Relay drive control device, control method, and storage medium

Abstract

The present disclosure relates to a relay drive control device, a control method, and a storage medium. The relay drive control device is configured to control driving of a relay for connecting a battery mounted on a vehicle and an external power supply. The relay drive control device includes a controller configured to supply, when driving the relay, an output voltage of the battery to the relay after increasing the output voltage to a voltage value at which the relay can be driven.

Description

Technical Field

[0001] This disclosure relates to a relay drive control device, control method, and storage medium. The relay drive control device is configured to, for example, control the drive of a relay used to connect a battery installed in a vehicle to an external power source. Background Technology

[0002] Japanese Unexamined Patent Application Publication No. 2014-079121 (JP 2014-079121 A) discloses an energy storage system comprising an energy storage device consisting of multiple single batteries connected in series, a relay for switching the connection and disconnection states between the energy storage device and a load, and a controller for controlling the drive of the relay by energizing or de-energizing a coil portion. In this energy storage system, the controller dynamically controls the voltage to be supplied to the coil portion based on the state of the relay, thereby appropriately driving the relay. Summary of the Invention

[0003] To drive the relay, the energy storage system described in JP 2014-079121 A requires, for example, a temperature sensor for deriving the drive voltage based on the relay's state, and multiple switches for extracting the derived drive voltage from the energy storage device consisting of single cells connected in series. Therefore, the cost and size (size and weight) of the energy storage system increase.

[0004] This disclosure provides a relay drive control device, control method, and storage medium, wherein a relay can be driven while suppressing increases in cost and size (size and weight).

[0005] The first aspect of this disclosure relates to a relay drive control device configured to control the drive of a relay for connecting a battery installed in a vehicle and an external power source. The relay drive control device includes a controller configured to, when the relay is driven, supply the output voltage to the relay after increasing the output voltage of the battery to a voltage value that allows the relay to be driven.

[0006] In a first embodiment, the relay drive control device may include a voltage converter configured to output an output voltage, converted into a drive voltage, to the controller. The output voltage may be input from the battery. The controller may be configured to, when driving the relay, control the voltage converter to increase the drive voltage input from the voltage converter to a first voltage value capable of driving the relay. The controller may be configured to supply the drive voltage to the relay when the relay is to be driven and the drive voltage reaches the first voltage value.

[0007] In the first embodiment, the controller can be configured to, when the relay is to be driven, supply the driving voltage to the relay after the controller has started controlling the voltage converter to increase the driving voltage to the first voltage value, and after a predetermined time period has elapsed before the driving voltage reaches the first voltage value.

[0008] In the first embodiment, the controller may be configured to control the voltage converter to reduce the driving voltage to a second voltage value after the relay has been driven by supplying the driving voltage to the relay.

[0009] In the first embodiment, the first voltage value may be a voltage value that enables the relay to be driven at the upper limit of a predetermined temperature range that allows the relay to be used.

[0010] In the first scheme, the second voltage value can be the voltage value at which the relay being driven is not switched to the off state.

[0011] In the first embodiment, the controller can be configured to determine whether the relay can be driven based on the state of the battery and the voltage converter.

[0012] In the first embodiment, the controller may be configured to change at least one of the predetermined time period and the rate at which the drive voltage increases to the first voltage value, based on information related to the temperature of the relay.

[0013] In the first embodiment, the external power source may be an external charging device to be plugged into the vehicle to supply power to the vehicle.

[0014] A second aspect of this disclosure relates to a control method executed by a computer of a relay drive control device configured to control the drive of a relay for connecting a battery installed in a vehicle to an external power source. The control method includes determining whether to drive the relay; when driving the relay, increasing the output voltage of the battery to a drive voltage capable of driving the relay; and when the output voltage reaches the drive voltage, supplying the drive voltage to the relay.

[0015] A third aspect of this disclosure relates to a non-transitory storage medium storing instructions executable by one or more processors of a computer for a relay drive control device, causing the processors to perform functions. The relay drive control device is configured to control the driving of a relay for connecting a battery installed in a vehicle to an external power source. The functions include determining whether to drive the relay, increasing the battery's output voltage to a driving voltage capable of driving the relay when the relay is driven, and supplying the driving voltage to the relay when the output voltage reaches the driving voltage.

[0016] According to the first, second, and third embodiments of this disclosure, the voltage used to drive the relay is controlled by using existing device configurations. Therefore, the relay can be driven appropriately while suppressing increases in device cost and size (size and weight). Attached Figure Description

[0017] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, wherein like symbols denote like elements, and wherein:

[0018] Figure 1 This is a functional block diagram of a relay drive control device and its peripheral components according to embodiments of the present disclosure;

[0019] Figure 2 This is a flowchart of the DC charging control process executed by a relay-driven control device.

[0020] Figure 3 This is a flowchart of the relay drive control process executed by the relay drive control device;

[0021] Figure 4 This is a flowchart of the relay diagnostic control process executed by the relay drive control device;

[0022] Figure 5 This is a flowchart for diagnosing the adhesion and closure of a positive DC relay; and

[0023] Figure 6 This is a flowchart for diagnosing the adhesion and closure of a negative DC relay. Detailed Implementation

[0024] When the vehicle battery is charged using an external power source, the relay drive control device of this disclosure performs control to increase the voltage of the charging relay, which drives the switching on / off state of charging, to a voltage value that can drive the relay even at high temperatures. Using this control, the charging relay can be driven appropriately.

[0025] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0026] Example

[0027] Configuration

[0028] Figure 1 This is a functional block diagram of the relay drive control device 10 and its peripheral components according to an embodiment of the present disclosure. Figure 1 The illustrated functional block includes a relay drive control unit 10, a drive battery 20, a charging relay (CHR) 30, and a plug connector 40. Figure 1 In the diagram, wide solid lines represent connection lines mainly used for power supply, narrow solid lines represent connection lines mainly used for voltage supply, and dashed lines represent connection lines used for control.

[0029] The relay drive control device 10, drive battery 20, charging relay 30, and plug connector 40 are mounted on a vehicle (electric vehicle), such as a plug-in hybrid electric vehicle (PHEV) or a battery electric vehicle (BEV) that uses an electric motor as its power source and can charge its battery using an external power source 50. The vehicle, including the relay drive control device 10, drive battery 20, charging relay 30, and plug connector 40, can connect the external power source 50 to the plug connector 40 via a charging cable 51. The external power source 50 described in this embodiment is an external charging device for supplying direct current (DC) power to the vehicle.

[0030] The drive battery 20 is a rechargeable secondary battery (such as a lithium-ion battery) and a high-voltage battery that supplies power to so-called main devices (not shown) such as a starter motor and a drive motor mounted on the vehicle. The drive battery 20 can receive power (and be charged) from an external power source 50 via a charging relay 30 and a plug connector 40. The drive battery 20 can supply power to the relay drive control device 10 via a system main relay (SMR) (not shown).

[0031] The charging relay (CHR) 30 is a switching element disposed between the drive battery 20 and the plug connector 40, and is used to control the connection and disconnection of the power path (power path) for charging the drive battery 20 using an external power supply 50. The charging relay 30 includes a DC relay 31 (hereinafter referred to as "positive DC relay 31") inserted into the power supply line on the positive (+) side of the power path, and a DC relay 32 (hereinafter referred to as "negative DC relay 32") inserted into the power supply line on the negative (-) side of the power path. The positive DC relay 31 and the negative DC relay 32 can independently switch between a drive state (ON operation) of electrically connected terminals and an off state (OFF operation) of electrically disconnected terminals based on the drive voltage supplied from the controller 12 of the relay drive control device 10, which will be described later. Each of the positive DC relay 31 and the negative DC relay 32 can be a mechanical relay, which brings the contacts into a conducting state by applying a voltage to the coil portion and causing current to flow. In the following description, when the positive DC relay 31 and the negative DC relay 32 are controlled together to the same operating state, this operating state is referred to as the operating state of the charging relay 30.

[0032] The plug connector 40 is a power interface used to connect the vehicle to an external power source 50 via the charging cable 51. When the vehicle is connected to the external power source 50 via the charging cable 51, the drive battery 20 is charged with power supplied from the external power source 50 during the period when the charging relay 30 is in the activated state.

[0033] The relay drive control device 10 is a device that controls the charging of the drive battery 20 by controlling the charging relay 30. Furthermore, the relay drive control device 10 is capable of controlling the power balance between the drive battery 20 and an auxiliary battery (not shown) that supplies power to an auxiliary device (not shown). According to this embodiment, the relay drive control device 10 includes a voltage converter 11, a controller 12, and a voltage detector 13.

[0034] The voltage converter 11 generates a drive voltage for driving the charging relay 30 based on the output voltage of the drive battery 20, and supplies the generated drive voltage to the controller 12. That is, the voltage converter 11 acts as a power converter that converts the electricity stored in the drive battery 20 with a battery-specific voltage into electricity with a drive voltage. The voltage converter 11 is typically a DC-DC converter capable of generating a drive voltage with a voltage value specified by the controller 12 and outputting it to the controller 12. For example, the voltage converter 11 can convert the electricity stored in the drive battery 20 into electricity with a predetermined voltage and supply it to auxiliary devices and auxiliary batteries.

[0035] The controller 12 controls the start and end of charging the drive battery 20 by switching the operating state of the charging relay 30 using power supplied from the voltage converter 11, based on the state of the drive battery 20 and the voltage of the output terminal of the charging relay 30 detected by the voltage detector 13. The controller 12 can obtain the state (voltage, current, temperature, etc.) of the drive battery 20 from the functional unit or system controlling the drive battery 20. The controller 12 can instruct the voltage converter 11 to increase, maintain, or decrease the voltage value of the driving voltage input to the voltage converter 11. The controller 12 is capable of diagnosing abnormalities (such as malfunctions of the charging relay 30). The processing performed by the controller 12 will be described later.

[0036] Voltage detector 13 detects the potential difference between the output voltage of the positive DC relay 31 and the output voltage of the negative DC relay 32 in the charging relay 30. Voltage detector 13 is a detection element such as a voltage sensor. The potential difference between the output voltage of the positive DC relay 31 and the output voltage of the negative DC relay 32 detected by voltage detector 13 is output to controller 12. Voltage detector 13 can be located in components other than relay drive control device 10.

[0037] The controller 12 may be configured with part or all of an electronic control unit (HV_ECU, charging ECU, etc.), which includes a processor (such as a microcomputer), memory, input / output interfaces, etc. The electronic control unit can read and execute programs stored in the memory through the processor to achieve part or all of the above functions.

[0038] control

[0039] Next, we will refer to further Figures 2 to 6 The control performed by the relay drive control device 10 according to this embodiment is described. The control performed by the relay drive control device 10 can be represented by "DC charging control" for controlling the charging of the drive battery 20, "relay drive control" for controlling the operating state of the charging relay 30, and "relay diagnostic control" for diagnosing whether an abnormality has occurred in the charging relay 30.

[0040] (1) DC charging control

[0041] Figure 2 This is a flowchart illustrating the process of DC charging control of the drive battery 20 using an external power supply 50, executed by the controller 12 of the relay drive control device 10. For example, when the charging cable 51 of the external power supply 50 is connected to the plug connector 40, Figure 2 The DC charging control shown has started.

[0042] Step S201

[0043] When DC charging of the vehicle is performed, controller 12 executes relay drive control to control the operating state of charging relay 30. (See below for further details.) Figure 3 The details of relay drive control are described. When controller 12 executes relay drive control, the process proceeds to step S202.

[0044] Step S202

[0045] The controller 12 determines whether the charging relay 30 is driven by relay drive control. This determination can be made based on the potential difference between the output voltage of the positive DC relay 31 and the output voltage of the negative DC relay 32 detected by the voltage detector 13.

[0046] When controller 12 determines that charging relay 30 is driven (step S202: Yes), the process proceeds to step S203. When controller 12 determines that charging relay 30 is not driven (step S202: No), DC charging control is terminated, and DC charging is not performed.

[0047] Step S203

[0048] Controller 12 performs DC charging control to charge the drive battery 20 using power from external power source 50. Known charging methods can be used for DC charging. When DC charging is performed and completed by controller 12, the process proceeds to step S204. When DC charging is complete, charging relay 30 is controlled to the off state.

[0049] Step S204

[0050] Controller 12 performs relay diagnostic control to diagnose any abnormalities in the charging relay 30. (See below for further details.) Figure 4 The details of relay diagnostic control are described. When controller 12 executes relay diagnostic control, the process proceeds to step S205.

[0051] Step S205

[0052] The controller 12 determines whether there is a problem with the diagnostic results in the charging relay 30. More specifically, the relay drive control device 10 determines whether the charging relay 30 is determined to be normal.

[0053] When the controller 12 determines that the diagnostic result of the charging relay 30 is not problematic (step S205: No), the DC charging control terminates. When the controller 12 determines that the diagnostic result of the charging relay 30 is problematic (step S205: Yes), the process proceeds to step S206.

[0054] Step S206

[0055] The controller 12 determines whether the charging cover is closed when the charging cable 51 is unplugged from the plug connector 40, and whether the vehicle's ignition switch is turned on (IG-ON). This determination can be made by the controller 12 obtaining information from a predetermined on-board device regarding, for example, the opening or closing of the charging cover and the ignition switch signal. Only when the controller 12 determines that the charging cover is closed and the ignition switch is on (step S206: Yes), the process proceeds to step S207.

[0056] Step S207

[0057] The controller 12 executes the relay diagnostic control again to re-diagnose whether the charging relay 30 is malfunctioning. This relay diagnostic control is the same process as the relay diagnostic control in step S204. When the controller 12 executes the relay diagnostic control again, the process proceeds to step S208. By setting a time limit, the re-diagnosis of the charging relay 30's malfunction can be repeated multiple times.

[0058] Step S208

[0059] The controller 12 determines whether there is a problem with the diagnostic results of the charging relay 30. More specifically, the relay drive control device 10 determines whether the charging relay 30 is determined to be normal.

[0060] When the controller 12 determines that the diagnostic result of the charging relay 30 is not problematic (step S208: No), the DC charging control terminates. When the controller 12 determines that the diagnostic result of the charging relay 30 is problematic (step S208: Yes), the process proceeds to step S209.

[0061] Step S209

[0062] Controller 12 confirms that charging relay 30 is in an abnormal state. When controller 12 confirms that charging relay 30 is abnormal, DC charging control is terminated.

[0063] For example, the user of the vehicle can be notified of the determination that the charging relay 30 is malfunctioning. For example, by using a function that displays the status of the charging equipment (such as a light-emitting diode (LED) light), a notification of the malfunction of the charging relay 30 can be given to the user.

[0064] The DC charging control controls whether to use an external power supply 50 to perform DC charging of the drive battery 20, and determines whether the charging relay 30 is normal or abnormal for the next DC charging.

[0065] (2) Relay drive control

[0066] Figure 3 It is shown in Figure 2The flowchart below shows the relay drive control process executed by the controller 12 of the relay drive control device 10 in step S201. It is assumed that before the relay drive control begins, the charging relay 30 is in an off state (OFF operation) with the terminal electrical disconnected.

[0067] Step S301

[0068] The controller 12 determines whether a "relay drive condition" is met to allow charging of the drive battery 20 from the external power source 50 by driving the charging relay 30. Examples of relay drive conditions include conditions where the drive battery 20 does not have a high voltage abnormality, conditions where the drive battery 20 does not have a high temperature abnormality, conditions where the output of the voltage converter 11 does not have a low voltage abnormality, conditions where the output of the voltage converter 11 does not have a high voltage abnormality, and conditions where the voltage converter 11 does not have a high temperature abnormality. Therefore, the relay drive condition is that all functions of the drive battery 20 and the voltage converter 11 exhibit predetermined normal values. Whether the relay drive condition is met can be determined based on results from a system (not shown) controlling and managing the drive battery 20 and a system (not shown) controlling and managing the voltage converter 11, or it can be determined by the controller 12 based on physical quantities (voltage, current, temperature, etc.) detected or acquired from the drive battery 20 and the voltage converter 11.

[0069] When the controller 12 determines that the relay drive condition of the charging relay 30 is met (step S301: Yes), the process proceeds to step S302. When the controller 12 determines that the relay drive condition of the charging relay 30 is not met (step S301: No), the relay drive control terminates.

[0070] When the relay drive control terminates due to unmet relay drive conditions of the charging relay 30, the vehicle user can be notified that any function of the drive battery 20 and voltage converter 11 has malfunctioned. For example, a notification that external charging cannot be performed can be given to the user by using a function that displays the status of charging equipment (such as LED lights).

[0071] Step S302

[0072] Controller 12 executes control to increase the drive voltage input from voltage converter 11. Specifically, controller 12 executes control to increase the drive voltage from its current value to a predetermined first voltage value (described later). Controller 12 increases the value of the drive voltage output by voltage converter 11 by changing the command value of the output voltage of voltage converter 11. The rate of increase of the voltage value is not limited, but can be changed based on information related to the temperature of charging relay 30, such as the charging duration in the previous DC charging control, the time elapsed since the completion of the previous DC charging control, and the external air temperature. For example, when the time elapsed since the completion of the previous DC charging control is short, or when the external air temperature is high, the temperature of charging relay 30 is estimated to be relatively higher than normal. Therefore, the rate of increase of the voltage value can be increased. With this change, charging relay 30 can be driven at an earlier time. When controller 12 executes control to increase the drive voltage, the process proceeds to step S303.

[0073] Step S303

[0074] The controller 12 determines whether the drive voltage input from the voltage converter 11 reaches a first voltage value. The first voltage value can be a driveable voltage value at which the charging relay 30 can be driven at the upper limit of a predetermined temperature range that allows its use. As described above, in a mechanical relay, the pull-in voltage, which is the operating voltage, increases as the temperature of the coil portion rises. Therefore, in this embodiment, the driveable voltage value, which is the first voltage value, is set to a voltage value that can drive the charging relay 30 even at the assumed highest temperature condition within the operating range, taking into account various voltage drops in the supply path (including the wiring harness).

[0075] When the controller 12 determines that the drive voltage has reached the driveable voltage value (step S303: Yes), the process proceeds to step S305. When the controller 12 determines that the drive voltage has not reached the driveable voltage value (step S303: No), the process proceeds to step S304.

[0076] Step S304

[0077] The controller 12 determines whether a predetermined time period has elapsed since the start of the drive voltage increase control. When the temperature of the charging relay 30 is low, the charging relay 30 can be driven even if the drive voltage is not a driveable voltage value. Therefore, when the drive voltage increase control takes a long time, this determination is made to drive the charging relay 30 before the drive voltage reaches a driveable voltage value. Therefore, the predetermined time period is arbitrarily set according to this purpose, such as the time period during which a drive delay of the charging relay 30 is allowed. Furthermore, the predetermined time period can be changed based on information related to the temperature of the charging relay 30, such as the charging duration in the previous DC charging control, the time elapsed since the completion of the previous DC charging control, and the external air temperature. For example, when the time elapsed since the completion of the previous DC charging control is short, or when the external air temperature is high, the temperature of the charging relay 30 is estimated to be relatively higher than normal. Therefore, the predetermined time period can be shortened. With this change, the charging relay 30 can be driven at an earlier time.

[0078] When controller 12 determines that a predetermined time period has elapsed since the start of the self-driving voltage increase control (step S304: Yes), the process proceeds to step S305. When controller 12 determines that a predetermined time period has not elapsed since the start of the self-driving voltage increase control (step S304: No), the process proceeds to step S303.

[0079] Step S305

[0080] The controller 12 supplies a drive voltage (power) to the charging relay 30. When the drive voltage has reached the driveable voltage value in step S303, the controller 12 supplies the driveable voltage value as the drive voltage to the charging relay 30. When a predetermined time period has elapsed before the drive voltage reaches the driveable voltage value in step S304, the controller 12 supplies the current voltage value output by the voltage converter 11 as the drive voltage to the charging relay 30. When the controller 12 supplies the drive voltage (power) to the charging relay 30, the process proceeds to step S306.

[0081] Step S306

[0082] The controller 12 determines whether the driving of the charging relay 30 is complete. More specifically, the controller 12 determines whether each of the positive DC relay 31 and the negative DC relay 32 is in a driving state with its terminals electrically connected. This determination can be made based on the potential difference between the output voltage of the positive DC relay 31 and the output voltage of the negative DC relay 32 obtained from the voltage detector 13. More specifically, the driving of the charging relay 30 can be determined to be complete when the potential difference between the two output voltages has reached the voltage supplied from the external power supply 50 (or the voltage of the driving battery 20).

[0083] When controller 12 determines that the driving of charging relay 30 is complete (step S306: Yes), the process proceeds to step S307. When controller 12 determines that the driving of charging relay 30 is not complete (step S306: No), controller 12 waits until charging relay 30 is driven.

[0084] Step S307

[0085] The controller 12 performs control to reduce the drive voltage input from the voltage converter 11. Specifically, the controller 12 performs control to reduce the drive voltage from the current voltage value to a predetermined second voltage value. As is typical of mechanical relays, the open-circuit voltage value, which is the non-operating voltage, is lower than the pull-in voltage value, which is the operating voltage. Therefore, the second voltage value can be set to a voltage value higher than the open-circuit voltage, allowing the charging relay 30 to maintain its driving state. The controller 12 reduces the drive voltage output by the voltage converter 11 by changing the command value of the output voltage of the voltage converter 11. When the controller 12 performs control to reduce the drive voltage, the relay drive control terminates.

[0086] By using relay drive control, the external power supply 50 can be used to DC charge the drive battery 20 by properly driving the charging relay 30, while suppressing the increase in cost and size (size and weight) of the relay drive control device 10.

[0087] (3) Relay Diagnostic Control

[0088] Figure 4 It is shown in Figure 2 The flowchart below shows the relay diagnostic control process executed by the controller 12 of the relay drive control device 10 in steps S204 and S207. It is assumed that when the relay diagnostic control is executed, power supply from the external power supply 50 to the plug connector 40 is stopped.

[0089] Step S401

[0090] Controller 12 performs a positive DC relay sticking closure diagnostic. More specifically, controller 12 diagnoses whether the contacts of positive DC relay 31 are stuck. See below for further details. Figure 5 The details of the positive DC relay sticking closure diagnosis are described. When the controller 12 performs the positive DC relay sticking closure diagnosis, the process proceeds to step S402.

[0091] Step S402

[0092] The controller 12 determines whether the positive DC relay 31 is considered normal by using the positive DC relay adhesion and closure diagnosis.

[0093] When the controller 12 determines that the positive DC relay 31 is normal (step S402: Yes), the process proceeds to step S403. When the controller 12 determines that the positive DC relay 31 is not normal (step S402: No), the process proceeds to step S408.

[0094] Step S403

[0095] Controller 12 performs a negative DC relay sticking closure diagnostic. More specifically, controller 12 diagnoses whether the contacts of negative DC relay 32 are stuck. See below for further details. Figure 6 The details of the negative DC relay sticking closure diagnosis are described. When the controller 12 performs the negative DC relay sticking closure diagnosis, the process proceeds to step S404.

[0096] Step S404

[0097] The controller 12 uses the negative DC relay adhesion closure diagnosis to determine whether the negative DC relay 32 is considered normal.

[0098] When controller 12 determines that negative DC relay 32 is normal (step S404: Yes), the process proceeds to step S405. When controller 12 determines that negative DC relay 32 is not normal (step S404: No), the process proceeds to step S408.

[0099] Step S405

[0100] In addition to the DC relay sticking closure diagnosis, the controller 12 also performs other diagnoses required to determine the state of the charging relay 30. When the controller 12 performs other diagnoses, the process proceeds to step S406.

[0101] The processes in steps S401 and S402, steps S403 and S404, and step S405 can be performed in a different order. If there are no other diagnostics, step S405 can be omitted.

[0102] Step S406

[0103] The controller 12 determines whether the charging relay 30 is considered normal, that is, whether the positive DC relay 31 and the negative DC relay 32 are considered normal.

[0104] When the controller 12 determines that the charging relay 30 is normal (step S406: Yes), the process proceeds to step S407. When the controller 12 determines that the charging relay 30 is not normal (step S406: No), the process proceeds to step S408.

[0105] Step S407

[0106] Controller 12 confirms that charging relay 30 is functioning normally. When controller 12 confirms that charging relay 30 is functioning normally, relay diagnostic control terminates.

[0107] Step S408

[0108] The controller 12 confirms that the charging relay 30 is malfunctioning. When the controller 12 confirms that the charging relay 30 is malfunctioning, the relay diagnostic control terminates.

[0109] Through relay diagnostic control, it is possible to predict in advance whether the next DC charging control of the drive battery 20 using the external power supply 50 can proceed normally.

[0110] (4) Diagnosis of DC relay adhesion and closure

[0111] Further reference Figure 5 describe Figure 4 The positive DC relay sticking closure diagnosis is performed in step S401. In the positive DC relay sticking closure diagnosis, a diagnosis is made as to whether a so-called sticking closure has occurred in the positive DC relay 31, in which the contacts are melted and stuck in a conductive state.

[0112] Step S501

[0113] The controller 12 controls the positive DC relay 31 to the off state and controls the negative DC relay 32 to enter the driving state. During this control period, the controller 12 only performs relay drive control on the negative DC relay 32 that is in the driving state. Figure 3 When the controller 12 controls the positive DC relay 31 to the off state and controls the negative DC relay 32 to the drive state, the process proceeds to step S502.

[0114] Step S502

[0115] The controller 12 determines whether a first time period has elapsed since the operating states of the positive DC relay 31 and the negative DC relay 32 were controlled. This determination is made to forcibly terminate the diagnostic process when the state of the positive DC relay 31 is unstable and its normal or abnormal status cannot be determined. Therefore, the first time period can be appropriately set based on, for example, the performance of the charging relay 30 and the vehicle's charging specifications.

[0116] When controller 12 determines that a first time period has elapsed since the operating states of positive DC relay 31 and negative DC relay 32 were controlled (step S502: Yes), the process proceeds to step S507. When controller 12 determines that a first time period has not elapsed since the operating states of positive DC relay 31 and negative DC relay 32 were controlled (step S502: No), the process proceeds to step S503.

[0117] Step S503

[0118] The controller 12 monitors the potential difference between the output voltage of the positive DC relay 31 and the output voltage of the negative DC relay 32. The potential difference between the two output voltages can be obtained from the voltage detector 13. When the controller 12 detects the potential difference between the two output voltages, the process proceeds to step S504.

[0119] Step S504

[0120] The controller 12 determines whether the potential difference between the output voltage of the positive DC relay 31 and the output voltage of the negative DC relay 32 is less than a predetermined threshold. This determination is made to determine whether the positive DC relay 31 is in an activated state or an unactivated state. Therefore, the threshold is set to any value between the voltage of the drive battery 20, which represents the potential difference between the two output voltages when both DC relays 31 and 32 are in an activated state, and a value where the potential difference between the two output voltages is essentially zero when both DC relays 31 and 32 are in an unactivated state.

[0121] When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is less than the threshold (step S504: Yes), the process proceeds to step S505. When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is equal to or greater than the threshold (step S504: No), the process proceeds to step S506.

[0122] Step S505

[0123] The controller 12 determines whether the potential difference between the output voltage of the positive DC relay 31 and the output voltage of the negative DC relay 32 remains less than a threshold for a second time period. This determination is made to determine whether the states of DC relays 31 and 32 are stable. Therefore, the second time period is set to any time period required to determine the state of DC relays 31 and 32.

[0124] When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is consistently less than the threshold for a second time period (step S505: Yes), the process proceeds to step S508. When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is not consistently less than the threshold for a second time period (step S505: No), the process proceeds to step S502.

[0125] Step S506

[0126] Controller 12 determines whether the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 remains equal to or greater than a threshold for a second time period. This determination is made to determine whether the states of DC relays 31 and 32 are stable. The second time period is described above in step S505.

[0127] When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is consistently equal to or greater than the threshold for a second time period (step S506: Yes), the process proceeds to step S509. When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is not consistently equal to or greater than the threshold for a second time period (step S506: No), the process proceeds to step S502.

[0128] Step S507

[0129] Controller 12 determines that it cannot determine whether the positive DC relay 31 is normal or abnormal (it is impossible to determine). When controller 12 determines that it is impossible to determine the positive DC relay 31, the process proceeds to step S510.

[0130] Step S508

[0131] The controller 12 determines that the positive DC relay 31 is normal (normal determination). When the controller 12 determines that the positive DC relay 31 is normal, the process proceeds to step S510.

[0132] Step S509

[0133] The controller 12 determines that the positive DC relay 31 has an adhesion and closure abnormality (abnormality determination). When the controller 12 determines that the positive DC relay 31 is abnormal, the process proceeds to step S510.

[0134] Step S510

[0135] The controller 12 controls the positive DC relay 31 and the negative DC relay 32 to the open state. When the controller 12 controls the positive DC relay 31 and the negative DC relay 32 to the open state, the positive DC relay adhesion closure diagnosis terminates.

[0136] By using the positive DC relay sticking and closing diagnostic method, the contact sticking abnormality of the positive DC relay 31 can be easily determined individually.

[0137] (5) Diagnosis of negative DC relay adhesion and closure

[0138] Further reference Figure 6 describe Figure 4The negative DC relay sticking closure diagnosis is performed in step S403. In the negative DC relay sticking closure diagnosis, a diagnosis is made as to whether a so-called sticking closure has occurred in the negative DC relay 32, in which the contacts are melted and stuck in a conductive state.

[0139] Step S601

[0140] The controller 12 controls the positive DC relay 31 to the driven state and the negative DC relay 32 to the disconnected state. During this control period, the controller 12 only performs relay drive control on the positive DC relay 31 that is in the driven state. Figure 3 When the controller 12 controls the positive DC relay 31 to the driving state and the negative DC relay 32 to the disconnected state, the process proceeds to step S602.

[0141] Step S602

[0142] The controller 12 determines whether a first time period has elapsed since the operating states of the positive DC relay 31 and the negative DC relay 32 were controlled. This determination is made to forcibly terminate the diagnostic process when the state of the negative DC relay 32 is unstable and its normal or abnormal status cannot be determined. Therefore, the first time period can be appropriately set based on, for example, the performance of the charging relay 30 and the vehicle's charging specifications.

[0143] When controller 12 determines that a first time period has elapsed since the operating states of positive DC relay 31 and negative DC relay 32 were controlled (step S602: Yes), the process proceeds to step S607. When controller 12 determines that a first time period has not elapsed since the operating states of positive DC relay 31 and negative DC relay 32 were controlled (step S602: No), the process proceeds to step S603.

[0144] Step S603

[0145] The controller 12 monitors the potential difference between the output voltage of the positive DC relay 31 and the output voltage of the negative DC relay 32. The potential difference between the two output voltages can be obtained from the voltage detector 13. When the controller 12 detects the potential difference between the two output voltages, the process proceeds to step S604.

[0146] Step S604

[0147] The controller 12 determines whether the potential difference between the output voltage of the positive DC relay 31 and the output voltage of the negative DC relay 32 is less than a predetermined threshold. This determination is made to determine whether the negative DC relay 32 is in an activated state or an unactivated state. Therefore, the threshold is set to any value between the voltage of the drive battery 20, which represents the potential difference between the two output voltages when both DC relays 31 and 32 are in an activated state, and a value where the potential difference between the two output voltages is essentially zero when both DC relays 31 and 32 are in an unactivated state.

[0148] When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is less than the threshold (step S604: Yes), the process proceeds to step S605. When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is equal to or greater than the threshold (step S604: No), the process proceeds to step S606.

[0149] Step S605

[0150] The controller 12 determines whether the potential difference between the output voltage of the positive DC relay 31 and the output voltage of the negative DC relay 32 remains less than a threshold for a second time period. This determination is made to determine whether the states of DC relays 31 and 32 are stable. Therefore, the second time period is set to any time period required to determine the state of DC relays 31 and 32.

[0151] When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is consistently less than the threshold for a second time period (step S605: Yes), the process proceeds to step S608. When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is not consistently less than the threshold for a second time period (step S605: No), the process proceeds to step S602.

[0152] Step S606

[0153] Controller 12 determines whether the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 remains equal to or greater than a threshold for a second time period. This determination is made to determine whether the states of DC relays 31 and 32 are stable. The second time period is described above in step S605.

[0154] When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is consistently equal to or greater than the threshold for a second time period (step S606: Yes), the process proceeds to step S609. When controller 12 determines that the potential difference between the output voltage of positive DC relay 31 and the output voltage of negative DC relay 32 is not consistently equal to or greater than the threshold for a second time period (step S606: No), the process proceeds to step S602.

[0155] Step S607

[0156] Controller 12 determines that it cannot determine whether the negative DC relay 32 is normal or abnormal (it is impossible to determine). When controller 12 determines that it is impossible to determine the negative DC relay 32, the process proceeds to step S610.

[0157] Step S608

[0158] Controller 12 determines that negative DC relay 32 is normal (normal determination). When controller 12 determines that negative DC relay 32 is normal, the process proceeds to step S610.

[0159] Step S609

[0160] The controller 12 determines that the negative DC relay 32 has an adhesion closure abnormality (abnormality determination). When the controller 12 determines that the negative DC relay 32 is abnormal, the process proceeds to step S610.

[0161] Step S610

[0162] The controller 12 controls the positive DC relay 31 and the negative DC relay 32 to the open state. When the controller 12 controls the positive DC relay 31 and the negative DC relay 32 to the open state, the negative DC relay adhesion closure diagnosis terminates.

[0163] By diagnosing the contact adhesion of the negative DC relay, the abnormal contact adhesion of the negative DC relay 32 can be easily determined independently.

[0164] Operation and Effect

[0165] As described above, in the relay drive control device 10 according to an embodiment of the present disclosure, when the charging relay (CHR) 30, which connects the drive battery 20 and the external power supply 50, is driven to perform DC charging, the voltage converter 11 that generates the drive voltage is controlled to increase the drive voltage to a voltage value (first voltage value) at which the charging relay 30 can be driven. Then, the drive voltage is supplied to the charging relay 30 at the earlier of the moment when the drive voltage reaches the driveable voltage value (first voltage value) and the moment when a predetermined time period has elapsed since the drive voltage began to increase.

[0166] Using this control, the first voltage value is set to be the voltage value that can drive the charging relay 30 at the upper limit of a predetermined temperature range that allows the charging relay 30 to be used. Therefore, even in a high-temperature environment where the charging relay 30 is assumed to be used, the charging relay 30 can be driven appropriately without changing the structure of the relay (the number of turns of the coil, the magnetic circuit, etc. in a mechanical relay). By providing a time limit based on a predetermined time period, the charging relay 30 can be driven earlier when the temperature of the charging relay 30 is not high.

[0167] In the relay drive control device 10 according to this embodiment, there is no need to add a dedicated voltage sensor or a dedicated temperature sensor for relay drive control. Therefore, the drive performance of DC relays 31 and 32 can be maintained, and the reliability and marketability of DC charging can be ensured, while reducing the cost and size (size and weight) of the device.

[0168] Although embodiments of the present disclosure have been described above, the present disclosure can be understood as a relay drive control device, a control method executed by a controller of the relay drive control device including a processor and a memory, a control program for executing the control method, a non-transitory computer-readable recording medium storing the control program, and a vehicle including a relay drive control device.

[0169] The relay drive control device disclosed herein can be used to control the drive of a relay used to connect a battery installed in a vehicle to an external power source.

Claims

1. A relay drive control device configured to control the drive of a relay for connecting a battery installed in a vehicle and an external power source, the relay drive control device being characterized by comprising: A controller configured to, when driving the relay, supply the output voltage to the relay after increasing the output voltage of the battery to a voltage value that allows the relay to be driven; as well as A voltage converter, configured to output the output voltage, converted into a drive voltage, to the controller, wherein: The output voltage is input from the battery; The controller is configured to, when driving the relay, control the voltage converter to increase the driving voltage input from the voltage converter to a first voltage value capable of driving the relay; as well as The controller is configured to supply the drive voltage to the relay when the relay is to be driven and the drive voltage reaches the first voltage value, and to change the rate at which the drive voltage increases to the first voltage value based on information related to the temperature of the relay.

2. The relay drive control device according to claim 1, characterized in that, The controller is configured to, when the relay is to be driven, supply the drive voltage to the relay after the controller has started controlling the voltage converter to increase the drive voltage to the first voltage value, and after a predetermined time period has elapsed before the drive voltage reaches the first voltage value.

3. The relay drive control device according to claim 1, characterized in that, The controller is configured to control the voltage converter to reduce the drive voltage to a second voltage value after the relay has been driven by supplying the drive voltage to the relay.

4. The relay drive control device according to claim 1, characterized in that, The first voltage value is the voltage value that enables the relay to be driven at the upper limit of a predetermined temperature range that allows the relay to be used.

5. The relay drive control device according to claim 3, characterized in that, The second voltage value is the voltage at which the relay being driven is not switched to the off state.

6. The relay drive control device according to claim 1, characterized in that, The controller is configured to determine whether the relay can be driven based on the state of the battery and the voltage converter.

7. The relay drive control device according to claim 2, characterized in that, The controller is configured to change the predetermined time period based on information related to the temperature of the relay.

8. The relay drive control device according to any one of claims 1 to 7, characterized in that, The external power source is an external charging device that is plugged into the vehicle to supply power to the vehicle.

9. A control method executed by a computer of a relay drive control device according to any one of claims 1 to 8, the relay drive control device being configured to control the drive of a relay for connecting a battery installed in a vehicle and an external power source, the control method being characterized in that it comprises: Determine whether to drive the relay; The output voltage of the battery is converted into a driving voltage; When driving the relay, the driving voltage is increased to a first voltage value that can drive the relay; Based on information related to the temperature of the relay, the rate at which the driving voltage increases to the first voltage value is changed; as well as When the driving voltage reaches the first voltage value, the driving voltage is supplied to the relay.

10. A non-transitory storage medium storing instructions executable by one or more processors of a computer for a relay drive control device according to any one of claims 1 to 8, and causing said one or more processors to perform a function, said relay drive control device being configured to control the drive of a relay for connecting a battery mounted on a vehicle and an external power source, said function being characterized by comprising: Determine whether to drive the relay; The output voltage of the battery is converted into a driving voltage; When driving the relay, the driving voltage is increased to a first voltage value that can drive the relay; Based on information related to the temperature of the relay, the rate at which the driving voltage increases to the first voltage value is changed; as well as When the driving voltage reaches the first voltage value, the driving voltage is supplied to the relay.

Images