Abnormality determination device

Abstract

An abnormality determination device (10) is provided with a first switch unit (21), a second switch unit (22), a conductive path (e.g., a second conductive path (82)), a voltage conversion unit (23), a voltage detection circuit (24), and a control unit (25). The first switch unit (21) is provided between the power supply unit (2) and the load (3). The second switch unit (22) is provided closer to the load (3) than the first switch unit (21). The conductive path is provided between the second switch section (22) and the load (3). The voltage conversion unit (23) performs a conversion operation for converting the voltage input from the electricity storage unit (4) side and outputting the converted voltage to the conductive path side. The control unit (25) causes the voltage conversion unit (23) to perform a conversion operation, controls the first switch unit (21) and the second switch unit (22) to be in an OFF state, and determines whether or not at least one of the first switch unit (21) and the second switch unit (22) is abnormal on the basis of the voltage detected by the voltage detection circuit (24).

Description

Technical Field

[0001] The present disclosure relates to an abnormality determination device. Background Art

[0002] Patent Document 1 discloses a power storage device connected between a main power supply and a load. The power storage device includes a power storage unit, a main power supply bypass FET, a load-side bypass FET, a power storage unit FET, a load-side FET, a voltage detection circuit, and a control unit. The power storage unit supplies power to the load. The main power supply bypass FET and the load-side bypass FET are connected in series between the main power supply and the load. The power storage unit FET and the load-side FET are connected in series between the power storage unit and the load. The voltage detection circuit detects the voltage at the connection point between the main power supply bypass FET and the load-side FET. When the voltage at this connection point exceeds a predetermined value while the main power supply bypass FET and the load-side bypass FET are turned off and the power storage unit FET is turned on, the control unit determines that a short circuit has occurred in either the main power supply bypass FET or the load-side bypass FET. With this configuration, power is supplied to the load from the power storage device, which serves as an auxiliary power source, making it possible to detect a short circuit in either the main power supply bypass FET or the load-side bypass FET without interrupting power supply to the load.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2008-182872 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, in the configuration of Patent Document 1, a voltage equal to the output voltage of the storage unit is supplied from the storage unit to the load. Therefore, the storage unit needs to set the charging voltage equal to the drive voltage of the load, leaving little room for choice.

[0008] An object of the present disclosure is to provide a technology capable of increasing the degree of freedom in selecting a power storage unit, which is used in a structure for detecting an abnormality when power is supplied from a power storage unit to a load and a switch between a power supply unit and a load is opened.

[0009] Technical solutions to problems

[0010] The abnormality determination device disclosed herein is used in an in-vehicle system including a power supply unit, a load, and a power storage unit, wherein the abnormality determination device includes:

[0011] a first switch unit, disposed between the power supply unit and the load;

[0012] a second switching unit connected in series with the first switching unit on the load side relative to the first switching unit;

[0013] a conductive path provided between the second switch portion and the load;

[0014] a voltage conversion unit, provided between the conductive path and the power storage unit;

[0015] a voltage detection circuit configured to detect a voltage at a connection portion between the first switch portion and the second switch portion; and

[0016] a control unit that controls the first switch unit, the second switch unit, and the voltage conversion unit,

[0017] The voltage conversion unit performs a conversion operation in which a voltage input from the power storage unit is converted and outputted to the conductive path side.

[0018] The control unit performs the following abnormality determination processing: causes the voltage conversion unit to perform the conversion action, controls the first switch unit and the second switch unit to be in an off state, and determines whether at least one of the first switch unit and the second switch unit is abnormal based on the voltage detected by the voltage detection circuit.

[0019] Effects of the Invention

[0020] The technology disclosed herein is a structure for detecting an abnormality when power is supplied from a power storage unit to a load and a switch between the power supply unit and the load is opened, thereby increasing the degree of freedom in selecting a power storage unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram schematically showing the configuration of an in-vehicle system including the abnormality determination device according to the first embodiment.

[0022] Figure 2 This is the first half of the flowchart of the processing performed by the control unit.

[0023] Figure 3 This is the second half of the flowchart of the processing performed by the control unit. DETAILED DESCRIPTION

[0024] [Description of Embodiments of the Present Disclosure]

[0025] The following lists and illustrates the embodiments of the present disclosure.

[0026] [1] An abnormality determination device for an on-vehicle system including a power supply unit, a load, and a power storage unit, wherein the abnormality determination device comprises:

[0027] a first switch unit, disposed between the power supply unit and the load;

[0028] a second switching unit connected in series with the first switching unit on the load side relative to the first switching unit;

[0029] a conductive path provided between the second switch portion and the load;

[0030] a voltage conversion unit, provided between the conductive path and the power storage unit;

[0031] a voltage detection circuit configured to detect a voltage at a connection portion between the first switch portion and the second switch portion; and

[0032] a control unit that controls the first switch unit, the second switch unit, and the voltage conversion unit,

[0033] The voltage conversion unit performs a conversion operation in which a voltage input from the power storage unit is converted and outputted to the conductive path side.

[0034] The control unit performs the following abnormality determination processing: causes the voltage conversion unit to perform the conversion action, controls the first switch unit and the second switch unit to be in an off state, and determines whether at least one of the first switch unit and the second switch unit is abnormal based on the voltage detected by the voltage detection circuit.

[0035] The abnormality determination device controls the first and second switching units to the off state and causes the voltage conversion unit to perform a conversion operation, thereby enabling power to be supplied from the power storage unit to the load. Furthermore, the output voltage of the power storage unit is converted by the voltage conversion unit and output to the load. Therefore, the output voltage of the power storage unit is less likely to be limited by the load's drive voltage. Consequently, the abnormality determination device can increase the freedom of choice of the power storage unit.

[0036] [2] The abnormality determination device according to [1], wherein:

[0037] The control unit causes the voltage conversion unit to perform the conversion operation, and when the voltage detected by the voltage detection circuit is the same as the output voltage of the power supply unit or is within a first range including the output voltage, determines that the first switching unit is abnormal, while the first switching unit and the second switching unit are controlled to be in an off state; and

[0038] The control unit causes the voltage conversion unit to perform the conversion action. When the first switch unit and the second switch unit are controlled to be in a disconnected state, when the voltage detected by the voltage detection circuit is the same as the output voltage of the voltage conversion unit or is within a second range including the output voltage, it is determined that the second switch unit is abnormal.

[0039] The abnormality determination device can distinguish between abnormalities in the first switch unit and abnormalities in the second switch unit.

[0040] [3] The abnormality determination device according to [1] or [2], wherein:

[0041] The control unit performs the abnormality determination process when an abnormality determination condition is satisfied in a state where the first switch unit and the second switch unit are controlled to be in an on state.

[0042] The above-mentioned abnormality judgment device can suppress the interruption of power supply to the load when the abnormality judgment condition is met while power is supplied from the power supply unit to the load, and switch the first switch unit and the second switch unit to the disconnected state to determine whether at least one of the first switch unit and the second switch unit is abnormal.

[0043] [4] The abnormality determination device according to [3], wherein:

[0044] The control unit controls the first switch unit and the second switch unit to be in an on state, and when the abnormality determination condition is satisfied, causes the voltage conversion unit to perform the conversion operation.

[0045] When a switching condition is met during the conversion operation, the control unit switches the first switch unit and the second switch unit to an off state, and determines whether at least one of the first switch unit and the second switch unit is abnormal based on the voltage detected by the voltage detection circuit.

[0046] The abnormality determination device causes the voltage conversion unit to perform a switching operation when an abnormality determination condition is met, and switches the first and second switching units to an off state after the switching condition is met. Therefore, the abnormality determination device can more reliably prevent a temporary power shortage to the load when the power supply source to the load is switched from the power supply unit to the power storage unit.

[0047] [5] The abnormality determination device according to any one of [1] to [4], wherein:

[0048] In the abnormality determination process, the control unit causes the voltage conversion unit to perform the conversion action, and determines whether the second switch unit is abnormal based on the voltage detected by the voltage detection circuit while controlling the first switch unit to be in an off state and the second switch unit to be in an on state.

[0049] The abnormality determination device can determine whether or not the second switch unit is abnormal in that it is not switched to the on state.

[0050] [6] The abnormality determination device according to any one of [1] to [5], wherein:

[0051] In the abnormality determination process, the control unit causes the voltage conversion unit to perform the conversion action, and determines whether the first switch unit is abnormal based on the voltage detected by the voltage detection circuit while controlling the first switch unit to be in the on state and the second switch unit to be in the off state.

[0052] The abnormality determination device can determine whether the first switch unit is abnormal in that it is not switched to the on state.

[0053] [Details of the embodiments of the present disclosure]

[0054] <First embodiment>

[0055] 1. Overview of In-Vehicle System 1

[0056] exist Figure 1 FIG2 shows an abnormality determination device 10 for an in-vehicle system 1. The in-vehicle system 1 is mounted on a vehicle. The in-vehicle system 1 includes a power supply unit 2, a load 3, a power storage unit 4, and the abnormality determination device 10. The in-vehicle system 1 can supply power from the power supply unit 2 to the load 3. When the output voltage of the power supply unit 2 reaches a low voltage state, the in-vehicle system 1 switches the power supply source to the load 3 from the power supply unit 2 to the power storage unit 4.

[0057] The power supply unit 2 is comprised of, for example, a battery. The battery may be a secondary battery such as a lead-acid battery or a lithium-ion battery, or may be another type of storage battery. The high-potential terminal of the power supply unit 2 is electrically connected to the first conductive path 81. The output voltage of the power supply unit 2 is applied to the first conductive path 81. The low-potential terminal of the power supply unit 2 is electrically connected to ground. In this embodiment, voltage refers to a voltage relative to ground potential.

[0058] The load 3 is an in-vehicle electrical device. One end of the load 3 is electrically connected to the second conductive path 82. The other end of the load 3 is electrically connected to the ground. The load 3 is driven by power supplied from the second conductive path 82.

[0059] The power storage unit 4 is composed of a power storage element. The power storage element can be a capacitor such as an EDLC or a battery such as a lithium-ion battery. The high-potential terminal of the power storage unit 4 is electrically connected to the third conductive path 83. The low-potential terminal of the power storage unit 4 is electrically connected to ground. The output voltage of the power storage unit 4 is applied to the third conductive path 83.

[0060] 2. Structure of Abnormality Determination Device 10

[0061] The abnormality determination device 10 includes a first switching unit 21 , a second switching unit 22 , a voltage conversion unit 23 , a voltage detection circuit 24 , and a control unit 25 .

[0062] The first switch unit 21 is provided between the power supply unit 2 and the load 3. In this embodiment, the first switch unit 21 is composed of an N-channel MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor). The first switch unit 21 can be composed of a single MOSFET or a structure comprising multiple MOSFETs connected in parallel. Furthermore, the first switch unit 21 can be composed of a semiconductor switching element other than an N-channel MOSFET or a mechanical switch having contacts.

[0063] The second switch section 22 is connected in series with the first switch section 21 on the load 3 side relative to the first switch section 21. In this embodiment, the second switch section 22 is composed of an N-channel MOSFET. The second switch section 22 can be composed of a single MOSFET or a structure in which multiple MOSFETs are connected in parallel. Furthermore, the second switch section 22 can be composed of a semiconductor switching element other than an N-channel MOSFET, or a mechanical switch having contacts.

[0064] The first switch section 21 and the second switch section 22 are connected in opposite directions. The first switch section 21 includes a body diode 21A. The second switch section 22 includes a body diode 22A. The anode of the body diode 21A is electrically connected to the anode of the body diode 22A. The cathode of the body diode 21A is electrically connected to the first conductive path 81. The cathode of the body diode 22A is electrically connected to the second conductive path 82. The second conductive path 82 is provided between the second switch section 22 and the power storage section 4. The second conductive path 82 is an example of a conductive path.

[0065] One end of the first switch section 21 is electrically connected to the first conductive path 81. One end of the first switch section 21 is electrically connected to the high-potential-side terminal of the power supply section 2 in a structure short-circuited with the high-potential-side terminal of the power supply section 2. The other end of the first switch section 21 is electrically connected to the intermediate conductive path 85. The intermediate conductive path 85 is provided between the first switch section 21 and the second switch section 22. The other end of the first switch section 21 is electrically connected to one end of the second switch section 22 in a structure short-circuited with one end of the second switch section 22. The other end of the second switch section 22 is electrically connected to the second conductive path 82. The other end of the second switch section 22 is electrically connected to the high-potential-side terminal of the load 3 in a structure short-circuited with the high-potential-side terminal of the load 3.

[0066] The first switch unit 21 and the second switch unit 22 both allow a bidirectional current to flow when in an on state, and block a bidirectional current from flowing when in an off state.

[0067] The voltage converter 23 is provided between the second conductive path 82 and the power storage unit 4. The voltage converter 23 performs a first conversion operation, converting a voltage input from the second conductive path 82 and outputting it to the power storage unit 4, and a second conversion operation, converting a voltage input from the power storage unit 4 and outputting it to the second conductive path 82. The second conversion operation is an example of a conversion operation. A fourth conductive path 84 is provided between the second conductive path 82 and the voltage converter 23. In the first conversion operation, the voltage converter 23 converts a voltage applied to the fourth conductive path 84 and applies it to the third conductive path 83. In the second conversion operation, the voltage converter 23 converts a voltage applied to the third conductive path 83 and applies it to the fourth conductive path 84. The voltage conversion performed by the voltage converter 23 can be either step-up or step-down. The voltage converter 23 is, for example, comprised of a DC-DC converter.

[0068] The voltage detection circuit 24 detects the voltage at the connection between the first switch section 21 and the second switch section 22. The intermediate conductive path 85 is an example of a connection. The voltage detection circuit 24 is electrically connected to the intermediate conductive path 85. The voltage detection circuit 24 detects the voltage across the intermediate conductive path 85 and outputs a signal representing the detected voltage. The signal output by the voltage detection circuit 24 is input to the control unit 25. The voltage detection circuit 24 may include or not include a voltage divider circuit to divide the voltage across the intermediate conductive path 85.

[0069] The control unit 25 controls the first switch unit 21, the second switch unit 22, and the voltage converter 23. The control unit 25 is configured, for example, to include a microcomputer. For example, the control unit 25 is configured as an MCU (Micro Controller Unit). The MCU controlling the first switch unit 21 and the second switch unit 22 may be the same as or different from the MCU controlling the voltage converter 23. The control unit 25 includes an information processing unit such as a CPU, and storage units such as ROM and RAM.

[0070] The control unit 25 performs the following abnormality determination processing: the control unit 25 causes the voltage conversion unit 23 to perform the second conversion operation, controls the first switch unit 21 and the second switch unit 22 to the off state, and determines whether at least one of the first switch unit 21 and the second switch unit 22 is abnormal based on the voltage detected by the voltage detection circuit 24. The abnormality is an abnormality in which the first switch unit 21 and the second switch unit 22 are not switched to the off state.

[0071] For example, when the voltage detected by the voltage detection circuit 24 is greater than a first threshold value, the control unit 25 determines that at least one of the first switch unit 21 and the second switch unit 22 is abnormal. The first threshold value is a value greater than 0V.

[0072] Alternatively, the control unit 25 determines that the first switch unit 21 is abnormal when the voltage detected by the voltage detection circuit 24 is equal to the output voltage of the power supply unit 2 or is within a first range that includes the output voltage. The lower limit of the first range is a value greater than 0 V. The control unit 25 determines that the second switch unit 22 is abnormal when the voltage detected by the voltage detection circuit 24 is equal to the output voltage of the voltage conversion unit 23 or is within a second range that includes the output voltage. The lower limit of the second range is greater than the upper limit of the first range.

[0073] The control unit 25 performs the above-described abnormality determination process when the abnormality determination condition is satisfied while the first switch unit 21 and the second switch unit 22 are controlled to be in the on state. The abnormality determination condition may be a condition that is satisfied whenever a predetermined time has passed, a condition that is satisfied at a predetermined time, or other conditions.

[0074] When the abnormality determination condition is satisfied while the first and second switch sections 21 and 22 are in the on state, the control section 25 causes the voltage conversion section 23 to perform the second conversion operation. When the switching condition is satisfied during the second conversion operation of the voltage conversion section 23, the control section 25 switches the first and second switch sections 21 and 22 to the off state and determines whether at least one of the first and second switch sections 21 and 22 is abnormal based on the voltage detected by the voltage detection circuit 24.

[0075] The switching condition is defined so as to be satisfied when the voltage conversion unit 23 is in a state where electric power required for driving the load 3 is supplied.

[0076] The switching condition may also be, for example, that the output voltage of the voltage converter 23 reaches or exceeds a threshold voltage. In this case, the control unit 25 sets the target voltage to a value greater than the output voltage of the power supply 2 when the first and second switch units 21 and 22 are in the off state. The control unit 25 then causes the voltage converter 23 to perform a second conversion operation to bring the output voltage to the target voltage. The threshold voltage is set, for example, to the target voltage. During the second conversion operation, the output voltage of the voltage converter 23 gradually increases. When the output voltage reaches the target voltage, the switching condition is satisfied. For example, the control unit 25 obtains the voltage of the fourth conductive path 84 and determines that the switching condition is satisfied when the obtained voltage exceeds the threshold voltage.

[0077] The switching condition may also be, for example, that the output current of the voltage converter 23 exceeds a threshold current. In this case, the control unit 25 also sets the target voltage to a value greater than the output voltage of the power supply 2 when the first and second switch units 21 and 22 are in the off state. The control unit 25 then causes the voltage converter 23 to perform a second conversion operation to bring the output voltage to the target voltage. During the second conversion operation, the output voltage of the voltage converter 23 gradually increases. When the output voltage reaches the target voltage, current flows from the voltage converter 23 to the load 3 in the fourth conductive path 84. The control unit 25, for example, obtains the current value flowing through the fourth conductive path 84 and determines that the switching condition has been met if the obtained current value exceeds the threshold current.

[0078] The switching condition may be that a predetermined time has passed since the voltage converter 23 started the second conversion operation. The switching condition may be that the load 3 provides a switching request signal.

[0079] In the abnormality determination process described above, the control unit 25 causes the voltage conversion unit 23 to perform a second conversion operation. While the first switch unit 21 is controlled to the OFF state and the second switch unit 22 is controlled to the ON state, the control unit 25 determines whether the second switch unit 22 is abnormal based on the voltage detected by the voltage detection circuit 24. This abnormality is caused by the second switch unit 22 not switching to the ON state. The control unit 25 determines that the second switch unit 22 is abnormal when, for example, the voltage detected by the voltage detection circuit 24 is below a second threshold. The second threshold is, for example, a value of 0V or greater. The second threshold is, for example, a value lower than the output voltage of the power supply unit 2 (for example, the voltage of the first conductive path 81) and lower than the output voltage of the voltage conversion unit 23 (for example, the voltage of the second conductive path 82 or the fourth conductive path 84).

[0080] In the abnormality determination process described above, the control unit 25 causes the voltage conversion unit 23 to perform a second conversion operation. While the first switch unit 21 is controlled to be in the on state and the second switch unit 22 is controlled to be in the off state, the control unit 25 determines whether the first switch unit 21 is abnormal based on the voltage detected by the voltage detection circuit 24. This abnormality is caused by the first switch unit 21 not switching to the on state. The control unit 25 determines that the first switch unit 21 is abnormal when, for example, the voltage detected by the voltage detection circuit 24 is below a third threshold. The third threshold is, for example, a value of 0V or greater. The third threshold is, for example, a value lower than the output voltage of the power supply unit 2 (for example, the voltage of the first conductive path 81) and lower than the output voltage of the voltage conversion unit 23 (for example, the voltage of the second conductive path 82 or the fourth conductive path 84).

[0081] 3. Operation of the Abnormality Determination Device 10

[0082] When the condition for starting to supply power to the load 3 is satisfied, the control unit 25 switches the first switch unit 21 and the second switch unit 22 to the on state. As a result, power is supplied from the power supply unit 2 to the load 3.

[0083] When a charging condition is met, control unit 25 causes voltage conversion unit 23 to perform a first conversion operation to charge power storage unit 4. The charging condition may be, for example, that the charging voltage of power storage unit 4 falls below the charging start voltage, or other conditions may be used. The charging start voltage is a value greater than 0V. When a charging completion condition is met, control unit 25 stops the first conversion operation performed by voltage conversion unit 23. For example, the charging completion condition is that the charging voltage of power storage unit 4 falls above the charging completion voltage. The charging completion voltage is a value greater than 0V, which is a value greater than the charging start voltage.

[0084] When the output voltage of the power supply unit 2 (e.g., the voltage of the first conductive path 81) reaches a low voltage state, the control unit 25 switches the first and second switch units 21 and 22 to an off state, causing the voltage conversion unit 23 to perform a second conversion operation. This allows the power supply source for the load 3 to be switched from the power supply unit 2 to the power storage unit 4. Furthermore, the low voltage state may occur when, for example, the output voltage of the power supply unit 2 falls below the failure determination voltage, when the output current of the power supply unit 2 (e.g., the current flowing through the first conductive path 81) exceeds an overcurrent threshold, or when these conditions persist for a predetermined period of time.

[0085] The control unit 25 takes the above-mentioned operation as a basic operation and performs the following operation when the abnormality determination condition is satisfied while power is supplied from the power supply unit 2 to the load 3: Figure 2 and Figure 3 The processing shown.

[0086] First, in step S10, the control unit 25 causes the voltage converter 23 to start the second conversion operation. Then, in step S11, the control unit 25 determines whether the aforementioned switching condition is satisfied. If the control unit 25 does not determine that the switching condition is satisfied, it repeats the process of step S11 until the switching condition is satisfied.

[0087] If the control unit 25 determines that the switching condition is met, it switches the first switch unit 21 and the second switch unit 22 to the off state in step S12. Then, in step S13, the control unit 25 determines whether at least one of the first switch unit 21 and the second switch unit 22 is abnormal based on the voltage detected by the voltage detection circuit 24.

[0088] If the control unit 25 determines that an abnormality is present in step S13, it performs abnormality handling in step S14. This abnormality handling is, for example, a process of notifying an external ECU that at least one of the first switch unit 21 and the second switch unit 22 is abnormal. After performing the abnormality handling, the control unit 25 ends the process. Figure 2 and Figure 3 The processing shown.

[0089] If the control unit 25 does not determine an abnormality in step S13, in step S20, the control unit 25 switches the first switch unit 21 to the on state while maintaining the second switch unit 22 in the off state. Then, in step S21, the control unit 25 determines whether the first switch unit 21 is abnormal based on the voltage detected by the voltage detection circuit 24.

[0090] If the control unit 25 determines that an abnormality is present in step S21, it performs abnormality handling in step S22. The abnormality handling is, for example, a process of notifying an external ECU of the abnormality of the first switch unit 21. After performing the abnormality handling, the control unit 25 ends the process. Figure 2 and Figure 3 The processing shown.

[0091] If the control unit 25 does not determine an abnormality in step S21, in step S23, it switches the first switch unit 21 to the OFF state and switches the second switch unit 22 to the ON state. Then, in step S24, the control unit 25 determines whether the second switch unit 22 is abnormal based on the voltage detected by the voltage detection circuit 24.

[0092] If the control unit 25 determines that the second switch unit 22 is abnormal in step S24, it performs abnormality handling in step S24. The abnormality handling process is, for example, a process of notifying the external ECU that the second switch unit 22 is abnormal. After performing the abnormality handling process, the control unit 25 ends. Figure 2 and Figure 3 The processing shown.

[0093] If the control unit 25 does not determine that an abnormality occurs in step S24, the process ends. Figure 2 and Figure 3 The processing shown.

[0094] The control unit 25 ends Figure 2 as well as Figure 3 After the processing shown, the first switch unit 21 and the second switch unit 22 are controlled to be in the on state, the voltage converter 23 is stopped, and the power supply unit 2 returns to the state of supplying power to the load 3 .

[0095] 4. Effect Examples

[0096] Abnormality determination device 10 controls first switch unit 21 and second switch unit 22 to the off state and causes voltage conversion unit 23 to perform the second conversion operation, thereby enabling power to be supplied from power storage unit 4 to load 3. Furthermore, the output voltage of power storage unit 4 is converted by voltage conversion unit 23 and output to load 3. Therefore, the output voltage of power storage unit 4 is less likely to be limited by the drive voltage of load 3. Consequently, abnormality determination device 10 can increase the degree of freedom in selecting power storage unit 4.

[0097] The abnormality determination device 10 can distinguish and determine an abnormality in the first switch unit 21 and an abnormality in the second switch unit 22 .

[0098] The abnormality determination device 10 can suppress the interruption of power supply to the load 3 when the abnormality determination condition is met while power is supplied from the power supply unit 2 to the load 3, and switch the first switch unit 21 and the second switch unit 22 to the disconnected state to determine whether at least one of the first switch unit 21 and the second switch unit 22 is abnormal.

[0099] Abnormality determination device 10 causes voltage conversion unit 23 to perform the second switching operation when the abnormality determination condition is satisfied, and then switches first switch unit 21 and second switch unit 22 to the off state after the switching condition is satisfied. Therefore, abnormality determination device 10 can more reliably prevent a temporary power shortage to load 3 when switching the power supply source to load 3 from power supply unit 2 to power storage unit 4.

[0100] The abnormality determination device 10 can determine whether the second switch unit 22 is abnormal in that it is not switched to the on state.

[0101] The abnormality determination device 10 can determine whether the first switch unit 21 is abnormal in that it is not switched to the on state.

[0102] <Other Implementation Methods>

[0103] The present disclosure is not limited to the embodiments described above and illustrated in the accompanying drawings. For example, the features of the above embodiments can be combined in various ways within the scope of non-contradiction. In addition, any feature of the above embodiments can be omitted as long as it is not explicitly stated as a necessary feature.

[0104] The embodiments disclosed herein are illustrative in all respects and should not be construed as restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is indicated by the claims, and is intended to include all modifications within the scope and meaning equivalent to the claims.

[0105] Marking Description

[0106] 1…In-vehicle system;

[0107] 2…power supply unit;

[0108] 3…load;

[0109] 4…power storage unit;

[0110] 10… abnormality determination device;

[0111] 21: a first switch unit;

[0112] 21A…body diode;

[0113] 22 ... a second switch unit;

[0114] 22A…body diode;

[0115] 23 ... voltage conversion unit;

[0116] 24…voltage detection circuit;

[0117] 25…Control Department;

[0118] 81 ...a first conductive path;

[0119] 82 ... a second conductive path (conductive path);

[0120] 83 ... a third conductive path;

[0121] 84 ... a fourth conductive path;

[0122] 85…Intermediate conductive path.

Claims

1. An abnormality determination device for a vehicle-mounted system including a power supply unit, a load, and a power storage unit, wherein: The abnormality determination device comprises: a first switch unit, disposed between the power supply unit and the load; a second switching unit connected in series with the first switching unit on the load side relative to the first switching unit; a conductive path provided between the second switch portion and the load; a voltage conversion unit, provided between the conductive path and the power storage unit; a voltage detection circuit for detecting a voltage at a connection portion between the first switch portion and the second switch portion; and a control unit that controls the first switch unit, the second switch unit, and the voltage conversion unit, The voltage conversion unit performs a conversion operation in which a voltage input from the power storage unit is converted and outputted to the conductive path side. The control unit performs the following abnormality determination processing: causes the voltage conversion unit to perform the conversion action, controls the first switch unit and the second switch unit to be in an off state, and determines whether at least one of the first switch unit and the second switch unit is abnormal based on the voltage detected by the voltage detection circuit.

2. The abnormality determination device according to claim 1, wherein: The control unit causes the voltage conversion unit to perform the conversion operation, and when the voltage detected by the voltage detection circuit is the same as the output voltage of the power supply unit or is within a first range including the output voltage, determines that the first switching unit is abnormal, while the first switching unit and the second switching unit are controlled to be in an off state; and The control unit causes the voltage conversion unit to perform the conversion action. When the first switch unit and the second switch unit are controlled to be in a disconnected state, when the voltage detected by the voltage detection circuit is the same as the output voltage of the voltage conversion unit or is within a second range including the output voltage, it is determined that the second switch unit is abnormal.

3. The abnormality determination device according to claim 1 or 2, wherein: The control unit performs the abnormality determination process when an abnormality determination condition is satisfied in a state where the first switch unit and the second switch unit are controlled to be in an on state.

4. The abnormality determination device according to claim 3, wherein: The control unit controls the first switch unit and the second switch unit to be in an on state, and when the abnormality determination condition is satisfied, causes the voltage conversion unit to perform the conversion operation. When a switching condition is met during the conversion operation, the control unit switches the first switch unit and the second switch unit to an off state, and determines whether at least one of the first switch unit and the second switch unit is abnormal based on the voltage detected by the voltage detection circuit.

5. The abnormality determination device according to claim 1 or 2, wherein: In the abnormality determination process, the control unit causes the voltage conversion unit to perform the conversion action, and determines whether the second switch unit is abnormal based on the voltage detected by the voltage detection circuit while controlling the first switch unit to be in an off state and the second switch unit to be in an on state.

6. The abnormality determination device according to claim 1 or 2, wherein: In the abnormality determination process, the control unit causes the voltage conversion unit to perform the conversion action, and determines whether the first switch unit is abnormal based on the voltage detected by the voltage detection circuit while controlling the first switch unit to be in the on state and the second switch unit to be in the off state.

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