Vehicle power supply system

Abstract

The present application relates to a vehicle power supply system that supplies electric power to loads mounted on a vehicle, the vehicle power supply system including: a main electric power supply source; a sub electric power supply source; a main power distribution control unit that distributes and supplies electric power of the main electric power supply source to a plurality of first loads; and a sub power distribution control unit that distributes and supplies electric power of the sub electric power supply source to a plurality of second loads, the sub power distribution control unit being connected to the main power distribution control unit so as to be able to supply electric power of the sub electric power supply source via a switch, the switch being controlled to a cut-off state when in a first state in which electric power can be supplied from the sub electric power supply source to the plurality of second loads.

Description

Technical Field

[0001] This disclosure relates to a system for supplying power to a load mounted on a vehicle. Background Technology

[0002] Japanese Patent No. 7398410 discloses a vehicle power supply system that can suppress the overall cost increase of the vehicle by reducing the diameter of the power lines in the wiring harness and reducing power loss. This vehicle power supply system describes a method of reducing power loss by supplying 48V power to high-power loads and supplying low-power loads with power at 12V, obtained by stepping down the 48V voltage.

[0003] Figure 4 The illustrated vehicle power supply system 500 is structurally equipped with a DC-DC converter (DDC) 510 and a battery 520 that serve as a power supply source, and a power distribution control unit 530 that includes multiple switches 531 to 536 to supply power to multiple loads 540 to 560.

[0004] In the vehicle power supply system 500, additional loads may be added due to the addition of onboard equipment, which would otherwise be distributed from the power distribution control unit 530. In this case, to handle the additional load, it is necessary to increase the output capacity of the DC-DC converter 510, increase the capacity of the battery 520, or improve the control capability of the power distribution control unit 530. Therefore, the existing structure must be modified, resulting in an increase in the size and cost of the vehicle power supply system 500. Summary of the Invention

[0005] This disclosure was made in view of the above-mentioned problems, and its object is to provide a vehicle power supply system that can increase the supply power in response to additional loads without affecting the existing structure.

[0006] To address the aforementioned issues, one aspect of the present disclosure is a vehicle power supply system that supplies power to loads mounted on a vehicle. The vehicle power supply system includes: a main power supply source; a secondary power supply source; a main power distribution control unit that distributes power from the main power supply source to a plurality of first loads; and a secondary power distribution control unit that distributes power from the secondary power supply source to a plurality of second loads. The secondary power supply source is connected to the main power distribution control unit and is capable of supplying power from the secondary power supply source via a switch. When in a first state where power can be supplied from the secondary power supply source to the plurality of second loads, the switch is controlled to be in an off state.

[0007] According to the vehicle power supply system disclosed above, the available power can be increased in response to additional loads without affecting the existing structure. Attached Figure Description

[0008] Hereinafter, the features, advantages, technical and industrial importance of exemplary embodiments of the present invention will be described with reference to the accompanying drawings, in which the same reference numerals denote the same constituent elements, wherein:

[0009] Figure 1 This is a schematic diagram of the structure of a vehicle power supply system and its peripheral components according to one embodiment of this disclosure.

[0010] Figure 2 This is a diagram illustrating a variation with an additional power source.

[0011] Figure 3 This diagram illustrates an application example of connecting a vehicle power supply system to the load of a regional structure.

[0012] Figure 4 It is a schematic diagram of the structure including the existing vehicle power supply system and its surrounding parts. Detailed Implementation

[0013] With respect to the vehicle power supply system disclosed herein, when an additional load is subsequently added to the vehicle's basic load structure, the power supply to that non-additional load is provided through the additional structure rather than through the existing structure. Therefore, the supplyable power can be increased in accordance with the added load without affecting the existing structure (maintaining the current rating unchanged).

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0015] Implementation

[0016] constitute

[0017] Figure 1 This is a schematic diagram illustrating an example of the structure of a vehicle power supply system 100 and its peripheral components, including an embodiment of this disclosure. Figure 1 The illustrated vehicle power supply system 100 includes a main DC-DC converter (main DDC) 110, an auxiliary battery 120, a main power distribution control unit 130, and an additional power supply 200. This vehicle power supply system 100 is, for example, mounted in a vehicle.

[0018] The main DC-DC converter 110 is a power converter that takes power from a high-voltage battery (not shown) such as a lithium-ion battery, converts the voltage (e.g., 48V) of the input high-voltage battery power to the required voltage (e.g., 12V) and outputs it to the main power distribution control unit 130.

[0019] The auxiliary battery 120 is a rechargeable secondary battery composed of lithium-ion batteries or the like. This auxiliary battery 120 can supply the power it stores to the main power distribution control unit 130.

[0020] The main power distribution control unit 130 is a structure (such as a power distribution ECU) used to supply and control power to multiple loads 140-160 (first loads) of various devices and equipment mounted on the vehicle, using the main DC-DC converter 110 and the auxiliary battery 120 as power sources (main power supply source). This main power distribution control unit 130 supplies and controls power via multiple switches 131-137. The multiple switches 131-137 use semiconductor relays. Furthermore, this... Figure 1 The number and configuration of the multiple switches 131 to 137 shown are just an example and are not limited to this.

[0021] The supplementary power supply 200 functions as a power source for multiple loads 230-250 in a vehicle that are added due to equipment or specification upgrades. This supplementary power supply 200 includes a secondary DC-DC converter (secondary DDC) 210 and a secondary power distribution control unit 220.

[0022] The secondary DC-DC converter 210 is a power converter that takes power from the same high-voltage battery (not shown) as the primary DC-DC converter 110, converts the voltage (e.g., 48V) of the input high-voltage battery power to the required voltage (e.g., 12V), and outputs it to the secondary power distribution control unit 220.

[0023] The secondary power distribution control unit 220 is a structure (such as a power distribution ECU) used to supply and control power to multiple loads 230-250 (secondary loads) additionally installed in the vehicle, using the secondary DC-DC converter 210 as a power supply source (secondary power supply source). This secondary power distribution control unit 220 supplies and controls power via multiple switches 221-224. The multiple switches 221-224 utilize semiconductor relays. Furthermore, this... Figure 1 The number and configuration of the multiple switches 221 to 224 shown are just an example and are not limited to this.

[0024] Variations

[0025] Figure 2 This is a variation of the vehicle power supply system 100 that uses an additional power supply 300 with a different structure than the additional power supply 200. The additional power supply 300 involved in this variation can be applied to situations where multiple loads 230 to 250 (second loads) mounted on the vehicle are added, including loads that operate under different voltages.

[0026] The additional power supply 300 includes a first secondary DC-DC converter (first secondary DDC) 311 and a secondary power distribution control unit 320. The secondary power distribution control unit 320 includes a second secondary DC-DC converter (secondary secondary DDC) 312 and multiple switches 221-224.

[0027] The first DC-DC converter 311 rectifies the voltage of the power input from the high-voltage battery to the voltage required by loads 230 and 240 (e.g., 48V) and outputs it to the secondary power distribution control unit 320. The second DC-DC converter 312 converts the voltage of the power input from the first DC-DC converter 311 (e.g., 48V) to the voltage required by load 250 (e.g., 12V).

[0028] By using the additional power supply 300 with the structure of multiple first DC-DC converters 311 and second DC-DC converters 312, it is possible to supply power with the optimal voltage to multiple loads 230~250 respectively.

[0029] Application examples

[0030] The vehicle power supply system 100 of this embodiment can also be connected to... Figure 3 The load connection of the area structure is shown. Figure 3 In the illustrated area structure, the load 140 connected to the main power distribution control unit 130 (area 1) is replaced by multiple loads 141, 142 connected to the power distribution control unit 410 (area 2). Figure 3 In the illustrated area structure, the load 150 connected to the main power distribution control unit 130 (area 1) is replaced by multiple loads 151, 152, and 153 connected to the power distribution control unit 420 (area 3).

[0031] The vehicle power supply system 100 of this embodiment can also be applied to loads with such regional structures.

[0032] control

[0033] Next, an example of control implemented in a vehicle power supply system 100 according to one embodiment of this disclosure will be described.

[0034] As a basic control of the vehicle power supply system 100, in order for the additional power supply 200 to function as a dedicated power supply for multiple loads 230 to 250, when in a state (first state) in which power can be supplied from the secondary DC-DC converter 210 (secondary power supply source) to multiple loads 230 to 250 (secondary loads), at least one of the switch 137 of the main power distribution control unit 130 and the switch 221 of the secondary power distribution control unit 220 is controlled to be in a cut-off state.

[0035] This control allows for the separation of the main DC-DC converter 110 and auxiliary battery 120 (main power supply) from the secondary DC-DC converter 210 (secondary power supply). Therefore, unnecessary current inflow from the main power supply to the secondary power distribution control unit 220 and from the secondary power supply to the main power distribution control unit 130 can be prevented. Furthermore, the supply of dark current to multiple loads 140-160 (first load) during vehicle parking can be made solely from the main power supply. This prevents frequent operation of the secondary DC-DC converter 210 (secondary power supply) and suppresses power consumption during parking.

[0036] Furthermore, as an extension of the vehicle power supply system 100, when the auxiliary DC-DC converter 210 (auxiliary power supply source) cannot supply power to the multiple loads 230-250 (secondary loads) (secondary state), all switches 131, 132, 133, and 137 of the main power distribution control unit 130 and switch 221 of the auxiliary power distribution control unit 220 are controlled to be in the on state. As an example of this secondary state, a case is shown where the auxiliary DC-DC converter 210 completes startup later than the main DC-DC converter 110 immediately after the vehicle is started.

[0037] Through this control, during the period until the preparation of power supply to the secondary DC-DC converter 210 (secondary power supply source) is completed, power from the primary DC-DC converter 110 and the auxiliary battery 120 (primary power supply source) can be temporarily supplied from multiple loads 230 to 250 (secondary load).

[0038] In addition, as a further extension of the control of the vehicle power supply system 100, when the main DC-DC converter 110 and the auxiliary battery 120 (main power supply source) are in a malfunctioning state (third state), the switches 131 and 133 of the main power distribution control unit 130 are controlled to be in the off state, and the switches 132 and 137 of the main power distribution control unit 130 and the switch 221 of the auxiliary power distribution control unit 220 are all controlled to be in the on state.

[0039] This control allows power to be supplied from the secondary DC-DC converter 210 (secondary power source) to the loads required for emergency back-off driving, including multiple loads 140-160 (first loads), instead of the main DC-DC converter 110 and the auxiliary battery 120 (main power source).

[0040] Functions and effects

[0041] As described above, the vehicle power supply system 100 according to one embodiment of this disclosure includes a main DC-DC converter 110, an auxiliary battery 120 (main power supply source), and a secondary DC-DC converter 210 (secondary power supply source). The vehicle power supply system 100 according to one embodiment of this disclosure includes a main power distribution control unit 130, which distributes power from the main DC-DC converter 110 and the auxiliary battery 120 to multiple loads (first loads) 140-160. The vehicle power supply system 100 according to one embodiment of this disclosure includes a secondary power distribution control unit 220, which distributes power from the secondary DC-DC converter 210 to multiple loads (second loads) 230-250, and is connected to the main power distribution control unit 130 to supply power to the secondary DC-DC converter 210 via a switch 221. According to one embodiment of the present disclosure, in a vehicle power supply system 100, when in a first state in which power can be supplied from the secondary DC-DC converter 210 to a plurality of second loads 230-250, the switch 221 is controlled to be in an off state.

[0042] This structure and control allow for an increase in available power to correspond with additional loads without affecting the existing structure. Furthermore, the additional power supply 200 is only required to be added to the vehicle power supply system 100 when the second loads 230-250 are added to the vehicle as optional components.

[0043] Furthermore, when the additional power source 200 is added to the vehicle power supply system 100, a portion of the loads 140-160 connected to the main power distribution control unit 130 can be connected to the auxiliary power distribution control unit 220. Additionally, a portion of the second load 230-250 connected to the auxiliary power distribution control unit 220 of the additional power source 200 can be connected to the main power distribution control unit 130. Such load replacement can be arbitrarily implemented depending on the load's mounting location and installation site within the vehicle.

[0044] The vehicle power supply system disclosed herein can be used in vehicles and the like, where the ability to continuously supply power for extended periods is limited by the DC-DC converter (current output rating) and the power distribution ECU (heat generation).

Claims

1. A vehicle power supply system for supplying power to a load mounted on a vehicle, wherein, have: Main power supply source; Secondary power supply sources; The main power distribution control unit distributes the power from the main power supply source to multiple first loads; as well as The secondary power distribution control unit distributes power from the secondary power supply source to multiple second loads, and is connected to the primary power distribution control unit so that it can supply power to the secondary power supply source via a switch. When in a first state where power can be supplied from the secondary power source to the plurality of second loads, the switch is controlled to be in an off state.

2. The vehicle power supply system according to claim 1, wherein, When the switch is in a second state where power cannot be supplied from the secondary power supply source to the plurality of second loads, it is controlled to be in the on state.

3. The vehicle power supply system according to claim 1, wherein, When in the third state, where the secondary power supply source supports the primary power supply source, the switch is controlled to be in the ON state.

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