Charging system and charging method for low-voltage power grid of vehicle and vehicle

Abstract

The invention relates to a charging system and method for a vehicle low-voltage power grid and a vehicle. The charging system comprises a charging module, one end of which is connected with the low-voltage power grid; the USB interface enables the other end of the charging module to be connected with external power supply equipment through a USB protocol; wherein the charging system transmits electric energy from power supply equipment to the low-voltage power grid.

Description

Technical Field

[0001] The present application relates to the technical field of charging a low-voltage power grid system of a vehicle. Background Art

[0002] Due to careless use and other reasons, the vehicle's low-voltage power grid may be out of power or too low in power, causing the vehicle to be unable to start. For example, the vehicle is parked for too long, or the lights and other devices are forgotten to be turned off after parking, causing the battery to be exhausted or too low in power. In traditional solutions, special charging equipment is generally used to charge the vehicle in this situation, or to charge the dead vehicle from another vehicle. These methods usually require two charging cables to connect the charging device or the other vehicle to the battery of the dead vehicle to charge the low-voltage power grid so that the vehicle can be started. The user first needs to find a special charging device or another available vehicle, and also needs to prepare a charging cable. The charging process is very inconvenient and time-consuming.

[0003] The information provided in this section is for the purpose of generally presenting the background of the present application and therefore may contain information that does not constitute prior art in the art. Summary of the invention

[0004] The purpose of this application is to solve or at least alleviate one or more problems existing in the prior art.

[0005] One aspect of the present application relates to a charging system for charging a low-voltage power grid of a vehicle, the charging system comprising: a charging module, one end of which is connected to the low-voltage power grid; a USB interface, which enables the other end of the charging module to be connected to an external power supply device via a USB protocol; wherein the charging system transmits electrical energy from the power supply device to the low-voltage power grid.

[0006] In an embodiment of the present application, optionally, the charging module includes a current conversion unit, and the current conversion unit is used to convert the electric energy from the power supply device to transmit it to the low-voltage power grid.

[0007] In an embodiment of the present application, optionally, the current conversion unit realizes direct current to direct current conversion.

[0008] In an embodiment of the present application, optionally, the charging module includes: a control unit, which controls the charging module, and a voltage sampling unit, which samples the real-time voltage of the low-voltage power grid and feeds back the voltage to the control unit, wherein when the real-time voltage is greater than or equal to the voltage threshold of the low-voltage power grid, the control unit controls the charging module not to transmit electric energy to the low-voltage power grid; when the real-time voltage is less than the voltage threshold of the low-voltage power grid, the control unit controls the charging module to transmit electric energy to the low-voltage power grid.

[0009] In an embodiment of the present application, optionally, the charging module includes: a current sampling unit, which samples the real-time current of the low-voltage power grid and feeds back the real-time current to the control unit, and the control unit adjusts the real-time current of the low-voltage power grid based on the difference between the real-time current and the target current of the low-voltage power grid.

[0010] In an embodiment of the present application, optionally, the control unit obtains the rated power of the power supply device through a USB protocol, and determines the target current based on a ratio of the rated power to the real-time voltage.

[0011] Another aspect of the present application relates to a method for charging a low-voltage power grid of a vehicle, comprising: establishing a USB connection, determining whether the low-voltage power grid needs to be charged, and if not, terminating the charging; if charging is required, performing the following steps: obtaining electrical energy from an external power supply device through a USB protocol, and transmitting the electrical energy from the power supply device to the low-voltage power grid.

[0012] In an embodiment of the present application, optionally, the step of determining whether the low-voltage power grid needs to be charged includes: sampling the real-time voltage of the low-voltage power grid and comparing the real-time voltage with a voltage threshold of the low-voltage power grid; when the real-time voltage is greater than or equal to the voltage threshold, charging is not required; when the real-time voltage is less than the voltage threshold, charging is required.

[0013] In an embodiment of the present application, optionally, when charging is required, the real-time current of the low-voltage power grid is sampled, and the real-time current of the low-voltage power grid is adjusted according to the difference between the real-time current and the target current of the low-voltage power grid, and then, the process returns to the above step of determining whether the low-voltage power grid needs to be charged.

[0014] In an embodiment of the present application, optionally, the target current of the low-voltage power grid is obtained by the ratio of the rated power of the power supply device to the real-time voltage, and the rated power of the power supply device is obtained by communicating with the power supply device.

[0015] In an embodiment of the present application, optionally, adjusting the current of the low-voltage power grid includes making the real-time current approach to or equal to the target current.

[0016] Yet another aspect of the present application relates to a vehicle, comprising a charging system according to any one of the above contents. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The disclosure of the present application will become more easily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present application. In addition, similar numbers in the drawings represent similar components, wherein:

[0018] Figure 1 A schematic diagram showing an embodiment of a charging system of the present application charging a low-voltage power grid of a vehicle;

[0019] Figure 2 A schematic diagram showing an embodiment of a charging system of the present application;

[0020] Figure 3 A flow chart showing an embodiment of a method for charging a low-voltage grid of a vehicle according to the present application. DETAILED DESCRIPTION

[0021] First of all, it should be noted that the following will illustrate the composition, characteristics and advantages of the charging system, charging method and vehicle according to the present application in an exemplary manner, but it should be understood that all descriptions are given for illustration only and should not be understood as forming any limitation on the present application. In this article, the technical terms "first" and "second" are only used for distinguishing purposes and are not intended to indicate their order and relative importance. The technical term "connected (or connected, etc.)" covers the direct connection of a specific component to another component and / or indirect connection to another component. In addition, unless otherwise clearly specified and limited, the dimensions, directions or positional relationships indicated by the technical terms "length", "width", "height", "upper", "top", "bottom" and the like are based on the dimensions, orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and cannot be understood as limitations on the present application.

[0022] In addition, for any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the drawings, the present application still allows any combination or deletion between these technical features (or their equivalents) without any technical obstacles, thereby obtaining more other embodiments of the present application that may not be directly mentioned herein. In addition, general matters that are already known to those skilled in the art will not be repeated herein.

[0023] The vehicle's low-voltage power grid includes a battery, which can supply power to auxiliary equipment such as vehicle instruments, and more importantly, can supply power to the vehicle's start-up. In the event that the low-voltage power grid is out of power or the power is too low, the vehicle will not be able to start. At this time, the low-voltage power grid needs to be charged first so that the vehicle can start. After the vehicle is successfully started, its engine or the vehicle's high-voltage power grid (such as the power battery of an electric vehicle) can work normally, and the low-voltage power grid can continue to be charged to maintain normal operation. The charging system and charging method of the present application can charge the low-voltage power grid of both fuel vehicles and electric vehicles to solve the problem that the low-voltage power grid cannot be started due to "power loss" or "power shortage".

[0024] In order to solve the technical problems existing in the prior art, the present application proposes a charging system, which can charge the low-voltage power grid of a vehicle through the USB protocol. Since the power supply equipment supporting the USB protocol is very popular in daily life, it can make it more convenient to charge the low-voltage power grid of the vehicle, making the power supply equipment more accessible. The power supply equipment supporting the USB protocol may include a "power bank" and other power supply equipment supporting the USB charging protocol.

[0025] In this application Figure 1 , an example of the connection relationship between the charging system 20 for charging the low-voltage power grid 30 of the vehicle and the power supply device 10 is shown. In general, the charging system 20 transmits the electric energy from the external power supply device 10 to the low-voltage power grid, wherein the power supply device 10 and the charging system 20 communicate and transmit electric energy through the USB protocol.

[0026] Figure 2 An embodiment of the charging system 20 of the present application is shown in more detail. The charging system 20 includes a charging module 22, one end of which is electrically connected to the low-voltage power grid of the vehicle through a low-voltage power grid interface 23, and the other end is provided with a USB interface, which is connected to an external power supply device via the USB protocol through the USB interface. The USB protocol in this article supports the functions of power transmission (or charging, power supply, etc.) and communication at the same time unless otherwise specified. An external power supply device refers to a device outside the vehicle, such as a separate mobile power supply or a power bank. The power supply device and USB interface in this article both support the same USB protocol, such as the same version of the standard USB protocol.

[0027] The charging module includes a current conversion unit 222. Figure 2 It is shown as DC-DC 222 in the figure, which represents the conversion from DC to DC, and can convert the DC power from the power supply device 10 into DC power that is adapted to the low-voltage power grid 30.

[0028] exist Figure 2In the embodiment of the present invention, the charging module 22 further includes a control unit 221, which can control the charging module so as to control the process of electric energy from the power supply device 10 to the charging system 20 and from the charging system 20 to the low-voltage power grid 20. The charging module 22 further includes a voltage sampling unit 224 and a current sampling unit 223, which are respectively used to sample the real-time voltage and real-time current of the low-voltage power grid and feed them back to the control unit 221. The voltage sampling unit 224 samples the real-time voltage of the low-voltage power grid 30, and the control unit 221 compares the real-time voltage with the voltage threshold of the low-voltage power grid, and controls the charging module 22 based on the comparison result of the real-time voltage and the voltage threshold. Specifically, when the real-time voltage of the low-voltage grid is greater than or equal to the voltage threshold of the low-voltage grid, it is considered that the low-voltage grid / vehicle is not in a "power failure" or "power deficit" state, and the low-voltage grid does not need to be charged, so the control unit 221 can control the charging module 22 not to transmit electric energy to the low-voltage grid 30; and when the real-time voltage of the low-voltage grid is less than the voltage threshold of the low-voltage grid, it is considered that the low-voltage grid / vehicle is in a "power failure" or "power deficit" state, and the low-voltage grid needs to be charged, and the control unit 221 can control the charging module 22 to transmit electric energy to the low-voltage grid 30. It should be noted that the voltage threshold of the low-voltage grid mentioned in this article can be a value or a range of values, and those skilled in the art can set it according to actual conditions.

[0029] The current sampling unit 223 can sample the real-time current of the low-voltage power grid and feed it back to the control unit 221, and the control unit 221 controls the charging module 22 based on the difference between the real-time current and the target current of the low-voltage power grid. Specifically, the control unit 221 can control the DC-DC 222 to make the real-time current of the low-voltage power grid closer to or equal to the target current. The target current is obtained by the ratio between the rated power of the power supply device 10 and the real-time voltage of the low-voltage power grid. The rated power of the power supply device 10 can be obtained from the power supply device 10 by the control unit 221 through the USB protocol. In one example, when the real-time current is lower than the target current, the control unit 221 controls the charging module 22 to increase the real-time current so that it approaches or is equal to the target current; when the real-time current is higher than the target current, the control unit 221 controls the charging module 22 to reduce the real-time current so that it approaches or is equal to the target current; when the real-time current is equal to the target current or the difference between the two is within an acceptable error range, the control unit 221 controls the charging module 22 to maintain the current real-time current.

[0030] The charging system 20 also includes a safety unit 225, which can be disconnected when the circuit is overloaded to protect the charging system and low-voltage power grid and other equipment. Figure 2 In the example of FIG. 5 , the charging system 20 includes a low-voltage grid interface 23 , and the charging system 20 is connected to the low-voltage grid of the vehicle through the low-voltage grid interface 23 .

[0031] The present application also proposes a method for charging a vehicle's low-voltage power grid. The method realizes charging through a USB protocol, which simplifies the inconvenience of the charging process when the vehicle's low-voltage power grid is "power off" or "power low". It can directly supply power to the vehicle's low-voltage power grid through common power supply equipment, shortening the time required for vehicle recovery.

[0032] Figure 3 A specific embodiment of the method for charging a vehicle low-voltage power grid of the present application is shown. In this method, a USB connection is established between a charging system 20 and a power supply device 10 outside the vehicle through the USB protocol. The power supply device 10 can be any power supply device that supports the USB protocol, such as a "mobile power supply" for charging electronic products such as mobile phones. After the USB connection is established, the rated power of the power supply device can be obtained through the USB protocol. The power supply device 10 and the charging system 20 are specifically connected through a USB interface 21.

[0033] In order to determine whether the low-voltage grid needs to be charged, the voltage of the low-voltage grid can be sampled for determination. Specifically, the control unit 221 compares the real-time voltage of the low-voltage grid 30 sampled by the voltage sampling unit 224 with the voltage threshold of the low-voltage grid. When the real-time voltage is greater than or equal to the voltage threshold of the low-voltage grid, it is determined that the low-voltage grid does not need to be charged, and charging can be stopped, and the method ends here; when the real-time voltage is less than the voltage threshold of the low-voltage grid, it is determined that the low-voltage grid needs to be charged.

[0034] When the real-time voltage is less than the voltage threshold of the low-voltage power grid, it is judged that the low-voltage power grid needs to be charged. At this time, the charging system 20 can establish a charging circuit, and can continuously sample the real-time voltage and real-time current of the low-voltage power grid for judgment. Among them, the target current of the low-voltage power grid is obtained by calculating the ratio of the rated power of the power supply equipment to the real-time voltage of the low-voltage power grid. If the real-time current of the low-voltage power grid is less than its target current, the control unit 221 controls the current conversion unit 222 to increase the real-time current of the low-voltage power grid so that the real-time current approaches or even equals the target current. If the real-time current of the low-voltage power grid is greater than its target current, the control unit 221 controls the current conversion unit 222 to reduce the real-time current of the low-voltage power grid so that the real-time current approaches or even equals the target current. If the real-time current of the low-voltage power grid is equal to its target current or the difference with the target current is within an acceptable error range, the control unit 221 controls the current conversion unit 222 to maintain the real-time current of the low-voltage power grid.

[0035] After adjusting the current of the low voltage grid, such as Figure 3As described above, we return to the step of determining whether the low-voltage grid needs to be charged. Specifically, the real-time voltage of the low-voltage grid is sampled, and the relationship between the real-time voltage and the voltage threshold is determined. If the judgment result is that charging needs to continue, the real-time current sampling, comparison and adjustment steps as described above are performed.

[0036] Apart from Figure 3 In addition to the above, the method of the present application also includes, when the current in the charging system of the vehicle low-voltage power grid is overloaded, stopping charging to protect the circuit equipment. This can be achieved by the insurance unit 225, which can be a protection device such as a fuse.

[0037] It should be noted that although Figure 3 In the above description, the steps of the charging method of the present application are described in a certain order, but those skilled in the art should understand that the order of one or more steps in the charging method of the present application can be adjusted, or some steps can be performed simultaneously. Figure 3 The step of obtaining the rated power is located before the step of voltage sampling, but the order of the two can also be adjusted (for example, the step of obtaining the rated power is adjusted to after the voltage sampling and before the step of comparing the real-time voltage with the voltage threshold, or the step of obtaining the rated power is adjusted to between the step of voltage comparison and the step of calculating the target current), or both can be performed simultaneously.

[0038] The specific embodiments described above in this application are only for more clearly describing the principles of this application, wherein each component is clearly shown or described to make the principles of this application easier to understand. Without departing from the scope of this application, those skilled in the art can easily make various modifications or changes to this application. Therefore, it should be understood that these modifications or changes should be included in the scope of patent protection of this application.

Claims

1. A charging system for charging a low-voltage power grid of a vehicle, the charging system comprising: A charging module, one end of which is connected to the low-voltage power grid; A USB interface, which enables the other end of the charging module to be connected to an external power supply device via the USB protocol; The charging system transmits electric energy from the power supply equipment to the low-voltage power grid.

2. The charging system according to claim 1, wherein: The charging module comprises a current conversion unit, and the current conversion unit is used to convert the electric energy from the power supply device to transmit it to the low-voltage power grid.

3. The charging system according to claim 2, wherein: The current conversion unit realizes direct current to direct current conversion.

4. The charging system according to claim 1, wherein: The charging module comprises: a control unit, which controls the charging module, A voltage sampling unit, which samples the real-time voltage of the low-voltage power grid and feeds it back to the control unit, Among them, when the real-time voltage is greater than or equal to the voltage threshold of the low-voltage power grid, the control unit controls the charging module not to transmit electric energy to the low-voltage power grid; when the real-time voltage is less than the voltage threshold of the low-voltage power grid, the control unit controls the charging module to transmit electric energy to the low-voltage power grid.

5. The charging system according to claim 4, wherein: The charging module comprises: A current sampling unit samples the real-time current of the low-voltage power grid and feeds it back to the control unit, and the control unit adjusts the real-time current of the low-voltage power grid based on the difference between the real-time current and the target current of the low-voltage power grid.

6. The charging system according to claim 5, wherein: The control unit obtains the rated power of the power supply device through the USB protocol, and determines the target current based on the ratio of the rated power to the real-time voltage.

7. A method for charging a low voltage power grid of a vehicle, comprising: Establish a USB connection, Determine whether the low-voltage power grid needs to be charged. If not, terminate the charging. If necessary, perform the following steps: Obtain power from an external power supply device through the USB protocol. The electric energy from the power supply device is transmitted to the low-voltage power grid.

8. The method according to claim 7, wherein: The step of determining whether the low-voltage power grid needs to be charged includes: sampling the real-time voltage of the low-voltage power grid and comparing the real-time voltage with the voltage threshold of the low-voltage power grid; when the real-time voltage is greater than or equal to the voltage threshold, charging is not required; when the real-time voltage is less than the voltage threshold, charging is required.

9. The method according to claim 7 further includes, when charging is required, sampling the real-time current of the low-voltage power grid, and adjusting the real-time current of the low-voltage power grid according to the difference between the real-time current and the target current of the low-voltage power grid, and then returning to the above step of determining whether the low-voltage power grid needs to be charged.

10. The method according to claim 9, wherein: The target current of the low-voltage power grid is obtained by the ratio of the rated power of the power supply device to the real-time voltage, and the rated power of the power supply device is obtained by communicating with the power supply device.

11. The method according to claim 9, wherein: Adjusting the current of the low-voltage power grid includes making the real-time current approach to or equal to the target current.

12. A vehicle comprising a charging system according to any one of claims 1-6.

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