Vehicle-mounted power supply system and electric vehicle

Abstract

The application provides a vehicle-mounted power supply system and an electric vehicle. The vehicle-mounted power supply system comprises a bidirectional vehicle-mounted charger, a direct-current converter, a first switch group and a controller. The first connection end of the bidirectional vehicle-mounted charger is connected with the output end of the direct-current converter through the first switch group, and the second connection end of the bidirectional vehicle-mounted charger is connected with the input end of the direct-current converter. The controller is used for controlling the first switch group to be conductive in the case that the direct-current converter fails, so that the power battery supplies power to the low-voltage load group through the bidirectional vehicle-mounted charger, and the power supply reliability of the low-voltage load group is improved, and the cost is lower.

Description

Technical Field

[0001] This application relates to the field of electric vehicles, and more particularly to an on-board power supply system and an electric vehicle. Background Technology

[0002] Currently, electric vehicles consist of a DC power source, a direct current-to-direct current (DC-DC) converter, and a low-voltage load. The DC-DC converter supplies power to the low-voltage load based on the DC power provided by the DC power source. However, in the event of a DC-DC converter failure, it cannot continue to supply power to the low-voltage load, resulting in low reliability of power supply to the low-voltage load. Summary of the Invention

[0003] This application provides an on-board power supply system and an electric vehicle that can continue to supply power to the low-voltage load group in the event of a DC-DC converter failure, thereby improving the power supply reliability of the low-voltage load group and reducing costs.

[0004] Firstly, this application provides an on-board power supply system, comprising a bidirectional on-board charger, a DC-DC converter, a first switch group, and a controller. The first connection terminal of the bidirectional on-board charger is connected to a low-voltage load group and the output terminal of the DC-DC converter via the first switch group, and the second connection terminal of the bidirectional on-board charger is connected to a power battery and the input terminal of the DC-DC converter. The controller is used to: control the first switch group to conduct in the event of a DC-DC converter failure, so that the power battery supplies power to the low-voltage load group through the bidirectional on-board charger, thereby improving the power supply reliability of the low-voltage load group and reducing cost.

[0005] In conjunction with the first aspect, in a first possible implementation, the aforementioned first switch group includes n sub-switch groups, the low-voltage load group includes m low-voltage loads, and the first connection terminal of the bidirectional on-board charger is connected to the m low-voltage loads and the output terminal of the DC-DC converter through the n sub-switch groups. The n sub-switch groups are connected in series, and each sub-switch group corresponds to one or more low-voltage loads, where n and m are positive integers. The controller is used to: control the n sub-switch groups to conduct in the event of a DC-DC converter failure, so that the power battery supplies power to the m low-voltage loads through the bidirectional on-board charger. It is understood that this allows the power battery to supply power to the m low-voltage loads when the DC power is sufficient, thereby improving the power supply reliability of the low-voltage loads.

[0006] In conjunction with the first possible implementation of the first aspect, in the second possible implementation, when n is greater than or equal to 2, the first connection terminal of the bidirectional on-board charger is connected to the first sub-switch group among the n sub-switch groups, and the nth sub-switch group among the n sub-switch groups is connected to the output terminal of the DC-DC converter. The controller described above is used to: in the event of a DC-DC converter failure, control the first i sub-switch groups among the n sub-switch groups to be turned on, and control the last ni sub-switch groups among the n sub-switch groups to be turned off, so that the power battery supplies power to the low-voltage loads corresponding to the first i sub-switch groups through the bidirectional on-board charger, where i is a positive integer greater than or equal to 1 and less than n. It is understood that when the DC power supplied by the power battery is low, priority can be given to supplying power to the low-voltage loads corresponding to the first i sub-switch groups, improving the power supply reliability of the low-voltage loads; in addition, the first i sub-switch groups can be selectively controlled to be turned on to achieve the purpose of supplying power to different low-voltage loads, improving the power supply flexibility of the low-voltage loads.

[0007] In conjunction with the first possible implementation of the first aspect, in the third possible implementation, the first connection terminal of the bidirectional on-board charger includes a first positive connection terminal and a first negative connection terminal. The first positive connection terminal of the bidirectional on-board charger is connected to the live wire of the AC power supply, and the first negative connection terminal of the bidirectional on-board charger is connected to the neutral wire of the AC power supply. The controller is used to: control the shutdown of n sub-switch groups when AC power is supplied, so that the bidirectional on-board charger supplies power to the low-voltage load corresponding to the nth sub-switch group through the DC-DC converter, thereby improving the power supply efficiency of the low-voltage load. The nth sub-switch group is connected to the output terminal of the DC-DC converter.

[0008] In conjunction with the third possible implementation of the first aspect, in the fourth possible implementation, when n is greater than or equal to 2, the first connection terminal of the bidirectional on-board charger is connected to the first sub-switch group among the n sub-switch groups. The controller is configured to: in the case of AC power supply, control the first x sub-switch groups among the n sub-switch groups to turn off, and control the last nx sub-switch groups among the n sub-switch groups to turn on, so that the bidirectional on-board charger supplies power to the low-voltage load corresponding to the x-th sub-switch group and the low-voltage load corresponding to the last nx sub-switch groups through a DC-DC converter, where x is a positive integer greater than or equal to 1 and less than n. It is understood that selectively controlling the last nx sub-switch groups to turn on can achieve the purpose of supplying power to different low-voltage loads, thereby improving the power supply flexibility for low-voltage loads.

[0009] In conjunction with the first possible implementation of the first aspect or the third possible implementation of the first aspect, in the fifth possible implementation, when n equals 1, the first switch group includes a sub-switch group, and the sub-switch group includes a first switch and a second switch. The first connection terminal of the bidirectional on-board charger includes a first positive connection terminal and a first negative connection terminal, and the output terminal of the DC-DC converter includes a positive output terminal and a negative output terminal. Specifically, the first positive connection terminal of the bidirectional on-board charger is connected to the first connection terminals of m low-voltage loads and the positive output terminal of the DC-DC converter via the first switch, and the first negative connection terminal of the bidirectional on-board charger is connected to the second connection terminals of m low-voltage loads and the negative output terminal of the DC-DC converter via the second switch.

[0010] In conjunction with the second or fourth possible implementation of the first aspect, in the sixth possible implementation, when the sub-switch group includes a first switch and a second switch, the first connection terminal of the bidirectional on-board charger includes a first positive connection terminal and a first negative connection terminal. The first positive connection terminal of the bidirectional on-board charger is connected to the first connection terminal of the first switch in the first sub-switch group, and the first negative connection terminal of the bidirectional on-board charger is connected to the first connection terminal of the second switch in the first sub-switch group. The second connection terminal of the first switch in the y-th sub-switch group is connected to the first connection terminal of the first switch in the (y+1)-th sub-switch group and the first connection terminal of the low-voltage load corresponding to the y-th sub-switch group. The second connection terminal of the second switch in the y-th sub-switch group is connected to the first connection terminal of the second switch in the (y+1)-th sub-switch group and the second connection terminal of the low-voltage load corresponding to the y-th sub-switch group, where y is a positive integer greater than or equal to 1 and less than n. The output terminals of the DC-DC converter include a positive output terminal and a negative output terminal. The second connection terminal of the first switch in the nth sub-switch group is connected to the first connection terminal of the low-voltage load corresponding to the nth sub-switch group and the positive output terminal of the DC-DC converter. The second connection terminal of the second switch in the nth sub-switch group is connected to the second connection terminal of the low-voltage load corresponding to the nth sub-switch group and the negative output terminal of the DC-DC converter.

[0011] In a seventh possible implementation, combining the fifth or sixth possible implementation of the first aspect, the on-board power supply system further includes a second switch group, through which the second connection terminal of the bidirectional on-board charger is connected to the power battery. The aforementioned controller is used to: control the second switch group to conduct in the event of a DC-DC converter failure, thereby enabling the power battery to output DC power to the bidirectional on-board charger, improving the power supply reliability for low-voltage loads.

[0012] In conjunction with the seventh possible implementation of the first aspect, in the eighth possible implementation, the first positive connection terminal of the bidirectional on-board charger is connected to the live wire of the AC power supply, and the first negative connection terminal of the bidirectional on-board charger is connected to the neutral wire of the AC power supply. The controller is used to: control the second switch group to conduct when AC power is supplied, thereby enabling the bidirectional on-board charger to output high-voltage DC power to the power battery for charging, thus improving the power supply efficiency for low-voltage loads.

[0013] In conjunction with the seventh or eighth possible implementation of the first aspect, in the ninth possible implementation, the on-board power supply system further includes a capacitor and a low-voltage battery, and the second switch group includes a third switch and a fourth switch. The positive output terminal of the aforementioned DC-DC converter is connected to the positive terminal of the low-voltage battery, and the negative output terminal of the DC-DC converter is connected to the negative terminal of the low-voltage battery. The second connection terminal of the bidirectional on-board charger includes a second positive connection terminal and a second negative connection terminal. The second positive connection terminal of the bidirectional on-board charger and the first connection terminal of the capacitor are connected to the positive terminal of the power battery via the third switch, and the second negative connection terminal of the bidirectional on-board charger and the second connection terminal of the capacitor are connected to the negative terminal of the power battery via the fourth switch. The aforementioned controller is used to control the n sub-switch groups to conduct, so that the low-voltage battery charges the capacitor through the bidirectional on-board charger, thereby avoiding the addition of a high-voltage slow-charging circuit in the on-board power supply system and reducing system costs. Furthermore, the controller is used to: detect the voltage across the capacitor, and control the third and fourth switches to turn on when the voltage across the capacitor is greater than or equal to a preset voltage threshold. This can prevent a large surge current from flowing through the power battery and burning it out, thereby improving the safety of the power battery and extending its service life.

[0014] Secondly, this application provides an electric vehicle including a power battery, a low-voltage load bank, and an on-board power supply system as provided in any of the first to ninth possible embodiments of the first aspect. The on-board power supply system is used to supply power to the low-voltage load bank based on DC power provided by the power battery, or to supply power to the power battery and the low-voltage load bank based on AC power provided by an AC power source. This can improve the power supply reliability and power supply flexibility of the low-voltage load bank, and reduce costs.

[0015] In this application, power can be supplied to the low-voltage load group in the event of a DC-DC converter failure, thereby improving the power supply reliability of the low-voltage load group and reducing costs. In addition, the low-voltage battery can charge the capacitor through a bidirectional on-board charger, thereby avoiding the need to add a high-voltage slow-charging circuit in the on-board power supply system, reducing system costs, and improving the safety of the power battery. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the application scenario of the vehicle power supply system provided in this application;

[0017] Figure 2 This is a structural schematic diagram of the vehicle power supply system provided in this application;

[0018] Figure 3 This is another structural schematic diagram of the vehicle power supply system provided in this application;

[0019] Figure 4 This is another structural schematic diagram of the vehicle power supply system provided in this application;

[0020] Figure 5 This is another structural schematic diagram of the vehicle power supply system provided in this application;

[0021] Figure 6A This is another structural schematic diagram of the vehicle power supply system provided in this application;

[0022] Figure 6B This is another structural schematic diagram of the vehicle power supply system provided in this application. Detailed Implementation

[0023] The on-board power supply system provided in this application is adapted to electric vehicle application scenarios. See [link / reference] Figure 1 , Figure 1 This is a schematic diagram illustrating the application scenario of the vehicle-mounted power supply system provided in this application. For example... Figure 1 As shown, an electric vehicle includes a power battery, a low-voltage load pack, and an on-board power supply system. The on-board power supply system is used to supply power to the low-voltage load pack based on DC power provided by the power battery, or to supply power to the power battery and the low-voltage load pack based on AC power provided by an AC power source. This can improve the power supply reliability and power supply flexibility of the low-voltage load pack, and reduce costs.

[0024] In one embodiment, the low-voltage load group can be low-voltage electrical equipment in the electric vehicle, including but not limited to at least one of headlights, windshield wipers, air conditioning, audio equipment, and instruments. The AC power source can be the AC mains, an AC charging station, or an uninterruptible power system (UPS).

[0025] The following will combine Figures 2 to 6B The on-board power supply system provided in this application and its working principle are illustrated with examples.

[0026] See Figure 2 , Figure 2 This is a structural schematic diagram of the vehicle-mounted power supply system provided in this application. For example... Figure 2As shown, the on-board power supply system 1 includes a bidirectional on-board charger 11, a DC-DC converter 12, a first switch group 13, and a controller 10. The first connection terminal of the bidirectional on-board charger 11 is connected to the low-voltage load group 2 and the output terminal of the DC-DC converter 12 via the first switch group 13, and the second connection terminal of the bidirectional on-board charger 11 is connected to the power battery 3 and the input terminal of the DC-DC converter 12.

[0027] In one embodiment, the controller 10 establishes wired or wireless communication with the bidirectional on-board charger 11, the DC-DC converter 12, and the first switch group 13 to control the operation of the bidirectional on-board charger 11, the operation of the DC-DC converter 12, and the on or off of the first switch group 13.

[0028] In one embodiment, the controller 10 is used to control the first switch group 13 to turn on in the event of a failure of the DC converter 12, so that the power battery 3 supplies power to the low-voltage load group 2 through the bidirectional on-board charger 11, thereby improving the power supply reliability of the low-voltage load group and reducing costs.

[0029] In one embodiment, a fault in DC-DC converter 12 can be determined when DC-DC converter 12 has no output. Specifically, controller 10 is used to detect the output voltage of DC-DC converter 12, and determines that DC-DC converter 12 has failed when the output voltage of DC-DC converter 12 is 0.

[0030] In one embodiment, the controller 10 is used to control the first switch group 13 to conduct in the event of a fault in the DC-DC converter 12. Based on a voltage command and the circuit topology of the bidirectional on-board charger 11, the controller obtains the switching modulation mode of the bidirectional on-board charger 11, and controls the bidirectional on-board charger 11 to output low-voltage DC power to supply power to the low-voltage load group 2 based on the switching modulation mode. At this time, the bidirectional on-board charger 11 is in reverse discharge mode. It is understood that the reverse discharge function of the bidirectional on-board charger 11 can be used to achieve the purpose of supplying power to the low-voltage load group 2, thereby improving the power supply reliability of the low-voltage load group 2.

[0031] In one embodiment, the low-voltage DC output by the bidirectional on-board charger 11 corresponds to the same voltage value given in the voltage command, which is determined by the rated input voltage of the low-voltage load group 2. For example, the given voltage value could be 12V or 24V.

[0032] In one embodiment, assuming the rated power of the bidirectional on-board charger 11 is 7kW and the rated voltage of the low-voltage DC power supply is 12V, the maximum emergency power output of the bidirectional on-board charger 11 without affecting the current stress of the bidirectional on-board charger 11 is greater than or equal to 360W. Assuming the rated power of the bidirectional on-board charger 11 is 7kW and the rated voltage of the low-voltage DC power supply is 24V, the maximum emergency power output of the bidirectional on-board charger 11 without affecting the current stress of the bidirectional on-board charger 11 is greater than or equal to 720W.

[0033] In one embodiment, where the on-board power supply system 1 is located within the electric vehicle, the low-voltage load group 2 can be low-voltage electrical equipment within the electric vehicle. The low-voltage load group 2 includes, but is not limited to, at least one of headlights, windshield wipers, air conditioning, audio equipment, and instrument clusters.

[0034] See Figure 3 , Figure 3 This is another structural schematic diagram of the vehicle-mounted power supply system provided in this application. (See diagram below.) Figure 3 As shown above, Figure 2 The first switch group 13 shown includes sub-switch groups 130a to 130n, and the low-voltage load group 2 includes low-voltage loads 20a to 20m. The first connection terminal of the bidirectional on-board charger 11 is connected to the output terminal of the DC-DC converter 12 via sub-switch groups 130a to 130n. Sub-switch groups 130a to 130n are connected in series, and each sub-switch group corresponds to one or more low-voltage loads, where n and m are positive integers. For example, sub-switch group 130a corresponds to low-voltage loads 20a and 20b, sub-switch group 130b corresponds to low-voltage load 20c, ..., and sub-switch group 130n corresponds to low-voltage load 20m.

[0035] In one embodiment, the number of low-voltage loads corresponding to each sub-switch group is greater than or equal to 1 and less than or equal to m.

[0036] In one embodiment, the controller 10 controls sub-switch groups 130a to 130n to conduct in the event of a failure in the DC-DC converter 12, so that the power battery 3 supplies power to low-voltage loads 20a to 20m via the bidirectional on-board charger 11. It is understood that supplying power to low-voltage loads 20a to 20m when the DC power supplied by the power battery 3 is sufficient improves the reliability of power supply to the low-voltage loads.

[0037] In one embodiment, when n is greater than or equal to 2, sub-switch group 130a is connected to the first connection terminal of the bidirectional on-board charger 11, and sub-switch group 130n is connected to the output terminal of the DC-DC converter 12. Sub-switch group 130a is the first sub-switch group among sub-switch groups 130a to 130n, and sub-switch group 130n is the nth sub-switch group among sub-switch groups 130a to 130n.

[0038] In one embodiment, when the priority of supplying power to the low-voltage load corresponding to the i-th sub-switch group is higher than the priority of supplying power to the low-voltage load corresponding to the (i+1)-th sub-switch group, the controller 10 is configured to control the first i sub-switch groups from sub-switch groups 130a to 130n to be turned on and the last ni sub-switch groups from sub-switch groups 130a to 130n to be turned off in the event of a DC-DC converter 12 failure. This allows the power battery 3 to supply power to the low-voltage loads corresponding to the first i sub-switch groups through the bidirectional on-board charger 11, where i is a positive integer greater than or equal to 1 and less than n. It is understood that supplying power to the low-voltage loads corresponding to the higher-priority first i sub-switch groups when the DC power supplied by the power battery 3 is low improves the reliability of power supply to the low-voltage loads. Furthermore, the ability to selectively control the first i sub-switch groups to supply power to different low-voltage loads improves the flexibility of power supply to the low-voltage loads.

[0039] For example, when i is 1, if the DC converter 12 fails, the controller 10 controls the sub-switch group 130a to turn on and controls the sub-switch groups 130b to 130n to turn off, so that the power battery 3 supplies power to the low-voltage load 20a and the low-voltage load 20b through the bidirectional on-board charger 11.

[0040] In one embodiment, the priority of powering each low-voltage load can be a parameter configured or stored by the controller 10, or it can be a parameter set by the user.

[0041] In one embodiment, the first connection terminal of the bidirectional on-board charger 11 includes a first positive connection terminal and a first negative connection terminal. The first positive connection terminal of the bidirectional on-board charger 11 is connected to the live wire of the AC power supply 4, and the first negative connection terminal of the bidirectional on-board charger 11 is connected to the neutral wire of the AC power supply 4. The first positive connection terminal and the first negative connection terminal of the bidirectional on-board charger 11 can be collectively referred to as the alternating current (AC) port of the bidirectional on-board charger 11. The AC power supply 4 can be an AC mains grid, an AC charging pile, or an uninterruptible power supply.

[0042] In one embodiment, the controller 10 controls the sub-switch groups 130a to 130n to turn off when the AC power supply 4 is on, so that the bidirectional on-board charger 11 supplies power to the low-voltage load 20m corresponding to the sub-switch group 130n through the DC converter 12, thereby improving the power supply efficiency of the low-voltage load 20a to 20m.

[0043] In one embodiment, when n is greater than or equal to 2, the controller 10, when powered by AC power supply 4, controls the first x sub-switch groups from sub-switch groups 130a to 130n to turn off, and controls the last nx sub-switch groups from sub-switch groups 130a to 130n to turn on, so that the bidirectional on-board charger 11 supplies power to the low-voltage load corresponding to the x-th sub-switch group and the low-voltage load corresponding to the last nx sub-switch groups through the DC-DC converter 12, where x is a positive integer greater than or equal to 1 and less than n. It is understood that the latter nx sub-switch groups can be selectively controlled to power different low-voltage loads, thereby improving the power supply flexibility for low-voltage loads. For example, when x is 1, the controller 10 controls the sub-switch group 130a to turn off and controls the sub-switch groups 130b to 130n to turn on when powered by AC power supply 4, so that the bidirectional on-board charger 11 supplies power to the low-voltage load 20a and the low-voltage loads 20b to 20m through the DC converter 12.

[0044] In one embodiment, when powered by AC power source 4, the bidirectional on-board charger 11 converts the AC power provided by AC power source 4 into high-voltage DC power, outputs high-voltage DC power to the power battery 3 to charge the power battery 3, and outputs high-voltage DC power to the DC-DC converter 12. At this time, the bidirectional on-board charger 11 is in forward charging mode. The DC-DC converter 12 converts the high-voltage DC power into low-voltage DC power to power low-voltage loads, thereby improving the power supply efficiency and power supply flexibility of low-voltage loads.

[0045] See Figure 4 , Figure 4 This is another structural schematic diagram of the vehicle-mounted power supply system provided in this application. (See diagram below.) Figure 4 As shown, the sub-switch group 130a includes a first switch K. 11 Second switch K 21 Sub-switch group 130b includes first switch K 12 Second switch K 22 ..., Sub-switch group 130n includes the first switch K 1n Second switch K 2n The first positive connection terminal of the bidirectional on-board charger 11 is connected to the first switch K. 11 The first negative connection terminal of the bidirectional on-board charger 11 is connected to the second switch K. 21The first connection end.

[0046] The second connection terminal of the first switch in the y-th sub-switch group is connected to the first connection terminal of the first switch in the (y+1)-th sub-switch group and the first connection terminal of the low-voltage load corresponding to the y-th sub-switch group. The second connection terminal of the second switch in the y-th sub-switch group is connected to the first connection terminal of the second switch in the (y+1)-th sub-switch group and the second connection terminal of the low-voltage load corresponding to the y-th sub-switch group. y is a positive integer greater than or equal to 1 and less than n. When y is 1, the first switch K... 11 The second connection terminal is connected to the first switch K. 12 The first connection terminal, the first connection terminal of low-voltage load 20a, and the first connection terminal of low-voltage load 20b, and the second switch K 21 The second connection terminal is connected to the second switch K. 22 The first connection terminal, the second connection terminal of low-voltage load 20a, and the second connection terminal of low-voltage load 20b. When y is 2, the first switch K 12 The second connection terminal connects to the first connection terminal of the first switch in the third sub-switch group and the first connection terminal of the low-voltage load 20c. The second switch K 22 The second connection terminal connects to the first connection terminal of the second switch in the third sub-switch group and the second connection terminal of the low-voltage load 20c.

[0047] The output terminals of the DC-DC converter 12 include a positive output terminal and a negative output terminal, and the first switch K 1n The second connection terminal connects the first connection terminal of the low-voltage load 20m and the positive output terminal of the DC converter 12. The second switch K 2n The second connection terminal is connected to the second connection terminal of the low-voltage load 20m and the negative output terminal of the DC converter 12.

[0048] In one embodiment, the series connection of sub-switch groups 130a to 130n includes: the series connection of the first switch in sub-switch groups 130a to 130n, namely the first switch K. 11 To the first switch K 1n Series connection; the second switch in sub-switch groups 130a to 130n is connected in series, i.e., the first switch K 21 To the first switch K 2n Series connection.

[0049] In one embodiment, "sub-switch group on" means that the first switch and the second switch in the sub-switch group are on, and "sub-switch group off" means that the first switch and the second switch in the sub-switch group are off. For example, when sub-switch group 130a is on, the first switch K... 11 Second switch K 21 Conduction; with sub-switch group 130a off, the first switch K 11Second switch K 21 Turn off.

[0050] In one embodiment, when n equals 1, the first switch group 13 includes a sub-switch group, and the number m of low-voltage loads corresponding to the sub-switch group is greater than or equal to 1. Taking a sub-switch group 130a and m equals 2 as an example, the first positive connection terminal of the bidirectional on-board charger 11 is connected to the first switch K. 11 The first connection terminal of the low-voltage load 20a and the first connection terminal of the low-voltage load 20b are connected to the positive output terminal of the DC-DC converter 12. The first negative connection terminal of the bidirectional on-board charger 11 is connected to the second switch K. 21 Connect the second connection terminal of the low-voltage load 20a, the second connection terminal of the low-voltage load 20b, and the negative output terminal of the DC-DC converter 12.

[0051] See Figure 5 , Figure 5 This is another structural schematic diagram of the vehicle-mounted power supply system provided in this application. (See diagram below.) Figure 5 As shown above, Figure 4 The on-board power supply system 1 shown also includes a second switch group 14, through which the second connection terminal of the bidirectional on-board charger 11 is connected to the power battery 3. The controller 10 establishes wired or wireless communication with the second switch group 14 to control the on or off of the second switch group 14.

[0052] In one embodiment, the controller 10 controls the second switch group 14 to conduct in the event of a fault in the DC-DC converter 12, thereby enabling the power battery 3 to output DC power to the bidirectional on-board charger 11. When powered by the AC power supply 4, the controller 10 controls the second switch group 14 to conduct, thereby enabling the bidirectional on-board charger 11 to output high-voltage DC power to the power battery 3 to charge it. It is understood that the specific switching states of sub-switch groups 130a to 130n can be found in the above description. Figure 3 and Figure 4 The corresponding implementation examples will not be described in detail here.

[0053] In one embodiment, the above Figure 4The on-board power supply system 1 shown also includes a capacitor C and a low-voltage battery 15. The second switch group 14 includes a third switch K3 and a fourth switch K4. The positive output terminal of the DC-DC converter 12 is connected to the positive terminal of the low-voltage battery 15, and the negative output terminal of the DC-DC converter 12 is connected to the negative terminal of the low-voltage battery 15. The second connection terminal of the bidirectional on-board charger 11 includes a second positive connection terminal and a second negative connection terminal. The second positive connection terminal of the bidirectional on-board charger 11 and the first connection terminal of the capacitor C are connected to the positive terminal of the power battery 3 via the third switch K3, and the second negative connection terminal of the bidirectional on-board charger 11 and the second connection terminal of the capacitor C are connected to the negative terminal of the power battery 3 via the fourth switch K4. When the input terminal of the DC-DC converter 12 includes a positive input terminal and a negative input terminal, the second positive connection terminal of the bidirectional on-board charger 11 is connected to the positive input terminal of the DC-DC converter 12, and the second negative connection terminal of the bidirectional on-board charger 11 is connected to the negative input terminal of the DC-DC converter 12. The second positive connection terminal and the second negative connection terminal of the bidirectional on-board charger 11 can be collectively referred to as the DC port of the bidirectional on-board charger 11.

[0054] In one embodiment, before turning on the third switch K3 and the fourth switch K4, the controller 10 controls the sub-switch groups 130a to 130n to turn on, so that the low-voltage battery 15 charges the capacitor C through the bidirectional on-board charger 11. It is understood that the current output from the positive terminal of the low-voltage battery 15 flows sequentially through the first switch K... 11 To the first switch K 1n Bidirectional on-board charger 11, capacitor C, bidirectional on-board charger 11 and first switch K 21 To the first switch K 2n The low-voltage battery 15 is returned to its negative terminal to form a pre-charge circuit, which is used to charge the capacitor C, thereby avoiding the need to add a high-voltage slow-charge circuit in the vehicle power supply system 1 and reducing system costs.

[0055] During the charging process of capacitor C, controller 10 detects the voltage across capacitor C and controls the third switch K3 and the fourth switch K4 to conduct when the voltage across capacitor C is greater than or equal to a preset voltage threshold. This prevents a large inrush current from flowing through the power battery 3 and burning it out, thereby improving the safety of the power battery 3 and extending its service life. The preset voltage threshold can be a parameter configured by controller 10 or a user-set parameter stored within controller 10.

[0056] In one embodiment, when powered by AC power source 4, the bidirectional on-board charger 11 is used to output high-voltage DC power to DC converter 12 based on the AC power provided by AC power source 4. DC converter 12 is used to convert the high-voltage DC power into low-voltage DC power to charge the low-voltage battery 15.

[0057] In one embodiment, when the first switch group 13 includes a sub-switch group 130n, the overall structure of the vehicle power supply system 1 is as follows: Figure 6A As shown, the first positive connection terminal of the bidirectional on-board charger 11 is connected via the first switch. 1n The first connection terminal of the low-voltage load 20m, the positive terminal of the low-voltage battery 15, and the positive output terminal of the DC-DC converter 12 are connected. The first negative connection terminal of the bidirectional on-board charger 11 is connected via a second switch. 2n The second connection terminal of the low-voltage load 20m is connected to the negative terminal of the low-voltage battery 15 and the negative output terminal of the DC-DC converter 12. It can be understood that the specific circuit connection method of the vehicle power supply system 1 can be found above. Figure 5 The corresponding implementation examples will not be described in detail here.

[0058] In one embodiment, the controller 10 controls the first switch in the event of a failure in the DC-DC converter 12. 1n Second switch 2n The third switch K3 and the fourth switch K4 are turned on, so that the power battery 3 supplies power to the low-voltage load 20m through the bidirectional on-board charger 11; when the AC power supply 4 is on, the first switch is controlled. 1n Second switch 2n Turn off and control the third switch K3 and the fourth switch K4 to turn on, so that the bidirectional on-board charger 11 charges the power battery 3 and supplies power to the low-voltage battery 15 and the low-voltage load 20m through the DC converter 12.

[0059] In one embodiment, the controller 10 controls the first switch before the third switch K3 and the fourth switch K4 are turned on. 1n Second switch 2n The circuit is turned on so that the low-voltage battery 15 charges the capacitor C through the bidirectional on-board charger 11. It can be understood that the current output from the positive terminal of the low-voltage battery 15 flows sequentially through the first switch K. 1n Bidirectional on-board charger 11, capacitor C, bidirectional on-board charger 11 and first switch K 2n The low-voltage battery 15 is returned to its negative terminal to form a pre-charge circuit, which is used to charge the capacitor C. This avoids the need to add a high-voltage slow-charge circuit to the on-board power supply system 1, reducing system costs. During the charging process of the capacitor C, the controller 10 detects the voltage across the capacitor C and controls the third switch K3 and the fourth switch K4 to turn on when the voltage across the capacitor C is greater than or equal to a preset voltage threshold, thereby improving the safety of the power battery 3.

[0060] In one embodiment, when the first switch group 13 includes sub-switch group 130b and sub-switch group 130n, the overall structure of the vehicle power supply system 1 is as follows: Figure 6BAs shown, the first positive connection terminal of the bidirectional on-board charger 11 is connected to the first switch. 12 The first negative connection terminal of the bidirectional on-board charger 11 is connected to the second switch. 22 First connection terminal, first switch 12 The second connection terminal is connected to the first switch. 1n The first connection terminal and the first connection terminal of the low-voltage load 20c, the second switch 22 The second connection terminal is connected to the second switch. 2n The first connection terminal and the second connection terminal of the low-voltage load 20c, the first switch 1n The second connection terminal connects to the first connection terminal of the low-voltage load 20m, the positive terminal of the low-voltage battery 15, and the positive output terminal of the DC-DC converter 12. The second switch... 2n The second connection terminal connects to the second connection terminal of the low-voltage load 20m, the negative terminal of the low-voltage battery 15, and the negative output terminal of the DC-DC converter 12. It can be understood that the specific circuit connection method of the vehicle power supply system 1 can be found above. Figure 5 The corresponding implementation examples will not be described in detail here.

[0061] In one embodiment, where the priority of supplying power to the low-voltage load 20c is higher than the priority of supplying power to the low-voltage load 20m, the controller 10 controls the first switch in the event of a fault in the DC-DC converter 12. 1n Second switch 2n The third switch K3 and the fourth switch K4 are turned on, and control the first switch. 12 Second switch 22 Disconnect the circuit to allow the power battery 3 to supply power to the low-voltage load 20b via the bidirectional on-board charger 11. In another embodiment, the controller 10 controls the first switch in the event of a failure in the DC-DC converter 12. 1n Second switch 2n First switch 12 Second switch 22 The third switch K3 and the fourth switch K4 are turned on, so that the power battery 3 supplies power to the low-voltage load 20b and the low-voltage load 20m through the bidirectional on-board charger 11. It can be understood that the first and second switches in different sub-switch groups can be selectively turned on to achieve the purpose of supplying power to different low-voltage loads, thereby improving the reliability and flexibility of power supply to low-voltage loads.

[0062] In one embodiment, the controller 10 controls the first switch when powered by the AC power supply 4. 12 Second switch 22 Turn off and control the first switch. 1n Second switch 2nThe third switch K3 and the fourth switch K4 are turned on, so that the bidirectional on-board charger 11 charges the power battery 3 and supplies power to the low-voltage battery 15, low-voltage load 20b, and low-voltage load 20m through the DC-DC converter 12. In another embodiment, the controller 10 controls the first switch when powered by the AC power supply 4. 12 Second switch 22 First switch 1n Second switch 2n The circuit is switched off, and the third switch K3 and the fourth switch K4 are switched on, so that the bidirectional on-board charger 11 charges the power battery 3 and supplies power to the low-voltage load 20m of the low-voltage battery 15 through the DC-DC converter 12. It is understood that the first and second switches in different sub-switch groups can be selectively switched on to achieve the purpose of supplying power to different low-voltage loads, thereby improving the power supply flexibility of low-voltage loads.

[0063] In one embodiment, the controller 10 controls the first switch before the third switch K3 and the fourth switch K4 are turned on. 12 Second switch 22 First switch 1n Second switch 2n The circuit is turned on so that the low-voltage battery 15 charges the capacitor C through the bidirectional on-board charger 11. It can be understood that the current output from the positive terminal of the low-voltage battery 15 flows sequentially through the first switch K. 1n First switch 12 Bidirectional on-board charger 11, capacitor C, bidirectional on-board charger 11, second switch 22 and the first switch K 2n The low-voltage battery 15 is returned to its negative terminal to form a pre-charge circuit, which is used to charge the capacitor C. This avoids the need to add a high-voltage slow-charge circuit to the on-board power supply system 1, reducing system costs. During the charging process of the capacitor C, the controller 10 detects the voltage across the capacitor C and controls the third switch K3 and the fourth switch K4 to turn on when the voltage across the capacitor C is greater than or equal to a preset voltage threshold, thereby improving the safety of the power battery 3.

[0064] In this application, the low-voltage load group 2 can be powered in the event of a failure of the DC converter 12, thereby improving the power supply reliability of the low-voltage load group and reducing costs. In addition, the low-voltage battery 15 can also charge the capacitor C through the bidirectional on-board charger 11, thereby avoiding the need to add a high-voltage slow charging circuit in the on-board power supply system 1, reducing system costs, and improving the safety of the power battery 3.

[0065] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A vehicle-mounted power supply system, characterized in that, The vehicle power supply system includes a bidirectional on-board charger, a DC-DC converter, a first switch group, a second switch group, a capacitor, a low-voltage battery, and a controller. The first connection terminal of the bidirectional on-board charger is connected to a low-voltage load group, the low-voltage battery, and the output terminal of the DC-DC converter via the first switch group. The second connection terminal of the bidirectional on-board charger is connected to the input terminal of the DC-DC converter and is connected to the power battery via the second switch group. The second switch group includes a third switch and a fourth switch. The second connection terminal of the bidirectional on-board charger includes a second positive connection terminal and a second negative connection terminal. The second positive connection terminal of the bidirectional on-board charger and the first connection terminal of the capacitor are connected to the positive terminal of the power battery via the third switch. The second negative connection terminal of the bidirectional on-board charger and the second connection terminal of the capacitor are connected to the negative terminal of the power battery via the fourth switch. The DC-DC converter is used to supply power to the low-voltage load group based on the DC power provided by the power battery or the bidirectional on-board charger. The controller is used for: In the event of a fault in the DC-DC converter, the first switch group is controlled to be turned on so that the low-voltage battery charges the capacitor through the bidirectional on-board charger. The voltage across the capacitor is detected, and if the voltage across the capacitor is greater than or equal to a preset voltage threshold, the third switch and the fourth switch are controlled to be turned on so that the power battery supplies power to the low-voltage load group through the bidirectional on-board charger.

2. The vehicle-mounted power supply system according to claim 1, characterized in that, The first switch group includes n sub-switch groups, and the low-voltage load group includes m low-voltage loads; the first connection terminal of the bidirectional on-board charger is connected to the m low-voltage loads and the output terminal of the DC-DC converter through the n sub-switch groups, the n sub-switch groups are connected in series, and each sub-switch group corresponds to one or more of the low-voltage loads, where n and m are positive integers; The controller is used for: In the event of a fault in the DC-DC converter, the n sub-switch groups are controlled to conduct, so that the power battery supplies power to the m low-voltage loads through the bidirectional on-board charger.

3. The vehicle-mounted power supply system according to claim 2, characterized in that, If n is greater than or equal to 2, the first sub-switch group in the n sub-switch groups is connected to the first connection terminal of the bidirectional on-board charger, and the nth sub-switch group in the n sub-switch groups is connected to the output terminal of the DC-DC converter; The controller is used for: In the event of a fault in the DC-DC converter, the first i sub-switch groups of the n sub-switch groups are turned on, and the last ni sub-switch groups of the n sub-switch groups are turned off, so that the power battery supplies power to the low-voltage load corresponding to the first i sub-switch groups through the bidirectional on-board charger, where i is a positive integer greater than or equal to 1 and less than n.

4. The vehicle-mounted power supply system according to claim 2, characterized in that, The first connection terminal of the bidirectional on-board charger includes a first positive connection terminal and a first negative connection terminal. The first positive connection terminal of the bidirectional on-board charger is connected to the live wire of the AC power supply, and the first negative connection terminal of the bidirectional on-board charger is connected to the neutral wire of the AC power supply. The controller is used for: When the AC power supply is on, the n sub-switch groups are controlled to turn off, so that the bidirectional on-board charger supplies power to the low-voltage load corresponding to the nth sub-switch group among the n sub-switch groups through the DC converter, and the nth sub-switch group is connected to the output terminal of the DC converter.

5. The vehicle-mounted power supply system according to claim 4, characterized in that, If n is greater than or equal to 2, the first sub-switch group among the n sub-switch groups is connected to the first connection terminal of the bidirectional on-board charger; The controller is used for: When the AC power supply is provided, the first x sub-switch groups of the n sub-switch groups are turned off, and the last nx sub-switch groups of the n sub-switch groups are turned on, so that the bidirectional on-board charger supplies power to the low-voltage load corresponding to the x-th sub-switch group and the low-voltage load corresponding to the last nx sub-switch groups through the DC converter, where x is a positive integer greater than or equal to 1 and less than n.

6. The vehicle-mounted power supply system according to claim 2 or 4, characterized in that, When n equals 1, the first switch group includes a sub-switch group, which includes a first switch and a second switch. The first connection terminal of the bidirectional on-board charger includes a first positive connection terminal and a first negative connection terminal, and the output terminal of the DC-DC converter includes a positive output terminal and a negative output terminal. The first positive connection terminal of the bidirectional on-board charger is connected to the first connection terminals of the m low-voltage loads and the positive output terminal of the DC-DC converter through the first switch. The first negative connection terminal of the bidirectional on-board charger is connected to the second connection terminals of the m low-voltage loads and the negative output terminal of the DC-DC converter through the second switch.

7. The vehicle-mounted power supply system according to claim 3 or 5, characterized in that, The sub-switch group includes a first switch and a second switch; The first connection terminal of the bidirectional on-board charger includes a first positive connection terminal and a first negative connection terminal. The first positive connection terminal of the bidirectional on-board charger is connected to the first connection terminal of the first switch in the first sub-switch group, and the first negative connection terminal of the bidirectional on-board charger is connected to the first connection terminal of the second switch in the first sub-switch group. The second connection terminal of the first switch in the y-th sub-switch group is connected to the first connection terminal of the first switch in the (y+1)-th sub-switch group and the first connection terminal of the low-voltage load corresponding to the y-th sub-switch group. The second connection terminal of the second switch in the y-th sub-switch group is connected to the first connection terminal of the second switch in the (y+1)-th sub-switch group and the second connection terminal of the low-voltage load corresponding to the y-th sub-switch group. y is a positive integer greater than or equal to 1 and less than n. The output terminal of the DC-DC converter includes a positive output terminal and a negative output terminal. The second connection terminal of the first switch in the nth sub-switch group is connected to the first connection terminal of the low-voltage load corresponding to the nth sub-switch group and the positive output terminal of the DC-DC converter. The second connection terminal of the second switch in the nth sub-switch group is connected to the second connection terminal of the low-voltage load corresponding to the nth sub-switch group and the negative output terminal of the DC-DC converter.

8. The vehicle-mounted power supply system according to any one of claims 4-5, characterized in that, The first positive connection terminal of the bidirectional on-board charger is connected to the live wire of the AC power supply, and the first negative connection terminal of the bidirectional on-board charger is connected to the neutral wire of the AC power supply. The controller is used for: When the AC power supply is applied, the second switch group is controlled to be turned on.

9. An electric vehicle, characterized in that, The electric vehicle includes a power battery, a low-voltage load pack, and an on-board power supply system as described in any one of claims 1-8; The on-board power supply system is used to supply power to the low-voltage load group based on the DC power provided by the power battery, or to supply power to the power battery and the low-voltage load group based on the AC power provided by the AC power source.

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