A vehicle capacitor and battery composite energy storage high and low voltage system and control method

Abstract

The application discloses a kind of vehicle capacitor and battery composite energy storage high-low voltage system and control method, belong to high pressure safety and low voltage power supply field, high-low voltage system includes high voltage part, low voltage part and vehicle controller;High voltage part includes high voltage power battery, capacitor, main relay, pre-charging relay and DC-DC controller;The main relay, pre-charging relay and DC-DC controller parallel the high voltage power battery, capacitor connects the main relay, pre-charging relay, capacitor is connected with load through IGBT module;Low voltage part includes low voltage battery, and low voltage battery is connected with the DC-DC controller through electromagnetic main switch;The vehicle controller signal is connected DC-DC controller, main relay, pre-charging relay, high voltage power battery, low voltage battery and IGBT module;Face different control signals when using, vehicle controller carries out the combination use of corresponding element, completes different power supply mode switching.

Description

Technical Field

[0001] This application relates to the fields of high-voltage safety and low-voltage power supply technology for vehicles, specifically to a high- and low-voltage energy storage system and control method for vehicles using a combination of capacitors and batteries. Background Technology

[0002] Traditional fuel-powered heavy-duty trucks rely on internal combustion engines for starting. At the moment of starting, the battery needs to provide a large current of several hundred amperes to the starter motor and spark plugs, so a large-capacity battery (usually 180Ah or more) must be installed. This not only increases the cost and weight of the vehicle, but also occupies valuable chassis space.

[0003] New energy heavy-duty trucks (pure electric, fuel cell, etc.) do not have internal combustion engines; their high-voltage power batteries supply power to the low-voltage system via DC-DC converters. Vehicle startup only requires activating the vehicle control unit (VCU) and battery management system (BMS), etc. The initial operating current of low-voltage electrical equipment is very small, theoretically eliminating the need for the large-capacity batteries found in traditional gasoline vehicles. However, due to concerns about high-voltage failure risks and excessive static power consumption, existing new energy heavy-duty trucks typically still use traditional large-capacity batteries.

[0004] This design leads to increased costs. Therefore, there is an urgent need for an innovative solution that allows new energy heavy-duty trucks to use small-capacity batteries while ensuring safety and reliability, thereby reducing overall vehicle cost and weight and optimizing space layout. Summary of the Invention

[0005] The purpose of this application is to provide a high- and low-voltage composite energy storage system and control method for vehicles using capacitors and batteries, so as to solve the above-mentioned defects caused by the prior art.

[0006] To achieve the above objectives, this application employs the following technical solution: In a first aspect, this application provides a high- and low-voltage composite energy storage system for vehicles using capacitors and batteries, which includes a high-voltage section and a low-voltage section. The high-voltage section includes a high-voltage power battery, a capacitor, a main relay, a pre-charge relay, and a DC-DC controller; The main relay, pre-charge relay, and DC-DC controller are connected in parallel to the high-voltage power battery. The capacitor is connected to the main relay and pre-charge relay, and the capacitor is connected to the load through the IGBT module. The low-voltage section includes a low-voltage battery, which is connected to the DC-DC controller via an electromagnetic master switch. And the vehicle controller; The vehicle controller is signal-connected to the DC-DC controller, the main relay, the pre-charge relay, the high-voltage power battery, the low-voltage storage battery, and the IGBT module; The vehicle controller controls the operation and shutdown of the DC-DC controller, the main relay, the precharge relay, and the IGBT module according to the control signal, and switches the power supply modes of the low-voltage battery, the high-voltage power battery, and the capacitor.

[0007] In a further embodiment of this application, a pre-charge resistor is connected between the pre-charge relay and the capacitor to limit the inrush current during high-voltage power-on.

[0008] In a further embodiment of this application, the vehicle controller signal is connected to a remote communication module; When the high-voltage power battery charge is lower than a preset value, the vehicle controller sends an alarm through the external platform of the remote communication module.

[0009] Further aspects of this application, The vehicle controller is configured to control the opening / closing of the main relay and the precharge relay, control the operation of the DC-DC controller, and allow the high-voltage power battery to supply power to the capacitor or the capacitor to supply power to the low-voltage section.

[0010] Further aspects of this application, The vehicle controller is configured to control the disconnection of the main relay and the precharge relay, and the capacitor discharges through the load.

[0011] Secondly, this application discloses a high and low voltage control method for a combined capacitor and battery energy storage system, comprising: According to the vehicle status, the vehicle controller control signal controls the operation and stop of the DC-DC controller, the main relay, the precharge relay and the IGBT module, and switches the power supply mode of the low-voltage battery, the high-voltage power battery and the capacitor. The vehicle status modes mentioned above include: Normal start mode is the power supply mode when the vehicle starts normally; The maintenance mode is the power supply mode used when the vehicle is undergoing normal maintenance. Sleep mode is the power supply mode when the vehicle enters a static sleep state; Further aspects of this application, The control methods in the normal startup mode include: When the vehicle controller detects that the capacitor voltage is within a preset range, the vehicle controller controls the DC-DC controller to enter the step-down mode, and the capacitor supplies power to the low-voltage circuit, thus powering the vehicle controller. When the vehicle controller closes the pre-charge relay, the high-voltage power battery charges the capacitor through the pre-charge resistor. When the capacitor voltage rises to a preset percentage of the battery's rated voltage, the main positive relay closes and the pre-charge relay opens, and the high-voltage power-on is completed. The high-voltage power battery continuously supplies power to the low-voltage circuitry.

[0012] Further aspects of this application, The control methods in the maintenance mode include: The vehicle controller receives a maintenance command and controls the DC-DC controller to stop working. The low-voltage battery supplies power to the low-voltage circuit; the vehicle controller controls the disconnection of the main positive relay and the pre-charge relay, and controls the capacitor to discharge through the load.

[0013] Further aspects of this application, The control methods in the hibernation mode include: The vehicle controller controls the capacitor to retain its initial voltage and enter sleep mode, and sets the vehicle controller to wake up periodically to detect the capacitor voltage; When the capacitor voltage drops to a preset value, the vehicle controller automatically switches to low-voltage battery power supply; when the low-voltage battery charge is lower than a preset value, the vehicle controller controls the high-voltage power battery to replenish the low-voltage battery until the low-voltage battery charge reaches the preset value.

[0014] Thirdly, this application discloses a computer-readable storage medium storing a computer program thereon, wherein the computer program, when executed by a processor, performs the steps of the above-described high and low voltage control method for combined capacitor and battery energy storage.

[0015] The beneficial effects of this application are as follows: When in use, this system can power the vehicle controller through a high-voltage power battery, a capacitor, and a low-voltage battery. The capacitor acts as an energy storage element and can charge the low-voltage battery when necessary, ensuring a continuous power supply to the vehicle controller. Even if the high-voltage power battery fails, it has an emergency function. In response to different control signals, the vehicle controller uses the corresponding combination of components to switch between different power supply modes, ensuring that the low-voltage system always has sufficient power. This makes it possible to use a small-capacity battery, significantly reducing the overall vehicle cost. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the high and low voltage composite energy storage system for vehicles using capacitors and batteries in an embodiment of this application. Figure 2 This is a logic diagram of the high and low voltage control method for the combined energy storage of capacitors and batteries in the embodiments of this application. Detailed Implementation

[0017] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other. Example 1

[0018] like Figure 1 As shown, this embodiment discloses a high- and low-voltage composite energy storage system for vehicles using capacitors and batteries. It includes a high-voltage section, a low-voltage section, and a vehicle control unit (VCU). The high-voltage section includes a high-voltage power battery, a capacitor, a main relay, a pre-charge relay, and a DC-DC controller. The main relay, pre-charge relay, and DC-DC controller are connected in parallel to the high-voltage power battery. The capacitor is connected to the main relay and pre-charge relay, and is connected to the load via an IGBT module. The low-voltage section includes a low-voltage battery, which is connected to the DC-DC controller via an electromagnetic master switch. The vehicle control unit is signal-connected to the DC-DC controller, main relay, pre-charge relay, high-voltage power battery, low-voltage battery, and IGBT module. The vehicle control unit controls the operation and shutdown of the DC-DC controller, main relay, pre-charge relay, and IGBT module according to control signals, switching the power supply modes of the low-voltage battery, high-voltage power battery, and capacitor. This system can control the pre-charge relay to close and the main positive relay to open via the vehicle controller, allowing the high-voltage power battery to charge the capacitor and store electrical energy. During normal driving, the pre-charge relay is opened and the main positive relay is closed, allowing the high-voltage power battery to supply power to the load. If the low-voltage battery charge is lower than a preset value, the DC-DC controller is controlled to replenish the low-voltage battery through the high-voltage side current. The vehicle controller uses the corresponding components to switch between different power supply modes, ensuring that the low-voltage system always has sufficient electrical energy.

[0019] In this embodiment, the system has added some safety components, including a first fuse, a second fuse, and a pre-charge resistor; High-voltage side connection: The positive output terminal of the high-voltage power battery is divided into three parallel paths. The first path connects to the lower end of the first fuse of the second path via the main positive relay. The second path connects to the output terminal of the main positive relay via the pre-charge relay, the pre-charge resistor, and the second fuse. After connecting, it connects to the positive terminal of the capacitor and the positive input terminal of the IGBT module. The third path connects to the high-voltage input terminal of the DC-DC controller via the second fuse of the DC-DC controller. The negative terminal of the high-voltage power battery is connected to the negative terminal of the high-voltage side of the DC-DC controller and the negative input terminal of the IGBT module.

[0020] Low-voltage side connection: The positive output terminal of the low-voltage side of the DC-DC controller in the high-voltage control cabinet is connected to one end of the electromagnetic main switch. The other end of the electromagnetic main switch is connected to the positive terminal of the low-voltage battery. The VCU is powered by the power supply at this point of the low-voltage main switch and is used to detect the voltage of the low-voltage power supply. The negative output terminal of the low-voltage side of the DC-DC controller and the negative terminal of the low-voltage battery are both connected to the chassis beam, with the chassis beam serving as the common ground terminal for the entire vehicle. The high-voltage power battery uses a lithium iron phosphate battery pack with a rated voltage of 618V and a capacity of 228Ah. Its positive and negative terminals are connected to the high-voltage control cabinet through a high-voltage wiring harness.

[0021] Precharge relay; 200Ω precharge resistor with a power of 150W; 600A rated current fuse connected in series in the high-voltage main circuit; 1200μF capacitor with a rated voltage of 1000V; IGBT module with a rated current of 450A; main positive relay with a rated current of 600A; 3kW DC-DC controller; and 6A fuse connected in series in the DC-DC circuit.

[0022] The small-capacity, low-voltage battery (12V / 24V) uses lithium iron phosphate batteries with a capacity of 10Ah and a rated voltage of 24V. Example 2

[0023] Based on the same inventive concept, as shown in the appendix Figure 2 As shown, this embodiment discloses a high and low voltage control method for composite energy storage of capacitors and batteries for vehicles. It includes controlling the operation and stop of the DC-DC controller, the main relay, the pre-charge relay and the IGBT module according to the vehicle state mode, and switching the power supply mode of the low-voltage battery, the high-voltage power battery and the capacitor. The vehicle state includes normal start mode, driving mode, maintenance mode, maintenance exit mode and vehicle static sleep mode.

[0024] (1) Normal start mode: After the vehicle is turned off and the power is cut off, the high-voltage bus capacitor maintains a voltage of about 200V. When the driver starts the vehicle by turning the key, the VCU is awakened and the voltage of the high-voltage bus capacitor is detected to be 210V, which is determined to meet the power supply conditions (200V to 240V).

[0025] The VCU controls the DC-DC controller to enter buck mode. In actual operation, the high-voltage bus capacitor supplies power to the low-voltage side, energizing the VCU, BMS, and high-voltage relay coils. Subsequently, the VCU closes the pre-charge relay, and the high-voltage power battery charges the capacitor through the pre-charge resistor. When the capacitor voltage rises to 95% of the battery's rated voltage (approximately 587V), the main positive relay closes and the pre-charge relay opens, completing the high-voltage power-on. The high-voltage power battery continuously supplies power to the low-voltage side circuit while monitoring the low-voltage battery's charge level. When the low-voltage battery's charge level drops below 60%, it is recharged until it reaches 90% of its charge level, at which point recharging stops.

[0026] (2) Driving mode: During vehicle operation, the VCU controls the DC-DC controller to work continuously, and the high-voltage power battery supplies power to the low-voltage side circuit of the vehicle.

[0027] (3) Entering maintenance mode: The maintenance personnel send a maintenance mode command through the diagnostic instrument. After receiving the command, the VCU controls the DC-DC controller to stop working, and at the same time, the low-voltage side circuit is powered by a small-capacity low-voltage battery; the main positive relay and the pre-charge relay are disconnected, and the control capacitor is forced to discharge through the motor windings, which can actually reduce the voltage to below 60V within 2 seconds. The maintenance personnel can operate safely, and the low-voltage system is continuously powered by a small-capacity low-voltage battery, supporting the diagnostic instrument to perform electrical appliance tests.

[0028] (4) Exiting maintenance mode: After maintenance is completed, the maintenance personnel send an exit command through the diagnostic instrument. The VCU maintains the small-capacity low-voltage battery to supply power to the low-voltage side line, executes the high-voltage power-on process, closes the pre-charge relay, and the high-voltage power battery charges the capacitor through the pre-charge resistor. After the main positive relay is closed, the VCU controls the DC-DC controller to start working, and the high-voltage power battery supplies power to the low-voltage side line. At the same time, it monitors the power of the small-capacity low-voltage battery. When the power of the low-voltage battery is lower than 60%, the VCU wakes up the high-voltage system, and the high-voltage power battery replenishes the low-voltage battery through the DC-DC controller. The replenishment stops after the power reaches 90%.

[0029] (5) Vehicle Static Dormancy State: After the vehicle is de-energized, the VCU controls the high-voltage bus capacitor to retain an initial voltage of 200V and enters sleep mode, and sets the VCU to wake up periodically to detect the capacitor voltage. According to actual measurements, the capacitor voltage drops to 80V after 7 days of static storage under normal temperature conditions, and the VCU automatically switches to power supply from the small-capacity low-voltage battery. After about 26 days of static storage, the charge of the small-capacity low-voltage battery is lower than 35%, and the VCU controls the vehicle to replenish the low-voltage battery (power supply from the high-voltage circuit, allowing high-voltage input to the DCDC controller, which converts the high-voltage electricity to a low voltage of about 28.2V through the power conversion of the DCDC controller, and uses the low-voltage electricity to replenish the battery). When the charge reaches 90%, the low-voltage battery stops replenishing.

[0030] This application reuses the existing capacitor in the motor controller as an energy storage element after power-off, and configures a 6-12Ah small-capacity low-voltage battery as auxiliary energy storage, forming a composite structure of capacitor as the main storage and battery as the auxiliary. This architecture eliminates the need for traditional 60-80kg large-capacity batteries; in maintenance mode, it automatically switches to small-capacity battery power supply and forces the capacitor to discharge to a safe voltage, allowing electrical appliance testing to be completed without an external power supply; by utilizing the original vehicle's DC-DC and VCU, hardware modifications are minimal, and it can be quickly integrated into existing new energy heavy truck platforms; it not only solves the industry pain points of short lead-acid battery life and frequent power loss, but also significantly reduces the total life cycle maintenance cost, possessing high engineering promotion value and market competitiveness. Example 3

[0031] Based on the same inventive concept, this embodiment discloses a computer-readable storage medium storing a computer program thereon, characterized in that the computer program, when executed by a processor, performs the steps of the high and low voltage control method for the combined energy storage of capacitors and batteries in Embodiment 2.

[0032] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0033] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0034] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1The function specified in one or more boxes.

[0035] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0036] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A high- and low-voltage composite energy storage system for vehicles, comprising capacitors and batteries, characterized in that, Includes high-pressure section and low-pressure section; The high-voltage section includes a high-voltage power battery, a capacitor, a main relay, a pre-charge relay, and a DC-DC controller; The main relay, pre-charge relay, and DC-DC controller are connected in parallel to the high-voltage power battery. The capacitor is connected to the main relay and pre-charge relay, and the capacitor is connected to the load through the IGBT module. The low-voltage section includes a low-voltage battery, which is connected to the DC-DC controller via an electromagnetic master switch. And the vehicle controller; The vehicle controller is signal-connected to the DC-DC controller, the main relay, the pre-charge relay, the high-voltage power battery, the low-voltage storage battery, and the IGBT module; The vehicle controller controls the operation and shutdown of the DC-DC controller, the main relay, the precharge relay, and the IGBT module according to the control signal, and switches the power supply modes of the low-voltage battery, the high-voltage power battery, and the capacitor.

2. The high- and low-voltage composite energy storage system for vehicles using capacitors and batteries according to claim 1, characterized in that, A pre-charge resistor is connected between the pre-charge relay and the capacitor to limit the inrush current during high-voltage power-on.

3. The high- and low-voltage composite energy storage system for vehicles using capacitors and batteries according to claim 1, characterized in that, The vehicle controller signal is connected to the remote communication module; When the high-voltage power battery charge is lower than a preset value, the vehicle controller sends an alarm through the external platform of the remote communication module.

4. The high- and low-voltage composite energy storage system for vehicles using capacitors and batteries according to claim 1, characterized in that, The vehicle controller is configured to control the opening / closing of the main relay and the precharge relay, control the operation of the DC-DC controller, and allow the high-voltage power battery to supply power to the capacitor or the capacitor to supply power to the low-voltage section.

5. The high- and low-voltage composite energy storage system for vehicles using capacitors and batteries according to claim 1, characterized in that, The vehicle controller is configured to control the disconnection of the main relay and the precharge relay, and the capacitor discharges through the load.

6. A method for high and low voltage control of a combined capacitor and battery energy storage system implemented by any one of claims 1 to 5, characterized in that, include According to the vehicle status, the vehicle controller control signal controls the operation and stop of the DC-DC controller, the main relay, the precharge relay and the IGBT module, and switches the power supply mode of the low-voltage battery, the high-voltage power battery and the capacitor. The vehicle status mentioned above includes: Normal start mode, which is the power supply mode when the vehicle starts normally; Maintenance mode, which is the power supply mode when the vehicle is undergoing normal maintenance; Sleep mode is the power supply mode when the vehicle enters a static sleep state.

7. The high and low voltage control method for combined capacitor and battery energy storage according to claim 6, characterized in that, The control methods in the normal startup mode include: When the vehicle controller detects that the capacitor voltage is within a preset range, the vehicle controller controls the DC-DC controller to enter the step-down mode, and the capacitor supplies power to the low-voltage circuit, thus powering the vehicle controller. When the vehicle controller closes the pre-charge relay, the high-voltage power battery charges the capacitor through the pre-charge resistor. When the capacitor voltage rises to a preset percentage of the battery's rated voltage, the main positive relay closes and the pre-charge relay opens, and the high-voltage power-on is completed. The high-voltage power battery continuously supplies power to the low-voltage circuitry.

8. The high and low voltage control method for combined capacitor and battery energy storage according to claim 6, characterized in that, The control methods in the maintenance mode include: The vehicle controller receives a maintenance command and controls the DC-DC controller to stop working. The low-voltage battery supplies power to the low-voltage circuit; the vehicle controller controls the disconnection of the main positive relay and the pre-charge relay, and controls the capacitor to discharge through the load.

9. The high and low voltage control method for combined capacitor and battery energy storage according to claim 6, characterized in that, The control methods in the hibernation mode include: The vehicle controller controls the capacitor to retain its initial voltage and enter sleep mode, and sets the vehicle controller to wake up periodically to detect the capacitor voltage; When the capacitor voltage drops to a preset value, the vehicle controller automatically switches to low-voltage battery power supply; when the low-voltage battery charge is lower than a preset value, the vehicle controller controls the high-voltage power battery to replenish the low-voltage battery until the low-voltage battery charge reaches the preset value.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the high and low voltage control method for the combined energy storage of capacitors and batteries as described in claim 6.

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