short-circuited to the end of the first positive side power line 32 in the resistor section 55. The source electrode 56C of the second relay 56 is electrically connected to the end of the resistor section 55 on the second positive-electrode-side power line 33 side, and is short-circuited to the end of the resistor section 55 on the second positive-electrode-side power line 33 side.

[0062] 2. Configuration of the control unit 57 of the vehicle-mounted power supply device 10

[0063] The vehicle-mounted power supply device 10 includes a control unit 57. The control unit 57 is configured to include a control circuit such as an integrated circuit. The control unit 57 includes a processing unit such as a CPU, a storage unit such as a memory, an input / output unit, etc. The control unit 57 controls the first SMR 51, the second SMR 52, the first relay 54, and the second relay 56.

[0064] The control unit 57 performs the first control when the starting condition for starting the charge and discharge of the battery 20 is satisfied. The starting condition is satisfied when the first SMR51, the second SMR52, the first relay 54, and the second relay 56 are in the disconnected state. The first control is a control in which the first SMR51 and the second relay 56 are controlled to be in the disconnected state and the second SMR52 and the first relay 54 are controlled to be in the connected state. In addition, the first control is a control in which the second SMR52 and the first relay 54 are switched to the connected state while the first SMR51 and the second relay 56 are maintained in the disconnected state. In the state in which the first control is performed, the power based on the battery 20 is supplied to the capacitor 22 via the parallel circuit 53. According to this structure, the current flowing in the power path 21 is suppressed by the resistor 55 of the parallel circuit 53. Therefore, the capacitor 22 can be charged while suppressing the damage of the first SMR51, the second SMR52, and the first relay 54. As the voltage of the capacitor 22 rises, the difference between the voltage of the capacitor 22 and the voltage of the battery 20 becomes smaller. As a result, the potential difference between both ends of the first SMR 51 becomes smaller, and the potential difference between both ends of the second SMR 52 becomes smaller.

[0065] The control unit 57 performs the second control when the first switching condition is satisfied during the execution of the first control. The second control is a control that controls the first SMR 51 to be in an OFF state and controls the second SMR 52, the first relay 54, and the second relay 56 to be in an ON state. In addition, the second control is a control that switches the second relay 56 to an ON state while keeping the first SMR 51 in an OFF state and the second SMR 52 and the first relay 54 in an ON state.

[0066] The first switching condition is, for example, a condition established when the current flowing in the parallel circuit 53 is equal to or less than the rated current of the second relay 56. The first switching condition is, for example, a condition set to be established when the current flowing in the parallel circuit 53 is equal to or less than the rated current of the second relay 56.

[0067] A first example of the first switching condition is that the potential difference between the two ends of the first SMR51 becomes less than the first threshold value. The control unit 57 obtains the potential difference between the two ends of the first SMR51 and determines whether the obtained potential difference becomes less than the first threshold value. The method by which the control unit 57 obtains the potential difference between the two ends of the first SMR51 is not limited. For example, the control unit 57 can obtain the potential difference between the two ends of the first SMR51 by receiving a signal obtained by amplifying the potential difference between the two ends of the first SMR51 using a differential amplifier. Alternatively, the control unit 57 can also obtain the potential difference between the two ends of the first SMR51 by respectively obtaining the voltage of the battery 20 and the voltage of the capacitor 22 and calculating their difference.

[0068] When the first switching condition is the first example, the vehicle-mounted power supply device 10 switches to the second control after making the potential difference between the two ends of the first SMR 51 less than the first threshold value. Therefore, the vehicle-mounted power supply device 10 can accurately determine the upper limit value of the current flowing through the second relay 56 in the second control. Therefore, the vehicle-mounted power supply device 10 can easily adopt a component suitable for the rated current of the second relay 56 as a component of the second relay 56.

[0069] A second example of the first switching condition is that the value of the current flowing through the parallel circuit 53 becomes less than the first threshold value. The control unit 57 obtains the value of the current flowing through the parallel circuit 53, and determines whether the obtained current value becomes less than the first threshold value. The method by which the control unit 57 obtains the value of the current flowing in the parallel circuit 53 is not limited. For example, a current sensor for detecting the current flowing through the parallel circuit 53 may be provided in the vehicle-mounted power supply system 100, and the control unit 57 obtains the detection value of the current sensor.

[0070] When the first switching condition is the second example, the vehicle-mounted power supply device 10 switches to the second control after making the value of the current flowing in the parallel circuit 53 less than the first threshold value. Therefore, the vehicle-mounted power supply device 10 can accurately determine the upper limit value of the current flowing through the second relay 56 in the second control. Therefore, the vehicle-mounted power supply device 10 can easily adopt a component suitable for the rated current of the second relay 56 as a component of the second relay 56.

[0071] A third example of the first switching condition is that a first time has passed since the start of the first control.

[0072] When the first switching condition is the third example, the vehicle-mounted power supply device 10 switches to the second control after the first time has passed since the start of the first control. That is, the vehicle-mounted power supply device 10 switches to the second control after the voltage of the capacitor 22 is increased to a certain extent by the first control. Therefore, the vehicle-mounted power supply device 10 can accurately determine the upper limit value of the current flowing through the second relay 56 in the second control to a certain extent through a simple structure. Therefore, the vehicle-mounted power supply device 10 can easily adopt a component suitable for the rated current of the second relay 56 as a component of the second relay 56.

[0073] A fourth example of the first switching condition is that the voltage of the capacitor 22 becomes equal to or greater than the first threshold voltage. The control unit 57 obtains the voltage of the capacitor 22 and determines whether the obtained voltage becomes equal to or greater than the first threshold voltage. The method by which the control unit 57 obtains the voltage of the capacitor 22 is not limited. For example, the control unit 57 may also obtain the voltage of the capacitor 22 detected by a known voltage detection circuit.

[0074] When the first switching condition is the fourth example, the vehicle-mounted power supply device 10 switches to the second control after the voltage of the capacitor 22 becomes equal to or higher than the first threshold voltage. That is, the vehicle-mounted power supply device 10 switches to the second control after the difference between the voltage of the battery 20 and the voltage of the capacitor 22 becomes smaller to a certain extent. Therefore, the vehicle-mounted power supply device 10 can accurately determine the upper limit value of the current flowing through the second relay 56 in the second control to a certain extent. Therefore, the vehicle-mounted power supply device 10 can easily adopt a component suitable for the rated current of the second relay 56 as a component of the second relay 56.

[0075] The control unit 57 performs the third control when the second switching condition is satisfied during the execution of the second control. The third control is a control for controlling the first relay 54 and the second relay 56 to be in the off state and controlling the first SMR 51 and the second SMR 52 to be in the on state. In addition, the third control is a control for switching the first relay 54 and the second relay 56 to the off state and switching the first SMR 51 to the on state while maintaining the second SMR 52 in the on state.

[0076] The second switching condition is, for example, a condition that is satisfied when the potential difference between the two ends of the first SMR 51 is less than or equal to a target value. The second switching condition is, for example, a condition that is set to be satisfied when the potential difference between the two ends of the first SMR 51 is less than or equal to a target value. The target value is, for example, 0.

[0077] The first example of the second switching condition is that the potential difference between the two ends of the first SMR51 becomes less than the second threshold value. When the first switching condition is the first example, the second threshold value is a value smaller than the first threshold value. The control unit 57 obtains the potential difference between the two ends of the first SMR51 and determines whether the obtained potential difference becomes less than the second threshold value. The method by which the control unit 57 obtains the potential difference between the two ends of the first SMR51 is not limited, and for example, it can be the same as the first example of the first switching condition.

[0078] When the second switching condition is the first example, the vehicle power supply device 10 switches to the third control after reducing the potential difference between both ends of the first SMR 51 to less than the second threshold. Therefore, the vehicle power supply device 10 can more reliably suppress the inrush current from flowing in the first SMR 51.

[0079] The second example of the second switching condition is that the value of the current flowing through the parallel circuit 53 becomes less than the second threshold value. When the first switching condition is the second example, the second threshold value is a value smaller than the first threshold value. The control unit 57 obtains the value of the current flowing through the parallel circuit 53, and determines whether the value of the obtained current becomes less than the second threshold value. The method by which the control unit 57 obtains the value of the current flowing in the parallel circuit 53 is not limited, for example, it can also be the same as the second example of the first switching condition.

[0080] When the second switching condition is the second example, the vehicle power supply device 10 switches to the third control after the value of the current flowing in the parallel circuit 53 decreases to or below the second threshold. Therefore, the vehicle power supply device 10 can more reliably suppress the inrush current from flowing in the first SMR 51 .

[0081] The third example of the second switching condition is that the second time has passed since the start of the second control. When the first switching condition is the third example, the second time is, for example, a time shorter than the first time. In this case, the vehicle-mounted power supply device 10 can easily ensure a longer first time, so it is easy to increase the voltage of the capacitor 22 when switching to the second control. Therefore, the vehicle-mounted power supply device 10 can easily use a component with a lower rated current as a component of the second relay 56.

[0082] When the second switching condition is the third example, the vehicle-mounted power supply device 10 can easily simplify the determination of whether the second switching condition is satisfied.

[0083] The fourth example of the second switching condition is that the voltage of the capacitor 22 becomes greater than the second threshold voltage. When the first switching condition is the fourth example, the second threshold voltage is a value greater than the first threshold voltage. The control unit 57 obtains the voltage of the capacitor 22 and determines whether the obtained voltage is greater than the first threshold. The method by which the control unit 57 obtains the voltage of the capacitor 22 is not limited, and for example, it may be the same as the fourth example of the first switching condition.

[0084] When the second switching condition is the fourth example, the vehicle-mounted power supply device 10 can switch the first SMR 51 to the on state after reducing the potential difference to a certain extent, even if the potential difference between the voltage of the capacitor 22 and the voltage of the battery 20 is not monitored. Therefore, the vehicle-mounted power supply device 10 can suppress the damage of the first SMR 51 associated with the switching to the on state to a certain extent with a simple structure.

[0085] 3. Operation of the vehicle-mounted power supply device 10

[0086] The control unit 57 of the vehicle-mounted power supply device 10 performs Figure 2 For example, when the first SMR 51, the second SMR 52, the first relay 54, and the second relay 56 are in the off state, the control unit 57 starts Figure 2 Processing shown.

[0087] The control unit 57 determines whether the above-mentioned start condition is satisfied in step S101. For example, when the control unit 57 receives an instruction to start charging and discharging from the upper ECU, it determines that the start condition is satisfied. When the control unit 57 determines that the start condition is not satisfied (in the case of No in step S101), the control unit 57 repeats the process of step S101 until the start condition is satisfied.

[0088] When the control unit 57 determines that the start condition is satisfied (if it is YES in step S101), the first control is started in step S102. That is, the control unit 57 switches the second SMR 52 and the first relay 54 to the ON state while maintaining the first SMR 51 and the second relay 56 in the OFF state. Thus, the capacitor 22 is charged via the parallel circuit 53 based on the power of the battery 20. That is, the current limited by the resistor 55 flows through the power path 21 to charge the capacitor 22.

[0089] The control unit 57 performs the process of step S103 during the execution of the first control. The control unit 57 determines whether the first switching condition is satisfied in step S103. When the control unit 57 determines that the first switching condition is not satisfied (in the case of No in step S103), the control unit 57 repeatedly performs the process of step S103 until the first switching condition is satisfied. During this period, the voltage of the capacitor 22 gradually increases, and the potential difference between the two ends of the first SMR 51 gradually decreases.

[0090] When the control unit 57 determines that the first switching condition is satisfied (if it is YES in step S103), it switches to the second control in step S104. That is, the control unit 57 switches the second relay 56 to the ON state while maintaining the first SMR 51 in the OFF state and the second SMR 52 in the ON state. As a result, the power based on the battery 20 bypasses the resistor 55 and charges the capacitor 22. In other words, the current based on the battery 20 is supplied to the capacitor 22 without being limited by the resistor 55.

[0091] The control unit 57 performs the process of step S105 during the execution of the second control. The control unit 57 determines whether the second switching condition is satisfied in step S105. When the control unit 57 determines that the second switching condition is not satisfied (in the case of No in step S105), the control unit 57 repeatedly performs the process of step S105 until the second switching condition is satisfied. During this period, the voltage of the capacitor 22 further increases, and the potential difference between the two ends of the first SMR 51 further decreases.

[0092] When the control unit 57 determines that the second switching condition is satisfied (if it is YES in step S105), it switches to the third control in step S106. That is, the control unit 57 switches the first relay 54 and the second relay 56 to the off state and switches the first SMR51 to the on state while maintaining the second SMR52 in the on state. By switching the first SMR51 to the on state in a state where the potential difference between the two ends of the first SMR51 is reduced, damage to the first SMR51 is suppressed. By executing the third control, the power based on the battery 20 is supplied to the power path 21 via the first SMR51, and is supplied to the drive unit 40 via the power path 21.

[0093] After switching to the third control, the control unit 57 ends Figure 2 Processing shown.

[0094] exist Figure 3In the figure, the solid line represents the change in the voltage of the capacitor 22 over time. When the start condition is met and the first control is started, the voltage of the capacitor 22 gradually rises from 0V. The rising speed of the voltage of the capacitor 22 is dulled as the voltage of the capacitor 22 approaches the voltage of the battery 20. The control unit 57 switches to the second control at the moment t1 when the rising speed of the voltage of the capacitor 22 is dulled. As a result, the rising speed of the voltage of the capacitor 22 is accelerated, and at the moment t2, the voltage of the capacitor 22 reaches the target voltage. Assuming that the control unit 57 does not switch to the second control at the moment t1, as shown by the curve represented by the dotted line, it takes a considerable amount of time for the voltage of the capacitor 22 to reach the target voltage. In contrast, the vehicle-mounted power supply device 10 can significantly shorten the time required for the voltage of the capacitor 22 to reach the target voltage by switching to the second control at the moment t1.

[0095] 4. Effect Examples

[0096] The vehicle-mounted power supply device 10 can precharge the capacitor 22 via the resistor 55 when the first SMR 51 and the second relay 56 are in the off state and the first relay 54 is in the on state. Furthermore, the vehicle-mounted power supply device 10 can bypass the resistor 55 and precharge the capacitor 22 more quickly when the first SMR 51 is in the off state and the first relay 54 and the second relay 56 are in the on state. Therefore, the vehicle-mounted power supply device 10 can perform precharging via the resistor 55, and can complete precharging the capacitor 22 more quickly while suppressing damage to the first SMR 51.

[0097] The vehicle-mounted power supply device 10 switches to the second control while the voltage of the capacitor 22 is increased to a certain extent in the first control, thereby avoiding the inrush current flowing through the first relay 54 and switching to a more rapid pre-charging. As a result, the vehicle-mounted power supply device 10 can complete the pre-charging of the capacitor 22 more quickly while suppressing damage to the first SMR 51.

[0098] In the vehicle-mounted power supply device 10 , since the second relay 56 is a contactless semiconductor relay, damage to the second relay 56 can be avoided when switching from the first control to the second control.

[0099] <Other Implementation Methods>

[0100] The present disclosure is not limited to the embodiments described above and illustrated in the drawings. For example, the features of the embodiments described above or later can be combined in all ways within the scope of non-contradiction. In addition, any feature of the embodiments described above or later can be omitted if it is not explicitly stated as a necessary feature. Furthermore, the embodiments described above can also be changed as follows.

[0101] In each of the above-mentioned embodiments, the second SMR 52 may not be provided.

[0102] In the above embodiment, the first SMR 51 is an example of a system main relay, but the second SMR 52 may be an example of a system main relay. In this case, the parallel circuit 53 is provided in parallel with the second SMR 52. In this case, the first SMR 51 may not be provided.

[0103] In the above embodiments, the first relay 54 is a mechanical relay, but may be a semiconductor relay. In the above embodiments, the second relay 56 is a semiconductor relay, but may be a mechanical relay.

[0104] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is intended to include all modifications within the scope of the claims or within the scope equivalent to the claims.

[0105] Description of Reference Numerals

[0106] 10…In-vehicle power supply device

[0107] 20…Battery

[0108] 21…Power Path

[0109] 22…Capacitor

[0110] 30…Positive side power line

[0111] 31…Negative side power line

[0112] 32…First positive electrode side electric power line

[0113] 33…Second positive side electric power line

[0114] 34…First negative electrode side power line

[0115] 35…Second negative pole side power line

[0116] 40…Driver

[0117] 41…Inverter

[0118] 42…Electric motor

[0119] 51…First system main relay (system main relay)

[0120] 51A…Contact, fixed contact

[0121] 51B…Contact, fixed contact

[0122] 51C…Contact, movable contact

[0123] 51D...Coil

[0124] 52…Second system main relay

[0125] 52A…Contact, fixed contact

[0126] 52B…Contact, fixed contact

[0127] 52C…Contact, movable contact

[0128] 52D...Coil

[0129] 53…Parallel circuit

[0130] 54…First relay

[0131] 54A…Contact, fixed contact

[0132] 54B…Contact, fixed contact

[0133] 54C…Contact, movable contact

[0134] 54D...Coil

[0135] 55…Resistor

[0136] 56…Second relay

[0137] 56A…Input

[0138] 56B…Drain

[0139] 56C…Source

[0140] 57…Control Department

[0141] 100…In-vehicle power supply system.

Claims

1. A vehicle-mounted power supply device for use in a vehicle-mounted power supply system, the vehicle-mounted power supply system comprising: a battery; a power path to which power based on the battery is supplied; and a capacitor connected to the power path, The vehicle-mounted power supply device comprises: a mechanical system main relay provided in the power path on the battery side relative to the capacitor; A parallel circuit, which is a structure in which the first relay and the resistor are connected in series, is provided in parallel with the system main relay; and The second relay is provided in parallel with the resistor.

2. The vehicle-mounted power supply device according to claim 1, in, The vehicle-mounted power supply device includes a control unit that controls the system main relay, the first relay, and the second relay. The control unit performs a first control of controlling the system main relay and the second relay to be in an OFF state and controlling the first relay to be in an ON state when a start condition for starting charge and discharge of the storage battery is satisfied, When a first switching condition is satisfied during execution of the first control, a second control is executed to control the system main relay to an OFF state and the first relay and the second relay to an ON state. When a second switching condition is satisfied during execution of the second control, a third control is executed to control the first relay and the second relay to be in an OFF state and to control the system main relay to be in an ON state.

3. The vehicle-mounted power supply device according to claim 2, in, The second relay is a semiconductor relay.

4. The vehicle-mounted power supply device according to claim 2 or 3, in, The first switching condition is that the potential difference between both ends of the system main relay or the value of the current flowing in the parallel circuit becomes equal to or less than a threshold value.

5. The vehicle-mounted power supply device according to claim 2 or 3, in, The first switching condition is that a first time has passed since the start of the first control.

6. The vehicle-mounted power supply device according to claim 5, in, The second switching condition is that a second time shorter than the first time has passed since the start of the second control.

7. The vehicle-mounted power supply device according to claim 2 or 3, in, The first switching condition is that the voltage of the capacitor becomes equal to or greater than a threshold voltage.

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