Power switching device

Abstract

The present application provides a power switching device, which can switch power supply in a power supply system capable of supplying power from a power supply unit and a power storage unit, and is advantageous in monitoring power supply from the power storage unit. A first switching unit supplies power to a first output path from a first conductive path when the voltage of the second conductive path is greater than that of the first conductive path in a prescribed first state, and supplies power to the first output path from a second conductive path when the voltage of the third conductive path is greater than that of the fourth conductive path in a prescribed second state. A second switching unit supplies power to a second output path from a fourth conductive path when the voltage of the third conductive path is greater than that of the fourth conductive path in a prescribed third state, and supplies power to the second output path from a third conductive path when the voltage of the third conductive path is greater than that of the fourth conductive path in a prescribed fourth state. A component unit allows current to flow from the second conductive path to the third conductive path when the voltage of the third conductive path is lower than that of the second conductive path in a prescribed state, and cuts off when the voltage of the third conductive path is not lower than that of the second conductive path.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a power switching device. BACKGROUND

[0002] In Patent Literature 1, one example of an in-vehicle power supply device is disclosed. The in-vehicle power supply device of Patent Literature 1 is an in-vehicle power supply device that supplies power to in-vehicle equipment from a secondary battery mounted on a vehicle. In the in-vehicle power supply device, a voltage compensation unit suppresses a drop in the power voltage supplied to the in-vehicle equipment and performs compensation in a case where the voltage supplied to the in-vehicle equipment becomes a first set value or less. A no-power supply unit supplies power of another secondary battery different from the secondary battery to a part of the in-vehicle equipment in a case where the voltage supplied to the in-vehicle equipment becomes a second set value smaller than the first set value or less.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2013-28295 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The technology of Patent Literature 1 is a structure in which a plurality of loads can be supplied with power based on power from another power supply in a case where power supply from a main power supply is interrupted, but does not envisage monitoring a path of power supply from another power supply.

[0008] The present disclosure provides a technology that is advantageous in monitoring power supply from a power storage unit in a power supply system in which power switching is possible from a power supply unit and the power storage unit.

[0009] TECHNICAL SOLUTION TO THE PROBLEM

[0010] A power switching device according to one embodiment of the present disclosure is a power switching device for switching power in a power supply system that includes a power supply unit, a power storage unit, and a power path that is a power supply path from the power supply unit, in which

[0011] The power switching device includes:

[0012] a first conductive path that is a path that receives power supply from the power path;

[0013] a second conductive path that is a path that supplies power based on the power storage unit;

[0014] a third conductive path that is a path that supplies power based on the power storage unit and is different from the second conductive path;

[0015] The fourth conductive path is a path that receives supply of electric power from the electric power path;

[0016] The first output path is a path that supplies electric power to the first load;

[0017] The second output path is a path that supplies electric power to the second load;

[0018] The first switching section switches in a manner that supplies electric power from the first conductive path to the first output path in a case where the voltage of the first conductive path is greater than the voltage of the second conductive path, and supplies electric power from the second conductive path to the first output path in a case where the voltage of the first conductive path is less than the voltage of the second conductive path;

[0019] The second switching section switches in a manner that supplies electric power from the fourth conductive path to the second output path in a case where the voltage of the fourth conductive path is greater than the voltage of the third conductive path, and supplies electric power from the third conductive path to the second output path in a case where the voltage of the fourth conductive path is less than the voltage of the third conductive path; and

[0020] The element section allows current to flow from the second conductive path to the third conductive path in a case where the voltage of the third conductive path is lower than the voltage of the second conductive path, and cuts off current flowing from the second conductive path to the third conductive path in a case where the voltage of the third conductive path is not lower than the voltage of the second conductive path.

[0021] Effects of Invention

[0022] The technology of the present disclosure is advantageous in that it enables switching of electric power in a power supply system that is capable of supplying electric power from a power supply section and an electric storage section, and in monitoring supply of electric power from the electric storage section. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a circuit diagram that schematically shows one example of a vehicle-mounted system including a power supply switching device of the first embodiment.

[0024] Figure 2 is an explanatory diagram that explains a state of supply of electric power in the vehicle-mounted system of Figure 1 based on a state in which supply of electric power from the electric storage section 12 is stopped.

[0025] Figure 3 is an explanatory diagram that explains a state of supply of electric power in the vehicle-mounted system of Figure 1 in which the power supply switching device performs the first supply operation and the second supply operation.

[0026] Figure 4 is a diagram illustrating a power supply state in a case where a power failure (a ground in a power path occurs) occurs in the vehicle-mounted system of Figure 1

[0027] Reference Signs

[0028] 2: vehicle-mounted system

[0029] 3: vehicle-mounted power supply system

[0030] 5: power supply switching device

[0031] 10: first device

[0032] 11: power control device

[0033] 12: power storage unit

[0034] 14: voltage conversion circuit

[0035] 16: control unit

[0036] 18: discharging circuit

[0037] 20: switch

[0038] 22: switch

[0039] 24: switch

[0040] 26: diode

[0041] 28: diode

[0042] 30: voltage detection unit

[0043] 31: resistor

[0044] 41: conductive path

[0045] 42: conductive path

[0046] 43: conductive path

[0047] 44: conductive path

[0048] 45: conductive path

[0049] 46: conductive path

[0050] 47: conductive path

[0051] 48: conductive path

[0052] 50: second device

[0053] 51: first conductive path

[0054] 52: second conductive path ​

[0055] 53: 3rd conductive path

[0056] 54: 4th conductive path

[0057] 61: 1st output path

[0058] 62: 2nd output path

[0059] 70: 1st switching section

[0060] 71: 1st diode (diode, element section)

[0061] 72: comparison circuit

[0062] 74: switching section

[0063] 74A: FET

[0064] 74B: FET

[0065] 80: 2nd switching section

[0066] 82: 2nd diode

[0067] 83: 3rd diode

[0068] 84: 4th diode (diode, cutoff section)

[0069] 91: power supply section

[0070] 94: power path

[0071] 101: 1st load

[0072] 102: 2nd load DETAILED DESCRIPTION

[0073] [Explanation of Embodiments of the Present Disclosure]

[0074] Hereinafter, embodiments of the present disclosure are exemplified. Furthermore, the features of the following examples of 〔1〕 to 〔4〕 can be arbitrarily combined in a non-contradictory combination.

[0075] 〔1〕 A power switching device for switching of a power supply in a power supply system provided with a power supply section, an electric storage section, and a power path that is a power supply path from the power supply section, wherein

[0076] the power switching device has:

[0077] a 1st conductive path that is a path that receives a power supply from the power path;

[0078] a 2nd conductive path that is a path that supplies a power based on the electric storage section;

[0079] The third conductive path is a path through which electric power based on the electric storage section is supplied, and is different from the second conductive path;

[0080] The fourth conductive path is a path through which electric power is supplied from the electric power path;

[0081] The first output path is a path through which electric power is supplied to a first load;

[0082] The second output path is a path through which electric power is supplied to a second load;

[0083] The first switching section switches in such a manner that electric power from the first conductive path is supplied to the first output path in a prescribed first state in which the voltage of the first conductive path is greater than the voltage of the second conductive path, and electric power from the second conductive path is supplied to the first output path in a prescribed second state in which the voltage of the first conductive path is less than the voltage of the second conductive path;

[0084] The second switching section switches in such a manner that electric power from the fourth conductive path is supplied to the second output path in a prescribed third state in which the voltage of the fourth conductive path is greater than the voltage of the third conductive path, and electric power from the third conductive path is supplied to the second output path in a prescribed fourth state in which the voltage of the fourth conductive path is less than the voltage of the third conductive path; and

[0085] The element section allows current to flow from the second conductive path to the third conductive path in a prescribed state in which the voltage of the third conductive path is lower than the voltage of the second conductive path, and cuts off current flowing from the second conductive path to the third conductive path in a state other than the prescribed state.

[0086] The power supply switching device described in the above [1] is capable of supplying power to the first load and the second load using power from the power storage section in the case where power supplied from the power supply section via the power passage is interrupted. Also, the power supply switching device of the above [1] allows current to flow from the second conductive passage to the third conductive passage in the case where the voltage of the third conductive passage is lower than the voltage of the second conductive passage in a prescribed state, and cuts off current flowing from the second conductive passage to the third conductive passage in the case where it is not the prescribed state. That is, the power supply switching device reflects whether or not it is the prescribed state to the third conductive passage, so if the third conductive passage is set as a monitoring object, it is advantageous in terms of monitoring power supply from the power storage section. The prescribed first state can be a state where the voltage of the first conductive passage is greater than the voltage of the second conductive passage, or a state where the voltage of the first conductive passage is greater than the voltage of the second conductive passage by a first prescribed value or more. The prescribed second state can be a state where the voltage of the first conductive passage is less than the voltage of the second conductive passage, or a state where the voltage of the first conductive passage is less than the voltage of the second conductive passage by a second prescribed value or more. The prescribed third state can be a state where the voltage of the fourth conductive passage is greater than the voltage of the third conductive passage, or a state where the voltage of the fourth conductive passage is greater than the voltage of the third conductive passage by a third prescribed value or more. The prescribed fourth state can be a state where the voltage of the fourth conductive passage is less than the voltage of the third conductive passage, or a state where the voltage of the fourth conductive passage is less than the voltage of the third conductive passage by a fourth prescribed value or more. In the case where the first prescribed value and the second prescribed value are adopted, the first prescribed value can be the same as or different from the second prescribed value. In the case where the third prescribed value and the fourth prescribed value are adopted, the third prescribed value can be the same as or different from the fourth prescribed value.

[0087] 〔2〕 The power switching device described in the above 〔1〕 has the following features. The above-mentioned first switching section has a switching section, a driving section, and a cutoff section, and the cutoff section has a diode. The above-mentioned switching section is provided between the above-mentioned first conductive path and the above-mentioned first output path, and in the on state, allows conduction between the above-mentioned first conductive path and the above-mentioned first output path, and in the off state, cuts off the conduction between the above-mentioned first conductive path and the above-mentioned first output path. In the case where the voltage of the above-mentioned first conductive path is greater than the voltage of the above-mentioned second conductive path or in the case where the voltage of the above-mentioned first conductive path is greater than the voltage of the above-mentioned second conductive path by a first prescribed value or more, the above-mentioned driving section sets the above-mentioned switching section to the on state, and in the case where the voltage of the above-mentioned first conductive path is less than the voltage of the above-mentioned second conductive path or in the case where the voltage of the above-mentioned first conductive path is less than the voltage of the above-mentioned second conductive path by a second prescribed value or more, the above-mentioned driving section sets the above-mentioned switching section to the off state. The above-mentioned second conductive path is electrically connected to the anode of the diode of the above-mentioned cutoff section, and the above-mentioned first output path is electrically connected to the cathode of the diode of the above-mentioned cutoff section.

[0088] The power switching device described in the above 〔2〕 can supply power based on the power supply section to the first output path in a manner that suppresses loss by setting the switching section to the on state in the state where the voltage of the first conductive path is relatively greater than the voltage of the second conductive path. On the other hand, the power switching device of 〔2〕 can immediately supply power based on the power storage section to the first output path via the diode in the state where the voltage of the first conductive path is relatively less than the voltage of the second conductive path.

[0089] 〔3〕 The power switching device described in the above 〔2〕 has the following features. The above-mentioned second switching section has a second diode and a third diode. The anode of the above-mentioned second diode is electrically connected to the above-mentioned fourth conductive path, and the cathode of the above-mentioned second diode is electrically connected to the above-mentioned second output path. The anode of the above-mentioned third diode is electrically connected to the above-mentioned third conductive path, and the cathode of the above-mentioned third diode is electrically connected to the above-mentioned second output path.

[0090] The power switching device described in the above 〔3〕 can more simply realize a structure in which, in the case where the power supply voltage based on the power supply section is relatively high, power is supplied to the second output path based on the power supply section, and in the case where the power supply voltage relatively decreases due to failure or the like, power can be immediately supplied to the second output path based on the power storage section.

[0091] 〔4〕 The power supply switching device according to any one of the above 〔1〕 to the above 〔3〕, having the following features. The power supply switching device has a power control device that controls supply of electric power from the power storage section. The power control device performs a first switching operation, a second switching operation, and a detection operation. The first switching operation is an operation that switches between a first supply operation of supplying electric power based on the power storage section to the second conductive path and a first stop operation of stopping supply of electric power from the power storage section to the second conductive path. The second switching operation is an operation that switches between a second supply operation of supplying electric power based on the power storage section to the third conductive path and a second stop operation of stopping supply of electric power from the power storage section to the third conductive path. The detection operation is an operation of detecting a voltage of the third conductive path in a state where the first supply operation and the second stop operation are performed.

[0092] The power supply switching device described in the above 〔4〕 can output electric power based on the power storage section to each of the separate paths (each of the second conductive path and the third conductive path), and can individually switch the output to each path. Furthermore, the power supply switching device uses one of the paths (the third conductive path) for both output and monitoring, and can confirm whether the output from the other path (the second conductive path) is being performed appropriately, so that monitoring of whether supply of electric power from the power storage section is being performed appropriately can be achieved with a simpler structure.

[0093] [Details of Embodiments of the Present Disclosure]

[0094] <First Embodiment>

[0095] 1. Outline of Vehicle-mounted System

[0096] A vehicle-mounted system 2 is shown in Figure 1 The vehicle-mounted system 2 of the Figure 1 The vehicle-mounted system 2 mainly has a vehicle-mounted power supply system 3, a first load 101, and a second load 102. The vehicle-mounted power supply system 3 is also referred to as a power supply system 3 in the following description. The vehicle-mounted system 2 is a system that causes a plurality of loads to operate by supplying electric power to the plurality of loads by the power supply system 3. In Figure 1 In the above

[0097] The first load 101 is an electrical component mounted on a vehicle. The first load 101 operates by accepting electric power supplied via a first output path 61. The type of the first load 101 is not limited. As the first load 101, various known vehicle-mounted components can be employed. The first load 101 can have a plurality of electrical components or can be a single electrical component.

[0098] The second load 102 is an electrical component mounted on the vehicle. The second load 102 operates by receiving electric power supplied via the second output passage 62. As the second load 102, various known vehicle-mounted components can be used. The second load 102 can include a plurality of electrical components or can be a single electrical component. The first load 101 and the second load 102 can be the same type of load or different types of loads.

[0099] The power supply system 3 is a system that supplies electric power to a plurality of loads included in the vehicle-mounted system 2. The power supply system 3 is configured as a system that supplies electric power to the first load 101 and the second load 102 with the power supply section 91 or the power storage section 12 serving as a power supply source. The power supply system 3 is a system that can supply electric power to the first load 101 and the second load 102 from the power supply section 91 and can supply electric power to the first load 101 and the second load 102 from the power storage section 12 in the case where the supply of electric power from the power supply section 91 is interrupted due to a failure or the like.

[0100] 2. Outline of Power Supply System

[0101] The power supply system 3 includes the power supply section 91, the power storage section 12, an electric power passage 94 that is a supply path of electric power from the power supply section 91, and the power supply switching device 5.

[0102] The power supply section 91 is a vehicle-mounted power supply that can supply electric power to the first load 101 and the second load 102. The power supply section 91 is configured as a known vehicle-mounted battery such as a lead battery. The power supply section 91 can be configured by a battery other than a lead battery, or can have a power supply unit other than a battery in place of or in addition to the battery. The power supply section 91 is electrically connected at a positive electrode to the electric power passage 94 and is electrically connected at a negative electrode to the ground. The power supply section 91 applies a constant value of direct-current voltage to the electric power passage 94. The voltage applied to the electric power passage 94 by the power supply section 91 can be slightly varied from the above constant value.

[0103] The power storage section 12 is a power supply that becomes a power supply source at least when the supply of electric power from the power supply section 91 is interrupted. The power storage section 12 is configured by a known power storage unit such as an electric double layer capacitor (EDLC). The power storage section 12 can be configured by a capacitor other than an electric double layer capacitor, or can have another power storage unit (battery or the like) in place of or in addition to the capacitor. The power storage section 12 is electrically connected at a positive electrode to the electrically conductive passage 45 and is electrically connected at a negative electrode to the ground. The output voltage of the power storage section 12 (voltage applied to the electrically conductive passage 45 by the power storage section 12) can be greater than or less than the output voltage of the power supply section 91 (voltage applied to the electric power passage 94 by the power supply section 91).

[0104] In this specification, a voltage refers to a voltage with respect to a ground potential (for example, 0 V) as long as not particularly limited, and is a potential difference from the ground potential. For example, a voltage applied to the power passage 94 refers to a potential difference between the power passage 94 and the ground potential.

[0105] The power passage 94 is a path that transmits the electric power based on the power supply section 91. The power passage 94 is electrically connected to the first conductive passage 51 and the fourth conductive passage 54. Figure 1 In the example, the power passage 94 is a path to which the output voltage of the power supply section 91 is applied. The power passage 94 is electrically connected to the first conductive passage 51 and the fourth conductive passage 54. A relay, a switch, or the like can also be provided in the power passage 94, and it can be possible to cut off the conduction of the power passage 94 by the relay or the switch.

[0106] 3. Structure of the power supply switching device

[0107] The power supply switching device 5 is a device for switching of the power supply in the power supply system 3. The power supply switching device 5 mainly includes the first device 10 and the second device 50.

[0108] The first device 10 is a backup device that can output the electric power based on the power storage section 12. The first device 10 includes the power storage section 12, the switches 20, 22, 24, the power control device 11, and the conductive passages 41, 42, 43, 44, 45. The first device 10 can output the electric power based on the power storage section 12 to the second conductive passage 52 and the third conductive passage 53, respectively.

[0109] The power control device 11 is a device that controls the supply of the electric power from the power storage section 12. The power control device 11 includes the voltage conversion circuit 14, the control section 16, the discharge circuit 18, the diodes 26, 28, the conductive passages 46, 47, 48, the voltage detection section 30, and the like.

[0110] The voltage conversion circuit 14 is constituted by, for example, a DC-DC converter or the like. The voltage conversion circuit 14 can perform a first conversion operation of stepping down or stepping up a direct-current voltage applied to the conductive passage 42 to apply an output voltage to the conductive passage 45. For example, when the switch 22 is in an on state, the voltage conversion circuit 14 performs the first conversion operation, thereby supplying a charging current based on the electric power from the power supply section 91 to the power storage section 12. The voltage conversion circuit 14 can perform a second conversion operation of stepping down or stepping up a direct-current voltage applied to the conductive passage 45 to apply an output voltage to the conductive passages 42, 47. For example, when the switch 22 is in an off state and the switch 24 is in an on state, the voltage conversion circuit 14 performs the second conversion operation, thereby applying a direct-current voltage based on the electric power from the power storage section 12 to the conductive passages 42, 43, and the second conductive passage 52. The operation of the voltage conversion circuit 14 is controlled by the control section 16.

[0111] The discharge circuit 18 is provided between the conductive path 48 and the conductive path 44, and is capable of performing a discharge operation of supplying a discharge current to the conductive path 44 based on a voltage applied to the conductive path 48 and a stop operation of stopping the discharge operation. The discharge circuit 18 can be constituted by a switch that switches between the conductive state and the non-conductive state between the conductive path 48 and the conductive path 44, or can be constituted by a DC-DC converter. In a case where the switch 20 is in the on state, or in a case where the voltage conversion circuit 14 applies the output voltage to the conductive path 47, the discharge circuit 18 performs the discharge operation, and thereby applies a direct-current voltage based on the electric power from the electric storage section 12 to the conductive path 44 and the third conductive path 53.

[0112] The conductive path 45 is a conductive path electrically connected to the positive electrode of the electric storage section 12. For example, the conductive path 45 is short-circuited in such a manner that the potential thereof becomes the same as the potential of the positive electrode of the electric storage section 12. The switch 20 is an element that switches between the conductive state (short-circuit state) and the non-conductive state (cut-off state) between the conductive path 45 and the conductive path 46. The conductive path 46 is a conductive path that short-circuits one end of the switch 20 and the anode of the diode 26. The diode 26 is an element whose anode is electrically connected to the conductive path 46 and whose cathode is electrically connected to the conductive path 48. The switch 20 is an element that switches between the conductive state and the non-conductive state between the conductive path 45 and the conductive path 46. When the switch 20 is in the on state, the output voltage of the electric storage section 12 is applied to the anode of the diode 26, and the anode of the diode 26 and the positive electrode of the electric storage section 12 become the same potential. When the switch 20 is in the off state, the conductive path 45 and the conductive path 46 are electrically separated, and the conduction between the conductive path 45 and the conductive path 46 is cut off.

[0113] The conductive path 47 is a conductive path capable of functioning as an output path from the voltage conversion circuit 14. The diode 28 is an element whose anode is electrically connected to the conductive path 47 and whose cathode is electrically connected to the conductive path 48. The conductive path 48 is a conductive path electrically connected to one end of the discharge circuit 18.

[0114] The conductive path 41 is a conductive path electrically connected to the power supply path 94. The potential of the conductive path 41 is set to the same potential as the potential of the power supply path 94. The conductive path 43 is a conductive path electrically connected to the second conductive path 52. The potential of the conductive path 43 is set to the same potential as the potential of the second conductive path 52. The conductive path 42 is a conductive path interposed between the conductive path 41 and the conductive path 43. The conductive path 42 becomes the same potential as or substantially the same potential as the conductive path 41 when the switch 22 is in the on state. The conductive path 42 becomes the same potential as or substantially the same potential as the conductive path 43 when the switch 24 is in the on state. The conductive path 42 is electrically connected to one end of the voltage conversion circuit 14, and is set to the conductive path on the input side at the time of the first conversion operation and to the conductive path on the output side at the time of the second conversion operation.

[0115] Further, the switches 20, 22, and 24 can be semiconductor switches such as FETs or mechanical relays.

[0116] The control section 16 is an information processing device having an information processing function, an arithmetic function, a control function, and the like. The control section 16 also functions as an arithmetic processing section. The control section 16 performs first control for causing the voltage conversion circuit 14 to perform the above-described first conversion operation and second control for causing the voltage conversion circuit 14 to perform the above-described second conversion operation. The control section 16 performs third control for causing the discharge circuit 18 to perform the above-described discharge operation and fourth control for causing the discharge circuit 18 to perform the above-described stop operation.

[0117] The voltage detection section 30 is a circuit that outputs a value, i.e., an analog voltage value, that can determine the value of the voltage applied to the third conductive path 53. The voltage detection section 30 can be a circuit that inputs a voltage value identical to the value of the voltage applied to the third conductive path 53 to the control section 16 or a circuit that inputs a value proportional to the value of the voltage applied to the third conductive path 53 to the control section 16. In the example shown in FIG. 1, the voltage detection section 30 is configured as a voltage dividing circuit composed of resistors 31 and 32, and a value obtained by voltage dividing the value of the voltage applied to the third conductive path 53 by the voltage dividing circuit is input to the control section 16 as a detection value. Figure 1

[0118] The second device 50 is a device that switches whether the electric power supplied to the first load 101 is based on the electric power of the power supply section 91 or based on the electric power of the power storage section 12. The second device 50 is also a device that switches whether the electric power supplied to the second load 102 is based on the electric power of the power supply section 91 or based on the electric power of the power storage section 12.

[0119] ​The second device 50 includes a first conductive path 51, a second conductive path 52, a third conductive path 53, a fourth conductive path 54, a first output path 61, a second output path 62, a first switching section 70, a second switching section 80, and a fourth diode 84.

[0120] The first conductive path 51 is a path that receives supply of electric power from the electric power path 94. The first conductive path 51 is electrically connected to the electric power path 94. The potential of the first conductive path 51 is set to the same potential as the potential of the electric power path 94.

[0121] The second conductive path 52 is a path that supplies electric power based on the electric power storage section 12. The second conductive path 52 is electrically connected to the conductive path 43. The potential of the second conductive path 52 is set to the same potential as the potential of the conductive path 43. When the switch 24 is in the on state, the potential of the second conductive path 52 is set to the same potential or substantially the same potential as the potential of the conductive path 42.

[0122] The third conductive path 53 is a path that supplies electric power based on the electric power storage section 12 and is a path different from the second conductive path 52. The third conductive path 53 is electrically connected to the conductive path 44. The potential of the third conductive path 53 is set to the same potential as the potential of the conductive path 44.

[0123] The first output path 61 is a path that supplies electric power to the first load 101. The first output path 61 is electrically connected to the first load 101. For example, a voltage applied to the first output path 61 is applied to one end of the first load 101.

[0124] The second output path 62 is a path that supplies electric power to the second load 102. The second output path 62 is electrically connected to the second load 102. For example, a voltage applied to the second output path 62 is applied to one end of the second load 102.

[0125] The fourth diode 84 corresponds to one example of the element portion. The fourth diode 84 electrically connects the anode thereof to the second conductive path 52, and electrically connects the cathode thereof to the third conductive path 53. The potential of the anode of the fourth diode 84 is set to the same potential as the potential of the second conductive path 52. The potential of the cathode of the fourth diode 84 is set to the same potential as the potential of the third conductive path 53. The fourth diode 84 allows current to flow from the second conductive path 52 to the third conductive path 53 in the case where the voltage of the third conductive path 53 is lower than the voltage of the second conductive path 52 in a prescribed state, and cuts off current flowing from the second conductive path 52 to the third conductive path 53 in the case where it is not the prescribed state. Specifically, in the case where the potential of the second conductive path 52 is greater than the potential of the third conductive path 53 to an extent exceeding the forward voltage Vf of the fourth diode 84, current flows from the second conductive path 52 to the third conductive path 53, and in the case where it is not such, current does not flow from the second conductive path 52 to the third conductive path 53.

[0126] The first switching portion 70 is a circuit that switches a power source for supplying electric power to the first output path 61. The first switching portion 70 is provided with a switching portion 74, a comparison circuit 72 corresponding to one example of the drive portion, and a first diode 71 corresponding to one example of the cutoff portion.

[0127] The comparison circuit 72 (driving section) is a circuit that sets the switch section 74 to the on state when the voltage of the first conductive path 51 is greater than the voltage of the second conductive path 52 or is greater than the voltage of the second conductive path 52 by a first prescribed value or more, and sets the switch section 74 to the off state when the voltage of the first conductive path 51 is less than the voltage of the second conductive path 52 or is less than the voltage of the second conductive path 52 by a second prescribed value or more. The comparison circuit 72 is configured as a known hysteresis comparator, for example. In the case where the first prescribed value and the second prescribed value are used, the first prescribed value and the second prescribed value can be the same or different. The first prescribed value and the second prescribed value can be 0 or a positive value. The comparison circuit 72 outputs a voltage signal of L level when the voltage of the first conductive path 51 is greater than the voltage of the second conductive path 52 by the first prescribed value or more, for example. The comparison circuit 72 switches to a state of outputting a voltage signal of H level when switching from a state of outputting a voltage signal of L level to a state where the voltage of the first conductive path 51 is less than the voltage of the second conductive path 52. In this case, the first prescribed value is a positive value that is greater than 0 and less than the voltage of the first conductive path 51 and the voltage of the second conductive path 52. The comparison circuit 72 switches to a state of outputting a voltage signal of L level when switching from a state of outputting a voltage signal of H level to a state where the voltage of the first conductive path 51 is greater than the voltage of the second conductive path 52 by the first prescribed value or more. The above-mentioned voltage signal of L level is a signal that indicates the on action of the switch section 74. The above-mentioned voltage signal of H level is a signal that indicates the off action of the switch section 74.

[0128] Further, the comparison circuit 72 can also be configured as a hysteresis comparator of other structure. For example, the comparison circuit 72 can also operate in a manner in which the switch section 74 is set to the on state when the voltage of the first conductive path 51 is greater than the voltage of the second conductive path 52, and is set to the off state when the voltage of the first conductive path 51 is less than the voltage of the second conductive path 52 by the second prescribed value or more. For example, the comparison circuit 72 can output a voltage signal of the L level when the voltage of the first conductive path 51 is greater than the voltage of the second conductive path 52, switch to a state of outputting a voltage signal of the H level when switching from the state of outputting the voltage signal of the L level to a state in which the voltage of the first conductive path 51 is less than the voltage of the second conductive path 52 by the second prescribed value or more, and switch to a state of outputting a voltage signal of the L level when switching from the state of outputting the voltage signal of the H level to a state in which the voltage of the first conductive path 51 is greater than the voltage of the second conductive path 52. Alternatively, the comparison circuit 72 can also be configured as a general comparator, in which case it is possible to output a voltage signal of the L level when the voltage of the first conductive path 51 is greater than the voltage of the second conductive path 52, set the switch section 74 to the on state, and output a voltage signal of the H level when the voltage of the first conductive path 51 is less than the voltage of the second conductive path 52, set the switch section 74 to the off state.

[0129] The switch section 74 is provided between the first conductive path 51 and the first output path 61, and allows conduction between the first conductive path 51 and the first output path 61 in the on state, and cuts off conduction between the first conductive path 51 and the first output path 61 in the off state. The switch section 74 has a pair of FETs 74A, 74B that are arranged in opposition to each other and connected in series. The FETs 74A, 74B are configured as P-channel type FETs (Field effect transistor), for example. The switch section 74 is in the off state when a voltage signal of the H level is output from the comparison circuit 72, and both of the FETs 74A, 74B are in the off state, cutting off conduction between the first conductive path 51 and the first output path 61 in both directions. The switch section 74 is in the on state when a voltage signal of the L level is output from the comparison circuit 72, and both of the FETs 74A, 74B are in the on state, allowing conduction between the first conductive path 51 and the first output path 61 in both directions.

[0130] The first conductive path 52 is electrically connected to the anode of the first diode 71 (cut-off portion), and the first output path 61 is electrically connected to the cathode of the first diode 71. The potential of the anode of the first diode 71 is set to the same potential as the potential of the second conductive path 52. The potential of the cathode of the first diode 71 is set to the same potential as the potential of the first output path 61. The first diode 71 causes current to flow from the second conductive path 52 to the first output path 61 when the potential of the second conductive path 52 is greater than the potential of the first output path 61 to an extent exceeding the forward voltage Vf of the first diode 71, and does not cause current to flow from the second conductive path 52 to the first output path 61 when this is not the case.

[0131] The first switching portion 70 thus configured supplies electric power from the first conductive path 51 to the first output path 61 when the voltage of the first conductive path 51 is relatively greater than the voltage of the second conductive path 52 in a prescribed first state (specifically, when at least the voltage of the first conductive path 51 is greater than the voltage of the second conductive path 52 by the first prescribed value or more), by setting the switch portion 74 to the on state. When the switch portion 74 is in the on state, a voltage identical to that of the first conductive path 51 (greater than the voltage of the second conductive path 52) is applied to the first output path 61, so current does not flow from the second conductive path 52 to the first output path 61. On the other hand, the first switching portion 70 supplies electric power from the second conductive path 52 to the first output path 61 when the voltage of the first conductive path 51 is relatively less than the voltage of the second conductive path 52 in a prescribed second state (specifically, when at least the voltage of the first conductive path 51 is less than the voltage of the second conductive path 52), by setting the switch portion 74 to the off state. When the switch portion 74 is in the off state, the supply of electric power from the first conductive path 51 to the first output path 61 is cut off, so the voltage of the first output path 61 is lower than the voltage of the second conductive path 52, and current flows from the second conductive path 52 to the first output path 61 via the first diode 71.

[0132] The second switching section 80 includes a second diode 82 and a third diode 83. The anode of the second diode 82 is electrically connected to the fourth conductive path 54, and a voltage based on the power supply section 91 is applied. The cathode of the second diode 82 is electrically connected to the second output path 62. The potential of the anode of the second diode 82 is set to the same potential as the potentials of the power path 94 and the fourth conductive path 54. The potential of the cathode of the second diode 82 is set to the same potential as the potential of the second output path 62. The anode of the third diode 83 is electrically connected to the third conductive path 53. The cathode of the third diode is electrically connected to the second output path 62. The potential of the anode of the third diode 83 is set to the same potential as the potential of the third conductive path 53. The potential of the cathode of the third diode 83 is set to the same potential as the potential of the second output path 62. The second switching section 80 sets a case where the voltage of the fourth conductive path 54 is greater than the voltage of the third conductive path 53 as a "predetermined third state", and in the third state, supplies power from the fourth conductive path 54 to the second output path 62. The second switching section 80 sets a case where the voltage of the fourth conductive path 54 is less than the voltage of the second conductive path 52 as a "predetermined fourth state", and in the fourth state, switches so as to supply power from the second conductive path 52 to the second output path 62. Specifically, in a case where the voltage of the fourth conductive path 54 is greater than the voltage of the third conductive path 53, current flows from the power path 94 and the fourth conductive path 54 to the second output path 62 via the second diode 82, and current does not flow from the third conductive path 53 to the second output path 62. In a case where the voltage of the third conductive path 53 is greater than the voltage of the fourth conductive path 54, current flows from the third conductive path 53 to the second output path 62 via the third diode 83, and current does not flow from the fourth conductive path 54 to the second output path 62.

[0133] 4. Operation of the power switching device

[0134] In the power switching device 5, the power control device 11 performs a first switching operation, a second switching operation, and a detection operation. The first switching operation is an operation of switching between a first supply operation of supplying power based on the power storage section 12 to the second conductive path 52 and a first stop operation of stopping the supply of power from the power storage section 12 to the second conductive path 52.

[0135] The control section 16 controls the switches 22, 24 in a manner that sets the switch 22 to the off state and sets the switch 24 to the on state, and causes the voltage conversion circuit 14 to perform the second conversion operation, in the case where the first supply operation is performed. The target value of the output voltage of the voltage conversion circuit 14 at the time of the second conversion operation is a value slightly smaller than the value of the voltage applied to the power passage 94 by the power supply section 91, and is a value larger than the minimum voltage required to cause the first load 101 to operate. The control section 16 controls so that the voltage conversion circuit 14 performs the step-up operation as the second conversion operation and outputs the voltage of the target value to the conductive passage 42, in the case where the above-described target value is larger than the voltage applied to the conductive passage 45 by the electric storage section 12 (the output voltage of the electric storage section 12). The control section 16 controls so that the voltage conversion circuit 14 performs the step-down operation as the second conversion operation and outputs the voltage of the target value to the conductive passage 42, in the case where the above-described target value is smaller than the voltage applied to the conductive passage 45 by the electric storage section 12 (the output voltage of the electric storage section 12). Furthermore, even if the voltage of the target value is output to the conductive passage 42 by the above-described second conversion operation, as long as current does not flow through the diodes 71, 84, it is possible to suppress consumption of the electric power from the electric storage section 12.

[0136] The control section 16 stops the operation of the voltage conversion circuit 14, for example, in the case where the above-described first stop operation is performed. The switch 22 can be set to the off state or the on state at the time of the first stop operation. The switch 24 can be set to the off state or the on state at the time of the first stop operation. Furthermore, the first stop operation can be an operation that sets the switch 24 to the off state while causing the voltage conversion circuit 14 to operate.

[0137] The second switching operation is an operation that switches between the second supply operation that supplies electric power based on the electric storage section 12 to the third conductive passage 53 and the second stop operation that stops the supply of electric power from the electric storage section 12 to the third conductive passage 53 via the discharge circuit 18.

[0138] The control section 16 causes the discharge circuit 18 to perform the discharge operation while performing at least one of the control that sets the switch 20 to the on state or the control that causes the voltage conversion circuit 14 to output the voltage to the conductive passage 47, in the case where the second supply operation is performed. The voltage applied to the conductive passage 44 and the third conductive passage 53 by the second supply operation is a value slightly smaller than the value of the voltage applied to the power passage 94 by the power supply section 91, and is a value larger than the minimum voltage required to cause the second load 102 to operate.

[0139] The following description is about the operation of the power supply system 3.

[0140] The power supply system 3 applies a voltage based on the power supply section 91 (for example, a voltage identical to the output voltage of the power supply section 91) to the power path 94, the first conductive path 51, and the fourth conductive path 54 even if the vehicle in which the vehicle-mounted system 2 is mounted is in a stop state (in a case where an ignition switch or the like is in an off state). Further, the power supply system 3, in the above stop state, does not perform the above first supply operation and the above second supply operation, and is cut off in a manner that no electric power is supplied from the power storage section 12 to the second conductive path 52 and the third conductive path 53. In this case, if it is a normal state in which a proper voltage based on the power supply section 91 is applied to the first conductive path 51 and the fourth conductive path 54, and the power control device 11 does not perform the first supply operation and the second supply operation, electric power is supplied to the first output path 61 and the second output path 62 based on the electric power from the power supply section 91. In Figure 2 the power supply state in this case is shown in FIG. 27. In a case where it is the above normal state and the power control device 11 does not perform the first supply operation and the second supply operation, electric power is supplied in a path indicated by an arrow shown in FIG. 27. Figure 2

[0141] The power supply system 3 starts the above first supply operation and the above second supply operation by the power control device 11 in a case where a predetermined prescribed start condition is satisfied. The prescribed start condition can be a condition such as "the vehicle becomes a start state", a condition such as "a certain time elapses from the start of the vehicle", a condition such as "the output voltage of the power storage section 12 reaches a prescribed value or more", or another condition. For example, the power control device 11 determines that the prescribed start condition is satisfied and starts the first supply operation and the second supply operation in a case where the vehicle in which the vehicle-mounted system 2 is mounted becomes a start state (in a case where an ignition switch or the like becomes an on state). Further, in the following description, a period in which the power control device 11 performs the first supply operation and the second supply operation is a normal operation period, and a period in which the power control device 11 performs a detection operation described later is a detection operation period.

[0142] In the normal operation period in which the power control device 11 performs the first supply operation and the second supply operation, a prescribed first voltage (a voltage of the above target value) based on the first supply operation is applied to the second conductive path 52, and a prescribed second voltage (a voltage based on discharge from the discharge circuit 18) based on the second supply operation is applied to the third conductive path 53. The above first voltage and the above second voltage can be identical or different. In the above normal operation period, in a case where the voltage of the first conductive path 51 is greater than the voltage of the second conductive path 52, electric power is supplied in a path indicated by an arrow shown in FIG. 28. Figure 3 ​The path indicated by arrow F1 supplies power from the power supply unit 91 to the first output path 61. When the voltage of the first conductive path 51 is less than the voltage of the second conductive path 52, [the power supply is activated]. Figure 3 The path indicated by arrow F2 supplies power from the energy storage unit 12 to the first output path 61. Additionally, during normal operation, if the voltage of the fourth conductive path 54 is greater than the voltage of the third conductive path 53, [the following is a continuation of the previous sentence]... Figure 3 The path indicated by arrow F3 supplies power from the power supply unit 91 to the second output path 62. When the voltage of the fourth conductive path 54 is less than the voltage of the third conductive path 53, [the power supply is activated]. Figure 3 The path indicated by arrow F4 in the diagram supplies power from the energy storage unit 12 to the second output path 62. Because of this operation, even during the aforementioned normal operation, for example... Figure 4 A ground fault occurs at position P1, and the voltage based on the power supply unit 91 is no longer applied to the first conductive path 51 and the fourth conductive path 54. This also immediately... Figure 4 The paths indicated by arrows F5 and F6 supply power from the energy storage unit 12 to the first load 101 and the second load 102. Furthermore, in this case, both FETs 74A and 74B are switched to the off state, thus preventing power supplied via the path of arrow F5 from bypassing the grounding portion.

[0143] Further, the electric power control device 11 can also perform a detection operation during a prescribed detection operation period. The detection operation period is a period from when a predetermined detection start condition is satisfied to when the detection operation is completed. The detection start condition can be a condition such as "the start switch of the vehicle changes from the off state to the on state", a condition such as "a certain period has elapsed since the end of the last detection operation", a condition such as "a certain period has elapsed since the start of the vehicle", or another condition. The electric power control device 11 starts the detection operation when the above-described detection start condition is satisfied. The detection operation is an operation of detecting the voltage of the third conductive path 53 in a state in which the first supply operation and the second stop operation are performed. Specifically, the electric power control device 11 detects the voltage of the third conductive path 53 in a state in which the first supply operation is performed in such a manner that a prescribed voltage (a voltage of a target value) is applied to the second conductive path 52, and the second stop operation is continued in such a manner that the current does not flow from the discharge circuit 18 to the conductive path 44. If the voltage of the third conductive path 53 detected by the above-described detection operation is greater than a threshold value, the control section 16 determines that it is normal, and if the voltage of the third conductive path 53 detected by the above-described detection operation is less than the threshold value, the control section 16 determines that it is abnormal. The threshold value used in this determination is a value that is greater than 0 and less than the above-described target value. The electric power control device 11 can also instruct a device having a display function or a device having a sound emitting function to perform notification (for example, abnormality display by a display mounted on the vehicle, sound notification by a buzzer or siren, or the like) indicating that there is an abnormality when it is determined that there is an abnormality in the above-described detection operation.

[0144] 5. Examples of Effects

[0145] The power switching device 5 can supply electric power to the first load 101 and the second load 102 using electric power from the electric storage section 12 in the case where the supply of electric power from the electric power section 91 via the electric power path 94 should be interrupted. Also, the power switching device 5 allows current to flow from the second conductive path 52 to the third conductive path 53 in the case where the voltage of the third conductive path 53 is lower than the voltage of the second conductive path 52, which is a prescribed state, and cuts off the current flowing from the second conductive path 52 to the third conductive path 53 in the case where it is not the prescribed state. That is, the power switching device 5 reflects whether or not it is the prescribed state to the third conductive path 53, so if the third conductive path 53 is set as a monitoring object, it is advantageous in terms of monitoring the supply of electric power from the electric storage section 12.

[0146] The power switching device 5 is capable of supplying electric power based on the power supply section 91 to the first output path 61 in a manner that loss is suppressed by setting the switch section 74 to the on state in a case where the voltage of the first conductive path 51 is greater than the voltage of the second conductive path 52. On the other hand, the power switching device 5 is capable of immediately supplying electric power based on the electric storage section 12 to the first output path 61 via the first diode 71 in a case where the voltage of the first conductive path 51 is less than the voltage of the second conductive path 52.

[0147] The power switching device 5 is capable of supplying electric power based on the power supply section 91 to the second output path 62 in a case where the power supply voltage based on the power supply section 91 is relatively high (specifically, in a case where the voltage of the fourth conductive path 54 is greater than the voltage of the third conductive path 53). On the other hand, the power switching device 5 is capable of immediately supplying electric power based on the electric storage section 12 to the second output path 62 in a case where the power supply voltage is relatively low due to failure or the like (specifically, in a case where the voltage of the fourth conductive path 54 is less than the voltage of the third conductive path 53). The power switching device 5 is capable of simply realizing such a function by the presence of the second switch section 80.

[0148] The power switching device 5 is capable of outputting electric power based on the electric storage section 12 to each of the separate paths (each of the second and third conductive paths 52 and 53), and is capable of individually switching the output to each path. Furthermore, the power switching device 5 uses one of the paths (the third conductive path 53) for both output and monitoring, and is capable of confirming whether or not the output from the other path (the second conductive path 52) is being performed properly, so it is capable of realizing monitoring of whether or not electric power supply from the electric storage section 12 is being performed properly by a simpler structure.

[0149] <Other Embodiments>

[0150] The present disclosure is not limited to the embodiments described above and illustrated in the drawings. For example, features of the above-described or hereinafter described embodiments can be combined in any manner as long as they are not contradictory. In addition, any feature of the above-described or hereinafter described embodiments can be omitted as long as it is not explicitly required. Further, the above-described embodiments can be changed as follows.

[0151] In the above-described embodiments, the electric storage section 12 is part of the power switching device 5, but the electric storage section 12 can be provided outside the power switching device 5.

[0152] In the above-described embodiments, the first device 10 is part of the power switching device 5, but the first device 10 can be provided outside the power switching device 5.

[0153] In the above-described embodiment, the first diode 71 is exemplified as the element section, but the element section can be a switch that turns on between the second conductive path 52 and the first output path 61 when a voltage signal of an L level is output from the comparison circuit 72 and turns off between the second conductive path 52 and the first output path 61 when a voltage signal of an H level is output.

[0154] In the above-described embodiment, the second switching section 80 is exemplified as one example of the second switching section, but the second switching section can be configured similarly to the first switching section 70. In the above-described embodiment, the first switching section 70 is exemplified as one example of the first switching section, but the first switching section can be configured similarly to the second switching section 80.

[0155] It should be understood that the embodiments disclosed herein are exemplary in all points, rather than limiting. The scope of the present application is not limited to the embodiments disclosed herein, and is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A power switching device for switching of a power source in a power source system having a power source unit, an electric storage unit, and a power passage which is a power supply path from the power source unit, wherein the power switching device has: a first conductive passage which is a path that receives supply of power from the power passage; a second conductive passage which is a path that supplies power based on the electric storage unit; a third conductive passage which is a path that supplies power based on the electric storage unit and is a different path from the second conductive passage; a fourth conductive passage which is a path that receives supply of power from the power passage and is a different path from the first conductive passage; a first output passage which is a path that supplies power to a first load; a second output passage which is a path that supplies power to a second load; a first switching unit that switches in a manner such that power from the first conductive passage is supplied to the first output passage in a prescribed first state in which a voltage of the first conductive passage is greater than a voltage of the second conductive passage, and power from the second conductive passage is supplied to the first output passage in a prescribed second state in which the voltage of the first conductive passage is less than the voltage of the second conductive passage; a second switching unit that switches in a manner such that power from the fourth conductive passage is supplied to the second output passage in a prescribed third state in which a voltage of the fourth conductive passage is greater than a voltage of the third conductive passage, and power from the third conductive passage is supplied to the second output passage in a prescribed fourth state in which the voltage of the fourth conductive passage is less than the voltage of the third conductive passage; and a component unit that allows current to flow from the second conductive passage to the third conductive passage in a prescribed state in which the voltage of the third conductive passage is lower than the voltage of the second conductive passage, and cuts off current flowing from the second conductive passage to the third conductive passage in a state other than the prescribed state.

2. The power switching device according to claim 1, wherein the first switching unit has a switching unit, a drive unit, and a cutoff unit that has a diode, the switching unit is provided between the first conductive passage and the first output passage, and in an on state, allows conduction between the first conductive passage and the first output passage, and in an off state, cuts off conduction between the first conductive passage and the first output passage, in a case where the voltage of the first conductive passage is greater than the voltage of the second conductive passage or in a case where the voltage of the first conductive passage is greater than the voltage of the second conductive passage by a first prescribed value or more, the drive unit sets the switching unit to the on state, and in a case where the voltage of the first conductive passage is less than the voltage of the second conductive passage or in a case where the voltage of the first conductive passage is less than the voltage of the second conductive passage by a second prescribed value or more, the drive unit sets the switching unit to the off state. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The first output path is electrically connected to a cathode of the diode of the cutoff section.

3. The power switching device according to claim 2, wherein The second cutoff section includes a second diode and a third diode, an anode of the second diode is electrically connected to the fourth conductive path, and a cathode of the second diode is electrically connected to the second output path, an anode of the third diode is electrically connected to the third conductive path, and a cathode of the third diode is electrically connected to the second output path.

4. The power switching device according to any one of claims 1 to 3, wherein The power switching device has a power control device that controls supply of electric power from the power storage section, the power control device performs a first switching operation, a second switching operation, and a detection operation, the first switching operation is an operation of switching between a first supply operation of supplying electric power based on the power storage section to the second conductive path and a first stop operation of stopping supply of electric power from the power storage section to the second conductive path, the second switching operation is an operation of switching between a second supply operation of supplying electric power based on the power storage section to the third conductive path and a second stop operation of stopping supply of electric power from the power storage section to the third conductive path, the detection operation is an operation of detecting a voltage of the third conductive path in a state in which the first supply operation and the second stop operation are performed.

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