Charging system

Abstract

To provide a technique capable of precisely determining the state of a form C contact relay.SOLUTION: A charging system includes a battery, a charging inlet, a power supply outlet, a DC charging route, an AC charging route, an AC power supply route, a system main relay, a form C contact relay, a first voltage sensor, a second voltage sensor, and a control unit. The form C contact relay is in a first closed state while a coil of the form C contact relay is not energized. The control unit is configured such that state detection processing for detecting the state of the form C contact relay can be executed. The state detection processing includes application processing, first determination processing, second determination processing, third determination processing and fourth determination processing.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a charging system. [Background technology]

[0002] Patent Document 1 discloses a charging system including a battery, a DC charging inlet, an AC charging inlet, a power supply outlet, an AC charging path connecting the battery and the AC charging inlet via an AC-DC conversion unit, a DC charging path connecting the battery and the DC charging inlet and connected in parallel to the AC charging path, an AC power supply path connecting the battery and the power supply outlet via a DC-AC inverter, a first system main relay provided in the AC charging path, and a second system main relay provided in the AC power supply path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-092310 Summary of the Invention [Problem to be solved by the invention]

[0004] Among charging systems, there is a charging system that includes a bidirectional charger installed in an AC charging path. In this charging system, the AC power supply path branches off from a section of the AC charging path that connects the charging inlet and the bidirectional charger toward the power supply outlet. The branch point where the AC power supply path branches off from the AC charging path is provided with a contact C relay that can be switched between a first closed state that connects the battery and the charging inlet via the bidirectional charger and a second closed state that connects the battery and the power supply outlet via the bidirectional charger. A technology that can determine the state of the contact C relay is desired.

[0005] This specification provides a technique that can accurately determine the state of a C-contact relay. [Means for solving the problem]

[0006] In a first aspect disclosed in the present specification, a charging system includes a battery, a charging inlet to which an external charging power source can be attached and detached, a power supply outlet to which an electrical device can be attached and detached, a DC charging path connecting the battery and the charging inlet, an AC charging path connecting the battery and the charging inlet via a bidirectional charger and connected in parallel to the DC charging path, an AC power supply path connecting the battery and the power supply outlet via the bidirectional charger and branching off from a section of the AC charging path connecting the charging inlet and the bidirectional charger towards the power supply outlet, a system main relay provided on the DC charging path and electrically connecting and disconnecting the battery from the charging inlet, and a C-contact relay provided at a branch point where the AC power supply path branches off from the AC charging path, The system includes a contact C relay switchable between a first closed state in which the battery and the charging inlet are connected via the bidirectional charger and a second closed state in which the battery and the power outlet are connected via the bidirectional charger; a first voltage sensor provided in the AC charging path between the charging inlet and the contact C relay and configured to detect a first voltage; a second voltage sensor provided in the AC charging path between the contact C relay and the bidirectional charger and configured to detect a second voltage; a third voltage sensor provided in the AC power supply path between the contact C relay and the power outlet and configured to detect a third voltage; and a control device connected to the first voltage sensor, the second voltage sensor, and the third voltage sensor, that controls the system main relay, the contact C relay, and the bidirectional charger. The contact C relay is in the first closed state when no current is applied to the coil of the contact C relay. The control device is configured to execute a state detection process that detects the state of the contact C relay.The state detection process includes an application process in which, while the system main relay is in a closed state, a switching command is given to the C-contact relay to switch the C-contact relay to the second closed state and the C-contact relay is applied with a voltage from the battery to the C-contact relay, and a first determination process in which, when the first voltage and the second voltage are equal and the third voltage is zero during the application process, the C-contact relay is determined to be welded to a contact on the AC charging path side. a second determination process for determining that the C-contact relay is fully welded when the first voltage, the second voltage, and the third voltage are the same while the application process is being performed; a third determination process for determining that the C-contact relay is normal or that a contact on the AC power supply path side is welded when the first voltage is zero and the second voltage and the third voltage are the same while the application process is being performed; and a fourth determination process for determining that the C-contact relay is short-circuited when the second voltage and the third voltage are zero while the application process is being performed.

[0007] The first voltage, second voltage, and third voltage when the voltage application process is being performed vary depending on the state of the C-contact relay. With the above configuration, the control device determines the state of the C-contact relay using the first voltage, second voltage, and third voltage when the voltage application process is being performed. Therefore, the state of the C-contact relay can be accurately determined. [Brief explanation of the drawings]

[0008] [Figure 1] 2 is a diagram showing a schematic configuration of an electric vehicle 2 in which a C-contact relay 32 is in a first closed state. FIG. [Figure 2] 10 is a diagram showing a schematic configuration of an electric vehicle 2 when a C-contact relay 32 is in a second closed state. FIG. [Figure 3] FIG. 10 is a flowchart of a state detection process. DETAILED DESCRIPTION OF THE INVENTION

[0009] The electric vehicle 2 will be described with reference to Figures 1 and 2. As an example, the electric vehicle 2 may be a battery electric vehicle, a hybrid electric vehicle, a fuel cell electric vehicle, or a plug-in hybrid electric vehicle. The electric vehicle 2 includes a charging system 10 and a traction motor (not shown).

[0010] The charging system 10 includes a battery 12, a charging inlet 14, and a power supply outlet 16. The battery 12 includes a plurality of battery cells. The battery cells are rechargeable battery cells, such as lithium-ion battery cells or all-solid-state battery cells. The charging inlet 14 is configured to allow an external charging power source 100 to be attached / detached. The external charging power source 100 is, for example, a DC charging stand, an AC charging stand, or a power outlet installed in a home or the like. The charging inlet 14 receives charging power for charging the battery 12 from the external charging power source 100. The power supply outlet 16 is configured to allow an electrical device to be attached / detached. The power supply outlet 16 outputs AC power to electrical devices such as home appliances, personal computers, smartphones, tablet devices, etc.

[0011] The charging system 10 further includes a DC charging path 20, an AC charging path 22, an AC power supply path 24, a bidirectional charger 26, a system main relay 28, a DC relay 30, a C-contact relay 32, a first voltage sensor 34, a second voltage sensor 36, and a third voltage sensor 38.

[0012] DC charging path 20 connects battery 12 and charging inlet 14. AC charging path 22 connects battery 12 and charging inlet 14 via bidirectional charger 26. AC charging path 22 is connected in parallel to DC charging path 20. AC power supply path 24 connects battery 12 and power supply outlet 16 via bidirectional charger 26. AC power supply path 24 branches off from a section of AC charging path 22 that connects charging inlet 14 and bidirectional charger 26 toward power supply outlet 16. In other words, the path of AC charging path 22 that is closer to battery 12 than contact C relay 32 is shared with AC power supply path 24.

[0013] The system main relay 28 and the DC relay 30 are provided in the DC charging path 20. The system main relay 28 is provided closer to the battery 12 than two connections of the DC charging path 20 with the AC charging path 22. The DC relay 30 is provided between the two connections of the DC charging path 20 with the AC charging path 22. The C-contact relay 32 is provided at a branch point (hereinafter simply referred to as the "branch point") where the AC power supply path 24 branches off from the AC charging path 22. The C-contact relay 32 is switchable between a first closed state in which the battery 12 and the charging inlet 14 are connected via the bidirectional charger 26, and a second closed state (see FIG. 2) in which the battery 12 and the power supply outlet 16 are connected via the bidirectional charger 26. The C-contact relay 32 is in the first closed state when a coil (not shown) of the C-contact relay 32 is not energized.

[0014] The bidirectional charger 26 can convert AC power supplied from the external charging power source 100 into DC power. The bidirectional charger 26 can also convert DC power supplied from the battery 12 into AC power.

[0015] The first voltage sensor 34 is provided in the AC charging path 22 between the charging inlet 14 and the branch point. The second voltage sensor 36 is provided in the AC charging path 22 between the branch point and the bidirectional charger 26. The third voltage sensor 38 is provided in the AC power supply path 24 between the power supply outlet 16 and the branch point.

[0016] The charging system 10 further includes a control device 40. The control device 40 is a computer device having a processor, a memory, etc. The control device 40 controls the operation of each component of the charging system 10.

[0017] (Status detection process; Figure 3) A state detection process executed by the control device 40 of the charging system 10 will be described with reference to Fig. 3. The control device 40 starts the process of Fig. 3 when an external charging power source that supplies DC power is connected to the charging inlet 14. The state detection process is a process for detecting the state of the C-contact relay 32 and determining whether or not to permit DC charging. In the initial state of Fig. 3, the system main relay 28 and the DC relay 30 are closed, and no current is applied to the coil of the C-contact relay 32.

[0018] In S10, the control device 40 issues a closing command to the system main relay 28. This connects the battery 12 and the charging inlet 14 via the bidirectional charger 26, as shown in FIG.

[0019] In S12, the control device 40 issues a switching command to the C-contact relay 32. The switching command is a command to switch the C-contact relay 32 to the second closed state.

[0020] In S14, the control device 40 activates the bidirectional charger 26. As a result, a voltage is applied from the battery 12 to the C-contact relay 32 via the AC charging path 22.

[0021] In S20, the control device 40 determines whether a first voltage condition is met, in which the first voltage V1 and the second voltage V2 are the same and the third voltage V3 is zero. If the first voltage condition is met (YES in S20), the control device 40 proceeds to S22, and if the first voltage condition is not met (NO in S20), the control device 40 proceeds to S30.

[0022] In S22, control device 40 determines that C-contact relay 32 is welded to the contact on the AC charging path 22 side. This is because when C-contact relay 32 is welded to the contact on the AC charging path 22 side, first voltage sensor 34 and second voltage sensor 36 are electrically connected via C-contact relay 32.

[0023] In S24, the control device 40 stores prohibition information that prohibits the execution of the DC charging process in memory. When S24 ends, the control device 40 ends the process of FIG.

[0024] In addition, in S30, the control device 40 determines whether a second voltage condition is met, in which the first voltage V1, the second voltage V2, and the third voltage V3 are the same. If the second voltage condition is met (YES in S30), the control device 40 proceeds to S32, and if the second voltage condition is not met (NO in S30), the control device 40 proceeds to S40.

[0025] In S32, the control device 40 determines that the C-contact relay 32 is fully welded. This is because when the C-contact relay 32 is fully welded, the first voltage sensor 34, the second voltage sensor 36, and the third voltage sensor 38 are electrically connected via the C-contact relay 32. After completing S32, the control device 40 proceeds to S24.

[0026] Furthermore, in S40, the control device 40 determines whether a third voltage condition is met, in which the first voltage V1 is zero and the second voltage V2 and the third voltage V3 are the same. If the third voltage condition is met (YES in S40), the control device 40 proceeds to S42, and if the third voltage condition is not met (NO in S40), the control device 40 proceeds to S50. Note that the first to third voltage conditions are not met when a fourth voltage condition is met, in which the first voltage V1 and the third voltage V3 are zero.

[0027] In S42, the control device 40 determines that the C-contact relay 32 is normal or that the contact on the AC power supply path 24 side is welded. This is because the second voltage sensor 36 and the third voltage sensor 38 are electrically connected via the C-contact relay 32 when the C-contact relay 32 is normal or that the contact on the AC power supply path 24 side is welded.

[0028] In S44, the control device 40 stores permission information permitting the execution of the DC charging process in memory. When S44 ends, the control device 40 ends the process of FIG.

[0029] Furthermore, in S50, the control device 40 determines that the C-contact relay 32 is short-circuited. This is because when the C-contact relay 32 is short-circuited, no voltage is applied to the first voltage sensor 34 and the third voltage sensor 38. After S50 is completed, the control device 40 proceeds to S44. In a modified example, the control device 40 may proceed to S24 after S50.

[0030] 3 is completed, the control device 40 executes the DC charging process if permission information is stored in memory. On the other hand, the control device 40 does not execute the DC charging process if prohibition information is stored in memory. With this configuration, it is possible to prevent DC power from flowing to the power outlet 16 and / or the bidirectional charger 26 while DC charging is being performed.

[0031] As described above, the charging system 10 includes the battery 12, the charging inlet 14, the power supply outlet 16, the DC charging path 20, the AC charging path 22, the AC power supply path 24, the system main relay 28, the C-contact relay 32, the first voltage sensor 34, the second voltage sensor 36, the third voltage sensor 38, and the control device 40. The C-contact relay 32 is in a first closed state when no current is flowing through the coil of the C-contact relay 32. The control device 40 is configured to be able to execute a state detection process (FIG. 3) that detects the state of the C-contact relay 32. The state detection process includes an application process (S14) in which, while the system main relay 28 is in a closed state, a switching command is given to the C-contact relay 32 to switch the C-contact relay 32 to a second closed state while the system main relay 28 is maintained in a closed state, and a voltage is applied from the battery 12 to the C-contact relay 32; a first determination process (S22) in which, while the voltage application process is being performed, if the first voltage V1 and the second voltage V2 are the same and the third voltage V3 is zero (YES in S20), the C-contact relay 32 is determined to be welded to the contact on the AC charging path side; and a second determination process (S23) in which, while the voltage application process is being performed, if the first voltage V1 and the second voltage V2 are the same and the third voltage V3 is zero (YES in S20), the C-contact relay 32 is determined to be welded to the contact on the AC charging path side. The method includes a second determination process (S32) for determining that the C-contact relay 32 is fully welded when the first voltage V1, the second voltage V2, and the third voltage V3 are the same (YES in S30), a third determination process (S42) for determining that the C-contact relay 32 is normal or welded to the second closed state when the first voltage V1 is zero and the second voltage V2 and the third voltage V3 are the same (YES in S40) while the application process is being executed, and a fourth determination process (S50) for determining that the C-contact relay 32 is short-circuited when the first voltage V1 and the third voltage V3 are zero (NO in S40) while the application process is being executed.

[0032] The first voltage V1, second voltage V2, and third voltage V3 during the application process differ depending on the state of the C-contact relay 32. With the above configuration, the control device 40 uses the first voltage V1, second voltage V2, and third voltage V3 during the application process to determine the state of the C-contact relay 32. Therefore, the state of the C-contact relay 32 can be accurately determined. [Explanation of symbols]

[0033] 2: electric vehicle, 10: charging system, 12: battery, 14: charging inlet, 16: power supply outlet, 20: DC charging path, 22: AC charging path, 24: AC power supply path, 26: bidirectional charger, 28: system main relay, 30: DC relay, 32: C-contact relay, 34: first voltage sensor, 36: second voltage sensor, 38: third voltage sensor, 40: control device, 100: charging power source

Claims

[Claim 1] A battery, A charging inlet that allows an external charging power source to be attached or detached, A power outlet that allows electrical devices to be attached and detached; a DC charging path connecting the battery and the charging inlet; an AC charging path that connects the battery and the charging inlet via a bidirectional charger and is connected in parallel to the DC charging path; an AC power supply path that connects the battery and the power supply outlet via the bidirectional charger and branches off from a section of the AC charging path that connects the charging inlet and the bidirectional charger toward the power supply outlet; a system main relay provided in the DC charging path and configured to electrically connect and disconnect the battery to and from the charging inlet; a C-contact relay provided at a branch point where the AC power supply path branches off from the AC charging path, the C-contact relay being switchable between a first closed state in which the battery and the charging inlet are connected via the bidirectional charger and a second closed state in which the battery and the power supply outlet are connected via the bidirectional charger; a first voltage sensor provided in the AC charging path between the charging inlet and the C-contact relay, the first voltage sensor detecting a first voltage; a second voltage sensor provided in the AC charging path between the C-contact relay and the bidirectional charger, the second voltage sensor detecting a second voltage; a third voltage sensor provided in the AC power supply path between the C-contact relay and the power supply outlet, the third voltage sensor detecting a third voltage; a control device connected to the first voltage sensor, the second voltage sensor, and the third voltage sensor, and configured to control the system main relay, the C-contact relay, and the bidirectional charger; Equipped with the C-contact relay is in the first closed state when a current is not applied to a coil of the C-contact relay, the control device is configured to be able to execute a state detection process for detecting a state of the C-contact relay, The state detection process includes: an application process in which, in a state in which the system main relay is closed, a switching command is given to the C-contact relay to switch the C-contact relay to the second closed state while the system main relay is maintained closed, and a voltage is applied from the battery to the C-contact relay; a first determination process of determining that the contact C relay is welded to a contact on the AC charging path side when the first voltage and the second voltage are equal and the third voltage is zero during the application process; a second determination process for determining that the C-contact relay is fully welded when the first voltage, the second voltage, and the third voltage are the same during the application process; a third determination process for determining that the contact C relay is normal or that a contact on the AC power supply path side is welded when the first voltage is zero and the second voltage and the third voltage are equal during the application process; a fourth determination process of determining that the contact C relay is short-circuited when the second voltage and the third voltage are zero during the application process; Including, charging system.

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