Vehicle control device

Abstract

To provide a vehicle control device capable of appropriately supplying power to a load part even when an abnormality occurs.SOLUTION: The power distribution ECU1 is a vehicular control device that is used in vehicles and controls distribution of electric power supplied from a plurality of power supplies 210 to a plurality of loads 220. The power distribution ECU1 includes first power source terminals, second power source terminals 12, a first power source line portion 31, a second power source line portion 32, a power source trunk line 40, load terminals 20, and a trunk line cut-off circuit 70. The inductor 140 provided on the power supply main line 40 and the first capacitor 131 having one end connected to the power supply main line 40 and the other end connected to the ground potential constitute a low-pass filter.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] TECHNICAL FIELD This disclosure relates to a vehicle control system. [Background technology]

[0002] Patent Document 1 discloses a power supply device that supplies power from multiple power sources to a load as a type of vehicle control device. This power supply device includes a switch unit that cuts off the power supplied from the power sources based on the detection result of the current detected by a current detection unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-120479 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for a function to distribute power to multiple loads. However, the power supply device in Patent Document 1 does not have a function to distribute power to multiple loads. Therefore, it is natural that the configuration in Patent Document 1 cannot properly supply power to the loads when an abnormality occurs in the circuitry related to the power supply device.

[0005] The present disclosure aims to provide a vehicle control device that can supply appropriate power to a load even when an abnormality occurs. [Means for solving the problem]

[0006] In order to achieve the above object, one disclosed embodiment comprises: A vehicle control device used in a vehicle, which distributes power supplied from a plurality of power sources (210) to a plurality of loads (220), comprising: a first power terminal (11) for connection to one of a plurality of power sources; a second power supply terminal (12) for connection to another one of the plurality of power supplies; a first power supply line portion (31) connected to a first power supply terminal; a second power supply line portion (32) connected to a second power supply terminal; a power trunk line (40) connecting the first power line section and the second power line section; a plurality of terminals for connection to a plurality of loads, at least one of which is connected to a first power supply line section and at least one of which is connected to a second power supply line section; and a main line interruption circuit (70) provided in the power supply main line, which switches between energization and interruption between the first power supply line section and the second power supply line section; a low-pass filter including an inductance unit (140, 141) provided on the power supply main line and a capacitor (131, 132) having one end connected to the power supply main line and the other end connected to a ground potential; The present invention relates to a vehicle control device.

[0007] In this aspect, the first power line section and the second power line section are electrically disconnected by bringing the main line interruption circuit into an interrupted state, so that even if an abnormality occurs in a circuit related to the vehicle control device, it is possible to properly supply power from the multiple power sources to the multiple load terminals, and ultimately to the loads connected to each load terminal.

[0008] In addition, a low-pass filter is formed by an inductance section provided in the power main line and a capacitor with one end connected to the power main line and the other end connected to ground potential. This low-pass filter reduces the voltage drop in the power main line when a ground fault occurs in the power main line. This prevents the voltage supplied to the load from dropping below the voltage required to operate the load before the main line interruption circuit is switched to the interrupted state.

[0009] The reference numbers in parentheses in the above and claims merely indicate an example of the correspondence with the specific configurations in the embodiments described below, and do not limit the technical scope in any way. Furthermore, claims not explicitly stated in the claims may be combined together if no particular problems arise in the combination. [Brief explanation of the drawings]

[0010] [Figure 1] 2 is a circuit diagram showing the configuration of a power distribution ECU according to the first embodiment. FIG. [Figure 2] FIG. 2 is a circuit diagram showing a configuration of a power supply interruption circuit. [Figure 3] FIG. 2 is a circuit diagram showing the configuration of a main line interruption circuit and a high-speed interruption unit. [Figure 4] FIG. 2 is a circuit diagram showing the configuration of a load shedding circuit. [Figure 5] FIG. 2 is a circuit diagram showing a configuration of an overvoltage detection unit. [Figure 6] FIG. 2 is a circuit diagram showing a configuration of a low-voltage detection unit. [Figure 7] FIG. 10 is a diagram illustrating a case where a ground fault occurs in the first section in the comparative example. [Figure 8] FIG. 4 is a diagram illustrating a case where a ground fault occurs in the first section in the first embodiment. [Figure 9] FIG. 10 is a diagram illustrating a case where a ground fault occurs in the second section in the comparative example. [Figure 10] FIG. 4 is a diagram illustrating a case where a ground fault occurs in the second section in the first embodiment. [Figure 11] FIG. 10 is a diagram illustrating a state in which a ground fault occurs between the inductor and the main line interruption circuit. [Figure 12] FIG. 3 is a circuit diagram showing the configuration of a power distribution ECU according to a first modification of the first embodiment. [Figure 13] FIG. 10 is a circuit diagram showing the configuration of a high-speed cutoff unit according to a second embodiment. [Figure 14] FIG. 10 is a circuit diagram showing the configuration of a load shedding circuit according to a third embodiment. [Figure 15] FIG. 10 is a circuit diagram showing the configuration of a load shedding circuit according to a fourth embodiment. [Figure 16] FIG. 10 is a circuit diagram showing the configuration of a load shedding circuit according to a fifth embodiment. [Figure 17] FIG. 20 is a circuit diagram showing a configuration for inspecting the ratio accuracy of a threshold generation resistive voltage divider in the sixth embodiment. [Figure 18] FIG. 20 is a diagram showing a process for inspecting relative accuracy in the sixth embodiment. [Figure 19] FIG. 23 is a circuit diagram showing a configuration for inspecting the ratio accuracy of a threshold generation resistive voltage divider in the seventh embodiment. [Figure 20] FIG. 20 is a circuit diagram showing a specific configuration of the DAC in FIG. 19. [Figure 21] FIG. 20 is a diagram showing a process for inspecting relative accuracy in the seventh embodiment. [Figure 22] 22 is a diagram showing time variations in the input voltage and output signal of the voltage determination unit when the process of FIG. 21 is executed. FIG. [Figure 23] FIG. 13 is a circuit diagram showing a configuration for inspecting the ratio accuracy of a threshold generation resistive voltage divider in the eighth embodiment. [Figure 24] FIG. 13 is a circuit diagram showing a configuration for inspecting the ratio accuracy of a threshold generation resistive voltage divider in the ninth embodiment. [Figure 25] FIG. 13 is a diagram showing a process for inspecting relative accuracy in the ninth embodiment. [Figure 26] 26 is a diagram showing time variations in the input voltage and output signal of the voltage determination unit when the process of FIG. 25 is executed. FIG. [Figure 27] FIG. 23 is a circuit diagram showing a configuration for inspecting the ratio accuracy of a power supply line resistance voltage divider in the tenth embodiment. [Figure 28] FIG. 23 is a diagram showing a process for inspecting relative accuracy in the tenth embodiment. [Figure 29] FIG. 23 is a circuit diagram showing a configuration for inspecting the ratio accuracy of a power supply line resistance voltage divider in the eleventh embodiment. [Figure 30] FIG. 23 is a circuit diagram showing a configuration for inspecting the ratio accuracy of a power supply line resistance voltage divider in the twelfth embodiment. [Figure 31] FIG. 23 is a circuit diagram showing a configuration for inspecting the ratio accuracy of a power supply line resistance voltage divider in the thirteenth embodiment. [Figure 32]FIG. 23 is a diagram showing a process for inspecting the relative accuracy in the thirteenth embodiment. [Figure 33] 33 is a diagram showing time variations in the input voltage and output signal of the voltage determination unit when the process of FIG. 32 is executed. FIG. [Figure 34] FIG. 22 is a circuit diagram showing a configuration of a fifteenth embodiment. [Figure 35] FIG. 23 is a diagram showing a process executed by a control unit in the fifteenth embodiment. [Figure 36] FIG. 22 is a circuit diagram showing the configuration of a sixteenth embodiment. [Figure 37] FIG. 22 is a circuit diagram showing a configuration of a seventeenth embodiment. [Figure 38] FIG. 22 is a diagram showing a list of setting patterns set in the seventeenth embodiment. [Figure 39] FIG. 10 is a diagram illustrating settings for setting pattern 1. [Figure 40] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 1. [Figure 41] FIG. 10 is a diagram illustrating settings for setting pattern 2. [Figure 42] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 2. [Figure 43] FIG. 10 is a diagram illustrating settings for setting pattern 3. [Figure 44] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 3. [Figure 45] FIG. 10 is a diagram illustrating settings for setting pattern 4. [Figure 46] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 4. [Figure 47] FIG. 10 is a diagram showing settings of setting pattern 5. [Figure 48] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 5. [Figure 49] FIG. 10 is a diagram showing the settings of setting pattern 6. [Figure 50] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 6. [Figure 51] FIG. 10 is a diagram showing settings for setting pattern 7. [Figure 52]FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 7. [Figure 53] FIG. 10 is a diagram showing the settings of setting pattern 8. [Figure 54] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 8. [Figure 55] FIG. 10 is a diagram showing the settings of setting pattern 9. [Figure 56] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 9. [Figure 57] FIG. 10 is a diagram showing the settings of setting pattern 10. [Figure 58] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 10. [Figure 59] FIG. 10 is a diagram showing the settings of setting pattern 11. [Figure 60] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 11. [Figure 61] FIG. 10 is a diagram showing the settings of setting pattern 12. [Figure 62] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 12. [Figure 63] FIG. 10 is a diagram showing the settings of setting pattern 13. [Figure 64] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 13. [Figure 65] FIG. 10 is a diagram showing the settings of setting pattern 14. [Figure 66] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 14. [Figure 67] FIG. 10 is a diagram showing the settings of setting pattern 15. [Figure 68] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 15. [Figure 69] FIG. 10 is a diagram showing the settings of setting pattern 16. [Figure 70] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 16. [Figure 71] FIG. 10 is a diagram showing the settings of setting pattern 17. [Figure 72]FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 17. [Figure 73] FIG. 10 is a diagram showing the settings of setting pattern 18. [Figure 74] FIG. 10 is a diagram showing a state in which each setting target is set in setting pattern 18. [Figure 75] FIG. 22 is a circuit diagram showing a configuration of an eighteenth embodiment. [Figure 76] FIG. 23 is a diagram showing processing executed by a control unit in the eighteenth embodiment. [Figure 77] FIG. 22 is a circuit diagram showing the configuration of a 19th embodiment. [Figure 78] FIG. 23 is a diagram showing a process in which the control unit inspects the second capacitor in the 19th embodiment. [Figure 79] FIG. 23 is a diagram showing a process in which the control unit inspects the first capacitor in the 19th embodiment. [Figure 80] FIG. 29 is a circuit diagram showing the configuration of a voltage detection unit in the twentieth embodiment. [Figure 81] FIG. 21 is a circuit diagram showing the configuration of a voltage detection unit in a twenty-first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] 1 is a vehicle control device used in a vehicle. The power distribution ECU 1 is mounted on the vehicle and electrically connected to a plurality of power sources 210 and a plurality of loads 220. Hereinafter, being electrically connected may be referred to simply as being connected.

[0012] The power distribution ECU 1 distributes power supplied from a plurality of power sources 210 to a plurality of loads 220. The power distribution ECU 1 may be a standalone control device that aggregates the power distribution function of the vehicle, or may be implemented in a control device together with other functional units.

[0013] As an example, the power distribution ECU 1 is implemented in a zone ECU. The zone ECU, together with the central ECU, on-board equipment, and communication lines, constitutes an on-board network system. The zone ECU is located in each of multiple zones predefined in the vehicle. One of the multiple zone ECUs may also function as the power distribution ECU 1. The zone ECU has a gateway function and enables mutual communication between networks with different communication methods by converting and relaying data. The zone ECU controls the on-board equipment based on commands from the central ECU. The zone ECU with the function of the power distribution ECU 1 controls the distribution of power to other zone ECUs as well as to individual ECUs, actuators, sensors, etc. that make up the on-board equipment.

[0014] <Configuration of power supply 210> The power supply 210 is a power supply mounted on the vehicle. The power supply 210 is capable of supplying power to the power distribution ECU 1. The power supply 210 includes a main power supply 211 and an auxiliary power supply 212. The main power supply 211, which is a first power supply, is the power supply 210 having a higher power supply capacity than the auxiliary power supply 212, which is a second power supply. The main power supply 211 is, for example, a DC-DC converter of the vehicle. The auxiliary power supply 212 is the power supply 210 having a lower power supply capacity than the main power supply 211. For example, the auxiliary power supply 212 is an auxiliary battery mounted on the vehicle. A lithium-ion battery can be used as the auxiliary battery. The power supply capacity of the main power supply 211 may be several times to several dozen times the power supply capacity of the auxiliary power supply 212.

[0015] <Load 220 Configuration> The loads 220 include the above-described zone ECUs, individual ECUs, actuators, sensors, and the like. The loads 220 consume power distributed by the power distribution ECU 1 to realize predetermined functions. The loads 220 include priority loads 221 and normal loads 222. The priority loads 221 are loads 220 to which power supply is prioritized over the normal loads 222. As an example, the priority loads 221 are loads 220 requiring redundancy. At least some of the loads 220 requiring redundancy are loads 220 related to safety-related functions. The priority loads 221 are, for example, on-board devices related to electric power steering and brake systems, other zone ECUs, and the like. The loads 220 other than the priority loads 221 are normal loads 222. The normal loads 222 are loads 220 that do not require redundancy and are low-priority (non-priority) loads 220 equipped with only low-priority functions.

[0016] <Configuration of Power Distribution ECU 1> The power distribution ECU 1 includes a plurality of power supply terminals 10, a plurality of load terminals 20, a power supply line KH, and a plurality of interrupter circuits.

[0017] The power supply terminal 10 is connected to the power supply 210. The power supply terminal 10 is integrally formed with a connector exposed outside the housing of the power distribution ECU 1. Power from the power supply 210 is supplied to the power supply terminal 10 through a wire harness or the like connected to the connector. The power supply terminal 10 includes a first power supply terminal 11 and a second power supply terminal 12. The first power supply terminal 11 is connected to a main power supply 211. Power is supplied to the first power supply terminal 11 from the main power supply 211. The second power supply terminal 12 is connected to an auxiliary power supply 212. Power is supplied to the second power supply terminal 12 from the auxiliary power supply 212. A larger power is supplied to the first power supply terminal 11 than to the second power supply terminal 12. Therefore, the first power supply terminal 11 is formed larger than the second power supply terminal 12 so that it can handle larger power.

[0018] The load terminal 20 is connected to the load 220. The load terminal 20 is integrally formed with a connector exposed outside the housing of the power distribution ECU 1. The load terminal 20 supplies power to the load 220 through a wire harness or the like connected to the connector. The load terminal 20 includes a first load terminal 21 and a second load terminal 22. The first load terminal 21 is connected to the first power supply line section 31 via the first load line section 51 but not via the power supply main line 40. The second load terminal 22 is connected to the second power supply line section 32 via the second load line section 52 but not via the power supply main line 40.

[0019] The first load terminal 21 further includes a first priority terminal 21a and a first normal terminal 21b. The second load terminal 22 further includes a second priority terminal 22a and a second normal terminal 22b. The first priority terminal 21a and the second priority terminal 22a are connected to a priority load 221. The first normal terminal 21b and the second normal terminal 22b are connected to a normal load 222.

[0020] One of the first priority terminals 21a and one of the second priority terminals 22a are connected to the same priority load 221. The first priority terminals 21a and the second priority terminals 22a connected to the same priority load 221 may be adjacent to each other. More specifically, the first priority connector including the first priority terminals 21a and the second priority connector including the second priority terminals 22a have the same shape. The first priority connector and the second priority connector are arranged adjacent to each other on the outside of the housing. The internal pin arrangements of the first priority connector and the second priority connector are the same. Furthermore, the first priority connector and the second priority connector may be integrally formed. Even with such integral formation of the connectors, the first priority terminals 21a and the second priority terminals 22a are configured to be adjacent to each other.

[0021] The power supply wiring KH is wiring formed between a plurality of power supply terminals 10 and a plurality of load terminals 20. The power supply wiring KH is formed by a copper conductive layer (wiring pattern) provided on a printed wiring board constituting the power distribution ECU 1. A bus bar mounted on the printed wiring board along the wiring pattern may form part of the power supply wiring KH. The bus bar is implemented in parallel with the wiring pattern in a location where the wiring pattern alone cannot carry the current. The power supply wiring KH is composed of a power supply wiring 30, a power supply trunk line 40, a load wiring 50, etc.

[0022] The power supply wiring 30 is a wiring connected to the power supply terminal 10. The power supply wiring 30 includes a first power supply line portion 31 and a second power supply line portion 32. The first power supply line portion 31 is a wiring portion connected to the first power supply terminal 11. Power is supplied to the first power supply line portion 31 from a main power supply 211. To accommodate the large power supplied from the main power supply 211, the wiring width (wiring cross-sectional area) of the first power supply line portion 31 is made wider (larger) than the wiring width of the second power supply line portion 32. The second power supply line portion 32 is a wiring portion connected to the second power supply terminal 12. Power is supplied to the second power supply line portion 32 from an auxiliary power supply 212. A power zener may be disposed in the section of the power supply wiring 30 between a power supply interruption circuit 60 (described later) and the power supply terminal 10. The power zener is a component for preventing voltage breakdown of the power supply interruption circuit 60 when a high voltage is output from the power supply 210.

[0023] The power supply trunk 40 is a wiring that is connected to both the first power supply line section 31 and the second power supply line section 32. Power is supplied to the power supply trunk 40 from the main power supply 211 and the auxiliary power supply 212, respectively, via the first power supply line section 31 and the second power supply line section 32. The wiring width (wiring cross-sectional area) of the power supply trunk 40 is the same as or wider (larger) than the wiring width of the first power supply line section 31. A trunk line interruption circuit 70, which will be described later, is provided in the middle of the power supply trunk 40. The section of the power supply trunk 40 between the first power supply line section 31 and the trunk line interruption circuit 70 is defined as a first section 41. The section of the power supply trunk 40 between the second power supply line section 32 and the trunk line interruption circuit 70 is defined as a second section 42.

[0024] The load wiring 50 is a wiring connected to the load terminal 20. The wiring width (cross-sectional area) of the load wiring 50 may be narrower (smaller) than the wiring width of the power supply trunk line 40. The wiring widths of the load wirings 50 may be different from each other. The load wiring 50 includes a first load line section 51 and a second load line section 52. The first load line section 51 connects the first power supply line section 31 and the first load terminal 21. The second load line section 52 connects the second power supply line section 32 and the second load terminal 22.

[0025] The interruption circuit is formed in the power supply wiring KH. The interruption circuit includes a power supply interruption circuit 60, a main line interruption circuit 70, and a load interruption circuit 80. When the interruption circuit is in the on state, the two wirings connected to the interruption circuit are connected and in a conducting state. On the other hand, when the interruption circuit is in the off state, the two wirings connected to the interruption circuit are in a conducting state.

[0026] The power supply interruption circuit 60 is an interruption circuit provided in the power supply wiring 30. The power supply interruption circuit 60 interrupts the connection between the power supply terminal 10 and the first load line section 51, and between the power supply terminal 10 and the power main line 40. Two power supply interruption circuits 60 are provided in the power supply wiring KH. A first power supply interruption circuit 60a is provided in the first power supply line section 31. A second power supply interruption circuit 60b is provided in the second power supply line section 32. The first power supply interruption circuit 60a interrupts the connection between the first power supply terminal 11 and the first load line section 51, and between the first power supply terminal 11 and the first section 41. The second power supply interruption circuit 60b interrupts the connection between the second power supply terminal 12 and the second load line section 52, and between the second power supply terminal 12 and the second section 42.

[0027] The main line interruption circuit 70 is an interruption circuit provided in the power supply main line 40. The main line interruption circuit 70 corresponds to an isolator, a backbone switch, or the like. The main line interruption circuit 70 is provided in the middle of the power supply main line 40 and connects the first power line section 31 and the second power line section 32. The main line interruption circuit 70 interrupts the connection between the first section 41 and the second section 42, and therefore the connection between the first power line section 31 and the second power line section 32. When the main line interruption circuit 70 is in an on state that does not interrupt the connection between the first power line section 31 and the second power line section 32, the first power supply terminal 11 is connected to the second load terminal 22. On the other hand, when the main line interruption circuit 70 is in an off state that interrupts the connection between the first power line section 31 and the second power line section 32, the first power supply terminal 11 is disconnected from the second load terminal 22. Furthermore, when the main line interruption circuit 70 is in the ON state, the second power supply terminal 12 is connected to the first load terminal 21. On the other hand, when the main line interruption circuit 70 is in the OFF state, the second power supply terminal 12 is disconnected from the first load terminal 21.

[0028] The load shedding circuit 80 is a shedding circuit provided in the load wiring 50. One load shedding circuit 80 is provided for each of the multiple first load line sections 51 and the multiple second load line sections 52. The load shedding circuit 80 includes a first load shedding circuit 80a provided in the first load line section 51 and a second load shedding circuit 80b provided in the second load line section 52. The load shedding circuit 80 is also distinguished by a priority load shedding circuit PC and a normal load shedding circuit NC. The priority load shedding circuit PC cuts off the connection between the priority terminals 21a and 22a, to which the priority load 221 is connected, and the load wiring 50. The normal load shedding circuit NC cuts off the connection between the normal terminals 21b and 22b, to which the normal load 222 is connected, and the load wiring 50.

[0029] The power distribution ECU 1 includes a plurality of priority load shedding circuits PC and a plurality of normal load shedding circuits NC (for example, two). One priority load shedding circuit PC is provided in the first load line section 51 and cuts off the connection between the first power supply line section 31 or the first section 41 and the first priority terminal 21a. The other priority load shedding circuit PC is provided in the second load line section 52 and cuts off the connection between the second power supply line section 32 or the second section 42 and the second priority terminal 22a. One normal load shedding circuit NC is provided in the first load line section 51 and cuts off the connection between the first power supply line section 31 or the first section 41 and the first normal terminal 21b. The other normal load shedding circuit NC is provided in the second load line section 52 and cuts off the connection between the second power supply line section 32 or the second section 42 and the second normal terminal 22b.

[0030] The voltage detection unit 90 detects the voltage of the load wiring 50 upstream of the load shedding circuit 80. The voltage of the load wiring 50 upstream of the load shedding circuit 80 is at the same potential as the power supply main line 40. Therefore, it can be said that the voltage detection unit 90 detects the voltage of the power supply main line 40. The voltage detection unit 90 includes a first voltage detection unit 91, a second voltage detection unit 92, and an OR circuit 95.

[0031] The first voltage detection unit 91 detects the voltage of the first load line section 51 upstream of the first load shedding circuit 80a. The first load line section 51 upstream of the first load shedding circuit 80a is at the same potential as the first section 41. Therefore, it can be said that the first voltage detection unit 91 detects the voltage of the first section 41. The second voltage detection unit 92 detects the voltage of the second load line section 52 upstream of the second load shedding circuit 80b. The second load line section 52 upstream of the second load shedding circuit 80b is at the same potential as the second section 42. Therefore, it can be said that the second voltage detection unit 92 detects the voltage of the second section 42. The first voltage detection unit 91 includes a first overvoltage detection unit 91a, a first undervoltage detection unit 91b, and an OR circuit 93. The second voltage detection section 92 includes a second overvoltage detection section 92 a that detects an overvoltage in the second load line section 52 , a second undervoltage detection section 92 b that detects a undervoltage in the second load line section 52 , and an OR circuit 94 .

[0032] The first overvoltage detection unit 91a detects whether the voltage of the first load line unit 51 is an overvoltage. The first overvoltage detection unit 91a detects the voltage of the first load line unit 51 on the first power supply line unit 31 side of the load shedding circuit 80. The first overvoltage detection unit 91a compares the detected voltage with an overvoltage threshold, and if the detected voltage is higher than the overvoltage threshold, outputs a signal indicating that an overvoltage has been detected. If the voltage of the first load line unit 51 under normal conditions is 12 V, the overvoltage threshold is, for example, 20 V. Therefore, a range higher than 20 V is outside the normal range. The signal indicating that an overvoltage has been detected is, for example, a Hi signal. When the voltage determination unit 152 outputs a signal indicating that an overvoltage has been detected, the high-speed circuit breaker 100 is activated, as described below. Therefore, the signal indicating that an overvoltage has been detected can also be said to be a signal for activating the high-speed circuit breaker 100. When the first overvoltage detector 91a does not detect an overvoltage, it outputs a signal indicating that an overvoltage has not been detected, for example, a Lo signal.

[0033] The first low-voltage detection unit 91b detects whether the voltage of the first load line unit 51 is low. The first low-voltage detection unit 91b detects the voltage of the first load line unit 51 on the first power supply line unit 31 side of the load shedding circuit 80. The first low-voltage detection unit 91b compares the detected voltage with a low-voltage threshold and, if the detected voltage is lower than the low-voltage threshold, outputs a signal indicating that a low voltage has been detected. The low-voltage threshold is, for example, 10 V. Therefore, a voltage lower than 10 V is outside the normal range. The signal indicating that a low voltage has been detected is, for example, a Hi signal. When the voltage determination unit 162 outputs a signal indicating that a low voltage has been detected, the high-speed cutoff unit 100 is also activated, as described below. Therefore, the signal indicating that a low voltage has been detected can also be considered a signal for activating the high-speed cutoff unit 100. When the first low-voltage detection unit 91b does not detect a low voltage, it outputs a signal indicating that a low voltage has not been detected, for example, a Lo signal.

[0034] The second overvoltage detection unit 92a detects whether the voltage of the second load line unit 52 is an overvoltage on the second power supply line unit 32 side of the load shedding circuit 80. The configuration of the second overvoltage detection unit 92a can be the same as that of the first overvoltage detection unit 91a. The second low voltage detection unit 92b detects whether the voltage of the second load line unit 52 is an undervoltage on the second power supply line unit 32 side of the load shedding circuit 80. The configuration of the second low voltage detection unit 92b can be the same as that of the first low voltage detection unit 91b.

[0035] A signal indicating the voltage detection result detected by the first overvoltage detection unit 91a and a signal indicating the voltage detection result detected by the first low-voltage detection unit 91b are input to the OR circuit 93. In addition, the signal indicating the voltage detection result detected by the first overvoltage detection unit 91a and the signal indicating the voltage detection result detected by the first low-voltage detection unit 91b are also input to the control unit 110.

[0036] A signal indicating the voltage detection result detected by the second overvoltage detection unit 92a and a signal indicating the voltage detection result detected by the second low-voltage detection unit 92b are input to an OR circuit 94. In addition, the signal indicating the voltage detection result detected by the second overvoltage detection unit 92a and the signal indicating the voltage detection result detected by the second low-voltage detection unit 92b are also input to the control unit 110.

[0037] The OR circuit 93 outputs a Hi signal to turn off the main line cutting circuit 70 when a Hi signal indicating that an overvoltage has been detected is input from the first overvoltage detection unit 91a, or when a Hi signal indicating that an undervoltage has been detected is input from the first undervoltage detection unit 91b.

[0038] The OR circuit 94 outputs a Hi signal to turn off the main line cutting circuit 70 when a Hi signal indicating that an overvoltage has been detected is input from the second overvoltage detection unit 92a, or when a Hi signal indicating that an undervoltage has been detected is input from the second undervoltage detection unit 92b.

[0039] The output signals of the OR circuits 93 and 94 are input to the OR circuit 95. The OR circuit 95 and the high-speed circuit breaker unit 100 are connected by a signal line 96. When a high signal is input from at least one of the OR circuits 93 and 94, the OR circuit 95 outputs a high signal to the signal line 96 as a signal for turning off the main line interruption circuit 70, i.e., cutting off the main line interruption circuit 70. One end of a signal line 97 is connected to the signal line 96. The signal line 97 is connected to the normal load shedding circuit NC. Therefore, the high signal output from the OR circuit 95 to the signal line 96 is input not only to the high-speed circuit breaker 100 but also to the normal load shedding circuit NC.

[0040] The high-speed interrupter 100 switches the on and off states of the main line interruption circuit 70. An output signal of the OR circuit 95 is input to the high-speed interrupter 100. The high-speed interrupter 100 switches the on and off states of the main line interruption circuit 70 based on the output signal of the OR circuit 95.

[0041] Signals indicating the voltage detection results from the first overvoltage detection unit 91a, the first low voltage detection unit 91b, the second overvoltage detection unit 92a, and the second low voltage detection unit 92b are input to the control unit 110. The control unit 110 is connected to drive units 121 and 122.

[0042] When a signal indicating a voltage abnormality is input from either the first overvoltage detection unit 91a or the first low voltage detection unit 91b, the control unit 110 outputs a signal to the drive unit 121 to cause the main line interruption circuit 70 to be cut off. Furthermore, when a signal indicating a voltage abnormality is input from either the second overvoltage detection unit 92a or the second low voltage detection unit 92b, the control unit 110 outputs a signal to the drive unit 122 to cause the main line interruption circuit 70 to be cut off. The hardware configuration of the control unit 110 can be, for example, a configuration including at least one processor and at least one memory.

[0043] The driving units 121 and 122 switch the on / off state of the main line breaking circuit 70 via some of the wiring of the high-speed breaker unit 100, independently of the control of the high-speed breaker unit 100. The driving units 121 and 122 can be implemented by gate driver ICs.

[0044] The power distribution ECU 1 further includes a first capacitor 131 and a second capacitor 132. When the first capacitor 131 and the second capacitor 132 are not distinguished from each other, they are referred to as capacitor 130. The first capacitor 131 has one end connected to the first section 41 and the other end connected to the ground potential of the power distribution ECU 1. The ground of the power distribution ECU 1 may also be referred to as the ECU ground. The second capacitor 132 has one end connected to the second section 42 and the other end connected to the ground potential of the power distribution ECU 1. The power distribution ECU 1 further includes an inductor 140. The inductor 140 is provided in the first section 41. The inductor 140 is an inductor component and is an example of a first inductance section and an inductance section.

[0045] <Breaking circuit configuration> Next, the power supply interruption circuit 60, the main line interruption circuit 70, and the load interruption circuit 80 will be described in detail with reference to FIGS.

[0046] The power supply interruption circuit 60 shown in Fig. 2 is a one-way interruption circuit that interrupts only the reverse current out of the forward current flowing from the power supply terminal 10 to the load terminal 20 (power supply main line 40) and the reverse current flowing from the load terminal 20 to the power supply terminal 10. The power supply interruption circuit 60 does not completely interrupt the forward current. The power supply interruption circuit 60 is configured to mainly include a switch unit 61. The switch unit 61 includes an FET (Field Effect Transistor) 62, a current detection unit 66, a voltage detection unit 67, a drive unit 68, and a control unit 69.

[0047] The FET 62 is an N-channel MOS (Metal-Oxide-Semiconductor) FET. The source of the FET 62 is connected to the power supply wiring 30 on the power supply 210 (power supply terminal 10) side. The drain of the FET 62 is connected to the power supply wiring 30 on the power supply main line 40 side. The gate of the FET 62 is connected to the drive unit 68. A body diode 63 is formed in the FET 62. The anode of the body diode 63 is connected to the power supply wiring 30 on the power supply 210 side. The cathode of the body diode 63 is connected to the power supply wiring 30 on the power supply main line 40 side.

[0048] The current detection unit 66 is provided on the power supply wiring 30 closer to the power supply 210 than the FET 62. The current detection unit 66 detects the value and direction of the current flowing through the power supply wiring 30. The current detection unit 66 outputs the detected current value and current direction to the control unit 69. The voltage detection unit 67 is connected to the power supply wiring 30 closer to the power supply main line 40 than the FET 62. The voltage detection unit 67 detects the value of the voltage on the power supply wiring 30. The voltage detection unit 67 outputs the detected voltage value to the control unit 69.

[0049] The driver 68 is connected to the gate of the FET 62. The driver 68 applies a predetermined voltage (hereinafter, gate voltage) to the gate of the FET 62 based on a command signal input from the controller 69. When the driver 68 applies the gate voltage, the source and drain of the FET 62 are brought into a conductive state (ON state). In contrast, when no gate voltage is applied, the source and drain of the FET 62 are brought into a non-conductive state (OFF state). Note that even when no gate voltage is applied, the FET 62 has a body diode 63, which allows a forward current to flow from the source to the drain.

[0050] The control unit 69 is connected to the drive unit 68. The control unit 69 switches the FET 62 between on and off states, and therefore the power supply wiring 30 between on and off states, by outputting a command signal to the drive unit 68. The control unit 69 acquires the current value and current direction detected by the current detection unit 66 and the voltage value detected by the voltage detection unit 67, and electrically reads the latest current value and voltage value of the power supply wiring 30. The control unit 69 determines the occurrence of an abnormality based on at least one of the current value and the voltage value. The control unit 69 compares at least one of the current value and the voltage value with a predetermined determination threshold. The control unit 69 detects abnormalities such as a ground fault, short circuit, or open circuit in the power supply system or the power supply wiring 30 based on the process of comparing the detected value with the determination threshold. The control unit 69 determines that a ground fault has occurred if a current is flowing toward the ground fault path and the voltage value is abnormal. The control unit 69 determines that an open circuit has occurred if the current has stopped flowing and the voltage value is abnormal. When the control unit 69 detects the occurrence of an abnormality, it cooperates with the drive unit 68 to turn the FET 62 off and cut off the current flow through the power supply line 30.

[0051] 3 is a bidirectional interruption circuit that interrupts both the current flowing from the first power supply line section 31 to the second power supply line section 32 and the current flowing from the second power supply line section 32 to the first power supply line section 31. The main line interruption circuit 70 includes two FETs 72a and 72b.

[0052] The FETs 72a and 72b are N-channel MOSFETs. The FETs 72a and 72b are connected to each other via an intermediate connecting line 74. The sources of the FETs 72a and 72b are connected to both ends of the intermediate connecting line 74. Note that, as an arrangement different from that shown in FIG. 3, the drains of the FETs 72a and 72b may be connected to both ends of the intermediate connecting line 74.

[0053] The drain of the FET 72a is connected to the first section 41. The drain of the FET 72b is connected to the second section 42. The gate of the FET 72a is connected to the driver 121 via a diode 107 provided in the high-speed cutoff unit 100. The gate of the FET 72b is connected to the driver 122 via a diode 108 provided in the high-speed cutoff unit 100. Body diodes 73a and 73b are formed in the FETs 72a and 72b. The anodes of the body diodes 73a and 73b are connected to the intermediate connection line portion 74. The cathode of the body diode 73a is connected to the first section 41. The cathode of the body diode 73b is connected to the second section 42.

[0054] The first voltage detection unit 91 detects whether the voltage of the first load line unit 51 is abnormal or normal. Abnormalities include overvoltage and undervoltage. The second voltage detection unit 92 detects whether the voltage of the second load line unit 52 is abnormal or normal. The detection results of the first voltage detection unit 91 and the second voltage detection unit 92 are input to the OR circuit 95 and the control unit 110.

[0055] The drivers 121 and 122 are connected to the gates of the FETs 72a and 72b, respectively, via diodes 107 and 108 included in the high-speed cutoff unit 100. The drivers 121 and 122 apply gate voltages to the gates of the FETs 72a and 72b based on command signals input from the control unit 110. When the drivers 121 and 122 apply the gate voltages, the sources and drains of the FETs 72a and 72b are conductive. In contrast, when no gate voltage is applied, the sources and drains of the FETs 72a and 72b are non-conductive. By combining the two FETs 72a and 72b, when no gate voltage is applied, the current flowing from the first section 41 to the second section 42 is blocked by the body diode 73a. Furthermore, the current flowing from the second section 42 to the first section 41 is blocked by the body diode 73b.

[0056] The control unit 110 is connected to two drive units 121 and 122. The hardware configuration of the control unit 110 can be a microcontroller equipped with a processor and memory. The control unit 110 outputs command signals to the drive units 121 and 122 to switch the on and off states of the FETs 72a and 72b, and thus the power supply main line 40 between energized and cut-off states. When the control unit 110 receives signals indicating an abnormal voltage from the first voltage detection unit 91 and the second voltage detection unit 92, the control unit 110 cooperates with the drive units 121 and 122 to turn off the FETs 72a and 72b and cut off the main line cut-off circuit 70. This cuts off the power supply main line 40.

[0057] By setting the main line interruption circuit 70 to the interrupted state, the first power supply line section 31 and the second power supply line section 32 are disconnected. Therefore, even if an abnormality occurs in a circuit related to the power distribution ECU 1, it is possible to properly supply power from the multiple power sources 210 to the multiple load terminals 20, and ultimately to the loads 220 connected to each load terminal 20.

[0058] The load shedding circuit 80 shown in FIG. 4 is a one-way shedding circuit that shedding only the forward current out of the forward current flowing from the power supply main line 40 toward the load terminal 20 and the reverse current flowing from the load terminal 20 toward the power supply main line 40. The load shedding circuit 80 does not completely shedding the reverse current. The load shedding circuit 80 is mainly configured to include a switch unit 81. The switch unit 81 includes an FET 82, a current detection unit 86, a voltage detection unit 87, a drive unit 88, and a control unit 89.

[0059] The FET 82 is an N-channel MOSFET. The FET 82 is provided on the load wiring 50. The source of the FET 82 is connected to the load wiring 50 on the load 220 (load terminal 20) side. The drain of the FET 82 is connected to the load wiring 50 on the power supply main line 40 side. The gate of the FET 82 is connected to the drive unit 88. A body diode 83 is formed in the FET 82. The anode of the body diode 83 is connected to the load wiring 50 on the load 220 side. The cathode of the body diode 83 is connected to the load wiring 50 on the power supply main line 40 side.

[0060] The current detection unit 86 is provided on the load wiring 50 closer to the power supply main line 40 than the FET 82. The current detection unit 86 detects the value and direction of the current flowing through the load wiring 50. The current detection unit 86 outputs the detected current value and current direction to the control unit 89. The voltage detection unit 87 is connected to the load wiring 50 closer to the load 220 than the FET 82. The voltage detection unit 87 detects the value of the voltage on the load wiring 50. The voltage detection unit 87 outputs the detected voltage value to the control unit 89.

[0061] The driver 88 is connected to the gate of the FET 82. The driver 88 applies a predetermined gate voltage to the gate of the FET 82 based on a command signal input from the controller 89. When the driver 88 applies the gate voltage, the source and drain of the FET 82 are brought into a conductive state. In contrast, when no gate voltage is applied, the source and drain of the FET 82 are brought into a non-conductive state. Note that even when no gate voltage is applied, the FET 82 has a body diode 83, which allows a reverse current to flow from the source to the drain.

[0062] The control unit 89 is connected to the drive unit 88. The control unit 89 switches the FET 82 between on and off states, and thus the load wiring 50 between energized and de-energized states, by outputting a command signal to the drive unit 88. The control unit 89 acquires the current value and current direction detected by the current detection unit 86 and the voltage value detected by the voltage detection unit 87, and electrically reads the latest current and voltage values ​​of the load shedding circuit 80. The control unit 89 determines whether an abnormality has occurred in the load wiring 50 based on at least one of the current and voltage values. The control unit 89 detects abnormalities such as a decrease in power supply and a sudden increase in current and voltage values ​​due to a ground fault, short circuit, open circuit, or other occurrence in the load system by comparing the detected value with a determination threshold. When the control unit 89 detects an abnormality, it transmits an abnormality notification signal indicating the occurrence of an abnormality in the load wiring 50 to the control unit 89 of another load shedding circuit 80, the control unit 110 of the main line shedding circuit 70, and the like. When a sticking failure or the like occurs in the switch unit 81, the control unit 89 transmits an abnormality notification signal indicating the occurrence of the failure to the other control units 89, the control unit 110, etc. The control unit 89 acquires an abnormality notification signal indicating the occurrence of an abnormality in the other load wiring 50 from the other control unit 89. When the control unit 89 detects the occurrence of an abnormality or acquires an abnormality notification signal from the other control unit 89, the control unit 89 cooperates with the drive unit 88 to turn the FET 82 to the off state and cut off the current flow through the load wiring 50.

[0063] <Configuration of voltage detection section> Next, the configurations of the first overvoltage detection unit 91a and the second overvoltage detection unit 92a will be described. The first overvoltage detection unit 91a and the second overvoltage detection unit 92a have the same configuration. When there is no need to distinguish between the first overvoltage detection unit 91a and the second overvoltage detection unit 92a, they will be referred to as overvoltage detection unit OVD.

[0064] FIG. 5 shows the configuration of the overvoltage detection unit OVD. The overvoltage detection unit OVD detects an overvoltage in the load wiring 50 upstream of the load shedding circuit 80. The voltage of the load wiring 50 upstream of the load shedding circuit 80 is at the same potential as the first section 41 of the power supply main line 40. Therefore, it can be said that the overvoltage detection unit OVD detects the voltage of the first section 41 of the power supply main line 40. The overvoltage detection unit OVD includes a power supply line resistance voltage divider 150, a threshold value generation resistance voltage divider 151, and a voltage determination unit 152. The power supply line resistance voltage divider 150 divides the voltage of the load wiring 50 upstream of the load shedding circuit 80. The power supply line resistance voltage divider 150 includes resistors R1 and R2. One end of the resistor R1 is connected to the load wiring 50 and the other end is connected to resistor R2. The other end of resistor R2 is connected to the ECU ground. The power supply line resistance voltage dividing section 150 may be connected to the power supply main line 40 to divide the voltage of the power supply main line 40 .

[0065] The threshold generation resistive voltage divider 151 generates an overvoltage threshold voltage (hereinafter referred to as the overvoltage threshold) by resistive voltage division. The threshold generation resistive voltage divider 151 includes resistors R3 and R4. One end of the resistor R3 is connected to the internal power supply of the power distribution ECU 1. The internal power supply supplies a reference voltage. The reference voltage is, for example, 5 V. The other end of the resistor R3 is connected to the resistor R4. The other end of the resistor R4 is connected to the ECU ground.

[0066] The voltage determination unit 152 is a comparator. The voltage between resistors R1 and R2 is input to a positive input terminal of the voltage determination unit 152. The overvoltage threshold generated by the threshold generation resistive voltage dividing unit 151, i.e., the voltage between resistors R3 and R4, is input to a negative input terminal of the voltage determination unit 152.

[0067] With this configuration, the overvoltage detection unit OVD detects whether the voltage of the load wiring 50 upstream of the load shedding circuit 80 is an overvoltage. In other words, the overvoltage detection unit OVD detects whether the voltage of the power supply main line 40 is an overvoltage. Suppose the normal voltage of the load wiring 50 is 12 V. For example, the overvoltage detection unit OVD is configured to detect an overvoltage when the voltage of the load wiring 50 exceeds 20 V.

[0068] Next, the configurations of the first low-voltage detection unit 91b and the second low-voltage detection unit 92b will be described. The first low-voltage detection unit 91b and the second low-voltage detection unit 92b have the same configuration. When there is no need to distinguish between the first low-voltage detection unit 91b and the second low-voltage detection unit 92b, they will be referred to as low-voltage detection unit LVD.

[0069] 6 shows the configuration of the low voltage detection unit LVD. The low voltage detection unit LVD includes a power supply line resistance voltage dividing unit 160, a threshold value generation resistance voltage dividing unit 161, and a voltage determination unit 162. The power supply line resistance voltage dividing unit 160 divides the voltage of the load wiring 50. The power supply line resistance voltage dividing unit 160 includes resistors R5 and R6. One end of the resistor R5 is connected to the load wiring 50, and the other end is connected to the resistor R6. The other end of the resistor R6 is connected to the ECU ground. The power supply line resistance voltage dividing unit 160 may be connected to the power supply main line 40 to divide the voltage of the power supply main line 40.

[0070] The threshold generation resistive voltage dividing unit 161 generates a low voltage threshold voltage (hereinafter referred to as low voltage threshold) by resistive voltage division. The threshold generation resistive voltage dividing unit 161 includes a resistor R7 and a resistor R8. One end of the resistor R7 is connected to a reference voltage. The other end of the resistor R7 is connected to the resistor R8. The other end of the resistor R8 is connected to the ECU ground.

[0071] The voltage determination unit 162 is a comparator. The polarity of the input terminal is opposite to that of the voltage determination unit 152 of the overvoltage detection unit OVD, and the voltage divided by the threshold generation resistance voltage divider 161 is input to the + input terminal of the voltage determination unit 162, and the voltage divided by the power supply line resistance voltage divider 160 is input to the - input terminal of the voltage determination unit 162. That is, the voltage between resistors R7 and R8 is input to the + input terminal of the voltage determination unit 162, and the voltage between resistors R5 and R6 is input to the - input terminal of the voltage determination unit 162.

[0072] With this configuration, the low voltage detection unit LVD detects whether the voltage of the load wiring 50 upstream of the load shedding circuit 80 has become low. In other words, the low voltage detection unit LVD detects whether the voltage of the power supply main line 40 has become low. For example, the low voltage detection unit LVD is configured to detect that the voltage of the load wiring 50 has become low when it falls below 10 V.

[0073] <Configuration of high-speed interrupter 100> Next, the configuration of the high-speed interrupter 100 will be described with reference to Fig. 3. When the voltage of the first section 41 and the first load line section 51 having the same potential as the first section 41 becomes abnormal, it is preferable to quickly interrupt the main line interrupter circuit 70 to prevent the voltage abnormality from affecting the voltage on the auxiliary power supply 212 side. Also, when the voltage of the second section 42 and the second load line section 52 having the same potential as the second section 42 becomes abnormal, it is preferable to quickly interrupt the main line interrupter circuit 70 to prevent the voltage abnormality from affecting the voltage on the main power supply 211 side.

[0074] Therefore, in order to turn off the main line interruption circuit 70 faster than when the control unit 110 outputs a command signal to the drive units 121 and 122 to turn off the main line interruption circuit 70, the high-speed interruption unit 100 is provided. The high-speed interruption unit 100 includes three FETs 101, 102, and 103. In addition, the high-speed interruption unit 100 includes resistors 104, 105, and 106, and diodes 107 and 108.

[0075] The FET 101 is an N-channel MOSFET and corresponds to the first transistor in the high-speed cutoff unit 100. The source of the FET 101 is connected to the ECU ground. The drain of the FET 101 is connected to the gates of the FETs 102 and 103. The gate of the FET 101 receives the output signal of the OR circuit 95. One end of the resistor 104 is connected to the gate of the FET 101, and the other end is connected to the source of the FET 101. Note that an NPN transistor may be used instead of the FET 101.

[0076] The FETs 102 and 103 are P-channel MOSFETs and correspond to the second and third transistors in the high-speed interrupter unit 100. PNP transistors may be used instead of the FETs 102 and 103. As shown in FIG. 3, the FETs 102 and 103 are connected to the trunk line interrupter circuit 70 without passing through the control unit 110. An output signal from an OR circuit 95 included in the voltage detection unit 90 is also input to the high-speed interrupter unit 100 without passing through the control unit 110.

[0077] The source of FET 102 is connected to the gate of FET 72a and the cathode of diode 107. The drain of FET 102 is connected to intermediate connecting line portion 74. The gate of FET 102 is connected to the drain of FET 101. One end of resistor 105 is connected to the source of FET 102, and the other end is connected to the gate of FET 102.

[0078] The source of FET 103 is connected to the gate of FET 72b and the cathode of diode 108. The drain of FET 103 is connected to intermediate connecting line portion 74. The gate of FET 103 is connected to the drain of FET 101. One end of resistor 106 is connected to the source of FET 103, and the other end is connected to the gate of FET 103.

[0079] The anode of diode 107 is connected to driver 121, and the cathode is connected to the gate of FET 72a and the source of FET 102. Diode 107 prevents unintended current from flowing through the path of FET 72a, wiring 1409, FET 102, and FET 101 after FET 101 is turned on and before FET 72a is turned off. Diode 108 has an anode connected to driver 122 and a cathode connected to the gate of FET 72b and the source of FET 103. Diode 108 prevents unintended current from flowing through the path of FET 72b, FET 103, wiring 109, and FET 101 after FET 101 is turned on and before FET 72b is turned off. Wiring 109 is provided so that drivers 121 and 122 can turn off FETs 102 and 103.

[0080] When drivers 121 and 122 apply gate voltages to FETs 72a and 72b and shutoff circuit 70 is conducting, if a Hi signal, which is a shutoff signal, is input from OR circuit 95, current flows between the source and drain of FET 101. This turns on FETs 102 and 103, and current flows between the source and drain of FET 102 and between the source and drain of FET 103. Then, as the source and drain of FET 102 are conducting, the potential difference between the gate and source of FET 72ab disappears, and FET 72a turns off. Furthermore, as the source and drain of FET 103 are conducting, the potential difference between the gate and source of FET 72b disappears, and FET 72b turns off.

[0081] The voltage detection unit 90 inputs a shutdown signal from the OR circuit 95 to the high-speed shutdown unit 100 based on the voltage of the power supply main line 40. This activates the high-speed shutdown unit 100. The high-speed shutdown unit 100 includes FETs 102 and 103 for switching the main line shutdown circuit 70 to the shutdown state. The FETs 102 and 103 respectively switch off the FETs 72a and 72b included in the main line shutdown circuit 70. The FETs 102 and 103 are connected to the FETs 72a and 72b without passing through the control unit 110. Furthermore, the FET 101 that activates the FETs 102 and 103 receives a shutdown signal from the voltage detection unit 90 without passing through the control unit 110. Therefore, the high-speed shutdown unit 100 can switch the main line shutdown circuit 70 to the shutdown state faster than the control unit 110 switches the main line shutdown circuit 70 to the shutdown state.

[0082] <Functions of the capacitor 130 and the inductor 140> Next, the capacitor 130 and the inductor 140 will be described. By using these, power can be supplied to the priority load 221 even if a ground fault occurs in the power supply main line 40. This will be described using several examples.

[0083] [Ground fault example 1: When the first section 41 has a ground fault] First, a case where a ground fault occurs in the first section 41 will be described. Before describing Example 1 of a ground fault in this embodiment, FIG. 7 shows, as a comparative example, a power distribution ECU 300 without an inductor 140. For ease of illustration, FIG. 7 omits some components such as the voltage detection unit 90, the high-speed interrupter 100, and the control unit 110. FIG. 7 also shows the energized states of the interrupter circuits 60, 70, and 80. As shown in FIG. 7, the interrupter circuits 60, 70, and 80 are all in the ON state.

[0084] In Figure 7, the first section 41 has a ground fault to the ECU ground. This ground fault causes the voltage of the power supply main line 40 to decrease. To calculate the voltage of the power supply main line 40 at the moment of the ground fault, the following impedances are defined. Z1 is the impedance of the wiring from the auxiliary power supply 212 to the second power supply terminal 12. Z2 is the impedance of the wiring from the auxiliary power supply 212 to the vehicle ground. Z3 is the impedance of the wiring from the ECU ground to the vehicle ground. Furthermore, the voltage of the auxiliary power supply 212 is defined as V1, the charging voltage of the second capacitor 132 is defined as V2, and the charging voltage of the first capacitor 131 is defined as V3.

[0085] The voltage in the first section 41 at the moment when the first section 41 is grounded to the ECU ground can be expressed by Equation 1. The voltage in the second section 42 can be expressed by Equation 2. Equation 1 and Equation 2 are the same.

[0086]

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[0087]

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[0088] 8, the power distribution ECU 1 of this embodiment includes an inductor 140. When the impedance of the inductor 140 is Z4 and Thevenin's theorem is used, the following equation is obtained.

[0089] First, when the second capacitor 132 is short-circuited, the current flowing through the portion Z3 (hereinafter referred to as the Z3 current) can be expressed by Equation 3, and the current flowing through the portion Z4 (hereinafter referred to as the Z4 current) is expressed by Equation 4.

[0090]

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[0091]

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[0092]

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[0093]

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[0094]

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[0095]

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[0096] Additionally, a low-pass filter is formed by the inductor 140 and the second capacitor 132. This low-pass filter can delay the voltage drop in the second section 42. Then, if the main line interruption circuit 70 is turned off while the low-pass filter is delaying the voltage drop in the second section 42, it is possible to prevent the voltage from the auxiliary power supply 212 to the prioritized load 221 from falling outside the normal range.

[0097] Because the first section 41 and the first load line section 51 are connected, if a ground fault occurs in the first section 41, the first low voltage detection section 91b also detects a low potential. This activates the high-speed cutoff section 100, and the main line cutoff circuit 70 is quickly turned off. This further prevents the voltage from the auxiliary power supply 212 to the priority load 221 from falling outside the normal range.

[0098] [Ground fault example 2: When the second section 42 has a ground fault] Next, a case where the second section 42 has a ground fault will be described. As in Example 1, FIG. 9 shows a power distribution ECU 300 without an inductor 140 as a comparative example. As shown in FIG. 9, the second section 42 has a ground fault to the ECU ground. When the second section 42 has a ground fault, as in Example 1, the voltage in the first section 41 is expressed by the above-described Equation 1, and the voltage in the second section 42 is expressed by the above-described Equation 2. Therefore, as in Example 1, if V1 = V2 = V3 = 12V and [Z1 Z2 Z3] = [1 μH 1 μH 0.5 μH], the voltage in the first section 41 and the voltage in the second section 42 at the moment when the second section 42 has a ground fault will each be 2.4V.

[0099] FIG. 10 shows a state in which the second section 42 has a ground fault in the power distribution ECU 1 of this embodiment. The charging voltage of the second capacitor 132 can be excluded from the calculation because both ends of the second capacitor 132 are short-circuited. Therefore, in the explanation of Example 2, the charging voltage of the first capacitor 131 is set to V2. Using Thevenin's theorem, Equations 9 to 12 are obtained. Equations 9 and 10 represent the Z3 current and Z4 current when the first capacitor 131 is short-circuited. Equations 11 and 12 represent the Z3 current and Z4 current when the auxiliary power supply 212 is short-circuited.

[0100]

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[0101]

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[0102]

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[0103]

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[0104]

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[0105]

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[0106] In this way, by providing the inductor 140, it is possible to maintain the voltage of the power supply main line 40 within the normal range even at the moment when a ground fault occurs in the second section 42. Furthermore, the inductor 140 and the first capacitor 131 form a low-pass filter. This low-pass filter delays the voltage drop in the first section 41. If the main line interruption circuit 70 is turned off while the low-pass filter delays the voltage drop in the first section 41, it is possible to prevent the voltage from the main power supply 211 to the priority load 221 from falling outside the normal range.

[0107] Because the second section 42 and the second load line section 52 are connected, if a ground fault occurs in the second section 42, the second low voltage detection section 92b also detects a low potential. This activates the high-speed cutoff section 100, and the trunk line cutoff circuit 70 is quickly turned off. This further prevents the voltage from the main power supply 211 to the priority load 221 from falling outside the normal range.

[0108] [Ground fault example 3: when a ground fault occurs between the inductor 140 and the main line interruption circuit 70] Next, a description will be given of a case where a ground fault occurs between the inductor 140 and the main line interruption circuit 70 in the first section 41. Note that the above-described Example 1 is an example where a ground fault occurs on the first power line section 31 side of the inductor 140 in the first section 41.

[0109] FIG. 11 shows a state in which a ground fault occurs between the inductor 140 and the main line interruption circuit 70 in the power distribution ECU 1. In the case of Example 3, the voltage in the first section 41 and the voltage in the second section 42 at the moment of the ground fault can also be expressed by Equations 13 and 14, respectively. Therefore, the voltage in the first section 41 at the moment of the ground fault is 14.4 V, which is within the normal range. However, even if the interruption circuit 70 is turned off, the charge stored in the first capacitor 131 flows to the ECU ground. Therefore, in the case of Example 3, even with the configuration of the power distribution ECU 1, the voltage in the first section 41 eventually reaches 0 V.

[0110] <Modification 1 of the First Embodiment> 12 shows the configuration of power distribution ECU 400, which is a first modification of the first embodiment. In power distribution ECU 400, an inductor 141 is added to second section 42 compared to power distribution ECU 1. Inductor 141 is an inductor component and is an example of a second inductance section and an inductance section. When the voltage of auxiliary power supply 212 is V1, the charging voltage of second capacitor 132 is V2, and the charging voltage of first capacitor 131 is V3, Equations 15 to 19 are obtained using Thévenin's theorem.

[0111] Equation 15 shows the Z3 current when the first capacitor 131 and the second capacitor 132 are shorted. Equation 16 shows the Z3 current when the auxiliary power supply 212 and the second capacitor 132 are shorted. Equation 17 shows the Z3 current when the auxiliary power supply 212 and the first capacitor 131 are shorted. Using Equations 15, 16, and 17, the voltage in the first section 41 can be expressed by Equation 18, and the voltage in the second section 42 can be expressed by Equation 19.

[0112]

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[0113]

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[0114]

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[0115]

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[0116]

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[0117] According to this modification of the first embodiment, by adding the inductor 141, the voltage in the second section 42 can be maintained within the normal voltage range even at the moment when a ground fault occurs in the section shown in FIG. 12 . Furthermore, the inductor 141 and the second capacitor 132 form a low-pass filter. This low-pass filter delays the voltage drop in the second section 42. If the main line interruption circuit 70 is turned off while the low-pass filter is delaying the voltage drop in the second section 42, power supply to the priority load 221 can be continued within the normal voltage range.

[0118] <Modification 2 of the First Embodiment> The first embodiment and the first modification of the first embodiment include inductors 140 and 141. These inductors 140 and 141 are inductor components mounted on a substrate. In this second modification, at least one of the inductors 140 and 141 is replaced with an inductance L of the substrate wiring. The inductance L of the substrate wiring can be expressed by Equation 20. In Equation 20, l is the length (mm) of the conductor, w is the width (mm) of the conductor, and t is the thickness (mm) of the conductor.

[0119]

number

[0120] <Modification 3 of the First Embodiment> In the first embodiment, the first power supply interruption circuit 60a and the second power supply interruption circuit 60b have the same configuration. Also, the two priority load interruption circuits PC have the same configuration. However, the first power supply interruption circuit 60a and the second power supply interruption circuit 60b can have at least a partial different configuration while having the same functions. Also, the two priority load interruption circuits PC can have at least a partial different configuration while having the same functions.

[0121] For example, different heat dissipation materials may be used for the FETs 62 included in the first power supply interruption circuit 60a and the second power supply interruption circuit 60b. Heat dissipation materials include various heat dissipating materials such as conductive adhesives, lead frames, and molding materials. By using different materials for these heat dissipation materials, different heat dissipation materials can be used. By using different heat dissipation materials for the FETs 62, the possibility of both the first power supply interruption circuit 60a and the second power supply interruption circuit 60b failing simultaneously due to a single event occurring in the power distribution ECU 1 can be reduced.

[0122] Furthermore, the first power supply interruption circuit 60a and the second power supply interruption circuit 60b can be configured with an IC, such as being configured as a single integrated circuit (hereinafter, IC), and the thermal characteristic materials that affect the thermal characteristics of this IC can be different from each other. Thermal characteristic materials include the number of pins, pin shape, and external size of the IC. Even if the thermal characteristic materials of the ICs are different from each other, the possibility of the first power supply interruption circuit 60a and the second power supply interruption circuit 60b failing simultaneously due to a single event occurring in the power distribution ECU 1 can be reduced.

[0123] Second Embodiment In the second embodiment, a high speed interrupter 500 different from the high speed interrupter 100 of the first embodiment will be described. 13 shows the high speed interrupter 500 of the second embodiment. The high speed interrupter 500 includes an FET 501, a resistor 502, and a wiring 503.

[0124] In the high-speed tripping unit 500, the FET 501 is the same as the FET 101 in the high-speed tripping unit 100 in that a tripping signal is input to the gate from the OR circuit 95. The source of the FET 501 is connected to the ECU ground. The drain of the FET 501 is connected to the gates of the FETs 72a and 72b via a wiring 503. One end of the resistor 502 is connected to the gate of the FET 501, and the other end is connected to the source of the FET 501.

[0125] When the first voltage detection unit 91 or the second voltage detection unit 92 detects a voltage abnormality and an interruption signal is input from the OR circuit 95 to the gate of FET 501, FET 501 turns on. When FET 501 is on, the gates of FET 72a and FET 72b are connected to the ECU ground potential, so FET 72a and FET 72b are in the off state. Even with this configuration of the high-speed interrupter 500, the main line interruption circuit 70 can be quickly switched to the interrupted state when the first voltage detection unit 91 or the second voltage detection unit 92 detects a voltage abnormality.

[0126] <Third embodiment> The third embodiment is another form of shutting down the load shedding circuit 80. FIG. 14 shows the configuration for shutting down the load shedding circuit 80 in the third embodiment. The third embodiment includes a load side high-speed shutoff unit 580 as the configuration for shutting down the load shedding circuit 80. The load side high-speed shutoff unit 580 includes an FET 581, a resistor 582, an FET 583, a resistor 584, and a diode 585.

[0127] The FET 581 is an N-channel MOSFET and corresponds to the first transistor in the load side high-speed cutoff unit 580. The source of the FET 581 is connected to the ECU ground. The drain of the FET 581 is connected to the gate of the FET 583. The output signal of the OR circuit 95 is input to the gate of the FET 581. One end of the resistor 582 is connected to the gate of the FET 581, and the other end is connected to the source of the FET 581.

[0128] The FET 583 is a P-channel MOSFET and corresponds to the second transistor in the load-side high-speed interruption unit 580. The FET 583 corresponds to a transistor connected to the load interruption circuit 80. The source of the FET 583 is connected to the gate of the FET 82 and the cathode of the diode 585. The drain of the FET 583 is connected to the load wiring 50, closer to the load 220 than the FET 82. The gate of the FET 583 is connected to the drain of the FET 581. The gate of the FET 583 is also connected to the driver 88. One end of the resistor 584 is connected to the source of the FET 583, and the other end is connected to the gate of the FET 583. The diode 585 has a cathode connected to the gate of the FET 82, and an anode connected to the driver 88, the drain of the FET 581, and the gate of the FET 583.

[0129] When the drive unit 88 applies a gate voltage to the FET 82, and an interruption signal is input from the OR circuit 95 to the gate of the FET 581, the FET 581 turns on. When the FET 581 turns on, the gate of the FET 583 becomes 0 V, and the FET 583 turns on. When the FET 583 turns on, the potential difference between the gate and source of the FET 82 becomes 0 V, and the FET 82 turns off. This operation allows the FET 82 to be quickly turned off when the first voltage detection unit 91 or the second voltage detection unit 92 detects an abnormality.

[0130] It is effective if the load-side high-speed shutoff unit 580 is provided to shut off the second load shutoff circuit 80b connected to the normal load 222 via the second normal terminal 22b. The reason for this is explained below. Suppose that the first voltage detection unit 91 detects that the voltage on the main power supply 211 side is abnormal. When an abnormality in the voltage on the main power supply 211 side is detected, power supply to the priority load 221 continues only from the auxiliary power supply 212. When power is supplied to the normal load 222 in addition to the priority load 221 from only the auxiliary power supply 212, it is possible that the power supply capacity of the auxiliary power supply 212 is insufficient, making it impossible to supply sufficient power to the priority load 221.

[0131] When the first voltage detection unit 91 detects that the voltage on the main power supply 211 side is abnormal, the load-side high-speed cutoff unit 580 can quickly cut off the second load cutoff circuit 80b connected to the normal load 222, thereby preventing a voltage drop on the auxiliary power supply 212 side. As a result, even when power is supplied to the priority load 221 only from the auxiliary power supply 212, it is possible to prevent the voltage applied to the priority load 221 from falling outside the normal range.

[0132] <Fourth embodiment> The fourth embodiment is also another form of shutting down the load shedding circuit 80. Fig. 15 shows the configuration for shutting down the load shedding circuit 80 in the fourth embodiment. In the fourth embodiment, a load side high-speed shutoff unit 680 is provided as the configuration for shutting down the load shedding circuit 80. The load side high-speed shutoff unit 680 includes one FET 681 and one resistor 682.

[0133] The source of the FET 681 is connected to the ECU ground. The drain of the 6ET581 is connected to the gate of the FET 82. The output signal of the OR circuit 95 is input to the gate of the FET 681. One end of the resistor 682 is connected to the gate of the FET 681, and the other end is connected to the source of the FET 681.

[0134] When the OR circuit 95 inputs a shutoff signal to the gate of FET 681 while the driver 88 is applying a gate voltage to FET 82, FET 681 turns on. By turning on FET 681, the gate of FET 82 becomes 0 V, turning FET 82 off. This operation allows FET 82 to be quickly turned off when the first voltage detector 91 or the second voltage detector 92 detects an abnormality. For the same reason as the load side high-speed shutoff unit 580, the load side high-speed shutoff unit 680 is also effective when provided to shut off the second load shutoff circuit 80b connected to the normal load 222 via the second normal terminal 22b.

[0135] Fifth Embodiment The fifth embodiment is also another form of shutting down the load shedding circuit 80. FIG. 16 shows the configuration for shutting down the load shedding circuit 80 in the fifth embodiment. In the fifth embodiment, a load side high-speed shutoff unit 780 is provided as a configuration for shutting down the load shedding circuit 80. The load side high-speed shutoff unit 780 includes an FET 781 and a resistor 782. Note that in the fifth embodiment, the load shedding circuit 80 includes a switch unit SW including an FET 82 and a driver 88. The switch unit SW is sometimes called an IPD (Intelligent Power Device). In addition to the FET 82 and driver 88, the switch unit SW includes one or more load functions, which are configured as a chip.

[0136] The FET 781 is an N-channel MOSFET. The source of the FET 781 is connected to the ECU ground. The drain of the FET 781 is connected to the drive unit 88 included in the switch unit SW. The output signal of the OR circuit 95 is input to the gate of the FET 781. One end of the resistor 782 is connected to the gate of the FET 781, and the other end is connected to the source of the FET 781.

[0137] When the OR circuit 95 inputs a shutoff signal to the gate of FET 781 while the driver 88 is applying a gate voltage to FET 82, FET 781 turns on. When FET 781 turns on, the voltage input to the driver 88 becomes 0 V. This causes the driver 88 to turn off FET 82. This operation allows FET 82 to be quickly turned off when the first voltage detector 91 or the second voltage detector 92 detects an abnormality. For the same reasons as the load-side high-speed shutoff unit 580, the load-side high-speed shutoff unit 780 is also effective when provided to shut off the second load shutoff circuit 80b connected to the normal load 222 via the second normal terminal 22b.

[0138] Sixth Embodiment The sixth embodiment is an embodiment in which the relative accuracy of the voltage dividing resistors of the threshold generation resistor divider 161 included in the low voltage detection unit LVD is inspected. This is because the relative accuracy of the threshold generation resistor divider 161 is important for the low voltage detection unit LVD to accurately detect low voltages. Note that hereinafter, the relative accuracy of the voltage dividing resistors will simply be referred to as relative accuracy. If the relative accuracy deteriorates due to resistor degradation or the like, low voltages cannot be detected accurately, and as a result, the main line interruption circuit 70 cannot operate correctly. It is not desirable for the vehicle to run with the main line interruption circuit 70 not operating correctly. Therefore, the relative accuracy of the threshold generation resistor divider 161 is inspected before the vehicle starts running, for example.

[0139] 17, the sixth embodiment includes an inspection voltage dividing section 170 and a switch 180 for inspection. The inspection voltage dividing section 170 includes two resistors R9 and R10 in parallel with the threshold generation resistive voltage dividing section 161. One end of the resistor R9 is connected to a reference voltage, and the other end is connected to the resistor R10. The other end of the resistor R10 is connected to the switch 180. The switch 180 is controlled to be turned on and off by the control section 110.

[0140] The voltage division value of the inspection voltage dividing unit 170, i.e., the voltage between resistors R9 and R10, is the inspection voltage and is input to the control unit 110. The voltage division ratio between resistors R9 and R10 is the same as the voltage division ratio between resistors R7 and R8 provided in the threshold generation resistor voltage dividing unit 161. For example, if the voltage division ratio between resistors R7 and R8 is 1:1, the voltage division ratio between resistors R9 and R10 is also 1:1. The voltage division value of the threshold generation resistor voltage dividing unit 161, i.e., the voltage between resistors R7 and R8, is also input to the control unit 110.

[0141] The control unit 110 inspects the relative accuracy of the resistance of the threshold generation resistive voltage dividing unit 161. The process by which the control unit 110 inspects the relative accuracy of the resistance of the threshold generation resistive voltage dividing unit 161 is shown in FIG. 18. In FIG. 18, in S1, the switch 180 is turned on. In S2, the divided voltage value of the threshold generation resistive voltage dividing unit 161 is AD converted. In S3, the divided voltage value of the inspection voltage dividing unit 170 is AD converted.

[0142] In S4, it is determined whether the difference between the voltage division value of the threshold generation resistive voltage division section 161 and the voltage division value of the inspection voltage division section 170 is within the standard range based on the values ​​AD converted in S2 and S3. The standard range is set in advance. If the determination result in S4 is YES, that is, the difference is within the standard range, the process proceeds to S5. In S5, the inspection result is PASS. If the determination result in S4 is NO, that is, the difference is not within the standard range, the process proceeds to S6. In S6, the inspection result is NG (fail). After S5 or S6 is executed, the process proceeds to S7. In S7, the switch 180 is turned off.

[0143] In this way, the sixth embodiment is provided with an inspection voltage divider unit 170, and by comparing the voltage division value of the threshold generation resistance voltage divider unit 161 with the voltage division value of the inspection voltage divider unit 170, the relative accuracy of the threshold generation resistance voltage divider unit 161 can be inspected before driving, etc.

[0144] Seventh Embodiment The seventh embodiment inspects the ratio accuracy of the threshold generation resistive voltage divider unit 161 using a configuration different from that of the sixth embodiment. As shown in Fig. 19, the seventh embodiment includes a digital-to-analog converter (hereinafter, referred to as DAC) 270 and a switch 180 for inspection. The switch 180 is controlled to be turned on and off by the control unit 110, as in the sixth embodiment.

[0145] The control unit 110 inputs a digital signal for generating a test voltage to the DAC 270. When this digital signal is input to the DAC 270, the DAC 270 generates a voltage corresponding to the input digital signal. The voltage generated by the DAC 270 is the test voltage, and the test voltage is input to the negative input terminal of the voltage evaluation unit 162 via the switch 180. The switch 180 is provided to prevent current from flowing from the power supply line resistance voltage dividing unit 160 to the DAC 270 when testing is not being performed. In addition, a signal line 280 is provided to monitor the voltage generated by the DAC 270. One end of the signal line 280 is connected between the switch 180 and the negative input terminal of the voltage evaluation unit 162, and the other end is connected to the control unit 110.

[0146] FIG. 20 shows an example of a specific configuration of the DAC 270. The DAC 270 shown in FIG. 20 includes a resistor 271, a capacitor 272, and a buffer 273. The resistor 271 and the capacitor 272 form a CR filter. The control unit 110 generates a PWM signal and inputs it to the DAC 270. When the PWM signal passes through the CR filter, a voltage proportional to the duty ratio of the PWM signal is output. The voltage is then stabilized by the buffer 273. The voltage stabilized by the buffer 273 is input to the negative input terminal of the voltage determination unit 162.

[0147] Fig. 21 shows the process by which the control unit 110 inspects the ratio accuracy in the seventh embodiment. In the explanation of Fig. 21, the voltage division ratio of the threshold generation resistance voltage dividing unit 161 is assumed to be 1:1. Fig. 22 shows the time changes in the voltage at the - input terminal and the + input terminal of the voltage determining unit 162 and the output signal of the voltage determining unit 162 when Fig. 21 is executed.

[0148] In S11, switch 180 is turned on. In S12, the output of voltage evaluation unit 162 is stored. At this time, it is assumed that switch 180 is turned on at time t1 in FIG. 22. At this time, in FIG. 22, 4V is input to the negative input terminal of voltage evaluation unit 162 as the divided voltage value from power supply line resistance voltage divider unit 160. Also, 2.5V is input to the positive input terminal of voltage evaluation unit 162. 2.5V is the voltage value when the voltage division ratio of threshold generation resistance voltage divider unit 161 is normal. When the above voltages are input to the negative input terminal and the positive input terminal of voltage evaluation unit 162, the output signal of voltage evaluation unit 162 becomes Lo.

[0149] In S13, 2.6V is output from DAC 270. 2.6V means a voltage slightly higher than the voltage value when the voltage division ratio of threshold generation resistive voltage divider 161 is normal. In S14, the output of voltage determination unit 162 is stored. If the voltage division ratio of threshold generation resistive voltage divider 161 is normal, the output signal of voltage determination unit 162 remains Lo even if 2.6V is output from DAC 270.

[0150] In S15, 2.4V is output from DAC 270. In Fig. 22, the voltage input to the - input terminal of voltage evaluation unit 162 at time t2 is 2.4V. In S16, the output of voltage evaluation unit 162 is stored. When the voltage input to the - input terminal of voltage evaluation unit 162 is 2.4V and 2.5V is input from threshold value generation resistive voltage divider unit 161 to the + input terminal of voltage evaluation unit 162, the output signal of voltage evaluation unit 162 is inverted to Hi.

[0151] In S17, based on the contents stored in S12 and the contents stored in S14, it is determined whether the output of voltage determination unit 162 after 2.6V is output from DAC 270 in S13 is inverted from the output of voltage determination unit 162 before 2.6V was output from DAC 270. If the determination result in S17 is NO, that is, if the output of voltage determination unit 162 is inverted by outputting 2.6V from DAC 270, the process proceeds to S18. If the process proceeds to S18, the resistance ratio exceeds 2%, and the test result is NG (fail).

[0152] If the determination result in S17 is YES, i.e., the output of voltage determination unit 162 is not inverted even when 2.6V is output from DAC 270, the process proceeds to S19. In S19, based on the contents stored in S12 and the contents stored in S16, it is determined whether the output of voltage determination unit 162 after 2.4V is output from DAC 270 in S15 is inverted from the output of voltage determination unit 162 before 2.4V was output from DAC 270. If the determination result in S19 is NO, i.e., the output of voltage determination unit 162 is not inverted even when 2.4V is output from DAC 270, the process proceeds to S18, and the test result is determined to be NG (fail).

[0153] On the other hand, if the determination result in S19 is YES, the process proceeds to S20. In S20, the resistance ratio is within 2%, so the test result is PASS. After S18 or S20 is executed, the process proceeds to S21. In S21, the switch 180 is turned off. As a result, the voltage input to the negative input terminal of the voltage determination unit 162 returns to 4 V, as shown at time t3 in FIG. 22.

[0154] As described above, the seventh embodiment is provided with the DAC 270, and the voltage output by the DAC 270 is compared with the voltage division value of the threshold generation resistor voltage division unit 161 by the voltage determination unit 162. This makes it possible to test the relative accuracy of the threshold generation resistor voltage division unit 161 before driving, etc. Furthermore, in the seventh embodiment, the voltage determination unit 162 is used in the test. Therefore, it is possible to test the relative accuracy including the offset voltage of the voltage determination unit 162. If the test result is PASS, it can be determined that the threshold generation resistor voltage division unit 161 and the voltage determination unit 162 are operating normally.

[0155] In the seventh embodiment, the output from the DAC 270 may also flow to the power supply line resistance voltage divider unit 160. Because resistors R5 and R6 of the power supply line resistance voltage divider unit 160 have high impedance, the current flowing from the DAC 270 to the power supply line resistance voltage divider unit 160 should not significantly affect the voltage that the DAC 270 inputs to the negative input terminal of the voltage evaluation unit 162. However, there is a possibility that the voltage that the DAC 270 inputs to the negative input terminal of the voltage evaluation unit 162 is an unintended voltage. Therefore, in the seventh embodiment, the control unit 110 monitors via the signal line 280 whether the voltage that the DAC 270 inputs to the negative input terminal of the voltage evaluation unit 162 is the intended voltage corresponding to the digital signal. This allows the test to be stopped if the voltage that the DAC 270 inputs to the negative input terminal of the voltage evaluation unit 162 is an unintended voltage.

[0156] Eighth Embodiment The eighth embodiment is also an embodiment for testing the relative accuracy of the threshold generation resistive voltage divider 161. The eighth embodiment is similar to the seventh embodiment. As shown in FIG. 23, the eighth embodiment differs from the seventh embodiment in that it does not include the switch 180. Furthermore, in the eighth embodiment, a buffer that becomes high impedance during normal times when no testing is being performed is used as the buffer 273. This makes it possible to eliminate the need for the switch 180.

[0157] Ninth Embodiment The ninth embodiment is also an embodiment for inspecting the relative accuracy of the threshold generation resistive voltage divider unit 161. As shown in FIG. 24, the ninth embodiment includes an inspection voltage divider unit 370 and four switches SW1, SW2, SW3, and SW4 for inspection. The inspection voltage divider unit 370 includes three resistors R11, R12, and R13. The three resistors R11, R12, and R13 are connected in series. The inspection voltage divider unit 370 generates an inspection voltage through resistive voltage division. One end of the resistor R11 is connected to a reference voltage and the other end is connected to a resistor R12. The other end of the resistor R12 is connected to one end of the resistor R13. The other end of the resistor R13 is connected to one end of a switch SW4. The other end of the switch SW4 is connected to the ECU ground. This switch SW4 is a switch for reducing dark current.

[0158] One end of switch SW1 is connected between resistors R5 and R6, and the other end is connected to the negative input terminal of voltage evaluation unit 162. One end of switch SW2 is connected between resistors R11 and R12, and the other end is connected to the positive input terminal of voltage evaluation unit 162. One end of switch SW3 is connected between resistors R12 and R13, and the other end is connected to the positive input terminal of voltage evaluation unit 162. The on / off of switches SW1, SW2, SW3, and SW4 are all controlled by control unit 110.

[0159] When switch SW2 is on and switch SW3 is off, the voltage between resistors R11 and R12 is input to the negative input terminal of voltage determination unit 162. When switch SW2 is off and switch SW3 is on, the voltage between resistors R12 and R13 is input to the negative input terminal of voltage determination unit 162.

[0160] When the voltage division ratio of resistors R7 and R8 of the threshold generation resistive voltage divider 161 is 1:1, the voltage division ratio of resistors R11, R12, and R13 is set to 1:0.083:1. By setting this voltage division ratio, 2.4V and 2.6V can be input to the negative input terminal of the voltage determination unit 162.

[0161] Fig. 25 shows the process in which the control unit 110 inspects the ratio accuracy of the threshold generation resistive voltage divider unit 161 in the ninth embodiment. Fig. 26 shows the time changes in the voltage at the - input terminal, the voltage at the + input terminal, and the output signal of the voltage determination unit 162 when Fig. 25 is executed.

[0162] 25, in S31, switch SW1 is turned off and switch SW4 is turned on. In S32, switch SW2 is turned on and switch SW3 is turned off. As a result, as shown at time t1 in FIG. 26, the voltage at the negative input terminal of voltage evaluation unit 162 drops from 4 V to 2.6 V. In S33, the output of voltage evaluation unit 162 is stored. Even if 2.6 V is input to the negative input terminal of voltage evaluation unit 162, this is higher than the 2.5 V input to the positive input terminal of voltage evaluation unit 162. Therefore, the output signal of voltage evaluation unit 162 remains Lo.

[0163] In S34, switch SW2 is turned off and switch SW3 is turned on. As a result, the voltage at the negative input terminal of voltage evaluation unit 162 drops to 2.4 V, as shown at time t2 in Fig. 26. In S35, the output of voltage evaluation unit 162 is stored. In Fig. 26, since the voltage at the negative input terminal of voltage evaluation unit 162 drops to 2.4 V at time t2, the output signal of voltage evaluation unit 162 becomes Hi.

[0164] In S36, it is determined whether the output signal of the voltage determination unit 162 has been inverted by turning on the switch SW2 and turning off the switch SW3. If the output signal of the voltage determination unit 162 has been inverted by turning on the switch SW2 and turning off the switch SW3, the determination result in S36 is NO. If the determination result in S36 is NO, the process proceeds to S37. In S37, the test result is determined to be NG.

[0165] If the output signal of the voltage evaluation unit 162 is not inverted even when switch SW2 is turned on and switch SW3 is turned off, the determination result in S36 becomes YES, and the process proceeds to S38. In S38, it is determined whether the output signal of the voltage evaluation unit 162 is inverted by turning switch SW2 off and switch SW3 on. If the determination result in S38 is NO, the process proceeds to S37, where the test result is determined to be NG. On the other hand, if the determination result in S38 is YES, the process proceeds to S39, where the test result is determined to be PASS. After S37 or S39 is executed, the process proceeds to S40. In S40, switch SW1 is turned on, and switches SW2, SW3, and SW4 are turned off. As a result, as shown at time t3 in FIG. 26, the voltage at the negative input terminal of the voltage evaluation unit 162 returns to 4 V, the voltage before the test.

[0166] Even in the ninth embodiment, the relative accuracy of the threshold generation resistive voltage dividing unit 161 can be inspected before driving, etc. Furthermore, in the ninth embodiment, the voltage determination unit 162 is used in the inspection of the relative accuracy. Therefore, the relative accuracy can be inspected including the offset voltage of the voltage determination unit 162. Furthermore, compared to the case where the DAC 270 is used as in the seventh embodiment, the inspection voltage dividing unit 370 generates a voltage to be input to the negative input terminal of the voltage determination unit 162 by resistive voltage division. Therefore, there is a possibility that costs can be reduced compared to the case where the DAC 270 is used.

[0167] Tenth Embodiment In the tenth embodiment, the relative accuracy of the power supply line resistance voltage divider section 160 is inspected. This is because, in order for the low voltage detection section LVD to accurately detect low voltages, not only the relative accuracy of the threshold generation resistance voltage divider section 161 but also the relative accuracy of the power supply line resistance voltage divider section 160 is important. If the relative accuracy of the power supply line resistance voltage divider section 160 deteriorates, low voltages cannot be detected accurately, and as a result, the main line interruption circuit 70 cannot operate correctly. Therefore, the relative accuracy of the power supply line resistance voltage divider section 160 is inspected before the vehicle is driven, for example.

[0168] The tenth embodiment differs from the sixth embodiment in that the test object is the power supply line resistance voltage dividing unit 160, but the configuration for testing is the same as that of the sixth embodiment. As shown in Fig. 27, the tenth embodiment includes a test voltage dividing unit 470 and two switches SW5 and SW6 for testing.

[0169] The inspection voltage divider 470 includes two resistors R14 and R15 connected in parallel with the power supply line resistance voltage divider 160. The inspection voltage divider 470 generates an inspection voltage by resistive voltage division. One end of the resistor R14 is connected to the upstream side of the resistor R5 in the load wiring 50, and the other end is connected to one end of the resistor R15. The other end of the resistor R15 is connected to one end of a switch SW5. The other end of the switch SW5 is connected to the ECU ground. One end of the switch SW6 is connected between the resistors R14 and R15, and the other end is connected to the control unit 110. The switch SW5 is provided to cut off current and reduce dark current. The switch SW6 is provided to prevent the voltage of the load wiring 50 from being supplied to the control unit 110 when SW5 is off. The switches SW5 and SW6 are controlled to be turned on and off by the control unit 110.

[0170] When switches SW5 and SW6 are on, the voltage division value of inspection voltage divider 470, i.e., the voltage between resistors R14 and R15, is input to control unit 110. The voltage division ratio between resistors R14 and R15 is set to be the same as the voltage division ratio between resistors R5 and R6 included in power line resistance voltage divider 160. For example, if the voltage division ratio between resistors R5 and R6 is 3:1, then the voltage division ratio between resistors R14 and R15 is also set to 3:1. The voltage division value of power line resistance voltage divider 160, i.e., the voltage between resistors R5 and R6, is also input to control unit 110.

[0171] The process by which the control unit 110 inspects the relative accuracy of the resistances of the power supply line resistance voltage dividing unit 160 is shown in Fig. 28. In Fig. 28, in S51, switches SW5 and SW6 are turned on. In S52, the divided voltage value of the power supply line resistance voltage dividing unit 160 is AD converted. In S53, the divided voltage value of the inspection voltage dividing unit 470 is AD converted.

[0172] In S54, it is determined whether the difference between the voltage division value of the power supply line resistance voltage division section 160 and the voltage division value of the inspection voltage division section 470 is within the standard range based on the values ​​AD converted in S52 and S53. The standard range is set in advance. If the determination result in S54 is YES, that is, the difference is within the standard range, the process proceeds to S55. In S5, the inspection result is PASS. If the determination result in S54 is NO, that is, the difference is not within the standard range, the process proceeds to S56. In S56, the inspection result is NG. After S55 or S56 is executed, the process proceeds to S57. In S57, the switches SW5 and SW6 are turned off.

[0173] In this way, the tenth embodiment is provided with an inspection voltage divider unit 470, and by comparing the voltage division value of the power supply line resistance voltage divider unit 160 with the voltage division value of the inspection voltage divider unit 470, the relative accuracy of the power supply line resistance voltage divider unit 160 can be inspected before driving, etc.

[0174] Eleventh Embodiment The eleventh embodiment is also an embodiment for inspecting the relative accuracy of the power supply line resistance voltage divider section 160. The eleventh embodiment differs from the seventh embodiment in that the inspection target is the power supply line resistance voltage divider section 160, but the configuration for inspection is the same as that of the seventh embodiment. As shown in Fig. 29, the eleventh embodiment includes a DAC 270 and a switch 180 for inspection, similar to the seventh embodiment.

[0175] As in the seventh embodiment, a digital signal for generating a test voltage is input to the DAC 270 from the control unit 110. A specific configuration of the DAC 270 may be the configuration shown in Fig. 20. In the eleventh embodiment, the test voltage generated by the DAC 270 is input to the + input terminal of the voltage determination unit 162 via the switch 180.

[0176] The method by which the control unit 110 inspects the relative accuracy of the power supply line resistance voltage divider unit 160 in the eleventh embodiment is the same as in the seventh embodiment, and is outlined as follows: The switch 180 is turned on, and a voltage slightly higher than the voltage normally input to the negative input terminal of the voltage evaluation unit 162 is input from the DAC 270, and it is confirmed whether the output signal of the voltage evaluation unit 162 is inverted. If the output signal of the voltage evaluation unit 162 is inverted, the inspection result is NG. Thereafter, a voltage slightly lower than the voltage normally input to the negative input terminal of the voltage evaluation unit 162 is input from the DAC 270, and it is confirmed whether the output signal of the voltage evaluation unit 162 is inverted. If the output signal of the voltage evaluation unit 162 is not inverted, the inspection result is NG. Thereafter, the switch 180 is turned off, and the inspection ends.

[0177] In this way, it is possible to inspect the relative accuracy of the power supply line resistance voltage dividing unit 160 before driving, etc. Furthermore, since the voltage determination unit 162 is used in the inspection, it is possible to inspect the relative accuracy of the power supply line resistance voltage dividing unit 160, including the offset voltage of the voltage determination unit 162.

[0178] <Twelfth embodiment> The twelfth embodiment is also an embodiment for inspecting the relative accuracy of the power supply line resistance voltage divider section 160. The twelfth embodiment is similar to the above-described eleventh and eighth embodiments. The twelfth embodiment is an embodiment in which the eighth embodiment is applied to inspecting the relative accuracy of the power supply line resistance voltage divider section 160. As shown in FIG. 30, the twelfth embodiment differs from the eleventh embodiment in that it does not include the switch 180. Furthermore, in the twelfth embodiment, a buffer that becomes high impedance during normal times when no inspection is being performed is used as the buffer 273. This makes it possible to eliminate the need for the switch 180.

[0179] <Thirteenth embodiment> The thirteenth embodiment is also an embodiment for inspecting the relative accuracy of the power supply line resistance voltage divider section 160. The thirteenth embodiment differs from the ninth embodiment in that the inspection target is the power supply line resistance voltage divider section 160, but the configuration for inspection is the same as that of the ninth embodiment.

[0180] As shown in FIG. 31 , the thirteenth embodiment includes an inspection voltage dividing unit 570 and four switches SW1, SW2, SW3, and SW4. The inspection voltage dividing unit 570 includes three resistors R16, R17, and R18. The three resistors R16, R17, and R18 are connected in series. The inspection voltage dividing unit 570 generates an inspection voltage by resistive voltage division. One end of the resistor R16 is connected to the load wiring 50 upstream of R5, and the other end is connected to the resistor R17. The other end of the resistor R17 is connected to one end of the resistor R18. The other end of the resistor R18 is connected to one end of the switch SW4. The other end of the switch SW4 is connected to the ECU ground. The switch SW4 is a switch for reducing dark current.

[0181] In the thirteenth embodiment, one end of the switch SW1 is connected between the resistors R7 and R8, and the other end is connected to the negative input terminal of the voltage evaluation unit 162. One end of the switch SW2 is connected between the resistors R16 and R17, and the other end is connected to the negative input terminal of the voltage evaluation unit 162. One end of the switch SW3 is connected between the resistors R17 and R18, and the other end is connected to the negative input terminal of the voltage evaluation unit 162.

[0182] When switch SW2 is on and switch SW3 is off, the voltage between resistors R16 and R17 is input to the + input terminal of voltage determination unit 162. When switch SW2 is off and switch SW3 is on, the voltage between resistors R17 and R18 is input to the + input terminal of voltage determination unit 162.

[0183] When the voltage division ratio of resistors R5 and R6 in power supply line resistance voltage divider 160 is 3:1, the voltage division ratio of resistors R16, R17, and R18 is set to 3.07:0.007:1. This voltage division ratio allows 4.1V and 3.9V to be input to the + input terminal of voltage determination unit 162. When the ratio accuracy of power supply line resistance voltage divider 160 is normal, the voltage division value of power supply line resistance voltage divider 160 is assumed to be 4.0V. 4.1V means a voltage slightly higher than the normal divided voltage value, and 3.9V means a voltage slightly lower than the normal divided voltage value.

[0184] Fig. 32 shows the process in which the control unit 110 inspects the ratio accuracy of the power supply line resistance voltage divider unit 160 in the thirteenth embodiment. Fig. 33 shows the time changes in the voltage at the - input terminal of the voltage determination unit 162, the voltage at the + input terminal, and the output signal of the voltage determination unit 162 when Fig. 32 is executed.

[0185] 32, in S61, switch SW1 is turned off and switch SW4 is turned on. In S62, switch SW2 is turned off and switch SW3 is turned on. As a result, as shown at time t1 in FIG. 33, the voltage at the + input terminal of voltage evaluation unit 162 rises from 2.5 V to 3.9 V. In S63, the output of voltage evaluation unit 162 is stored. Even though 3.9 V is input to the + input terminal of voltage evaluation unit 162, this is lower than the 4.0 V input to the - input terminal of voltage evaluation unit 162. Therefore, the output signal of voltage evaluation unit 162 remains Lo.

[0186] In S64, switch SW2 is turned on and switch SW3 is turned off. As a result, as shown at time t2 in Fig. 33, the voltage at the + input terminal of voltage evaluation unit 162 rises to 4.1 V. In S65, the output of voltage evaluation unit 162 is stored. In Fig. 33, since the voltage at the + input terminal of voltage evaluation unit 162 has risen to 4.1 V at time t2, the output signal of voltage evaluation unit 162 is Hi.

[0187] In S66, it is determined whether the output signal of the voltage determination unit 162 has been inverted by turning off the switch SW2 and turning on the switch SW3. If the output signal of the voltage determination unit 162 has been inverted by turning off the switch SW2 and turning on the switch SW3, the determination result in S66 is NO. If the determination result in S66 is NO, the process proceeds to S67. In S67, the test result is determined to be NG.

[0188] If the output signal of the voltage evaluation unit 162 is not inverted even when switch SW2 is turned off and switch SW3 is turned on, the determination result in S66 becomes YES, and the process proceeds to S68. In S68, it is determined whether the output signal of the voltage evaluation unit 162 is inverted by turning on switch SW2 and turning off switch SW3. If the determination result in S68 is NO, the process proceeds to S67, where the test result is determined to be NG. On the other hand, if the determination result in S68 is YES, the process proceeds to S69, where the test result is determined to be PASS. After S67 or S69 is executed, the process proceeds to S70. In S70, switch SW1 is turned on, and switches SW2, SW3, and SW4 are turned off. As a result, as shown at time t3 in FIG. 33, the voltage at the + input terminal of the voltage evaluation unit 162 returns to 2.5 V, the voltage before the test.

[0189] Even in the thirteenth embodiment, the relative accuracy of the power supply line resistance voltage dividing unit 160 can be inspected before driving, etc. Furthermore, in the thirteenth embodiment, the voltage determination unit 162 is used in the inspection of the relative accuracy. Therefore, the relative accuracy can be inspected including the offset voltage of the voltage determination unit 162. Furthermore, compared to the case where the DAC 270 is used, the inspection voltage dividing unit 570 generates a voltage to be input to the negative input terminal of the voltage determination unit 162 by resistive voltage division. Therefore, there is a possibility that costs can be reduced compared to the case where the DAC 270 is used.

[0190] <Fourteenth embodiment> The sixth to thirteenth embodiments have been described as embodiments for determining whether an abnormality has occurred in the low-voltage detection unit LVD. The determination methods in the sixth to thirteenth embodiments can also be applied to the overvoltage detection unit OVD. Below, an overview of the application of the determination methods in the sixth to thirteenth embodiments to the overvoltage detection unit OVD will be described.

[0191] When the sixth embodiment is applied to the overvoltage detection circuit OVD, an inspection voltage divider 170 and a switch 180 are provided in parallel with the threshold generation resistance voltage divider 151. When the seventh embodiment is applied to the overvoltage detection circuit OVD, the inspection voltage generated by the DAC 270 is input to the + input terminal of the voltage judgment circuit 152. When the eighth embodiment is applied to the overvoltage detection circuit OVD, the inspection voltage generated by the DAC 270 is also input to the + input terminal of the voltage judgment circuit 152. When the ninth embodiment is applied to the overvoltage detection circuit OVD, the inspection voltage generated by the inspection voltage divider 370 is input to the + input terminal of the voltage judgment circuit 152. When the tenth embodiment is applied to the overvoltage detection circuit OVD, an inspection voltage divider 470 and a switch SW5 are provided in parallel with the power supply line resistance voltage divider 150. When the eleventh embodiment is applied to the overvoltage detection unit OVD, the test voltage generated by the DAC 270 is input to the + input terminal of the voltage evaluation unit 152 via the switch 180. When the twelfth embodiment is applied to the overvoltage detection unit OVD, the test voltage generated by the DAC 270 is input to the + input terminal of the voltage evaluation unit 152. When the thirteenth embodiment is applied to the overvoltage detection unit OVD, the test voltage generated by the test voltage divider unit 570 is input to the + input terminal of the voltage evaluation unit 152. In an embodiment in which the ratio accuracy including the offset voltage of the voltage evaluation unit 152 is tested, if the test result is PASS, it can be determined that the power supply line resistance voltage divider unit 150 and the voltage evaluation unit 152 are operating normally.

[0192] <Fifteenth embodiment> The fifteenth embodiment is an embodiment for checking the responsiveness of the main line interruption circuit 70. When the voltage detection unit 90 detects a voltage abnormality, the main line interruption circuit 70 needs to be able to quickly disconnect the power between the first section 41 and the second section 42. Therefore, the responsiveness of the main line interruption circuit 70 is checked.

[0193] FIG. 34 shows the configuration of the fifteenth embodiment. In the fifteenth embodiment, a transistor Tr1, a resistor R19, and a power supply main line 43 are provided to check the responsiveness of the main line interruption circuit 70. The transistor Tr1 is an inspection transistor that activates the voltage detection unit 90, thereby causing the OR circuit 95 to output an interruption signal. The transistor Tr1 is an N-channel MOSFET, and its drain is connected between resistors R5 and R6 of the power supply line resistance voltage divider unit 160, its source is connected to the ECU ground, and its gate is connected to the control unit 110. When the transistor Tr1 is turned on, a 0V signal is input to the negative input terminal of the voltage evaluation unit 162. This 0V signal is an inspection signal. When the 0V signal is input to the negative input terminal of the voltage evaluation unit 162, the OR circuit 95 outputs an interruption signal to the high-speed interrupter 100. In FIG. 34, the transistor Tr1 is configured to activate the first low-voltage detection unit 91b, but it may also be configured to activate the second low-voltage detection unit 92b.

[0194] One end of resistor R19 is connected to intermediate connection line portion 74, and the other end is connected to the ECU ground. Power supply trunk line 43 connects intermediate connection line portion 74 and control unit 110 so that control unit 110 can detect the voltage of intermediate connection line portion 74.

[0195] 35 shows the processing executed by the control unit 110 in the fifteenth embodiment. Before this processing is executed, the system is in a normal state, with the main power supply 211 and auxiliary power supply 212 on, and the first power supply cutting circuit 60a, second power supply cutting circuit 60b, and main line cutting circuit 70 on, i.e., in a conductive state.

[0196] In S81, transistor Tr1 is turned on. As a result, a 0V signal, which is an inspection signal, is input to the negative input terminal of voltage determination unit 162. In S82, the voltage of intermediate connection line 74 is monitored by monitoring the voltage of power supply main line 43. By turning on Tr1 in S81, a cutoff signal is output from OR circuit 95 to high-speed cutoff unit 100, which turns off FETs 72a and 72b. Due to the presence of resistor R19, when FETs 72a and 72b are turned off, the voltage of intermediate connection line 74 decreases.

[0197] In S83, it is determined whether the voltage of the intermediate connection line portion 74 has become equal to or lower than a specified voltage. If the determination result in S83 is NO, the process returns to S82 and continues to monitor the voltage of the intermediate connection line portion 74. If the determination result in S83 is YES, the process proceeds to S84.

[0198] In S84, it is determined whether the time from when transistor Tr1 was turned on in S81 until the voltage of intermediate connection line portion 74 fell below a specified value is within a specified time. If the determination result in S84 is YES, the process proceeds to S85, where a pass / fail decision is made. On the other hand, if the determination result in S84 is NO, the process proceeds to S86, where a fail / fail decision is made.

[0199] In this way, the interruption response of the main line interruption circuit 70 can be confirmed, and the power distribution ECU can self-diagnose the interruption response of the main line interruption circuit 70 before driving, for example.

[0200] <16th embodiment> The sixteenth embodiment is also an embodiment for checking the responsiveness of the trunk line interruption circuit 70. The sixteenth embodiment is a modification of the fifteenth embodiment. FIG. 36 shows the configuration of the sixteenth embodiment. The sixteenth embodiment does not include a high-speed interruption unit 100. Therefore, the interruption signal from the OR circuit 95 is input to the control unit 110. When the interruption signal is input, the control unit 110 outputs a signal to the drive units 121 and 122 to turn off the FETs 72a and 72b. With this configuration, it may take longer for the voltage of the intermediate connection line unit 74 to fall below a specified value after the transistor Tr1 is turned on than with a configuration including the high-speed interruption unit 100. However, the process for checking the responsiveness of the trunk line interruption circuit 70 is the same as in the fifteenth embodiment.

[0201] Seventeenth Embodiment The seventeenth embodiment is an embodiment for detecting a stuck state of the interrupter circuits 60, 70, and 80. The configuration of the seventeenth embodiment is shown in Fig. 37. Note that configuration not related to detecting a stuck state of the interrupter circuits 60, 70, and 80 is omitted from Fig. 37.

[0202] The power distribution ECU 800 shown in FIG. 37 includes a voltage detection unit 810, a current detection unit 820, an internal power supply 830, and capacitors 831 and 832.

[0203] The voltage detection unit 810 detects, as voltages on the main power supply 211 side, the voltage between the first power supply terminal 11 and the first power supply interruption circuit 60a, the voltage of the first load line section 51 upstream of the load interruption circuit 80, and the voltage between the load interruption circuit 80 and the first load terminal 21. The voltage detection unit 810 also detects, as voltages on the auxiliary power supply 212 side, the voltage between the second power supply terminal 12 and the second power supply interruption circuit 60b, the voltage of the second load line section 52 upstream of the load interruption circuit 80, and the voltage between the load interruption circuit 80 and the second load terminal 22.

[0204] In the seventeenth embodiment and other embodiments, the voltage detection unit 810 may detect, instead of the voltage of the first load line unit 51 upstream of the load shedding circuit 80, the voltage of the first power supply line unit 31 or the first section 41 in a section having the same potential as the voltage of the first load line unit 51 upstream of the load shedding circuit 80. Furthermore, instead of the voltage of the second load line unit 52 upstream of the load shedding circuit 80, the voltage detection unit 810 may detect, instead of the voltage of the second load line unit 52 upstream of the load shedding circuit 80, the voltage of the second power supply line unit 32 or the second section 42 in a section having the same potential as the voltage of the second load line unit 52 upstream of the load shedding circuit 80. The control unit 110 acquires a value indicating the voltage detected by the voltage detection unit 810.

[0205] The current detection unit 820 detects, as currents on the main power supply 211 side, the current between the first power supply terminal 11 and the first power supply interruption circuit 60a, and the current between the load interruption circuit 80 and the first load terminal 21. The current detection unit 820 detects, as currents on the auxiliary power supply 212 side, the current between the second power supply terminal 12 and the second power supply interruption circuit 60b, and the current between the load interruption circuit 80 and the second load terminal 22. The control unit 110 acquires values ​​indicating the currents detected by the current detection unit 820.

[0206] Internal power supply 830 is provided inside power distribution ECU 800 and supplies power to load 220. In FIG. 37 , internal power supply 830 is connected to first load line section 51 via capacitor 831, and also connected to second load line section 52 via capacitor 831. However, as will be described later, internal power supply 830 can also be connected to first power supply line section 31 or second power supply line section 32. Internal power supply 830 has a lower voltage than main power supply 211 and auxiliary power supply 212. Capacitors 831 and 832 are provided to prevent current from flowing to internal power supply 830 during normal operation when interrupter circuits 60, 70, and 80 are not being inspected. Therefore, the anodes of both capacitors 831 and 832 are connected to internal power supply 830.

[0207] Control unit 110 detects stuck interrupter circuits 60, 70, 80, a ground fault on the main power supply 211 side or the auxiliary power supply 212 side, a short to power, and an open circuit in load 221 by setting the on / off states of interrupter circuits 60, 70, 80 and the on / off states of main power supply 211 and auxiliary power supply 212 to various setting patterns that are set for abnormality detection. Setting to a setting pattern means that control unit 110 issues instructions to the setting target according to the setting pattern. Figure 38 lists the setting patterns, the abnormalities that each setting pattern detects, and how to confirm the abnormality.

[0208] [Setting pattern 1] Setting pattern 1 is a setting for determining whether the first power supply interruption circuit 60a is stuck on. Fig. 39 shows the setting of setting pattern 1. Fig. 40 shows the state in which each setting target is set in setting pattern 1 and the position at which the voltage is detected. Note that configurations unrelated to setting pattern 1 are omitted in Fig. 40. The same applies to subsequent similar figures.

[0209] In setting pattern 1, the main power supply 211 is turned off and the auxiliary power supply 212 is turned on. The first power supply interruption circuit 60a is turned off and the second power supply interruption circuit 60b is turned on. The first load interruption circuit 80a and the second load interruption circuit 80b may be on or off. The main line interruption circuit 70 is turned on. With these settings, the voltage detection unit 810 detects the voltage between the first power supply terminal 11 and the first power supply interruption circuit 60a.

[0210] Because the main power supply 211 and the first power supply interruption circuit 60a are both off, the voltage detection unit 810 normally detects 0 V. However, if the first power supply interruption circuit 60a is stuck on, the voltage of the auxiliary power supply 212 is also applied between the second power supply interruption circuit 60b and the second power supply terminal 12 via the second power supply line unit 32, the power supply main line 40, and the first power supply line unit 31, causing the voltage detection unit 810 to detect 12 V. Therefore, by setting setting pattern 1 and detecting the voltage between the first power supply terminal 11 and the first power supply interruption circuit 60a, the control unit 110 can determine whether the first power supply interruption circuit 60a is stuck on.

[0211] [Setting pattern 2] Setting pattern 2 is a setting for determining whether the first power supply interruption circuit 60a is stuck off. The setting of setting pattern 2 is shown in Fig. 41. Furthermore, Fig. 42 shows the state in which each setting target is set in setting pattern 2 and the position at which the voltage is detected.

[0212] In setting pattern 2, the main power supply 211 is turned on and the auxiliary power supply 212 is turned off. The first power supply interruption circuit 60a is turned on and the second power supply interruption circuit 60b is turned off. The first load interruption circuit 80a and the second load interruption circuit 80b may be turned on or off. The trunk line interruption circuit 70 is turned on. With these settings, the voltage detection unit 810 detects the voltage between the first power supply terminal 11 and the first power supply interruption circuit 60a and the voltage of the first load line section 51 upstream of the first load interruption circuit 80a. The control unit 110 then determines whether the first power supply interruption circuit 60a is stuck off based on the potential difference between the voltage between the first power supply terminal 11 and the first power supply interruption circuit 60a and the voltage of the first load line section 51 upstream of the first load interruption circuit 80a.

[0213] Under normal circumstances, the main power supply 211 is on and the first power supply interruption circuit 60a is on, so the voltages upstream and downstream of the first power supply interruption circuit 60a are the same. Therefore, the potential difference is 0 V. However, if the first power supply interruption circuit 60a is stuck off, current from the main power supply 211 flows through the body diode 63 of the FET 62 included in the first power supply interruption circuit 60a. Also, because the auxiliary power supply 212 is off, no voltage is supplied from the auxiliary power supply 212 to the first load line section 51. Note that it is sufficient that the voltage from the auxiliary power supply 212 is not supplied to the first load line section 51, so it is sufficient that any one of the auxiliary power supply 212, the second power supply interruption circuit 60b, and the main line interruption circuit 70 is off.

[0214] If the voltage drop across the body diode 63 is 0.7 V, the potential difference when the first power supply interruption circuit 60a is fixed off will be 0.7 V. As described above, by setting setting pattern 2 and calculating the above potential difference, the control unit 110 can determine whether the first power supply interruption circuit 60a is fixed off.

[0215] [Setting pattern 3] Setting pattern 3 is also a setting for determining whether first power supply interruption circuit 60a is stuck off. The setting of setting pattern 3 is shown in Fig. 43. Furthermore, Fig. 44 shows the state in which each setting target is set in setting pattern 3 and the position at which the voltage is detected.

[0216] In setting pattern 3, the main power supply 211 is turned off and the auxiliary power supply 212 is turned on. The first power supply interruption circuit 60a is turned on and the second power supply interruption circuit 60b is also turned on. The first load interruption circuit 80a and the second load interruption circuit 80b may be on or off. The main line interruption circuit 70 is turned on. With these settings, the voltage detection unit 810 detects the voltage between the first power supply terminal 11 and the first power supply interruption circuit 60a.

[0217] The auxiliary power supply 212 is on, and the first power supply interruption circuit 60a, the second power supply interruption circuit 60b, and the main line interruption circuit 70 are all on. Therefore, under normal circumstances, the voltage detection unit 810 detects 12 V. However, if the first power supply interruption circuit 60a is stuck off, the voltage from the auxiliary power supply 212 is not supplied between the first power supply terminal 11 and the first power supply interruption circuit 60a. Furthermore, since the main power supply 211 is off, no voltage is supplied from the main power supply 211 either. Therefore, if the first power supply interruption circuit 60a is stuck off, the voltage detection unit 810 detects 0 V.

[0218] As described above, by setting setting pattern 3 and detecting the voltage between first power supply terminal 11 and first power supply interruption circuit 60a, control unit 110 can determine whether first power supply interruption circuit 60a is stuck off.

[0219] [Setting pattern 4] Setting pattern 4 is a setting for detecting a ground fault in the first power supply interruption circuit 60a. A ground fault in the first power supply interruption circuit 60a means that the wiring connected to the first power supply interruption circuit 60a has a ground fault. A ground fault in the first power supply interruption circuit 60a occurs, for example, when a ground fault occurs in the harness connecting the main power supply 211 and the first power supply terminal 11. FIG. 45 shows the setting of setting pattern 4. FIG. 46 shows the state in which each setting object is set in setting pattern 4 and the position at which the current is detected. Setting pattern 4 is the same as setting pattern 3 for determining whether the first power supply interruption circuit 60a is stuck off. The difference from the case in which the first power supply interruption circuit 60a is stuck off is that the current detection unit 820 detects the current between the first power supply terminal 11 and the first power supply interruption circuit 60a.

[0220] The auxiliary power supply 212 is on, and the first power supply interruption circuit 60a, second power supply interruption circuit 60b, and main line interruption circuit 70 are all on, but the auxiliary power supply 212 is off. Therefore, under normal conditions, no current flows between the first power supply terminal 11 and the first power supply interruption circuit 60a. However, as shown in FIG. 46, if a ground fault occurs in the FET 62 of the first power supply interruption circuit 60a, current flows from the auxiliary power supply 212 through the second power supply line section 32, the power supply main line 40, and the first power supply line section 31 to the ECU ground. Therefore, the current detection unit 820 detects a ground fault current. As described above, by using setting pattern 4 and detecting the current between the first power supply terminal 11 and the first power supply interruption circuit 60a, the control unit 110 can detect a ground fault in the first power supply interruption circuit 60a.

[0221] [Setting pattern 5] Setting pattern 5 is also a setting for detecting a ground fault in first power supply interruption circuit 60a. The setting of setting pattern 5 is shown in Fig. 47. Moreover, Fig. 48 shows the state in which each setting target is set in setting pattern 5, the position where voltage is detected, and the position where voltage is applied from internal power supply 830.

[0222] In setting pattern 5, the main power supply 211 is turned off and the auxiliary power supply 212 is turned on. The first power supply interruption circuit 60a is turned off and the second power supply interruption circuit 60b is turned on. The first load interruption circuit 80a and the second load interruption circuit 80b may be on or off. The main line interruption circuit 70 is turned on. With these settings, the voltage detection unit 810 detects the voltage between the first power supply terminal 11 and the first power supply interruption circuit 60a. Then, a voltage is applied from the internal power supply 830 between the first power supply terminal 11 and the first power supply interruption circuit 60a. The voltage of the internal power supply 830 is lower than the voltage of the main power supply 211. For example, the voltage of the main power supply 211 is 12 V and the voltage of the internal power supply 830 is 10 V.

[0223] Because the main power supply 211 is off and the first power supply interruption circuit 60a is also off, 9.3V, which is the 10V from the internal power supply 830 reduced by the forward voltage of the capacitor 831, is applied between the first power supply terminal 11 and the first power supply interruption circuit 60a. Therefore, under normal circumstances, the voltage detection unit 810 detects 9.3V. However, if a ground fault occurs in the FET 62 of the first power supply interruption circuit 60a, the voltage between the first power supply terminal 11 and the first power supply interruption circuit 60a will be 0V. The reason why the auxiliary power supply 212, second power supply interruption circuit 60b, and main line interruption circuit 70 are turned on is to supply power to the load 221.

[0224] From the above, by setting pattern 5 and applying voltage from the internal power supply 830 between the first power supply terminal 11 and the first power supply interruption circuit 60a, and detecting the voltage between the first power supply terminal 11 and the first power supply interruption circuit 60a, the control unit 110 can detect a ground fault in the first power supply interruption circuit 60a.

[0225] As explained for setting patterns 1 to 5, while giving instructions according to the setting patterns, control unit 110 determines whether or not an abnormality has occurred in first power supply interruption circuit 60a based on the voltage or current of first power line unit 31. In this way, it is possible to self-diagnose whether or not an abnormality has occurred in first power supply interruption circuit 60a.

[0226] [Setting pattern 6] Setting pattern 6 is a setting for detecting a stuck-on state of second power supply interruption circuit 60b. Fig. 49 shows the setting of setting pattern 6. Fig. 50 shows the state in which each setting target is set in setting pattern 6 and the position at which the voltage is detected.

[0227] In setting pattern 6, the main power supply 211 is turned on and the auxiliary power supply 212 is turned off. The first power supply interruption circuit 60a is turned on and the second power supply interruption circuit 60b is turned off. The first load interruption circuit 80a and the second load interruption circuit 80b may be on or off. The main line interruption circuit 70 is turned on. With these settings, the voltage detection unit 810 detects the voltage between the second power supply terminal 12 and the second power supply interruption circuit 60b.

[0228] Because the auxiliary power supply 212 and the second power supply interruption circuit 60b are both off, the voltage detection unit 810 normally detects 0 V. However, if the second power supply interruption circuit 60b is stuck on, the voltage of the main power supply 211 is also applied between the second power supply terminal 12 and the second power supply interruption circuit 60b via the first power supply line unit 31, the power supply trunk line 40, and the second power supply line unit 32, causing the voltage detection unit 810 to detect 12 V. Therefore, by setting setting pattern 6 and detecting the voltage between the second power supply terminal 12 and the second power supply interruption circuit 60b, the control unit 110 can determine whether the second power supply interruption circuit 60b is stuck on.

[0229] [Setting pattern 7] Setting pattern 7 is a setting for determining whether second power supply interruption circuit 60b is stuck off. Fig. 51 shows the setting of setting pattern 7. Fig. 52 shows the state in which each setting target is set in setting pattern 7 and the position at which the voltage is detected.

[0230] In setting pattern 7, the main power supply 211 is turned off and the auxiliary power supply 212 is turned on. The first power supply interruption circuit 60a is turned off and the second power supply interruption circuit 60b is turned on. The first load interruption circuit 80a and the second load interruption circuit 80b may be on or off. The trunk line interruption circuit 70 is turned on. With these settings, the voltage detection unit 810 detects the voltage between the second power supply terminal 12 and the second power supply interruption circuit 60b and the voltage of the second load line section 52 upstream of the second load interruption circuit 80b. The control unit 110 then determines whether the second power supply interruption circuit 60b is stuck off based on the potential difference between the voltage between the second power supply terminal 12 and the second power supply interruption circuit 60b and the voltage of the second load line section 52 upstream of the second load interruption circuit 80b.

[0231] Under normal conditions, the auxiliary power supply 212 is on and the second power supply interruption circuit 60b is on, so the voltages upstream and downstream of the second power supply interruption circuit 60b are the same. Therefore, the potential difference is 0 V. However, if the second power supply interruption circuit 60b is stuck off, current from the auxiliary power supply 212 flows through the body diode 63 of the FET 62 included in the second power supply interruption circuit 60b. Furthermore, since the main power supply 211 is off, no voltage is supplied from the main power supply 211 to the second load line section 52. Note that it is sufficient that the voltage from the main power supply 211 is not supplied to the second load line section 52, so it is sufficient that any one of the main power supply 211, the first power supply interruption circuit 60a, and the main line interruption circuit 70 is off.

[0232] If the voltage drop across the body diode 63 is 0.7 V, the potential difference when the second power supply interruption circuit 60b is fixed off will be 0.7 V. As described above, by setting setting pattern 7 and calculating the above potential difference, the control unit 110 can determine whether the second power supply interruption circuit 60b is fixed off.

[0233] [Setting pattern 8] Setting pattern 8 is also a setting for determining whether second power supply interruption circuit 60b is stuck off. Fig. 53 shows the setting of setting pattern 8. Fig. 54 shows the state in which each setting target is set in setting pattern 8 and the position at which the voltage is detected.

[0234] In setting pattern 8, the main power supply 211 is turned on and the auxiliary power supply 212 is turned off. The first power supply interruption circuit 60a is turned on and the second power supply interruption circuit 60b is also turned on. The first load interruption circuit 80a and the second load interruption circuit 80b may be on or off. The main line interruption circuit 70 is turned on. With these settings, the voltage detection unit 810 detects the voltage between the second power supply terminal 12 and the second power supply interruption circuit 60b.

[0235] The main power supply 211 is on, and the first power supply interruption circuit 60a, the second power supply interruption circuit 60b, and the trunk line interruption circuit 70 are all on. Therefore, under normal circumstances, the voltage detection unit 810 detects 12 V. However, if the second power supply interruption circuit 60b is stuck off, the voltage from the main power supply 211 is not supplied between the second power supply terminal 12 and the second power supply interruption circuit 60b. Furthermore, since the auxiliary power supply 212 is off, no voltage is supplied from the auxiliary power supply 212 either. Therefore, if the second power supply interruption circuit 60b is stuck off, the voltage detection unit 810 detects 0 V.

[0236] As described above, by setting setting pattern 8 and detecting the voltage between second power supply terminal 12 and second power supply interruption circuit 60b, control unit 110 can determine whether second power supply interruption circuit 60b is stuck off.

[0237] [Setting pattern 9] Setting pattern 9 is a setting for detecting a ground fault in the second power supply interruption circuit 60b. The setting of setting pattern 9 is shown in Fig. 55. Also, Fig. 56 shows the state in which each setting target is set in setting pattern 9 and the position at which the current is detected.

[0238] Setting pattern 9 is the same as setting pattern 8 for determining whether second power supply interruption circuit 60b is stuck off. The difference from the case where second power supply interruption circuit 60b is determined to be stuck off is that current detection unit 820 detects the current between second power supply terminal 12 and second power supply interruption circuit 60b.

[0239] The main power supply 211 is on, and the first power supply interruption circuit 60a, the second power supply interruption circuit 60b, and the trunk line interruption circuit 70 are all on, but the auxiliary power supply 212 is off. Therefore, under normal conditions, no current flows between the second power supply terminal 12 and the second power supply interruption circuit 60b. However, as shown in FIG. 56, if a ground fault occurs in the FET 62 of the second power supply interruption circuit 60b, current flows from the main power supply 211 through the first power supply line section 31, the power supply trunk line 40, and the second power supply line section 32 to the ECU ground. Therefore, the current detection unit 820 detects a ground fault current. As described above, by using setting pattern 9 and detecting the current between the second power supply terminal 12 and the second power supply interruption circuit 60b, the control unit 110 can detect a ground fault in the second power supply interruption circuit 60b.

[0240] [Setting pattern 10] Setting pattern 10 is also a setting for detecting a ground fault in second power supply interruption circuit 60b. Fig. 57 shows the setting of setting pattern 10. Fig. 58 shows the state in which each setting target is set in setting pattern 10, the position where voltage is detected, and the position where voltage is applied from internal power supply 830.

[0241] In setting pattern 10, the main power supply 211 is turned on and the auxiliary power supply 212 is turned off. The first power supply interruption circuit 60a is turned on and the second power supply interruption circuit 60b is turned off. The first load interruption circuit 80a and the second load interruption circuit 80b may be on or off. The main line interruption circuit 70 is turned on. With these settings, the voltage detection unit 810 detects the voltage between the second power supply terminal 12 and the second power supply interruption circuit 60b. Then, a voltage is applied from the internal power supply 830 between the second power supply terminal 12 and the second power supply interruption circuit 60b.

[0242] Because auxiliary power supply 212 is off and second power supply interruption circuit 60b is also off, 9.3V, which is the 10V from internal power supply 830 reduced by the forward voltage of capacitor 831, is applied between second power supply terminal 12 and second power supply interruption circuit 60b. Therefore, under normal circumstances, voltage detection unit 810 detects 9.3V. However, if a ground fault occurs in FET 62 of second power supply interruption circuit 60b, the voltage between second power supply terminal 12 and second power supply interruption circuit 60b will be 0V. The reason why main power supply 211, first power supply interruption circuit 60a, and main line interruption circuit 70 are on is to supply power to load 221.

[0243] As described above, by setting pattern 10 and applying a voltage from the internal power supply 830 between the second power supply terminal 12 and the second power supply interruption circuit 60b, and detecting the voltage between the second power supply terminal 12 and the second power supply interruption circuit 60b, the control unit 110 can detect a ground fault in the second power supply interruption circuit 60b.

[0244] [Setting pattern 11] Setting pattern 11 is a setting for detecting a power short on the power supply side. The setting of setting pattern 11 is shown in Figure 59. Also, the state in which each setting target is set in setting pattern 11 and the position where the voltage is detected are shown in Figure 60.

[0245] In setting pattern 11, the main power supply 211 is turned on and the auxiliary power supply 212 is turned off. The first power supply interruption circuit 60a and the second power supply interruption circuit 60b are turned on. The first load interruption circuit 80a and the second load interruption circuit 80b may be on or off. The main line interruption circuit 70 is turned on. With these settings, the voltage detection unit 810 detects the voltage between the second power supply terminal 12 and the second power supply interruption circuit 60b.

[0246] Because auxiliary power supply 212 is off and main line interruption circuit 70 is also off, under normal conditions, the voltage between second power supply terminal 12 and second power supply interruption circuit 60b is 0V. However, if there is a short-to-power problem between the path through which main power supply 211 supplies power to power distribution ECU 800 and the path through which auxiliary power supply 212 supplies power to power distribution ECU 800, the voltage between second power supply terminal 12 and second power supply interruption circuit 60b becomes 12V.

[0247] As described above, by setting setting pattern 11 and detecting the voltage between the second power supply terminal 12 and the second power supply interruption circuit 60b, the control unit 110 can detect a power short on the power supply side. Note that in this setting pattern 11, the second power supply interruption circuit 60b may also be turned off. Furthermore, when the second power supply interruption circuit 60b is turned off, the main line interruption circuit 70 may be turned on. In other words, it is sufficient that at least one of the second power supply interruption circuit 60b and the main line interruption circuit 70 is turned off.

[0248] [Setting pattern 12] Setting pattern 12 is a setting for detecting a stuck-on state of the first load shedding circuit 80a. The setting of setting pattern 12 is shown in Fig. 61. Also, Fig. 62 shows the state in which each setting target is set in setting pattern 12 and the position at which the voltage is detected.

[0249] In setting pattern 12, the main power supply 211 is turned on, and the auxiliary power supply 212 is also turned on. The first power supply interruption circuit 60a and the second power supply interruption circuit 60 are also turned on. The first load interruption circuit 80a is turned off. The second load interruption circuit 80b may be turned on or off. The main line interruption circuit 70 is turned on. Note that the auxiliary power supply 212 and the second power supply interruption circuit 60b may be turned off. Furthermore, when the auxiliary power supply 212, the second power supply interruption circuit 60b, and the main line interruption circuit 70 are turned on, one or both of the main power supply 211 and the first power supply interruption circuit 60a may be turned off. With this setting, the voltage detection unit 810 detects the voltage between the first load interruption circuit 80a and the first load terminal 21.

[0250] With the above settings, a voltage of 12V is supplied to the first load line section 51. However, because the first load shedding circuit 80a is off, under normal circumstances, 0V will be present between the first load shedding circuit 80a and the first load terminal 21. If the first load shedding circuit 80a is stuck on, 12V will also be present between the first load shedding circuit 80a and the first load terminal 21. From the above, by using setting pattern 12 and detecting the voltage between the first load shedding circuit 80a and the first load terminal 21, the control section 110 can detect that the first load shedding circuit 80a is stuck on.

[0251] [Setting pattern 13] Setting pattern 13 is also a setting for detecting stuck-on of first load shedding circuit 80a. The setting of setting pattern 13 is shown in Fig. 63. Also, Fig. 64 shows the state in which each setting target is set in setting pattern 13, the position where voltage is detected, and the position where voltage is applied from internal power supply 830.

[0252] In setting pattern 13, the main power supply 211 is turned on, and the auxiliary power supply 212 is also turned on. The first power supply interruption circuit 60a and the second power supply interruption circuit 60 are also turned on. The first load interruption circuit 80a is turned off. The second load interruption circuit 80b may be turned on or off. The main line interruption circuit 70 is turned on. As with setting pattern 12, the auxiliary power supply 212 and the second power supply interruption circuit 60b may be turned off. Furthermore, when the auxiliary power supply 212, the second power supply interruption circuit 60b, and the main line interruption circuit 70 are turned on, one or both of the main power supply 211 and the first power supply interruption circuit 60a may be turned off. With this setting, the voltage detection unit 810 detects the voltage between the first load interruption circuit 80a and the first load terminal 21. The internal power supply 830 applies a voltage between the first load interruption circuit 80a and the first load terminal 21.

[0253] With the above settings, a voltage of 12 V is supplied to the first load line section 51. However, the first load shedding circuit 80 a is turned off. Therefore, under normal conditions, the voltage between the first load shedding circuit 80 a and the first load terminal 21 is 9.3 V, which is supplied from the internal power supply 830 via the capacitor 831. On the other hand, if the first load shedding circuit 80 a is stuck on, 12 V is also supplied between the first load shedding circuit 80 a and the first load terminal 21. As a result, by detecting the voltage between the first load shedding circuit 80 a and the first load terminal 21 while applying voltage from the internal power supply 830 between the first load shedding circuit 80 a and the first load terminal 21 using setting pattern 13, the control unit 110 can detect whether the first load shedding circuit 80 a is stuck on.

[0254] [Setting pattern 14] Setting pattern 14 is a setting for detecting a stuck-off state of the first load shedding circuit 80a. The setting of setting pattern 14 is shown in Fig. 65. Also, Fig. 66 shows the state in which each setting target is set in setting pattern 14 and the position at which the voltage is detected.

[0255] In setting pattern 14, the main power supply 211 is turned on, and the auxiliary power supply 212 is also turned on. The first power supply interruption circuit 60a and the second power supply interruption circuit 60 are also turned on. The first load interruption circuit 80a is also turned on. The second load interruption circuit 80b may be turned on or off. The main line interruption circuit 70 is turned on. As with setting patterns 12 and 13, the auxiliary power supply 212 and the second power supply interruption circuit 60b may be turned off. Furthermore, when the auxiliary power supply 212, the second power supply interruption circuit 60b, and the main line interruption circuit 70 are turned on, one or both of the main power supply 211 and the first power supply interruption circuit 60a may be turned off. With these settings, the voltage detection unit 810 detects the voltage between the first load interruption circuit 80a and the first load terminal 21.

[0256] With the above settings, a voltage of 12V is supplied to the first load line section 51. Because the first load shedding circuit 80a is on, under normal circumstances the voltage between the first load shedding circuit 80a and the first load terminal 21 will be 12V. However, if the first load shedding circuit 80a is stuck off, the voltage between the first load shedding circuit 80a and the first load terminal 21 will be 0V. As a result, by using setting pattern 14 and detecting the voltage between the first load shedding circuit 80a and the first load terminal 21, the control section 110 can detect that the first load shedding circuit 80a is stuck off.

[0257] [Setting pattern 15] Setting pattern 15 is also a setting for detecting a stuck-off state of first load shedding circuit 80a. The setting of setting pattern 15 is shown in Fig. 67. Also, Fig. 68 shows the state in which each setting target is set in setting pattern 15, the position where voltage is detected, and the position where voltage is applied by internal power supply 830.

[0258] Setting pattern 15 is the same as setting pattern 14. As shown in Fig. 68, a voltage is applied from the internal power supply 830 between the first load shedding circuit 80a and the first load terminal 21. Then, the voltage detection unit 810 detects the voltage between the first load shedding circuit 80a and the first load terminal 21.

[0259] With the above settings, a voltage of 12 V is supplied to the first load line section 51. Because the first load shedding circuit 80 a is on, under normal circumstances the voltage between the first load shedding circuit 80 a and the first load terminal 21 is 12 V. However, if the first load shedding circuit 80 a is stuck off, the voltage between the first load shedding circuit 80 a and the first load terminal 21 is 9.3 V, which is supplied from the internal power supply 830 via the capacitor 831. As described above, by using setting pattern 15 and applying voltage from the internal power supply 830 between the first load shedding circuit 80 a and the first load terminal 21, the control section 110 can detect that the first load shedding circuit 80 a is stuck off by detecting the voltage between the first load shedding circuit 80 a and the first load terminal 21.

[0260] [Setting pattern 16] Setting pattern 16 is a setting for detecting an open circuit on the load side. Fig. 69 shows the setting of setting pattern 16. Fig. 70 shows the state in which each setting target is set in setting pattern 16 and the position at which the current is detected.

[0261] Setting pattern 16 is the same as setting patterns 14 and 15. As shown in Fig. 70, when detecting an open circuit on the load side, current detection unit 820 detects the current between first load shedding circuit 80a and first load terminal 21.

[0262] When the above configuration is performed, a steady-state current flows between the first load interruption circuit 80a and the first load terminal 21 under normal conditions. The steady-state current is a current that corresponds to the resistance value of the load 220. On the other hand, if the first load terminal 21 is open, no current flows between the first load interruption circuit 80a and the first load terminal 21. As described above, by using setting pattern 16 and detecting the current between the first load interruption circuit 80a and the first load terminal 21, the control unit 110 can detect that the first load terminal 21 is open.

[0263] [Setting pattern 17] Setting pattern 17 is a setting for detecting a ground fault on the load side. Fig. 71 shows the setting of setting pattern 17. Fig. 72 shows the state in which each setting target is set in setting pattern 17 and the position at which the current is detected.

[0264] Setting pattern 17 is the same as setting pattern 16, and is also the same in that the current between the first load shedding circuit 80a and the first load terminal 21 is detected by a current detection unit 820, as shown in FIG.

[0265] Under normal conditions, a steady-state current flows between the first load interruption circuit 80a and the first load terminal 21. On the other hand, if a ground fault occurs on the load side of the first load line section 51, a ground fault current flows between the first load interruption circuit 80a and the first load terminal 21. The ground fault current is a current greater than the steady-state current. From the above, by using setting pattern 17 and detecting the current between the first load interruption circuit 80a and the first load terminal 21, the control unit 110 can detect that a ground fault has occurred on the load side of the first load interruption circuit 80a.

[0266] [Setting pattern 18] Setting pattern 18 is a setting for detecting a power fault on the load side. Figure 73 shows the setting of setting pattern 18. Figure 74 shows the state in which each setting target is set in setting pattern 18 and the position at which the voltage is detected. As shown in Figure 73, setting pattern 18 is the same as setting patterns 12 and 13. As shown in Figure 74, voltage detection unit 810 detects the voltage between first load shedding circuit 80a and first load terminal 21.

[0267] With the above settings, a voltage of 12V is supplied to the first load line section 51. However, because the first load shedding circuit 80a is off, under normal circumstances, 0V will be present between the first load shedding circuit 80a and the first load terminal 21. On the other hand, if a short to power occurs on the load side of the first load shedding circuit 80a, 12V will be present between the first load shedding circuit 80a and the first load terminal 21. From the above, by using setting pattern 18 and detecting the voltage between the first load shedding circuit 80a and the first load terminal 21, it is possible to detect that a short to power has occurred on the load side of the first load shedding circuit 80a.

[0268] <Eighteenth embodiment> The eighteenth embodiment is an embodiment for inspecting the capacitance of the capacitor 130. The configuration of a power distribution ECU 900 of the eighteenth embodiment is shown in FIG. 75. For convenience of illustration, components unrelated to the configuration for inspecting the capacitance of the capacitor 130 are omitted from FIG. 75. The power distribution ECU 900 includes a voltage detection unit 910, a first-section transistor Tr2, and a second-section transistor Tr3. Here, the first-section transistor Tr2 and the second-section transistor Tr3 are N-channel MOSFETs.

[0269] The first-section transistor Tr2 has a drain connected to the first section 41, a source connected to the ECU ground, and a gate connected to the control unit 110. The second-section transistor Tr3 has a drain connected to the second section 42, a source connected to the ECU ground, and a gate connected to the control unit 110. The voltage detection unit 920 detects the voltage in the first section 41 and the voltage in the second section 42. The voltage detection unit 920 is connected to the control unit 110.

[0270] 76 shows the process in which the control unit 110 inspects the capacitance of the first capacitor 131 or the second capacitor 132 in the eighteenth embodiment. Before the inspection, the main power supply 211 and the auxiliary power supply 212 are both on. The power supply interruption circuit 60, the main line interruption circuit 70, and the load interruption circuit 80 are also on, and the first capacitor 131 and the second capacitor 132 are in a charged state.

[0271] In S91, the load shedding circuit 80 and the main line shedding circuit 70 are turned off. When inspecting the capacitance of the second capacitor 132 connected to the first section 41, the load shedding circuit 80 that is turned off is the first load shedding circuit 80a. When inspecting the capacitance of the first capacitor 131 connected to the second section 42, the load shedding circuit 80 that is turned off is the second load shedding circuit 80b.

[0272] In S92, one or both of the power supply and the power supply cutoff circuit 60 are turned off. When inspecting the capacitance of the second capacitor 132, one or both of the main power supply 211 and the first power supply cutoff circuit 60a are turned off. When inspecting the capacitance of the first capacitor 131, one or both of the auxiliary power supply 212 and the second power supply cutoff circuit 60b are turned off.

[0273] In S93, when the capacitance of the second capacitor 132 is to be inspected, the transistor Tr2 in the first section is turned on. Since the processes of S91 and S92 have been performed in advance, the charge stored in the second capacitor 132 passes through the transistor Tr2 in the first section and is discharged. When the capacitance of the first capacitor 131 is to be inspected, the transistor Tr3 in the second section is turned on. Since the processes of S91 and S92 have been performed in advance, the charge stored in the first capacitor 131 passes through the transistor Tr3 in the second section and is discharged.

[0274] In S94, the voltage of the power supply main line 40 is monitored using the voltage detection unit 910. When inspecting the capacitance of the second capacitor 132, the voltage of the first section 41 is monitored. When inspecting the capacitance of the first capacitor 131, the voltage of the second section 42 is monitored.

[0275] In S95, it is determined whether a predetermined time has elapsed since the first-section transistor Tr2 or the second-section transistor Tr3 was turned on. The predetermined time is a fixed time set in advance. If the determination result in S95 is NO, the process returns to S94 and continues to monitor the voltage. If the determination result in S95 is YES, the process proceeds to S96.

[0276] In S96, it is determined whether the voltage after a predetermined time has elapsed is equal to or greater than a specified value. If the determination result in S96 is YES, the process proceeds to S97, where the capacitance of capacitor 130 is determined to be acceptable. On the other hand, if the determination result in S96 is NO, the process proceeds to S98, where the capacitance of capacitor 130 is determined to be unacceptable.

[0277] According to the eighteenth embodiment, the first capacitor 131 is discharged from a charged state, and after a predetermined time has elapsed, it is determined whether or not the capacitance of the first capacitor 131 is abnormal based on the voltage in the first section 41. Also, the second capacitor 132 is discharged from a charged state, and after a predetermined time has elapsed, it is determined whether or not the capacitance of the second capacitor 132 is abnormal based on the voltage in the second section 42. This configuration makes it possible to self-diagnose whether or not the capacitances of the first capacitor 131 and the second capacitor 132 are abnormal. Because the capacitances of both the first capacitor 131 and the second capacitor 132 can be inspected, a sudden drop in the voltage supplied to the load 220 can be prevented even if a ground fault occurs in either the first section 41 or the second section 42.

[0278] <Nineteenth embodiment> The 19th embodiment is an embodiment in which the capacitance of the capacitor 130 is inspected while power is being supplied to a specific load 220. There may be a load 220 that requires power under any conditions, whether the vehicle is parked or running. Therefore, in the 19th embodiment, the capacitance of the capacitor 130 is inspected while power is being supplied to a specific load 220.

[0279] The configuration of a power distribution ECU 1000 according to the 19th embodiment is shown in Figure 77. For ease of illustration, components unrelated to the configuration for inspecting the capacitance of capacitor 130 are omitted from Figure 77. As with the 18th embodiment, power distribution ECU 1000 includes a first-section transistor Tr2, a second-section transistor Tr3, and a voltage detection unit 910. Furthermore, power distribution ECU 1000 includes a first inspection shutoff circuit 1001 and a second inspection shutoff circuit 1002.

[0280] The first inspection shutoff circuit 1001 is provided in the first inspection power line 1011 and switches between a conducting state and a cutoff state between the first section 41 and the load side trunk 1020. The second inspection shutoff circuit 1002 is provided in the second inspection power line 1012 and switches between a conducting state and a cutoff state between the second section 42 and the load side trunk 1020. The first inspection power line 1011 connects the first section 41 and the load side trunk 1020. The second inspection power line 1012 connects the second section 42 and the load side trunk 1020.

[0281] The load side trunk 1020 includes a load side trunk first section 1021 and a load side trunk second section 1022. The load side trunk first section 1021 connects the first inspection power line 1011 to the downstream side of the first load line section 51 of the first load shedding circuit 80a. The load side trunk first section 1021 can also be said to be connected to the first load terminal 21. The load side trunk second section 1022 connects the second inspection power line 1012 to the downstream side of the second load line section 52 of the second load shedding circuit 80b. The load side trunk second section 1022 can also be said to be connected to the second load terminal 22. A capacitor 1031 is provided in the load side trunk first section 1021 to prevent backflow from the load side. A capacitor 1032 is also provided in the load side trunk second section 1022 to prevent backflow from the load side.

[0282] 78 shows the process in which the control unit 110 in the 19th embodiment inspects the capacitance of the second capacitor 132 connected to the first section 41. Before inspection, the main power supply 211 and the auxiliary power supply 212 are both on. The power supply interruption circuit 60, the main line interruption circuit 70, and the load interruption circuit 80 are also on. Meanwhile, the first inspection interruption circuit 1001 and the second inspection interruption circuit 1002 are off. Therefore, the first capacitor 131 and the second capacitor 132 are in a charged state.

[0283] In S101, the second inspection breaking circuit 1002 is turned on. In S102, the first load breaking circuit 80a is turned off, and the main line breaking circuit 70 is also turned off. Even if the first load breaking circuit 80a and the main line breaking circuit 70 are turned off in S102, because the second inspection breaking circuit 1002 is turned on, power is supplied from the auxiliary power supply 212 to the first load terminal 21 via the second inspection power line 1012 and the load-side main line first section 1021.

[0284] In S103, one or both of the main power supply 211 and the first power supply cutoff circuit 60a are turned off. In S104, the first-section transistor Tr2 is turned on. Since the processes of S102 and S103 have been performed in advance, the charge stored in the second capacitor 132 passes through the first-section transistor Tr2 and is discharged.

[0285] In S105, the voltage detection unit 910 is used to monitor the voltage in the first section 41. In S106, it is determined whether a predetermined time has elapsed since the transistor Tr2 in the first section was turned on. If the determination result in S106 is NO, the process returns to S105 and continues monitoring the voltage. If the determination result in S106 is YES, the process proceeds to S107.

[0286] In S107, it is determined whether the voltage after a predetermined time has elapsed is equal to or greater than a specified value. If the determination result in S107 is YES, the process proceeds to S108, where the capacitance of the second capacitor 132 is determined to be acceptable. On the other hand, if the determination result in S107 is NO, the process proceeds to S109, where the capacitance of the second capacitor 132 is determined to be unacceptable.

[0287] 79 shows a process in the 19th embodiment in which the control unit 110 inspects the capacitance of the first capacitor 131 connected to the second section 42. The state before inspection is the same as when inspecting the capacitance of the second capacitor 132, and the first capacitor 131 and the second capacitor 132 are in a charged state.

[0288] In S111, the first inspection breaking circuit 1001 is turned on. In S112, the second load breaking circuit 80b is turned off, and the main line breaking circuit 70 is turned off. Even if the second load breaking circuit 80b and the main line breaking circuit 70 are turned off in S112, because the first inspection breaking circuit 1001 is turned on, power is supplied from the main power supply 211 to the second load terminal 22 via the first inspection power line 1011 and the load-side main line second section 1022.

[0289] In S113, the auxiliary power supply 212 and / or the second power supply cutoff circuit 60b is turned off. In S114, the second-section transistor Tr3 is turned on. Since the processes of S112 and S113 have been performed in advance, the charge stored in the first capacitor 131 passes through the second-section transistor Tr3 and is discharged.

[0290] In S115, the voltage detection unit 910 is used to monitor the voltage in the second section 42. In S116, it is determined whether a predetermined time has elapsed since the second section transistor Tr3 was turned on. If the determination result in S116 is NO, the process returns to S115 and continues monitoring the voltage. If the determination result in S116 is YES, the process proceeds to S117.

[0291] In S117, it is determined whether the voltage after a predetermined time has elapsed is equal to or greater than a specified value. If the determination result in S117 is YES, the process proceeds to S118, where the capacitance of the first capacitor 131 is determined to be acceptable. On the other hand, if the determination result in S117 is NO, the process proceeds to S119, where the capacitance of the first capacitor 131 is determined to be unacceptable.

[0292] <Twentieth Embodiment> The twentieth embodiment is another embodiment of the overvoltage detection unit OVD and the low-voltage detection unit LVD. A voltage detection unit 1100 shown in Fig. 80 has the functions of the overvoltage detection unit OVD and the low-voltage detection unit LVD. The voltage detection unit 1100 includes an FET 1101, a shunt resistor 1102, a driver 1103, an amplifier 1104, and a controller 1105.

[0293] The FET 1101 is an N-channel MOSFET, with its drain connected to the power supply, its source connected to the ECU ground, and its gate connected to the drive unit 1103. The shunt resistor 1102 has one end connected to the source of the FET 1101 and the other end connected to the ECU ground. The drive unit 1103 applies a gate voltage to the gate of the FET 1101 to turn on the FET 1101. The amplifier 1104 amplifies the voltage across the shunt resistor 1102. The amplifier 1104 is, for example, an operational amplifier. The control unit 1105 performs AD conversion on the voltage amplified by the amplifier 1104. The control unit 1105 detects overvoltage and undervoltage based on the AD-converted value.

[0294] <Twenty-first embodiment> The 21st embodiment is also an embodiment of an overvoltage detection unit OVD and a low voltage detection unit LVD. A voltage detection unit 1200 shown in Fig. 81 has the functions of the overvoltage detection unit OVD and the low voltage detection unit LVD. The voltage detection unit 1200 includes a switch unit 1201, a resistor 1204, a drive unit 1205, and a control unit 1206.

[0295] The switch unit 1201 has a configuration sometimes called an IPD. The switch unit 1201 includes an FET 1202 and a current source 1203. The FET 1202 is an N-channel MOSFET, with its drain connected to the power supply, its source connected to the ECU ground, and its gate connected to the drive unit 1205. One end of the resistor 1204 is connected to the current source 1203, and the other end is connected to the ECU ground. The resistor 1204 has a resistance value that allows 1 / N of the current flowing through the FET 1202 when it is on to flow. N is, for example, 10,000. The drive unit 1205 applies a gate voltage to the gate of the FET 1202 to turn on the FET 1202. The control unit 1206 acquires the voltage between the current source 1203 and the resistor 1204, and performs AD conversion of the acquired voltage.

[0296] (Other embodiments) Although one embodiment of the present disclosure has been described above, the present disclosure should not be construed as being limited to the above embodiment, and can be applied to various embodiments and combinations within the scope that does not deviate from the gist of the present disclosure.

[0297] The control unit may be configured by a microcontroller mainly including a CPU (Central Processing Unit), or may be configured by hardware circuits such as discrete circuits. Furthermore, the functions of the control unit may be provided by an SoC, an ASIC, an FPGA, or the like. SoC stands for System on Chip, ASIC stands for Application Specific Integrated Circuit, and FPGA stands for Field-Programmable Gate Array.

[0298] In this disclosure, the term "connected" may refer to a direct connection to another element, or an indirect connection via an intervening element.

[0299] The controller and methods described herein may be implemented by a special-purpose computer comprising a processor programmed to perform one or more functions embodied in a computer program. Alternatively, the apparatus and methods described herein may be implemented by special-purpose hardware logic circuitry. Alternatively, the apparatus and methods described herein may be implemented by one or more special-purpose computers comprising a processor executing a computer program in combination with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium. [Explanation of symbols]

[0300] 11...first power supply terminal, 12...second power supply terminal, 20...load terminal, 21...load terminal, first load terminal, 22...load terminal, second load terminal, 31...first power supply line section, 32...second power supply line section, 40...power supply main line, 60a...first power supply interruption circuit, 60b...second power supply interruption circuit, 62...MOS transistor, 70...main line interruption circuit, 131...capacitor, first capacitor, 132...capacitor, second capacitor, 140...inductance section, first inductance section, 141...inductance section, second inductance section, 210...power supply, 220...load

Claims

1. A vehicle control device that is used in a vehicle and distributes power supplied from a plurality of power sources (210) to a plurality of loads (220), comprising: a first power supply terminal (11) for connection to one of the plurality of power supplies; a second power supply terminal (12) for connection to another one of the plurality of power supplies; a first power supply line portion (31) connected to the first power supply terminal; a second power supply line portion (32) connected to the second power supply terminal; a power supply trunk line (40) connecting the first power supply line portion and the second power supply line portion; a plurality of terminals for connection to the plurality of loads, at least one of which is connected to the first power supply line section and at least one of which is connected to the second power supply line section; and a main line interruption circuit (70) provided in the power supply main line and configured to switch between energization and interruption between the first power supply line portion and the second power supply line portion; a low-pass filter including an inductance unit (140, 141) provided in the power supply main line and a capacitor (131, 132) having one end connected to the power supply main line and the other end connected to a ground potential; A vehicle control device comprising:

2. At least one of the first load terminals (21) which are the load terminals connected to the first power supply line section and at least one of the second load terminals (22) which are the load terminals connected to the second power supply line section are priority terminals for connection to the same priority load which has priority over other loads in power supply. The vehicle control device according to claim 1 .

3. The capacitors include a first capacitor (131) having one end connected to the power supply main line on the first power supply line section side of the main line interruption circuit and the other end connected to the ground potential, and a second capacitor (132) having one end connected to the power supply main line on the second power supply line section side of the main line interruption circuit and the other end connected to the ground potential. The vehicle control device according to claim 1 .

4. The inductance section includes a first inductance section (140) provided in the power supply main line closer to the first power supply line section than the main line interruption circuit, and a second inductance section (141) provided in the power supply main line closer to the second power supply line section than the main line interruption circuit. The vehicle control device according to claim 3 .

5. The inductance portion is formed by the substrate wiring of the power supply main line. The vehicle control device according to claim 1 .

6. the inductance unit is an inductor component provided in the power supply main line, The vehicle control device according to claim 1 .

7. a first power supply cutoff circuit (60a) provided in the first power supply line section and switching between energization and cutoff; a second power supply cutoff circuit (60b) provided in the second power supply line section and switching between energization and cutoff, the first power supply cutoff circuit and the second power supply cutoff circuit each include a MOS transistor (62); the MOS transistor included in the first power supply cutoff circuit and the MOS transistor included in the second power supply cutoff circuit have different heat dissipation members; The vehicle control device according to claim 1 .

8. a first power supply cutoff circuit (60a) provided in the first power supply line section and switching between energization and cutoff; a second power supply cutoff circuit (60b) provided in the second power supply line section and switching between energization and cutoff, the first power supply cutoff circuit and the second power supply cutoff circuit each include an integrated circuit; the integrated circuit included in the first power supply cutoff circuit and the integrated circuit included in the second power supply cutoff circuit are made of materials with different thermal properties. The vehicle control device according to claim 1 .

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