An oil-electric hybrid system charging and discharging circuit and system

Abstract

The utility model discloses a kind of oil-electric hybrid system charge-discharge circuit and system, comprising: battery cell group, high voltage distribution box, whole vehicle controller, motor controller and engine controller;Battery cell group includes battery main cell group and battery slave cell group, battery main cell group and battery slave cell group are connected with motor controller respectively by high voltage distribution box;High voltage distribution box, motor controller and engine controller are all connected with whole vehicle controller signal.This application is by constructing the double cell structure including main cell group and slave cell group, in combination with the coordination mechanism of whole vehicle controller, the automatic calibration and safety protection of battery system are realized.Compared with the mode that user needs to deliberately fill regularly in prior art, SOC calibration can be completed without user intervention in this embodiment, and by the independent resource configuration of slave cell group, the power compensation capability is provided for main cell group, and the risk of overcharge and overdischarge is avoided.

Description

Technical Field

[0001] This utility model relates to the field of hybrid vehicle technology, and in particular to a charging and discharging circuit and system for a hybrid electric vehicle system. Background Technology

[0002] In hybrid vehicle systems, the use of lithium iron phosphate (LFP) batteries as energy storage devices faces significant challenges. The battery state-of-charge (SOC) calibration process is inherently difficult, primarily due to the flat voltage plateau of LFP batteries. This results in insufficient accuracy of voltage-based estimation methods, making it difficult for the system to reliably identify the actual remaining charge. To address the calibration issue, existing vehicles typically require dedicated charging interfaces, forcing users to schedule regular full-charge operations. This not only increases overall vehicle manufacturing costs and structural complexity but also significantly reduces user convenience, requiring active user intervention to maintain system accuracy. Furthermore, battery systems are prone to overcharging or over-discharging during operation, especially under dynamic conditions. Such issues accelerate battery performance degradation, shorten lifespan, and may pose potential safety risks. Some technologies attempt to assist calibration by adjusting engine operating modes to achieve low-current charging, but this method deviates the engine from its efficient operating range, leading to a decrease in overall vehicle energy efficiency and failing to balance battery management and fuel economy optimization. Utility Model Content

[0003] In view of this, the present invention provides a charging and discharging circuit for a hybrid electric system, which has the advantages of automatically calibrating the state of charge of the battery without requiring the user to deliberately arrange periodic full charging operations, and effectively reducing the risk of overcharging and over-discharging of the battery cells.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A charging and discharging circuit for a hybrid electric vehicle system includes: a battery cell pack, a high-voltage distribution box, a vehicle controller, a motor controller, and an engine controller; the battery cell pack includes a main battery cell pack and a slave battery cell pack, which are respectively connected to the motor controller through the high-voltage distribution box; the high-voltage distribution box, the motor controller, and the engine controller are all signal-connected to the vehicle controller.

[0006] Preferably, the high-voltage distribution box integrates a main positive relay, a main negative relay, and a manual maintenance switch. The positive terminals of the main battery cell group and the battery slave cell group are both connected to the main positive relay, and the negative terminals of the main battery cell group and the battery slave cell group are both connected to the main negative relay. A manual maintenance switch is provided between the positive terminal of the main battery cell group and the main positive relay.

[0007] Preferably, the high-voltage distribution box also integrates a battery management system and a bidirectional DC-DC converter. The battery is connected from the positive and negative terminals of the cell pack to the main positive relay and the main negative relay respectively through the bidirectional DC-DC converter. The bidirectional DC-DC converter is connected to the vehicle controller through the battery management system.

[0008] Preferably, the high-voltage distribution box also integrates a current sensor, which is installed in the circuit between the main battery cell group and the main negative relay.

[0009] This utility model also proposes a hybrid electric vehicle system, including a hybrid electric vehicle charging and discharging circuit of any of the above embodiments, an engine, a motor, and a power coupling device; the engine and the motor are connected through the power coupling device to achieve power coupling; the engine controller is connected to the engine, and the motor controller is connected to the motor.

[0010] The beneficial effects of this utility model are as follows: Compared with the prior art, this application achieves automatic calibration and safety protection of the battery system by constructing a dual-cell structure including a main cell group and a slave cell group, combined with the coordination mechanism of the vehicle controller. Compared with the prior art that requires users to deliberately charge the battery at full capacity periodically, this embodiment can complete SOC calibration without user intervention. At the same time, through the independent resource configuration of the slave cell group, it provides power compensation capability for the main cell group, avoiding the risks of overcharging and over-discharging. Therefore, this technical solution not only improves the service life of the battery system but also optimizes the user experience.

[0011] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the charging and discharging circuit of this utility model.

[0013] Figure Labels

[0014] 1. Battery cell pack; 11. Main battery cell pack; 12. Secondary battery cell pack;

[0015] 2. High-voltage distribution box; 21. Main positive relay; 22. Main negative relay; 23. Manual maintenance switch; 24. Battery management system; 25. Bidirectional DC-DC converter; 26. Current sensor;

[0016] 3. Vehicle controller; 4. Motor controller; 5. Engine controller; 6. Engine; 7. Motor; 8. Power coupling device. Detailed Implementation

[0017] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0019] The following is for reference. Figure 1 The charging and discharging circuit of the hybrid electric system in the embodiments of this utility model is described.

[0020] This application discloses a charging and discharging circuit for a hybrid electric vehicle system, including: a battery cell pack 1, a high-voltage distribution box 2, a vehicle controller 3, a motor controller 4, and an engine controller 5; the battery cell pack 1 includes a main battery cell pack 11 and a secondary battery cell pack 12, which are respectively connected to the motor controller 4 through the high-voltage distribution box 2; the high-voltage distribution box 2, the motor controller 4, and the engine controller 5 are all signal-connected to the vehicle controller 3.

[0021] The battery cell pack 1 is an energy storage unit composed of multiple individual battery cells connected in series or parallel, and its main function is to provide power support for the hybrid system. Specifically, the main battery cell pack 11 and the slave battery cell pack 12 can be implemented using combinations of cells of different capacities or types, such as lithium iron phosphate batteries, ternary lithium batteries, or other suitable power battery types, with the aim of meeting the energy requirements of the hybrid system under normal operation and special working conditions. Furthermore, the division between the main battery cell pack 11 and the slave battery cell pack 12 can be achieved through physical isolation or electrical isolation, for example, by managing the two sets of cells separately through an independent battery management system 24, or by using relay control to achieve independent switching of the operating states of the two sets of cells.

[0022] The high-voltage distribution box 2 is a key device for distributing and managing high-voltage electrical energy. Its main function is to control and protect the charging and discharging path of the battery cell pack 1. The vehicle controller 3, as the core control unit of the hybrid system, mainly coordinates and schedules the operating status of each subsystem.

[0023] The innovation of this application lies in constructing a dual-cell structure comprising a main cell group and a slave cell group, combined with the coordination mechanism of the vehicle controller 3, to achieve automatic calibration and safety protection of the battery system. Compared to existing technologies that require users to deliberately charge the battery at full capacity periodically, this embodiment can complete SOC calibration without user intervention. Simultaneously, through the independent resource configuration of the slave cell group, it provides power compensation capability to the main cell group, avoiding the risks of overcharging and over-discharging. Therefore, this technical solution not only improves the battery system's lifespan but also optimizes the user experience.

[0024] The working principle of this embodiment is as follows: A hybrid electric vehicle charging and discharging circuit achieves its function through the coordinated operation of battery cell group 1, high-voltage distribution box 2, vehicle controller 3, motor controller 4, and engine controller 5. Battery cell group 1 includes a main battery cell group 11 and a secondary battery cell group 12, both connected to the motor controller 4 via the high-voltage distribution box 2, thus forming independent and controllable charging and discharging paths. The high-voltage distribution box 2, as the core management unit, is responsible for flexibly switching and isolating the charging and discharging states of the two cell groups, ensuring that the main cell group focuses on power output under normal operating conditions, while the secondary cell group serves as a backup resource for calibration or compensation operations under specific conditions. Furthermore, the high-voltage distribution box 2, motor controller 4, and engine controller 5 are all signal-connected to the vehicle controller 3, thereby achieving real-time monitoring and unified scheduling of the system status. Specifically, the vehicle controller 3 dynamically adjusts the charging and discharging strategy based on the received signals, triggering the secondary cell group to participate in the calibration process of the main cell group at appropriate times, and simultaneously intervening in abnormal charging and discharging processes to avoid the risk of overcharging or over-discharging of the cells. Through the combined operation of the above-mentioned technical features, this technical solution can automatically calibrate the battery SOC without user intervention and effectively prevent the performance degradation of the battery cell caused by overcharging or over-discharging. This solves the problems of difficult battery SOC calibration, avoiding users deliberately charging the battery at full capacity on a regular basis, and preventing overcharging and over-discharging of the battery cell.

[0025] In some embodiments, for example Figure 1 As shown, the high-voltage distribution box 2 integrates a main positive relay 21, a main negative relay 22, and a manual maintenance switch 23. The positive terminals of the main battery cell group 11 and the battery slave cell group 12 are both connected to the main positive relay 21, and the negative terminals of the main battery cell group 11 and the battery slave cell group 12 are both connected to the main negative relay 22. A manual maintenance switch 23 is provided between the positive terminal of the main battery cell group 11 and the main positive relay 21.

[0026] Among them, the main positive relay 21 is a key component used to control the on / off state of the high-voltage circuit. It can be implemented using an electromagnetic relay or a solid-state relay, and its purpose is to prevent overcharging or over-discharging by quickly cutting off the high-voltage circuit. The main negative relay 22 is another core switching element designed symmetrically with the main positive relay 21. It can also be implemented using an electromagnetic relay or a solid-state relay, and its purpose is to ensure that the negative circuit can be synchronously disconnected under abnormal conditions, thereby avoiding the risk of deep discharge. The manual maintenance switch 23 is a physical-level disconnection device, which can be implemented using a mechanical switch or a fuse switch, and its purpose is to provide maintenance personnel with a safe isolation means independent of the electronic control system.

[0027] Specifically, this technical solution integrates a main positive relay 21 and a main negative relay 22 inside the high-voltage distribution box 2, constructing a complete circuit control system. The main positive relay 21 and main negative relay 22 execute on / off operations according to real-time commands from the vehicle controller 3. Upon detecting abnormal states such as pre-overvoltage or pre-undervoltage, they can quickly disconnect the high-voltage circuit, effectively protecting the battery system from overcharging or over-discharging. Simultaneously, integrating the relays into the high-voltage distribution box 2 reduces redundant external wiring connections, improving circuit response speed and overall system stability. The connection of the positive terminals of both the main battery cell group 11 and the secondary battery cell group 12 to the main positive relay 21 achieves centralized control of the positive path. When the main positive relay 21 is disconnected, the positive circuit of the entire system is completely isolated, preventing overcharge current surges under abnormal operating conditions. Similarly, the design of connecting the negative terminals of both the main battery cell group 11 and the secondary battery cell group 12 to the main negative relay 22 ensures synchronous disconnection of the negative circuit, promptly cutting off the negative path when the risk of deep discharge occurs. In addition, the introduction of the manual maintenance switch 23 provides extra safety, especially in the event of a failure of the electronic control system, allowing operators to manually disconnect the high-voltage circuit to ensure absolute safety of the maintenance environment.

[0028] The above technical solutions not only solve the problem of the high-voltage circuit being unable to be safely disconnected during maintenance, but also significantly improve the safety and reliability of the battery system during charging and discharging, thereby extending battery life and optimizing system performance.

[0029] In some embodiments, for example Figure 1 As shown, the high-voltage distribution box 2 also integrates a battery management system 24 and a bidirectional DC-DC 25. The battery is connected from the positive and negative terminals of the cell pack 12 to the main positive relay 21 and the main negative relay 22 respectively through the bidirectional DC-DC 25. The bidirectional DC-DC 25 is connected to the vehicle controller 3 through the battery management system 24.

[0030] The battery management system 24 is an electronic device used to monitor the battery status in real time and control the charging and discharging process, with the aim of ensuring that the battery is always within a safe operating range. The bidirectional DC-DC converter 25 is a power electronic device capable of bidirectional DC voltage conversion, with the aim of completing the energy transfer between the main battery cell group and the slave battery cell group.

[0031] Specifically, this technical solution deeply integrates the battery management system 24 and the bidirectional DC-DC converter 25 into the high-voltage distribution box 2, constructing a closed-loop control system for battery management. The battery management system 24 integrated within the high-voltage distribution box 2 can collect parameters such as battery voltage, current, and temperature in real time, and transmit this information to the vehicle controller 3 via signal connections. This allows the vehicle controller 3 to coordinate the operation of components such as the engine 6 and motor 7 according to the actual battery status. The bidirectional DC-DC converter 25, through its connection with the main positive relay 21 and the main negative relay 22, enables bidirectional energy flow between the main cell group and the slave cell group under the command of the battery management system 24. When the main cell group needs full charge calibration, the bidirectional DC-DC converter 25 can draw energy from the slave cell group for constant current charging; when the main cell group experiences pre-undervoltage or pre-overvoltage, the bidirectional DC-DC converter 25 can transfer excess energy to the slave cell group, thereby preventing overcharging and over-discharging of the cells. This integration method not only improves system response speed and reliability but also achieves seamless battery maintenance and extends battery life.

[0032] The above technical solutions solve the problems of difficult battery SOC calibration and overcharge / over-discharge risks in hybrid systems, achieving the goal of battery maintenance without user intervention or reliance on engine low-power mode, significantly improving vehicle energy efficiency and user experience.

[0033] In some embodiments, for example Figure 1 As shown, the high-voltage distribution box 2 also integrates a current sensor 26, which is installed in the circuit between the main battery cell group 11 and the main negative relay 22. The current sensor 26 is used to monitor changes in current in the circuit in real time.

[0034] Specifically, a precise monitoring mechanism for the main cell group current is constructed by integrating a current sensor 26 into the circuit between the main cell group 11 and the main negative relay 22. The main negative relay 22 serves as the converging node for the negative current of the main cell group; all charging and discharging currents must flow through this path, enabling the sensor to comprehensively capture real-time current data of the main cell group. This data is used by the battery management system 24 to dynamically correct the battery state-of-charge (SOC) calculation, especially during full-charge calibration, adjusting charging parameters based on the actual current value to avoid SOC estimation distortion caused by the voltage platform characteristics of lithium iron phosphate batteries. Simultaneously, current fluctuations are continuously monitored during system operation. When an abnormal current trend is detected, the battery management system 24 can immediately activate the bidirectional DC-DC converter 25, utilizing instantaneous power compensation from the cell group to provide a buffer response time for the main cell group, effectively suppressing the risk of overcharging or over-discharging. Furthermore, this design ensures that current monitoring is unaffected by the status of the manual maintenance switch 23 or the main positive relay 21, thereby improving the accuracy of charge and discharge control and system safety.

[0035] This utility model also proposes a hybrid electric system, including a hybrid electric system charging and discharging circuit of any of the above embodiments, an engine 6, a motor 7, and a power coupling device 8; the engine 6 and the motor 7 are connected through the power coupling device 8 to achieve power coupling; the engine controller 5 is connected to the engine 6, and the motor controller 4 is connected to the motor 7.

[0036] The core innovation of this embodiment lies in combining the dual-cell structure of the main and slave cell groups with the coordination mechanism of the vehicle controller 3. This solves the problem of difficult battery SOC calibration in hybrid systems and eliminates the need for users to deliberately charge the batteries to full capacity periodically. Simultaneously, by using the slave cell group to compensate the main cell group's power and dynamically adjusting the charging and discharging process, the risks of overcharging and over-discharging are avoided, significantly extending battery life. Furthermore, the engine 6 and motor 7 work collaboratively through the power coupling device 8, ensuring that the engine 6 always operates in the high-efficiency range, thereby improving the overall vehicle fuel economy.

[0037] In its implementation, the hybrid electric vehicle's charging and discharging circuit, based on the aforementioned structure, includes components such as main and slave battery cell groups. It can automatically perform full-charge calibration of the battery during normal vehicle operation and idle states, without user intervention. Engine 6, as an internal combustion engine power source, provides continuous and stable driving force, avoiding low-power operation modes under system coordination and ensuring it always operates within its high-efficiency range. Electric motor 7, as an electric power source, complements engine 6 in outputting power, supporting the power requirements of the hybrid system and reducing inefficient operating conditions of engine 6. The power coupling device 8 establishes the mechanical connection between engine 6 and electric motor 7, transmitting and integrating their power, providing the physical basis for engine 6 to operate in its high-efficiency range.

[0038] Furthermore, engine controller 5 is connected to engine 6, receiving control commands to precisely adjust the start-stop and operating status of engine 6, optimizing the operating point to maintain high-efficiency operation. Motor controller 4 is connected to motor 7, receiving control commands to control the power output and response of motor 7, working in conjunction with engine controller 5 to achieve smooth power switching. These features work together to address battery health and calibration issues in the charging / discharging circuit. Engine 6 and motor 7, in cooperation with the power coupling device 8 and the controller, achieve efficient power output. The entire system can complete SOC calibration without user intervention in normal operating mode, preventing battery damage. Simultaneously, the efficient operation of engine 6 significantly improves the overall vehicle energy efficiency.

[0039] The charging and discharging circuit of the hybrid electric system according to the embodiments of this utility model, as well as other components and operations of the system, are known to those skilled in the art and will not be described in detail here.

[0040] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0041] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A charging and discharging circuit for a hybrid electric vehicle system, characterized in that, include: Battery cell packs, high-voltage distribution boxes, vehicle controllers, motor controllers, and engine controllers; The battery cell assembly includes a main battery cell assembly and a slave battery cell assembly, and the main battery cell assembly and the slave battery cell assembly are respectively connected to the motor controller through the high-voltage distribution box; The high-voltage distribution box, the motor controller, and the engine controller are all connected to the vehicle controller via signal connections.

2. The charging and discharging circuit of the hybrid electric system according to claim 1, characterized in that, The high-voltage distribution box integrates a main positive relay, a main negative relay, and a manual maintenance switch. The positive terminals of the main battery cell group and the battery slave cell group are both connected to the main positive relay, and the negative terminals of the main battery cell group and the battery slave cell group are both connected to the main negative relay. A manual maintenance switch is provided between the positive terminal of the main battery cell group and the main positive relay.

3. The charging and discharging circuit of the hybrid electric system according to claim 2, characterized in that, The high-voltage distribution box also integrates a battery management system and a bidirectional DC-DC converter. The battery is connected from the positive and negative terminals of the cell pack to the main positive relay and the main negative relay respectively through the bidirectional DC-DC converter. The bidirectional DC-DC converter is connected to the vehicle controller through the battery management system.

4. The charging and discharging circuit of the hybrid electric system according to claim 3, characterized in that, The high-voltage distribution box also integrates a current sensor, which is installed in the circuit between the main battery cell group and the main negative relay.

5. A hybrid electric vehicle system, characterized in that, Includes the charging and discharging circuit, engine, motor and power coupling device of the hybrid electric system belonging to any one of claims 1-4 above; The engine and the electric motor are connected via a power coupling device to achieve power coupling; The engine controller is connected to the engine, and the motor controller is connected to the motor.

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