Power switching control system

Abstract

A power switching control system includes a switching unit configured to switch connection and disconnection between a load provided with an operation priority and a power supply that supplies power to the load, the load and the power supply being connected to a power supply path; a power supply failure detection unit that detects a power supply failure caused by an abnormality on a power supply side or a load side; and a control unit that controls the switching unit. When the power supply failure detection unit detects the power supply failure, and a residual capacity, a charging rate, or a voltage of a plurality of power supplies is less than or equal to a predetermined threshold, the control unit sequentially disconnects the loads from the power supply path by the switching unit starting from one of the plurality of loads having a lowest operation priority among the operation priorities to gradually reduce a supply current from the power supply to the loads.

Description

Technical Field

[0001] This disclosure relates to a power switching control system. Background Technology

[0002] In vehicle power systems where a main power supply, a secondary power supply, and multiple auxiliary loads are connected in parallel, it is known, as disclosed in patent document JP2017-127112A, that when the output power from the main power supply decreases, more power is supplied from the secondary power supply to auxiliary loads with higher operating priority. As disclosed in patent document JP2019-062727A, in vehicle power systems comprising multiple power systems for redundant operation, it is known that even if an anomaly occurs in some power systems, the power supply and loads of the power systems experiencing the anomaly are continued to be used as much as possible.

[0003] In the on-board power system described in patent document JP2017-127112A, redundant operation becomes impossible when a failure occurs in the DC / DC converter that adjusts the power supplied from the auxiliary battery to each auxiliary load. In other words, there is a high dependence on the DC / DC converter and low reliability. Furthermore, the DC / DC converter is expensive and large.

[0004] In the vehicle power system described in patent document JP2019-062727A, if the remaining capacity of the power supply (battery) of the abnormal power system is insufficient, it is considered that the load with high operating priority cannot continue to be used. Summary of the Invention

[0005] This disclosure provides a power switching control system in which multiple power supplies are connected in parallel to a power supply path for redundant operation, and multiple loads are connected in parallel to the power supply path. When a power failure occurs due to an anomaly on the power supply side or the load side, power can be supplied to the load with high operating priority for the required period of time, even if the remaining capacity of the power supply is insufficient.

[0006] A power switching control system includes: a switching unit configured to switch the connection and disconnection between multiple loads with assigned operating priorities and multiple power supplies supplying power to the multiple loads, wherein the multiple loads and the multiple power supplies are connected in parallel to a power supply path; a power fault detection unit configured to detect power faults caused by abnormalities on the power supply side or the load side; and a control unit configured to control the switching unit. When the power fault detection unit detects a power fault, and the remaining capacity, charging rate, or voltage of the multiple power supplies is less than or below a predetermined threshold, the control unit disconnects the multiple loads from the power supply path via the switching unit, starting with the load having the lowest operating priority among the loads, to gradually reduce the supply current from the power supply to the loads. Attached Figure Description

[0007] Figure 1 This is a diagram illustrating an on-board power system including a power switching control system according to an embodiment of the present disclosure;

[0008] Figure 2 It is a graph showing the change in the charging rate [%] of the main battery or auxiliary battery from autonomous driving to stopping;

[0009] Figure 3 This is a table showing the control of the third to fifth switches under the conditions of a power failure due to an anomaly on the main battery side or the auxiliary battery side, the remaining capacity [Ah] of the normal battery being less than a threshold, and maintaining power supply to an important load with priority 1 during evacuation driving time;

[0010] Figure 4 This is a table showing the control of the third to fifth switches under the conditions that a power failure occurs due to an anomaly on the critical load side with priority 3, the remaining capacity [Ah] of the main battery and the auxiliary battery is less than the threshold, and power is maintained to the critical load with priority 1 during the evacuation driving time;

[0011] Figure 5 This is a table showing the control of the third to fifth switches under the condition that a power failure occurs due to an anomaly on the critical load side with priority 2, the remaining capacity [Ah] of the main battery and the auxiliary battery is less than the threshold, and power is maintained to the critical load with priority 1 during the evacuation driving time;

[0012] Figure 6 This is a table showing the control of the third to fifth switches under the conditions that a power failure occurs due to an anomaly on the critical load side with priority 1, the remaining capacity [Ah] of the main battery and the auxiliary battery is less than the threshold, and power is maintained to the critical load with priority 2 during the evacuation driving time;

[0013] Figure 7 It is used for explanation Figure 1 The flowchart of the power switching control system process;

[0014] Figure 8 It is used for explanation Figure 1 The flowchart of the power switching control system process;

[0015] Figure 9 It is used for explanation Figure 1 The flowchart of the power switching control system process;

[0016] Figure 10 It is used for explanation Figure 1 The flowchart of the power switching control system process;

[0017] Figure 11 This is a diagram illustrating an on-board power system including a power switching control system according to another embodiment of the present disclosure;

[0018] Figure 12 It is used for explanation Figure 11 The flowchart of the power switching control system; and

[0019] Figure 13 It is used for explanation Figure 11 The flowchart shows the processing of the power switching control system. Detailed Implementation

[0020] In the following description, this disclosure will be based on preferred embodiments. This disclosure is not limited to the embodiments described below, and modifications may be appropriately made to the embodiments described below without departing from the spirit of this disclosure. In the embodiments described below, some configurations are not shown or described, and known or widely understood techniques are appropriately applied to omitted technical details to the extent that they do not contradict the following description.

[0021] Figure 1 This is a diagram illustrating an on-board power system 1 including a power switching control system 10 according to an embodiment of the present disclosure. Figure 1 As shown, the vehicle power system 1 includes a main battery 2, a secondary battery 3, a high-voltage or low-voltage DC power supply 4, and a power switching control system 10. In the vehicle power system 1, the main battery 2 and the secondary battery 3 are connected in parallel to a common load L and multiple critical loads IL1 to IL3 (three in this embodiment). In the vehicle power system 1, power is supplied from the main battery 2 and the secondary battery 3 to the common load L and the critical loads IL1 to IL3 during normal driving. That is, in the vehicle power system 1, the power supply is redundant during normal driving. When the vehicle is stopped, the power supply is not redundant.

[0022] The vehicle power system 1 includes a battery management system (BMS) 5 that manages the main battery 2, a BMS 6 that manages the auxiliary battery 3, and an electronic control unit (ECU) 7 that controls the entire vehicle power system 1. The BMS 5 sends information about the status of the main battery 2 (remaining capacity [Ah], state of charge (SOC) [%], and power supply voltage [V]) to the ECU 7, and the BMS 6 sends information about the status of the auxiliary battery 3 (remaining capacity [Ah], SOC [%], and power supply voltage [V]) to the ECU 7.

[0023] The output terminal of the high-voltage or low-voltage DC power supply 4 is connected to the input terminal 10A of the power switching control system 10 via power supply line 8A. The main battery 2 is connected to power supply line 8A via BMS5, and the general load L is also connected to power supply line 8A.

[0024] Examples of main battery 2 include a 12V lead-acid battery or a lithium-ion battery. In this embodiment, main battery 2 is a 12V lead-acid battery. Examples of common loads L include air conditioning (A / C), audio, side marker lights, fog lights, and defrosters.

[0025] The high-voltage or low-voltage DC power supply 4 includes a DC / DC converter (not shown) that steps down a high voltage, such as 48V, to a low voltage, such as 12V, and outputs the low-voltage power to the main battery 2, the auxiliary battery 3, the general load L, the important loads IL1 to IL3, the power switching control system 10, etc.

[0026] The input terminal 10A and input or output terminal 10B of the power switching control system 10 are connected via power supply line 8B, and the input or output terminal 10B of the power switching control system 10 and the auxiliary battery 3 are connected via power supply line 8C through BMS6.

[0027] Examples of auxiliary battery 3 include a 12V lithium-ion battery or nickel-metal hydride battery, or a lead-acid battery, which can be connected to a lead-acid battery. In this embodiment, auxiliary battery 3 is a lithium-ion battery that can be connected to a lead-acid battery.

[0028] The power switching control system 10 is provided with multiple output terminals 10C, 10D and 10E. Output terminal 10C is connected to the critical load IL1 via power supply line 8D, output terminal 10D is connected to the critical load IL2 via power supply line 8E, and output terminal 10E is connected to the critical load IL3 via power supply line 8F.

[0029] Examples of critical loads IL1 with the highest operating priority (hereinafter referred to as Priority 1) may include electric brakes, electric parking brakes, auxiliary devices for electric steering (steer-by-wire (SBW)), door locks, electronic power steering, auxiliary devices for advanced driver assistance systems (ADAS), main power supply for data communication modules (DCM), main power supply for airbag devices, cameras, driver-side headlights, and head-up displays.

[0030] Examples of critical loads IL2 with the second highest operational priority (hereinafter referred to as Priority 2) may include ECU 7, the master unit of the electric power steering system, the master unit of ADAS, the remote parking ECU, instruments, and cameras. Examples of critical loads IL3 with the third highest operational priority (hereinafter referred to as Priority 3) may include sideslip or slip prevention devices (Vehicle Dynamics Control (VDC)) and passenger-side headlights.

[0031] The power switching control system 10 includes a first switch 11 and a second switch 12. The first switch 11 and the second switch 12 are disposed on the power supply line 8B. The first switch 11 is disposed on the input terminal 10A side (i.e., the main battery 2 side), and the second switch 12 is disposed on the input or output terminal 10B side (i.e., the auxiliary battery 3 side).

[0032] Power supply line 8G is connected between the first switch 11 and the second switch 12 in power supply line 8B. Power supply line 8G and output terminal 10C are connected via power supply line 8H, power supply line 8G and output terminal 10D are connected via power supply line 8I, and power supply line 8G and output terminal 10E are connected via power supply line 8J. That is, the important load IL1 with priority 1 is connected to power supply line 8G via power supply lines 8D and 8H, the important load IL2 with priority 2 is connected to power supply line 8G via power supply lines 8E and 8I, and the important load IL3 with priority 3 is connected to power supply line 8G via power supply lines 8F and 8J. Therefore, important loads IL1 to IL3 are connected in parallel to power supply line 8G.

[0033] Using the connection point P between power supply lines 8B and 8G as the boundary, the vehicle power system 1 is divided into a main battery 2 side and a secondary battery 3 side. A first switch 11 is located on the main battery 2 side, connecting the main battery 2, the high-voltage or low-voltage DC power supply 4, and the common load L to or disconnecting them from the power switching control system 10. Simultaneously, a second switch 12 is located on the secondary battery 3 side, connecting or disconnecting the secondary battery 3 from the power switching control system 10.

[0034] The power switching control system 10 includes a third switch 13, a fourth switch 14, and a fifth switch 15. The third switch 13 is located on power supply line 8H, which connects a priority 1 important load IL1 to power supply line 8G. The fourth switch 14 is located on power supply line 8I, which connects a priority 2 important load IL2 to power supply line 8G. The fifth switch 15 is located on power supply line 8J, which connects a priority 3 important load IL3 to power supply line 8G.

[0035] The third switch 13 connects the critical load IL1 with priority 1 to or disconnects it from power supply line 8G. The fourth switch 14 connects the critical load IL2 with priority 2 to or disconnects it from power supply line 8G. The fifth switch 15 connects the critical load IL3 with priority 3 to or disconnects it from power supply line 8G.

[0036] Examples of the first switches 11 to the fifth switches 15 may include mechanical relays and semiconductor relays such as metal-oxide-semiconductor field-effect transistors (MOSFETs). The power switching control system 10 includes a switch control unit 30. The first switches 11 to the fifth switches 15 are connected to the switch control unit 30 via switch control lines SCL and are switched on or off (ON or OFF) by control signals sent from the switch control unit 30.

[0037] The switch control unit 30 is communicatively connected to the ECU 7 via the communication interface 21. The ECU 7 sends information about the status of the main battery 2 received from the BMS 5 and information about the status of the auxiliary battery 3 received from the BMS 6 to the switch control unit 30.

[0038] The power switching control system 10 includes a first current or voltage sensor 16 to a fifth current or voltage sensor 20, a first power fault determination unit 31, and a second power fault determination unit 32. The first current or voltage sensor 16 to the fifth current or voltage sensor 20 measures at least one of a current value [A] and a voltage value [V], and sends the value to the first power fault determination unit 31 and the second power fault determination unit 32.

[0039] A first current or voltage sensor 16 is disposed between the input terminal 10A on the power supply line 8B and the first switch 11, and a second current or voltage sensor 17 is disposed between the second switch 12 on the power supply line 8B and the input or output terminal 10B. A third current or voltage sensor 18 is disposed between the third switch 13 and the output terminal 10C, a fourth current or voltage sensor 19 is disposed between the fourth switch 14 and the output terminal 10D, and a fifth current or voltage sensor 20 is disposed between the fifth switch 15 and the output terminal 10E.

[0040] The first power supply fault determination unit 31 determines the existence of a power supply fault based on at least one of the current value [A] and voltage value [V] received from the first current or voltage sensor 16 and the second current or voltage sensor 17, or the difference ΔV (potential difference) between the received voltage values ​​[V] and the positive or negative (current direction) of the current value [A]. Specifically, when a power supply fault occurs, the first power supply fault determination unit 31 determines whether the abnormality on the main battery 2 side or the abnormality on the auxiliary battery 3 side caused the power supply fault. The first power supply fault determination unit 31 sends the determination result to the switch control unit 30.

[0041] The second power supply fault determination unit 32 determines the presence of a power supply fault based on at least one of the current value [A] and voltage value [V] received from the third current or voltage sensor 18 to the fifth current or voltage sensor 20. Specifically, when a power supply fault occurs, the second power supply fault determination unit 32 determines which of the critical loads IL1 to IL3 is abnormal and causes the power supply fault. The second power supply fault determination unit 32 sends the determination result to the switch control unit 30.

[0042] Examples of power supply failures may include: momentary interruptions or momentary power failures caused by faults in the high-voltage or low-voltage DC power supply 4 (internal short circuits), grounding faults, etc.; voltage drops caused by faults in the high-voltage or low-voltage DC power supply 4 (output reduction), degradation of the main battery 2 or the auxiliary battery 3, etc.; and voltage fluctuations caused by faults in the high-voltage or low-voltage DC power supply 4, etc.

[0043] For example, the threshold values ​​used as determination conditions for the first power supply fault determination unit 31 may be: a normal voltage value [V] of 8V or higher and 16V or lower; a voltage drop threshold of less than 8V; and an overcurrent threshold of 150A or higher. For example, the threshold values ​​used as determination conditions for the second power supply fault determination unit 32 may be: a voltage drop threshold of 5V or lower; and an overcurrent threshold of 30A or higher.

[0044] The switch control unit 30 has a self-diagnostic (DIAG) function, and when the switch control unit 30 receives a determination result indicating the presence of a power fault from the first power fault determination unit 31 or the second power fault determination unit 32, it sends a DIAG signal to the ECU 7. The DIAG signal includes: information about the abnormal state of the vehicle power system 1 (detailed information about the abnormality causing the power fault, etc.), and information such as the measurement values ​​of the first current or voltage sensor 16 to the fifth current or voltage sensor 20.

[0045] When the voltage on the main battery 2 side and the voltage on the auxiliary battery 3 side compete, the switch control unit 30 turns on all the first switches 11 to the fifth switches 15. Therefore, the high-voltage or low-voltage DC power supply 4 supplies power to the main battery 2, the auxiliary battery 3, the ordinary load L, and the critical loads IL1 to IL3.

[0046] Even when the auxiliary battery 3 is charging, the switch control unit 30 keeps all first switches 11 through fifth switches 15 on. Therefore, the high-voltage or low-voltage DC power supply 4 supplies power to the main battery 2, auxiliary battery 3, general load L, and critical loads IL1 through IL3. While the auxiliary battery 3 is charging, the second switch 12 remains on until the auxiliary battery 3 is fully charged. During this period, power redundancy control is not performed, and the ADAS system stops autonomous driving and switches to manual driving.

[0047] Furthermore, when the secondary battery 3 is fully charged (here, the voltage on the main battery 2 side is greater than the voltage on the secondary battery 3 side), the switch control unit 30 disconnects the second switch 12. Therefore, the high-voltage or low-voltage DC power supply 4 supplies power to the main battery 2, the general load L, and the critical loads IL1 to IL3.

[0048] Additionally, when the switch control unit 30 receives a signal from the ECU7 notifying the vehicle to stop idling, the switch control unit 30 disconnects the first switch 11 and connects the second switch 12. Furthermore, the third to fifth switches 15 are connected. Therefore, the high-voltage or low-voltage DC power supply 4 is disconnected from the critical loads IL1 to IL3, and the auxiliary battery 3 is connected to the critical loads IL1 to IL3 to supply power to them.

[0049] Here, when the vehicle is a gasoline vehicle, the high-voltage or low-voltage DC power supply 4 is an alternator, and when the engine restarts from idle stop, the output voltage fluctuates due to starting rotation. Therefore, when the engine stops idling, the switch control unit 30 temporarily disconnects the first switch 11 to disconnect the high-voltage or low-voltage DC power supply 4 from the critical loads IL1 to IL3, and switches the power supply from the auxiliary battery 3 to the critical loads IL1 to IL3. Thus, when the engine restarts from idle stop, the voltage fluctuations of the high-voltage or low-voltage DC power supply 4 are prevented from affecting the critical loads IL1 to IL3.

[0050] When the first power failure determination unit 31 determines that a power failure has occurred due to an abnormality on the main battery 2 side, the switch control unit 30 disconnects the first switch 11. Therefore, the main battery 2 side with the abnormality is disconnected from the vehicle power system 1, and power supply is maintained from the auxiliary battery 3 in its normal state to the critical loads IL1 to IL3. Simultaneously, when the first power failure determination unit 31 determines that a power failure has occurred due to an abnormality on the auxiliary battery 3 side, the switch control unit 30 disconnects the second switch 12. Therefore, the auxiliary battery 3 side with the abnormality is disconnected from the vehicle power system 1, and power supply is maintained from the main battery 2 in its normal state to the critical loads IL1 to IL3.

[0051] When the second power failure determination unit 32 determines that a power failure has occurred due to an abnormality on any one of the critical loads IL1 to IL3, the switch control unit 30 shuts off the switch (any one of the third switch 13 to the fifth switch 15) corresponding to any of the critical loads IL1 to IL3 with the abnormality. Therefore, any critical load IL1 to IL3 with the abnormality is disconnected from the vehicle power system 1, and power supply is maintained to the remaining loads of the critical loads IL1 to IL3 in normal condition.

[0052] Incidentally, in vehicles equipped with ADAS systems (autonomous driving functions), examples of functions related to autonomous driving include the determination functions of the main or auxiliary ADAS devices, the display functions of the instrument cluster and head-up display, the braking functions of skid or slip prevention devices or electric brakes, the steering functions of the main and auxiliary electric steering devices, and the cognitive functions of cameras and headlights. During autonomous driving in a vehicle equipped with an ADAS system, when the first power failure determination unit 31 or the second power failure determination unit 32 determines that a power failure has occurred, that is, when it is found that power supply to at least one of the critical loads IL1 to IL3 that enable the functions related to autonomous driving cannot be maintained, the vehicle needs to stop at a safe position.

[0053] Here, it is necessary to maintain power supply to the normal critical loads IL1 to IL3 during the time from autonomous driving to the vehicle stopping at a safe location (hereinafter referred to as evacuation driving time). For example, assuming the evacuation driving time is more than 180 seconds, if the current consumption of critical loads IL1 to IL3 is 60 [A], then the remaining capacity [Ah] of the main battery 2 or the auxiliary battery 3 needs to be more than 3Ah.

[0054] Therefore, when it is found that the switch control unit 30 cannot maintain power supply to at least one of the critical loads IL1 to IL3 during autonomous driving, the on and off control of the third switch 13 to the fifth switch 15 is executed, so that power supply to the critical load IL1 (or IL2) with high operational priority is maintained during evacuation driving time. The processing of the power switching control system 10 during vehicle evacuation driving will be described below.

[0055] Figure 2 This is a graph showing the change in the state of charge (SOC [%)) of the main battery 2 or auxiliary battery 3 from autonomous driving to a standstill (during evacuation driving time). As shown by the dotted line in the graph, when the main battery 2 or auxiliary battery 3 is fully charged (SOC = 100%), it is able to maintain power supply to all critical loads IL1 to IL3 during evacuation driving time. However, as shown by the double-dotted line in the graph, if all third switches 13 to fifth switches 15 remain on during evacuation driving time according to the charge rate of the main battery 2 or auxiliary battery 3, it may be impossible to maintain power supply to all critical loads IL1 to IL3.

[0056] Therefore, when the first power failure determination unit 31 determines that a power failure has occurred on the main battery 2 side and the remaining capacity [Ah] of the auxiliary battery 3 is equal to or higher than a threshold (e.g., 3Ah), the switch control unit 30 disconnects the first switch 11, keeps the second switch 12 on, and keeps the third switch 13 to the fifth switch 15 on. Thus, power supply from the auxiliary battery 3 to all critical loads IL1 to IL3 is maintained during evacuation driving time. Simultaneously, when the first power failure determination unit 31 determines that a power failure has occurred on the main battery 2 side and the remaining capacity [Ah] of the auxiliary battery 3 is less than a threshold, the switch control unit 30 disconnects the first switch 11, keeps the second switch 12 and the third switch 13 on, and disconnects the fourth switch 14 and the fifth switch 15 in the order of the fifth switch 15 and the fourth switch 14. That is, in this case, the fourth switch 14 and the fifth switch 15 are disconnected sequentially, starting with the switch with the lower operating priority among the corresponding critical loads IL2 and IL3. Therefore, the supply current from the auxiliary battery 3 to the critical loads IL1 and IL3 gradually decreases during the evacuation driving time, and the discharge time of the auxiliary battery 3 is extended, so as to maintain the power supply to the critical load IL1 with priority 1.

[0057] Furthermore, when the first power failure determination unit 31 determines that a power failure is caused by an abnormality on the auxiliary battery 3 side, and the remaining capacity [Ah] of the main battery 2 is equal to or higher than a threshold (e.g., 3Ah), the switch control unit 30 disconnects the second switch 12, keeps the first switch 11 on, and keeps the third switch 13 to the fifth switch 15 on. Therefore, power supply from the main battery 2 to all critical loads IL1 to IL3 is maintained during the evacuation driving time. Simultaneously, when the first power failure determination unit 31 determines that a power failure is caused by an abnormality on the auxiliary battery 3 side, and the remaining capacity [Ah] of the main battery 2 is less than a threshold, the switch control unit 30 disconnects the second switch 12, keeps the first switch 11 and the third switch 13 on, and disconnects the fourth switch 14 and the fifth switch 15 in the order of the fifth switch 15 and the fourth switch 14. Therefore, the supply current from the main battery 2 to the critical loads IL1 to IL3 gradually decreases during the evacuation driving time, and the discharge time of the main battery 2 is prolonged, thus maintaining power supply to the critical load IL1 with priority 1.

[0058] Figure 3 This is a table showing the control of the third switch 13 to the fifth switch 15 under the condition that a power failure occurs due to an anomaly on the main battery side 2 or the auxiliary battery side, the remaining capacity [Ah] of the normal battery is less than a threshold, and power supply to the critical load IL1 with priority 1 is maintained during the evacuation driving time. As shown in the table, in the first phase of the evacuation driving time ( Figure 2 During phase 1 of the evacuation period, switches 13 through 15 remain closed. Then, during the second phase of the evacuation driving time... Figure 2 In the second phase of the evacuation period, the fifth switch 15, corresponding to the critical load IL3 with priority 3 (low), is disconnected, and in the third phase of the evacuation driving time ( Figure 2 During time phase 3), the fourth switch 14, corresponding to the important load IL2 with priority 2 (intermediate), is disconnected. Therefore, the supply current from the main battery 2 or the auxiliary battery 3 to the important loads IL1 to IL3 gradually decreases to, for example, 60A, 40A, and 20A.

[0059] Furthermore, when the second power failure determination unit 32 determines that a power failure is caused by an anomaly on the important load IL3 side with priority 3, and the remaining capacity [Ah] of the main battery 2 or the auxiliary battery 3 is equal to or higher than a threshold (e.g., 3Ah), the switch control unit 30 keeps the first switch 11 to the fourth switch 14 on and disconnects the fifth switch 15. Therefore, power supply from the main battery 2 and the auxiliary battery 3 to the important loads IL1 and IL2 is maintained during the evacuation driving time. Simultaneously, when the second power failure determination unit 32 determines that a power failure is caused by an anomaly on the important load IL3 side with priority 3, and the remaining capacity [Ah] of the main battery 2 and the auxiliary battery 3 is less than a threshold, the switch control unit 30 keeps the first switch 11 to the third switch 13 on, disconnects the fifth switch 15, and disconnects the fourth switch 14 midway through the evacuation driving time. Therefore, the supply current from the main battery 2 or the auxiliary battery 3 to the critical loads IL1 and IL2 with priorities 1 and 2 gradually decreases during the evacuation driving time, and the discharge time of the main battery 2 and the auxiliary battery 3 is extended, so as to maintain the power supply to the critical load IL1 with priority 1.

[0060] Figure 4 This is a table showing the control of the third to fifth switches 15 under the condition that a power failure occurs due to an anomaly on the side of the critical load IL3 with priority 3 (low), the remaining capacity [Ah] of the main battery 2 and the auxiliary battery 3 is less than a threshold, and power supply to the critical load IL1 with priority 1 (high) is maintained during the evacuation driving time. As shown in the table, in the first phase (time phase 1) of the evacuation driving time, the fifth switch 15 corresponding to the critical load IL3 with priority 3 is turned off, and the third switch 13 and the fourth switch 14 corresponding to the critical loads IL1 and IL2 with priorities 1 and 2 remain on. Next, in the second phase (time phase 2) of the evacuation driving time, the fourth switch 14 corresponding to the critical load IL2 with priority 2 (intermediate) is turned off. Then, in the third phase (time phase 3) of the evacuation driving time, the third switch 13 corresponding to the critical load IL1 with priority 1 (intermediate) remains on. Therefore, the supply current from the main battery 2 and the auxiliary battery 3 to the critical loads IL1 and IL2 with priorities 1 and 2 gradually decreases to, for example, 40A, 20A and 20A during the evacuation driving time.

[0061] Furthermore, when the second power failure determination unit 32 determines that a power failure is caused by an anomaly on the important load IL2 side with priority 2, and the remaining capacity [Ah] of the main battery 2 or the auxiliary battery 3 is equal to or higher than a threshold (e.g., 3Ah), the switch control unit 30 keeps the first switch 11 to the third switch 13 and the fifth switch 15 on, and disconnects the fourth switch 14. Therefore, power supply from the main battery 2 and the auxiliary battery 3 to the important loads IL1 and IL3 is maintained during the evacuation driving time. Simultaneously, when the second power failure determination unit 32 determines that a power failure is caused by the important load IL2 side with priority 2, and the remaining capacity [Ah] of the main battery 2 and the auxiliary battery 3 is less than a threshold, the switch control unit 30 keeps the first switch 11 to the third switch 13 on, disconnects the fourth switch 14, and disconnects the fifth switch 15 midway through the evacuation driving time. Therefore, the supply current from the main battery 2 and the auxiliary battery 3 to the critical loads IL1 and IL3 with priorities 1 and 3 gradually decreases during the evacuation driving time, and the discharge time of the main battery 2 and the auxiliary battery 3 is extended, so as to maintain the power supply to the critical load IL1 with priority 1.

[0062] Figure 5 This is a table showing the control of the third to fifth switches 15 under the condition that a power failure occurs due to an anomaly on the side of the critical load IL2 with priority 2 (intermediate), the remaining capacity [Ah] of the main battery 2 and the auxiliary battery 3 is less than a threshold, and power supply to the critical load IL1 with priority 1 (high) is maintained during the evacuation driving time. As shown in the table, in the first phase (time phase 1) of the evacuation driving time, the fourth switch 14 corresponding to the critical load IL2 with priority 2 is turned off, and the third switch 13 and the fifth switch 15 corresponding to the critical loads IL1 and IL3 with priorities 1 and 3 (low) remain on. Next, in the second phase (time phase 2) of the evacuation driving time, the fifth switch 15 corresponding to the critical load IL3 with priority 3 is turned off. Then, in the third phase (time phase 3) of the evacuation driving time, the third switch 13 corresponding to the critical load IL1 with priority 1 (intermediate) remains on. Therefore, the supply current from the main battery 2 and the auxiliary battery 3 to the critical loads IL1 and IL3 with priorities 1 and 3 gradually decreases to, for example, 40A, 20A and 20A during the evacuation driving time.

[0063] Furthermore, when the second power failure determination unit 32 determines that a power failure has occurred due to an anomaly on the side of the important load IL1 with priority 1, and the remaining capacity [Ah] of the main battery 2 or the auxiliary battery 3 is equal to or higher than a threshold (e.g., 3Ah), the switch control unit 30 keeps the first switch 11, the second switch 12, the fourth switch 14, and the fifth switch 15 on, and disconnects the third switch 13. Therefore, power supply from the main battery 2 and the auxiliary battery 3 to the important loads IL2 and IL3 with priorities 2 and 3 is maintained during the evacuation driving time. Simultaneously, when the second power failure determination unit 32 determines that a power failure has occurred due to an anomaly on the side of the important load IL1 with priority 1, and the remaining capacity [Ah] of the main battery 2 and the auxiliary battery 3 is less than a threshold, the switch control unit 30 keeps the first switch 11, the second switch 12, the fourth switch 14, and the fifth switch 15 on, disconnects the third switch 13, and disconnects the fifth switch 15 midway through the evacuation driving time. Therefore, the supply current from the main battery 2 and the auxiliary battery 3 to the critical loads IL2 and IL3 with priorities 2 and 3 gradually decreases during the evacuation driving time, and the discharge time of the main battery 2 and the auxiliary battery 3 is extended, so as to maintain the power supply to the critical load IL2 with priority 2.

[0064] Figure 6 This is a table showing the control of the third to fifth switches 15 under the condition that a power failure occurs due to an anomaly on the side of the critical load IL1 with priority 1 (high), the remaining capacity [Ah] of the main battery 2 and the auxiliary battery 3 is less than a threshold, and power supply to the critical load IL2 with priority 2 (intermediate) is maintained during the evacuation driving time. As shown in the table, in the first phase (time phase 1) of the evacuation driving time, the third switch 13 corresponding to the critical load IL1 with priority 1 is turned off, and the fourth switch 14 and the fifth switch 15 corresponding to the critical loads IL2 and IL3 with priorities 2 and 3 (low) remain on. Next, in the second phase (time phase 2) of the evacuation driving time, the fifth switch 15 corresponding to the critical load IL3 with priority 3 is turned off. Then, in the third phase (time phase 3) of the evacuation driving time, the fourth switch 14 corresponding to the critical load IL2 with priority 2 (intermediate) remains on. Therefore, the supply current from the main battery 2 and the auxiliary battery 3 to the important loads IL2 and IL3 with priorities 2 and 3 gradually decreases to, for example, 40A, 20A and 20A during the evacuation driving time.

[0065] Figures 7 to 10 This is a flowchart illustrating the processing of the power switching control system 10 of this embodiment. When the vehicle starts, the processing shown in the flowchart begins, and the processing proceeds to step S1.

[0066] In step S1, the switch control unit 30 turns on all first switches 11 to fifth switches 15. Therefore, the main battery 2 and the auxiliary battery 3 are connected to the ordinary load L and the critical loads IL1 to IL3, and power is supplied to the ordinary load L and the critical loads IL1 to IL3. Additionally, the switch control unit 30 obtains information from the ECU7 regarding the remaining capacity [Ah] of the main battery 2 held by the BMS5 and the remaining capacity [Ah] of the auxiliary battery 3 held by the BMS6.

[0067] Next, in step S2, the second power supply fault determination unit 32 determines whether all critical loads IL1 to IL3 are in a normal state without any abnormalities such as overcurrent. If a positive determination is made in step S2, the process proceeds to step S3; otherwise, the process proceeds to step S4. Figure 9 Step S21 in the process.

[0068] In step S3, the first power failure determination unit 31 determines whether both the main battery 2 side and the auxiliary battery 3 side are in a normal state where no power failure has occurred. If an affirmative determination is made in step S3, the process proceeds to step S4; if a negative determination is made in step S3, the process proceeds to step S31.

[0069] In step S4, the switch control unit 30 determines whether the vehicle has stopped. If a positive determination is made in step S4, the process ends; if a negative determination is made in step S4, the process proceeds to step S1.

[0070] In step S31, the first power failure determination unit 31 determines whether the power failure is caused by an abnormality on the main battery 2 side or by an abnormality on the secondary battery 3 side. If it is determined in step S31 that the power failure is caused by an abnormality on the main battery 2 side, the process proceeds to step S32; and if it is determined in step S31 that the power failure is caused by an abnormality on the secondary battery 3 side, the process proceeds to... Figure 8 Step S311 in the process.

[0071] In step S32, the switch control unit 30 disconnects the first switch 11. Next, in step S33, the switch control unit 30 sends a DIAG signal to the ECU 7. Then, in step S34, the switch control unit 30 determines whether the remaining capacity [Ah] of the auxiliary battery 3 is 3Ah or more. If a positive determination is made in step S34, the process proceeds to step S35; if a negative determination is made in step S34, the process proceeds to step S36.

[0072] In step S35, the switch control unit 30 keeps the third switch 13 to the fifth switch 15 closed and maintains power supply from the auxiliary battery 3 to the critical loads IL1 to IL3. The process proceeds from step S35 to step S4. Meanwhile, in step S36, the switch control unit 30 keeps the third switch 13 to the fifth switch 15 closed during the first phase (time phase 1) of the evacuation driving time. Next, in step S37, the switch control unit 30 disconnects the fifth switch 15 during the second phase (time phase 2) of the evacuation driving time. Next, in step S38, the switch control unit 30 disconnects the fourth switch 14 during the third phase (time phase 3) of the evacuation driving time. The process proceeds from step S38 to step S4.

[0073] exist Figure 8 In step S311, the switch control unit 30 disconnects the second switch 12. Next, in step S312, the switch control unit 30 sends a DIAG signal to the ECU 7. Then, in step S313, the switch control unit 30 determines whether the remaining capacity [Ah] of the main battery 2 is 3Ah or more. If a positive determination is made in step S313, the process proceeds to step S314; if a negative determination is made in step S313, the process proceeds to step S315.

[0074] In step S314, the switch control unit 30 keeps the third switch 13 to the fifth switch 15 closed and maintains power supply from the main battery 2 to the critical loads IL1 to IL3. The process proceeds from step S314 to... Figure 7 Step S4. Simultaneously, in step S315, the switch control unit 30 keeps the third switch 13 to the fifth switch 15 closed during the first phase (time phase 1) of the evacuation driving time. Next, in step S316, the switch control unit 30 disconnects the fifth switch 15 during the second phase (time phase 2) of the evacuation driving time. Next, in step S317, the switch control unit 30 disconnects the fourth switch 14 during the third phase (time phase 3) of the evacuation driving time. Processing proceeds from step S317 to... Figure 7 Step S4 in the process.

[0075] exist Figure 9 In step S21, the second power supply fault determination unit 32 determines whether the measured value of the third current or voltage sensor 18 corresponding to the critical load IL1 is an abnormal value. If a positive determination is made in step S21, the process proceeds to step S22, and if a negative determination is made in step S21, the process proceeds to step S211.

[0076] In step S211, the second power supply fault determination unit 32 determines whether the measured value of the fourth current or voltage sensor 19 corresponding to the critical load IL2 is an abnormal value. If a positive determination is made in step S211, the process proceeds to step S212; and if a negative determination is made in step S211, the process proceeds to step S223. Figure 10 Step S221 in the process.

[0077] In step S22, the switch control unit 30 disconnects the third switch 13 corresponding to the critical load IL1. Next, in step S23, the switch control unit 30 sends a DIAG signal to the ECU 7. Then, in step S24, the switch control unit 30 determines whether the remaining capacity [Ah] of the main battery 2 or the auxiliary battery 3 is 3Ah or more. If a positive determination is made in step S24 (if the remaining capacity [Ah] of at least one of the main battery 2 and the auxiliary battery 3 is 3Ah or more), the process proceeds to step S25; if a negative determination is made in step S24, the process proceeds to step S26.

[0078] In step S25, the switch control unit 30 keeps the fourth switch 14 and the fifth switch 15 corresponding to the critical loads IL2 and IL3 closed. Processing continues from step S25... Figure 7 Step S4. Simultaneously, in step S26, the switch control unit 30 keeps the fourth switch 14 and the fifth switch 15 corresponding to the critical loads IL2 and IL3 closed during the first phase (time phase 1) of the evacuation driving time. Next, in step S27, the switch control unit 30 keeps the fourth switch 14 and the fifth switch 15 corresponding to the critical loads IL2 and IL3 closed during the second phase (time phase 2) of the evacuation driving time. Next, in step S28, the switch control unit 30 disconnects the fifth switch 15 corresponding to the critical load IL3 during the third phase (time phase 3) of the evacuation driving time. Processing proceeds from step S28 to... Figure 7 Step S4 in the process.

[0079] In step S212, the switch control unit 30 disconnects the fourth switch 14 corresponding to the critical load IL2. Next, in step S213, the switch control unit 30 sends a DIAG signal to the ECU 7. Then, in step S214, the switch control unit 30 determines whether the remaining capacity [Ah] of the main battery 2 or the auxiliary battery 3 is 3Ah or more. If a positive determination is made in step S214, the process proceeds to step S215; if a negative determination is made in step S214, the process proceeds to step S216.

[0080] In step S215, the switch control unit 30 keeps the third switch 13 and the fifth switch 15 corresponding to the critical loads IL1 and IL3 closed. Processing proceeds from step S215 to... Figure 7 Step S4. Simultaneously, in step S216, the switch control unit 30 keeps the third switch 13 and the fifth switch 15 corresponding to the critical loads IL1 and IL3 closed during the first phase (time phase 1) of the evacuation driving time. Next, in step S217, the switch control unit 30 keeps the third switch 13 and the fifth switch 15 corresponding to the critical loads IL1 and IL3 closed during the second phase (time phase 2) of the evacuation driving time. Next, in step S218, the switch control unit 30 disconnects the fifth switch 15 corresponding to the critical load IL3 during the third phase (time phase 3) of the evacuation driving time.

[0081] The process proceeds from step S218 to... Figure 7 Step S4 in the process.

[0082] exist Figure 10 In step S221, the switch control unit 30 disconnects the fifth switch 15 corresponding to the critical load IL3. Next, in step S222, the switch control unit 30 sends a DIAG signal to the ECU 7. Then, in step S223, the switch control unit 30 determines whether the remaining capacity [Ah] of the main battery 2 or the auxiliary battery 3 is 3Ah or more. If a positive determination is made in step S223, the process proceeds to step S224; if a negative determination is made in step S223, the process proceeds to step S225.

[0083] In step S224, the switch control unit 30 keeps the third switch 13 and the fourth switch 14 corresponding to the critical loads IL1 and IL2 closed. Processing proceeds from step S224 to... Figure 7 Step S4. Simultaneously, in step S225, the switch control unit 30 keeps the third switch 13 and the fourth switch 14 corresponding to the critical loads IL1 and IL2 closed during the first phase (time phase 1) of the evacuation driving time. Next, in step S226, the switch control unit 30 keeps the third switch 13 and the fourth switch 14 corresponding to the critical loads IL1 and IL2 closed during the second phase (time phase 2) of the evacuation driving time. Next, in step S227, the switch control unit 30 disconnects the fourth switch 14 corresponding to the critical load IL2 during the third phase (time phase 3) of the evacuation driving time.

[0084] The process proceeds from step S227 to... Figure 7 Step S4 in the process.

[0085] As described above, in the power switching control system 10 of this embodiment, when the first power fault determination unit 31 or the second power fault determination unit 32 determines that a power fault has occurred due to an abnormality on the main battery 2 side, the auxiliary battery 3 side, or the critical loads IL1 to IL3 side, the switch control unit 30 determines whether the remaining capacity [Ah] of both the main battery 2 and the auxiliary battery 3 is equal to or higher than a predetermined threshold. The switch control unit 30 disconnects the abnormal battery between the main battery 2 and the auxiliary battery 3 via the first switch 11 and the second switch 12. When the remaining capacity [Ah] of both the main battery 2 and the auxiliary battery 3 is less than the predetermined threshold, the switch control unit 30 disconnects the critical loads IL1 to IL3 in sequence, starting with the critical loads with the lowest operating priority, via the third switch 13 to the fifth switch 15, thereby gradually reducing the supply current to the critical loads IL1 to IL3.

[0086] Therefore, during the evacuation driving time following a power failure due to an anomaly on the main battery 2 side or the auxiliary battery 3 side, the discharge time of the main battery 2 and the auxiliary battery 3, whose remaining capacity [Ah] is less than the remaining capacity [Ah] in the fully charged state, can be extended to maintain power supply to the important load IL1 (or IL2) with high operating priority.

[0087] Furthermore, when the second power failure determination unit 32 determines that a power failure is caused by an anomaly on the critical loads IL1 to IL3, the switch control unit 30 determines whether the remaining capacity [Ah] of both the main battery 2 and the auxiliary battery 3 is equal to or higher than a predetermined threshold. Additionally, the switch control unit 30 disconnects the critical loads IL1 to IL3 with the anomaly via the third switch 13 to the fifth switch 15. When the remaining capacity [Ah] of both the main battery 2 and the auxiliary battery 3 is less than the predetermined threshold, the switch control unit 30 uses the third switch 13 to the fifth switch 15 to disconnect the normal critical loads IL1 to IL3 in sequence, starting with the normal critical loads with the lowest operating priority, thereby gradually reducing the supply current to the critical loads IL1 to IL3.

[0088] Therefore, during the evacuation driving time following a power failure due to an anomaly on any side of the critical loads IL1 to IL3, the discharge time of the main battery 2 and the auxiliary battery 3, whose remaining capacity [Ah] is less than the remaining capacity [Ah] in the fully charged state, can be extended to maintain power supply to the normal critical loads IL1 (or IL2) with high operating priority.

[0089] In the above embodiments, an unexpected situation (so-called double failure) exists, in which the first power failure determination unit 31 determines that the power failure is caused by an abnormality on the main battery 2 or the auxiliary battery 3 side, and the second power failure determination unit 32 determines that the power failure is caused by an abnormality on the critical loads IL1 to IL3. However, when the second power failure determination unit 32 determines that the power failure is caused by an abnormality on the critical loads IL1 to IL3, and the first power failure determination unit 31 determines that the power failure is caused by an abnormality on the main battery 2 side or the auxiliary battery 3 side, the remaining capacity [Ah] of the normal battery in the main battery 2 and the auxiliary battery 3 can be confirmed, and the normal critical load in the critical loads IL1 to IL3 can be operated by power supply from the normal battery.

[0090] Figure 11 This is a diagram illustrating an on-board power system 1 including a power switching control system 100 according to another embodiment of the present disclosure. (See diagram) Figure 11 As shown, the power switching control system 100 of this embodiment includes: a power storage unit 102 connected to one end of the power supply line 8G (opposite to the connection point P, which serves as the starting end); and a sixth switch 104 that connects or disconnects the power storage unit 102 from the power supply line 8G. For configurations identical to those in the above embodiments, repeated descriptions will be omitted, and the descriptions will be used in conjunction with those of the above embodiments.

[0091] Examples of energy storage unit 102 include a 12V lead-acid battery, a 12V lithium-ion battery or nickel-metal hydride battery that can be connected to the lead-acid battery, or a double-layer capacitor (including a built-in DC / DC converter). Energy storage unit 102 is a redundant power source that supplies power to critical loads IL1 to IL3 in the event of a power failure in both the main battery 2 and the auxiliary battery 3. Therefore, the switch control unit 30 keeps energy storage unit 102 fully charged by keeping the sixth switch 104 always on.

[0092] Figure 12 and Figure 13 This is a flowchart illustrating the processing of the power switching control system 100 of this embodiment. When the vehicle starts, the processing shown in the flowchart begins, and the processing proceeds to step S1001. For processes that are the same as those in the above embodiment, repeated descriptions will be omitted, and the descriptions will be combined with those in the above embodiment.

[0093] In step S1001, the switch control unit 30 turns on all the first to sixth switches 11 to 15 and 104. Therefore, the main battery 2 and the auxiliary battery 3 are connected to the ordinary load L, the critical loads IL1 to IL3, and the energy storage unit 102, and supply power to the ordinary load L, the critical loads IL1 to IL3, and the energy storage unit 102. The switch control unit 30 obtains information from the ECU7 regarding the remaining capacity [Ah] of the main battery 2 held by the BMS5 and the remaining capacity [Ah] of the auxiliary battery 3 held by the BMS6, and also obtains information regarding the remaining capacity [Ah] of the energy storage unit 102.

[0094] Next, in step S2, the second power supply fault determination unit 32 determines whether all critical loads IL1 to IL3 are in a normal state without any abnormalities such as overcurrent. If a positive determination is made in step S2, the process proceeds to step S3; otherwise, the process proceeds to step S4. Figure 9 Step S21 in the process.

[0095] In step S3, the first power failure determination unit 31 determines whether both the main battery 2 side and the auxiliary battery 3 side are in a normal state where there is no abnormality that would cause a power failure. If a positive determination is made in step S3, the process proceeds to step S4; if a negative determination is made in step S3, the process proceeds to step S1002.

[0096] In step S4, the switch control unit 30 determines whether the vehicle has stopped. If a positive determination is made in step S4, the process ends; if a negative determination is made in step S4, the process proceeds to step S1001.

[0097] In step S1002, the switch control unit 30 determines whether a power failure has occurred due to an abnormality in either the main battery 2 side or the auxiliary battery 3 side. If an affirmative determination is made in step S1002, the process proceeds to step S31; and if a negative determination is made in step S1002 (if a power failure has occurred due to an abnormality in both the main battery 2 side and the auxiliary battery 3 side), the process proceeds to... Figure 13 Step S1003 in the process.

[0098] Steps S31 to S38 are the procedures for handling power failures caused by abnormalities on both sides of the main battery, and are the same as those in the above embodiment. After making a negative determination in S31... Figure 8 The processing in steps S311 to S317 is the processing when a power failure occurs due to an abnormality on the auxiliary battery 3 side, and is the same as the processing in the above embodiment.

[0099] exist Figure 13In step S1003, the switch control unit 30 disconnects the first switch 11 and the second switch 12 while keeping the third switch 13 to the fifth switch 15 and the sixth switch 104 on. Next, in step S1004, the switch control unit 30 sends a DIAG signal to the ECU 7.

[0100] Next, in step S1005, the switch control unit 30 determines whether the remaining capacity [Ah] of the energy storage unit 102 is 3Ah or more. If a positive determination is made in step S1005, the process proceeds to step S1006, and if a negative determination is made in step S1005, the process proceeds to step S1007.

[0101] In step S1006, the switch control unit 30 keeps the third switch 13 to the fifth switch 15 closed and maintains power supply from the energy storage unit 102 to the critical loads IL1 to IL3. The process proceeds from step S1006 to... Figure 12 Step S4. Simultaneously, in step S1007, the switch control unit 30 keeps the third switch 13 to the fifth switch 15 closed during the first phase (time phase 1) of the evacuation driving time. Next, in step S1008, the switch control unit 30 disconnects the fifth switch 15 during the second phase (time phase 2) of the evacuation driving time. Next, in step S1009, the switch control unit 30 disconnects the fourth switch 14 during the third phase (time phase 3) of the evacuation driving time. Processing proceeds from step S1009 to... Figure 12 Step S4 in the process.

[0102] As described above, in the power switching control system 100 of this embodiment, the energy storage unit 102 is configured as a redundant power supply, and when an anomaly causing a power failure occurs in both the main battery 2 and the auxiliary battery 3, the energy storage unit 102 supplies power to the critical loads IL1 to IL3. In the power switching control system 100 of this embodiment, when the first power failure determination unit 31 determines that a power failure has occurred due to an anomaly on both the main battery 2 side and the auxiliary battery 3 side, the switch control unit 30 determines whether the remaining capacity [Ah] of the energy storage unit 102 is equal to or higher than a predetermined threshold. When the remaining capacity [Ah] of the energy storage unit 102 is lower than the predetermined threshold, the switch control unit 30 uses the third switch 13 to the fifth switch 15 to disconnect the critical loads IL1 to IL3 in sequence, starting with the critical loads with the lowest operating priority, thereby gradually reducing the supply current to the critical loads IL1 to IL3.

[0103] Therefore, during the evacuation driving time following a power failure due to anomalies on both the main battery 2 side and the auxiliary battery 3 side, the discharge time of the energy storage unit 102, whose remaining capacity [Ah] is less than the remaining capacity [Ah] in the fully charged state, can be extended in order to maintain power supply to the important load IL1 (or IL2) with high operating priority.

[0104] In current vehicle power systems, the number of energy storage units is increasing because each critical load is equipped with an energy storage unit to maintain power supply to the critical load. However, the power switching control system 10 according to this embodiment can maintain power supply to critical loads IL1 and IL2 using only the main battery 2 and the auxiliary battery 3, or even the energy storage unit 102 provided in the power switching control system 10, by controlling the opening and closing of the first switch 11 to the fifth switch 15.

[0105] While this disclosure has been described above based on the embodiments described above, this disclosure is not limited to the embodiments described above. Modifications can be made to the embodiments described above without departing from the spirit of this disclosure, or known and well-known techniques can be appropriately combined.

[0106] For example, in the above embodiment, three critical loads IL1 to IL3 are provided, but the number of critical loads IL1 to IL3 can be appropriately increased or decreased. When two critical loads IL1 and IL2 are provided, during evacuation driving time following a power failure due to an anomaly on the main battery 2 side or the auxiliary battery 3 side, the load with the lower operating priority of the two critical loads IL1 and IL2 can be disconnected from the power switching control system 10 or 100.

[0107] In the above embodiment, when the remaining capacity [Ah] of the main battery 2, the auxiliary battery 3, and the energy storage unit 102 is less than a predetermined threshold, the evacuation driving time is controlled as follows: critical loads IL1 to IL3 are disconnected starting with the critical load having the lowest operating priority. However, for example, the evacuation driving time control can be performed when the remaining capacity [Ah] of the main battery 2, the auxiliary battery 3, and the energy storage unit 102 is equal to or less than the predetermined threshold. Furthermore, the evacuation driving time control can also be performed when the state of charge (SOC) or voltage of the main battery 2, the auxiliary battery 3, and the energy storage unit 102 is less than or equal to the predetermined threshold.

[0108] According to a first aspect of this disclosure, a power switching control system (10) includes: a switching unit (11, 12, 13, 14, 15) configured to switch the connection and disconnection between a plurality of loads (IL1, IL2, IL3) with operating priorities and a plurality of power supplies (2, 3, 102) supplying power to the plurality of loads (IL1, IL2, IL3), the plurality of loads (IL1, IL2, IL3) and the plurality of power supplies (2, 3, 102) being connected in parallel to a power supply path (8G); a power fault detection unit (31, 32) configured to detect a power fault caused by an abnormality on the power supply side or the load side; and a control unit (30) configured to control the switching unit (11, 12, 13, 14, 15). When the power failure detection unit (31, 32) detects a power failure and the remaining capacity, charging rate or voltage of multiple power supplies (2, 3, 102) is less than or below a predetermined threshold, the control unit (30) uses the switching unit (11, 12, 13, 14, 15) to disconnect multiple loads (IL1, IL2, IL3) from the power supply path (8G) in sequence, starting with the load (IL1, IL2, IL3) with the lowest operating priority among the loads (IL1, IL2, IL3), so as to gradually reduce the supply current from the power supply (2, 3, 102) to the loads (IL1, IL2, IL3).

[0109] According to a second aspect of this disclosure, there are three or more loads (IL1, IL2, IL3), and when the power supply fault detection unit (31, 32) detects a power supply fault caused by an abnormality on the load side, and the remaining capacity, charging rate, or voltage of multiple power supplies (2, 3, 102) is less than or below a predetermined threshold, the control unit (30) disconnects at least one load with an abnormality from the power supply path (8G) through the switching unit (11, 12, 13, 14, 15), and then disconnects two or more normal loads (IL1, IL2, IL3) from the power supply path (8G) in sequence, starting with the load with the lowest operating priority among the loads (IL1, IL2, IL3), through the switching unit (11, 12, 13, 14, 15), to gradually reduce the supply current from the power supply (2, 3, 102) to the loads (IL1, IL2, IL3).

[0110] According to a third aspect of this disclosure, the plurality of power sources (2, 3, 102) include a main battery (2), a secondary battery (3), and an energy storage unit (102). The switching units (11, 12, 13, 14, 15) include: a first switch (11) configured to switch the connection and disconnection between the main battery (2) and the power supply path (8G); a second switch (12) configured to switch the connection and disconnection between the secondary battery (3) and the power supply path (8G); and a plurality of third switches (13, 14, 15) configured to switch the connection and disconnection between loads (IL1, IL2, IL3) and the power supply path (8G). The control unit (30) is configured to perform: a first process, when the power failure detection unit (31) detects a power failure caused by an anomaly on the main battery side and a power failure caused by an anomaly on the secondary battery side, a first switch (11) disconnects the main battery (2) from the power supply path (8G), a second switch (12) disconnects the secondary battery (3)c from the power supply path (8G), and the energy storage unit (102) supplies power to the loads (IL1, IL2, IL3); and a second process following the first process, when the remaining capacity, charging rate, or voltage of the energy storage unit (102) is less than or below a predetermined threshold, a third switch (13, 14, 15) disconnects multiple loads (IL1, IL2, IL3) from the power supply path (8G) in sequence, starting with the load (IL1, IL2, IL3) with the lowest operating priority, to gradually reduce the supply current from the energy storage unit (102) to the loads (IL1, IL2, IL3).

[0111] According to this disclosure, in a power supply system in which multiple power sources are connected in parallel to the power supply path for redundant operation and multiple loads are connected in parallel to the power supply path, when a power failure occurs due to an anomaly on the power supply side or the load side, even if the remaining capacity of the power source in a power supply state is insufficient, it is possible to maintain power supply to the load with high operating priority for the required time.

Claims

1. A power switching control system, comprising: A switching unit configured to switch the connection and disconnection between multiple loads with set operating priorities and multiple power supplies supplying power to the multiple loads, wherein the multiple loads and the multiple power supplies are connected in parallel to the power supply path; A power failure detection unit is configured to detect power failures caused by abnormalities on the power supply side or the load side. as well as A control unit, configured to control the switching unit, wherein... When the power failure detection unit detects a power failure, and the remaining capacity, charging rate, or voltage of the plurality of power supplies is less than or below a predetermined threshold, the control unit disconnects the plurality of loads from the power supply path via the switching unit, starting with the load having the lowest operating priority among the plurality of loads, in order to gradually reduce the supply current from the power supply to the load. The multiple power sources include a main battery, a secondary battery, and an energy storage unit. The switching unit includes: a first switch configured to switch the connection and disconnection between the main battery and the power supply path; a second switch configured to switch the connection and disconnection between the auxiliary battery and the power supply path; and a plurality of third switches configured to switch the connection and disconnection between the load and the power supply path; and Control unit, which is configured to perform: First processing: When the power failure detection unit detects a power failure caused by an anomaly on the main battery side and a power failure caused by an anomaly on the secondary battery side, the first switch disconnects the main battery from the power supply path, the second switch disconnects the secondary battery from the power supply path, and the energy storage unit supplies power to the load; and In the second process following the first process: when the remaining capacity, charging rate, or voltage of the energy storage unit is less than or below the predetermined threshold, the third switch disconnects the plurality of loads from the power supply path in sequence, starting with the load having the lowest operating priority among the plurality of loads, to gradually reduce the supply current from the energy storage unit to the load.

2. The power switching control system according to claim 1, wherein, The load consists of three or more, and When the power failure detection unit detects a power failure caused by an anomaly on the load side, and the remaining capacity, charging rate, or voltage of the plurality of power supplies is less than or below the predetermined threshold, the control unit disconnects at least one load with the anomaly from the power supply path via the switching unit, and then disconnects two or more normal loads from the power supply path via the switching unit in sequence, starting with the load with the lowest operating priority, to gradually reduce the supply current from the power supply to the load.

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