Charging and discharging circuit of vehicle-mounted energy storage system and vehicle-mounted energy storage system

Abstract

The utility model discloses a kind of charging and discharging circuit and vehicle-mounted energy storage system of vehicle-mounted energy storage system, charging and discharging circuit includes charging module control circuit unit, discharging module control circuit unit, charging port insertion detection unit, automobile generator start-stop detection unit and battery management system;Charging port insertion detection unit connects charging module control circuit unit, charging module control circuit unit connects battery management system, battery management system connects discharging module control circuit unit, automobile generator start-stop detection unit connects battery management system;Battery management system controls charging module control circuit unit and discharging module control circuit unit to charge and discharge.

Description

Technical Field

[0001] This application belongs to the field of vehicle-mounted energy storage technology, specifically referring to a charging and discharging circuit for a vehicle-mounted energy storage system and the vehicle-mounted energy storage system itself. Background Technology

[0002] In the automotive field, existing onboard energy storage systems often suffer from simplistic and crude charging control. For example, they may start charging simply based on whether the input voltage reaches the operating voltage. This can lead to over-discharging of the starter battery, shortening its lifespan and affecting the vehicle's normal starting. Furthermore, the lack of refined voltage management during the charging process not only affects charging efficiency but may also damage the battery, shortening the lifespan of both the battery and onboard electrical components. Utility Model Content

[0003] To overcome the shortcomings of the prior art, this application provides a charging and discharging circuit for an on-board energy storage system and an on-board energy storage system that can solve the problem of not being able to charge according to real-time voltage.

[0004] This utility model provides a charging and discharging circuit for an on-board energy storage system. The charging and discharging circuit includes a charging module control circuit unit, a discharging module control circuit unit, a charging port insertion detection unit, an automotive generator start / stop detection unit, and a battery management system.

[0005] The charging port insertion detection unit is connected to the charging module control circuit unit, the charging module control circuit unit is connected to the battery management system, the battery management system is connected to the discharging module control circuit unit, and the vehicle generator start / stop detection unit is connected to the battery management system; the battery management system controls the charging module control circuit unit and the discharging module control circuit unit to perform charging and discharging.

[0006] Furthermore, according to the charging and discharging circuit of the vehicle-mounted energy storage system provided in this application, the charging module control circuit unit includes a solar charging circuit and a car generator charging circuit. One end of the solar charging circuit and the car generator charging circuit are connected to the charging port insertion detection unit, and the other end is connected to the battery management system.

[0007] Furthermore, according to the charging and discharging circuit of the vehicle-mounted energy storage system provided in this application, the solar charging circuit includes a first fuse FU1, a first transistor QT1, a second transistor QT2, a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6.

[0008] One end of the first fuse FU1 is connected to the battery management system, and the other end of the first fuse FU1 is connected to the collector of the first transistor QT1. The base of the first transistor QT1 is connected to the battery management system, and the emitter of the first transistor QT1 is connected to the base of the second transistor QT2. The collector of the base of the second transistor QT2 is grounded, and the emitter of the second transistor QT2 serves as a node connecting the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6, respectively. The other ends of the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are respectively connected to the gates of the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4. The drains of the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 are connected to each other. The sources of the first switch Q1 and the third switch Q3 are connected to each other and connected to the charging port insertion detection unit. The sources of the second switch Q2 and the fourth switch Q4 are connected to each other and connected to the battery management system.

[0009] Furthermore, according to the charging and discharging circuit of the vehicle energy storage system provided in this application, the vehicle generator charging circuit includes a second fuse FU2, a fourth transistor QT4, a fifth transistor QT5, a fifth switch Q5, a sixth switch Q6, a seventh switch Q7, an eighth switch Q8, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, and an eleventh resistor R11.

[0010] One end of the second fuse FU2 is connected to the battery management system, and the other end of the second fuse FU2 is connected to the collector of the fourth transistor QT4. The base of the fourth transistor QT4 is connected to the battery management system, and the emitter of the fourth transistor QT4 is connected to the base of the fifth transistor QT5. The collector of the base of the fifth transistor QT5 is grounded, and the emitter of the fifth transistor QT5 serves as a node connecting the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11. The eighth resistor R8, the... The other ends of the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11 are respectively connected to the gates of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, and the eighth switch Q8. The drains of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, and the eighth switch Q8 are interconnected. The sources of the fifth switch Q5 and the seventh switch Q7 are interconnected and connected to the charging port insertion detection unit. The sources of the sixth switch Q6 and the eighth switch Q8 are interconnected and connected to the battery management system.

[0011] Furthermore, according to the charging and discharging circuit of the vehicle-mounted energy storage system provided in this application, the charging port insertion detection unit includes a solar charging detection circuit and a vehicle generator charging detection circuit;

[0012] One end of the solar charging detection circuit is connected to the solar charging interface, and the other end is connected to the solar charging circuit and the battery management system; one end of the vehicle generator charging detection circuit is connected to the vehicle generator charging interface, and the other end is connected to the vehicle generator charging circuit and the battery management system.

[0013] Furthermore, according to the charging and discharging circuit of the vehicle-mounted energy storage system provided in this application, the solar charging detection circuit includes a positive terminal interface J1, a negative terminal interface J4, a diode D1, a first resistor R1, a second resistor R2, a first capacitor C1, and a diode DZ1.

[0014] The positive terminal J1 is connected to the positive terminal of the solar charging interface, and the negative terminal J4 is connected to the negative terminal of the solar charging interface and marked as GND. The voltage of the solar charging interface flows through the diode D1 and then through the voltage divider circuit composed of the first resistor R1 and the second resistor R2. After being filtered by the first capacitor C1, it is output to the battery management system. The diode DZ1 is a port protection device of the battery management system. The battery management system collects voltage signals.

[0015] Furthermore, according to the charging and discharging circuit of the vehicle energy storage system provided in this application, the vehicle generator charging detection circuit includes a positive terminal J2, a negative terminal J3, a diode D3, a twelfth resistor R12, a thirteenth resistor R13, a third capacitor C3, and a diode DZ3.

[0016] The positive terminal J2 is connected to the positive terminal of the car alternator charging interface, and the negative terminal J3 is connected to the negative terminal of the car alternator charging interface and marked as GND. The voltage of the car alternator charging interface flows through the diode D3, then through the voltage divider circuit composed of the twelfth resistor R12 and the thirteenth resistor R13, and is filtered by the third capacitor C3 before being output to the battery management system. The diode DZ3 is a port protection device of the battery management system, and the battery management system collects voltage signals.

[0017] Furthermore, according to the charging and discharging circuit of the vehicle-mounted energy storage system provided in this application, the discharging module control circuit unit includes an output port voltage detection circuit, which is connected to the output terminal of the charging module control circuit unit.

[0018] The output port voltage detection circuit includes diode D101, resistor R101, resistor R102, capacitor C101, and diode DZ101.

[0019] The voltage of the battery management system passes through the diode D101, then through the voltage divider circuit composed of resistors R101 and R102, and is filtered by the capacitor C101 before being connected to the voltage acquisition port of the battery management system. The diode D101 is a protection device for the voltage acquisition port of the battery management system, and the battery management system acquires the voltage signal.

[0020] Furthermore, according to the charging and discharging circuit of the vehicle-mounted energy storage system provided in this application, the battery management system includes a microcontroller.

[0021] This application also provides an on-board energy storage system, which includes an energy storage battery and a charging and discharging circuit for the on-board energy storage system provided in this application.

[0022] The beneficial effects of this utility model are as follows: According to the charging and discharging circuit and vehicle energy storage system provided in this application, charging efficiency is optimized and the battery and vehicle electrical components are protected through precise control of charging and discharging conditions, while also ensuring the safe use of the vehicle's starting battery. Furthermore, it integrates a comprehensive management system encompassing solar charging, vehicle alternator charging, and a battery management system (BMS), with each module working collaboratively to achieve comprehensive management of the energy storage system. Attached Figure Description

[0023] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the charging and discharging circuit of the vehicle-mounted energy storage system provided in this embodiment.

[0025] Figure 2 This is a schematic diagram of the circuit structure of the charging module control circuit unit provided in this embodiment.

[0026] Figure 3 This is a schematic diagram of the circuit structure of the discharge module control circuit unit provided in this embodiment.

[0027] Figure 4 This is a schematic diagram of the circuit structure of the battery management system provided in this embodiment.

[0028] Figure 5 This is a schematic diagram of the power supply circuit structure in the charging module control circuit unit provided in this embodiment.

[0029] Figure 6This is a schematic diagram of the automotive generator start / stop detection unit provided in this embodiment.

[0030] Figure 7 This is a schematic diagram of the communication interface structure of the charging and discharging circuit provided in this embodiment. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0032] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. 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 indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0034] The embodiments of this application will now be further described in conjunction with the accompanying drawings and specific implementation details.

[0035] Figure 1 This is a schematic diagram of the charging and discharging circuit of the vehicle-mounted energy storage system provided in this embodiment.

[0036] like Figure 1 As shown, the charging and discharging circuit includes a charging module control circuit unit, a discharging module control circuit unit, a charging port insertion detection unit, an automotive alternator start / stop detection unit, and a battery management system. The charging port insertion detection unit is connected to the charging module control circuit unit, the charging module control circuit unit is connected to the battery management system, the battery management system is connected to the discharging module control circuit unit, and the automotive alternator start / stop detection unit is connected to the battery management system. The battery management system controls the charging module control circuit unit and the discharging module control circuit unit to perform charging and discharging.

[0037] Specifically, the charging module control circuit unit includes a solar charging circuit and a car generator charging circuit. One end of the solar charging circuit and the car generator charging circuit are connected to the charging port insertion detection unit, and the other end is connected to the battery management system.

[0038] In the vehicle alternator charging circuit, when the alternator is used as the charging power source, the battery management system first checks whether the charging voltage has reached the set starting charging voltage. If the charging voltage reaches the set starting charging voltage, charging begins; if the charging voltage does not reach the set starting charging voltage, charging is not allowed. This protects the vehicle's starting battery from depletion.

[0039] In the solar charging circuit, the battery management system performs intelligent control based on the charging voltage conditions to improve charging efficiency and optimize the charging process, such as reducing charging hiccups.

[0040] In the discharge module control circuit unit, based on a set reasonable discharge voltage range, when the discharge module control circuit unit detects that the lithium battery voltage is lower than the set value, it first stops charging and communicates with the battery management system to confirm its status. If the battery management system malfunctions, causing the voltage to be too low, it controls the charging module control circuit unit to stop charging until the fault is resolved. If the battery management system detects that the battery has entered an undervoltage protection state, it controls the charging module control circuit unit to first perform trickle charging, and then switch to fast charging after the charging voltage reaches the set value, in order to protect battery quality and the lifespan of vehicle electrical components.

[0041] Figure 2 This is a schematic diagram of the circuit structure of the charging module control circuit unit provided in this embodiment.

[0042] like Figure 2As shown, the solar charging circuit performs input port voltage threshold detection, including a first fuse FU1, a first transistor QT1, a second transistor QT2, a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6.

[0043] One end of the first fuse FU1 is connected to the battery management system, and the other end of the first fuse FU1 is connected to the collector of the first transistor QT1. The base of the first transistor QT1 is connected to the battery management system, and the emitter of the first transistor QT1 is connected to the base of the second transistor QT2. The collector of the base of the second transistor QT2 is grounded, and the emitter of the second transistor QT2 serves as a node connecting the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6, respectively. The other ends of the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are respectively connected to the gates of the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4. The drains of the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 are connected to each other. The sources of the first switch Q1 and the third switch Q3 are connected to each other and connected to the charging port insertion detection unit. The sources of the second switch Q2 and the fourth switch Q4 are connected to each other and connected to the battery management system.

[0044] The automotive generator charging circuit performs input port voltage threshold detection, including a second fuse FU2, a fourth transistor QT4, a fifth transistor QT5, a fifth switch Q5, a sixth switch Q6, a seventh switch Q7, an eighth switch Q8, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, and an eleventh resistor R11.

[0045] One end of the second fuse FU2 is connected to the battery management system, and the other end of the second fuse FU2 is connected to the collector of the fourth transistor QT4. The base of the fourth transistor QT4 is connected to the battery management system, and the emitter of the fourth transistor QT4 is connected to the base of the fifth transistor QT5. The collector of the base of the fifth transistor QT5 is grounded, and the emitter of the fifth transistor QT5 serves as a node connecting the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11. The eighth resistor R8, the... The other ends of the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11 are respectively connected to the gates of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, and the eighth switch Q8. The drains of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, and the eighth switch Q8 are interconnected. The sources of the fifth switch Q5 and the seventh switch Q7 are interconnected and connected to the charging port insertion detection unit. The sources of the sixth switch Q6 and the eighth switch Q8 are interconnected and connected to the battery management system.

[0046] The charging port insertion detection unit includes a solar charging detection circuit and an automotive alternator charging detection circuit; one end of the solar charging detection circuit is connected to the solar charging interface, and the other end is connected to the solar charging circuit and the battery management system; one end of the automotive alternator charging detection circuit is connected to the automotive alternator charging interface, and the other end is connected to the automotive alternator charging circuit and the battery management system.

[0047] The charging port insertion detection unit provided in this embodiment can accurately identify and distinguish the source of vehicle charging, that is, it can clearly identify whether the charging is coming from the vehicle's alternator port or the solar port. When charging through the solar port is detected, the battery management system will automatically switch to maximum power point tracking (MPPT) mode to optimize solar energy utilization efficiency. When the battery management system detects that both the solar port and the alternator port meet the charging conditions, it will prioritize the alternator port as the charging source according to preset priority logic, and simultaneously suspend the charging process at the solar port to ensure the efficiency and rationality of the charging strategy. This design aims to meet the needs of different charging scenarios and improve the overall charging efficiency and the level of intelligent energy management.

[0048] With this design, the charging port insertion detection unit provided in this embodiment can intelligently manage and coordinate the charging process of different energy ports, ensuring efficient energy utilization and stable system operation.

[0049] The solar charging detection circuit determines the charging input port, including the positive interface J1, the negative interface J4, the diode D1, the first resistor R1, the second resistor R2, the first capacitor C1, and the diode DZ1.

[0050] The positive terminal J1 is connected to the positive terminal of the solar charging interface, and the negative terminal J4 is connected to the negative terminal of the solar charging interface and marked as GND. The voltage of the solar charging interface flows through the diode D1 and then through the voltage divider circuit composed of the first resistor R1 and the second resistor R2. After being filtered by the first capacitor C1, it is output to the battery management system. The diode DZ1 is a port protection device of the battery management system. The battery management system collects voltage signals.

[0051] Specifically, when connecting the solar panel, the positive terminal should be connected to the J1 interface (marked SE_IN), and the negative terminal should be connected to the J4 interface (marked GND). The voltage generated by the solar panel then flows through diode D1, passes through a voltage divider circuit composed of resistors R1 and R2, is filtered by C1, and is then sent to the SE_ADC port of the microcontroller. DZ1 is a microcontroller port protection device. This SE_ADC port has an analog-to-digital converter (ADC) function and can acquire voltage signals. Based on the voltage value acquired by the SE_ADC port, the microcontroller evaluates whether the input port meets the preset charging conditions. Once it is confirmed that the input and output voltage values ​​simultaneously meet the charging conditions, the microcontroller will send a signal through its DC_TX communication interface to the BMS_RX interface of the battery management system (BMS), indicating that the solar input is ready for charging and requesting the start of the charging process.

[0052] When the Battery Management System (BMS) is not in a protected state and the battery pack is not fully charged (i.e., less than 100%), the BMS will initiate the charging process by sending a charging authorization signal to the charging module's receiver DC_RX via its communication interface BMS_TX. Upon receiving this signal, the microcontroller (MCU) inside the charging module activates its SE_EN port, outputting a high level to the base of transistor QT1, causing a path to be formed between the collector and emitter of QT1. Subsequently, the DC input source DC_IN flows through fuse FU1, the CE path of QT1, and a series of resistors R8 to R11, finally reaching the gates of MOSFETs Q1 to Q4, triggering these MOSFETs to conduct. The current from the solar power supply then flows through the drain-source (DS) of MOSFETs Q1 to Q4. At this time, pin 5 of the charging control unit U1 detects the voltage input, confirming that the MOSFETs at the input terminal are correctly turned on. In response, pin 11 of U1 sends an interrupt signal to pin 29 of the charging module MCU. After receiving this signal, the MCU takes into account both the solar input current and the real-time battery voltage data, and sends the corresponding working mode configuration command to the charging management chip U1 through the IIC bus (specifically the SDA data line and the SCL clock line) to precisely control the charging process.

[0053] The automotive generator charging detection circuit determines the charging input port, including the positive interface J2, the negative interface J3, the diode D3, the twelfth resistor R12, the thirteenth resistor R13, the third capacitor C3, and the diode DZ3.

[0054] The positive terminal J2 is connected to the positive terminal of the car alternator charging interface, and the negative terminal J3 is connected to the negative terminal of the car alternator charging interface and marked as GND. The voltage of the car alternator charging interface flows through the diode D3, then through the voltage divider circuit composed of the twelfth resistor R12 and the thirteenth resistor R13, and is filtered by the third capacitor C3 before being output to the battery management system. The diode DZ3 is a port protection device of the battery management system, and the battery management system collects voltage signals.

[0055] The detection and charging circuit of the car alternator charging input terminal are basically the same as those of solar charging, and the working mode is also basically the same, so they will not be described in detail here.

[0056] Figure 3 This is a schematic diagram of the circuit structure of the discharge module control circuit unit provided in this embodiment.

[0057] like Figure 3 As shown, the voltage threshold detection of the output port of the discharge module control circuit unit includes an output port voltage detection circuit, which is connected to the output terminal of the charging module control circuit unit.

[0058] The discharge module control circuit unit provided in this embodiment integrates an automatic charging condition evaluation system, which can intelligently monitor the real-time status of the charging port. Once the charging module control circuit unit detects that the charging prerequisites are met, it immediately sends a charging request signal to the battery management system (BMS) via a serial communication interface. After receiving this request, the BMS comprehensively considers the current battery status and system safety conditions, such as whether the battery is full, whether there is an overcurrent or overvoltage risk, or a system fault, and autonomously decides whether to perform a charging operation. If the BMS determines that the current conditions are not suitable for charging, such as when the battery is already fully charged or the system detects any potential safety hazards (such as overcurrent, overvoltage, or faults), it will quickly send a clear instruction to the charging module to refuse charging and the charging module will enter a low-power standby mode to save energy and protect the system from unnecessary losses. Once the fault is cleared or the protection state is released, the BMS will automatically send a wake-up signal to the charging module, instructing it to exit the low-power mode and prepare to resume the charging function.

[0059] The output port voltage detection circuit includes diode D101, resistor R101, resistor R102, capacitor C101, and diode DZ101.

[0060] The voltage of the battery management system passes through the diode D101, then through the voltage divider circuit composed of resistors R101 and R102, and is filtered by the capacitor C101 before being connected to the voltage acquisition port of the battery management system. The diode D101 is a protection device for the voltage acquisition port of the battery management system, and the battery management system acquires the voltage signal.

[0061] Specifically, after the charging and discharging circuit of the vehicle energy storage system provided in this embodiment starts working, the positive terminal of the battery pack of the vehicle energy storage system is connected to P+ of the discharge module control circuit unit, the load of the battery pack is connected to the negative terminal of the battery management system, and after passing through the charging and discharging MOS, it reaches P-. The voltage of the battery management system flows through diode D101, and after passing through the voltage divider circuit composed of resistors R101 and R102, it is filtered by C101 and sent to the BMS_ADC port of the microcontroller. DZ101 is a microcontroller port protection device. The microcontroller evaluates whether the output port (total voltage of BMS) meets the preset charging conditions based on the voltage value collected by the BMS_ADC port.

[0062] Figure 4 This is a schematic diagram of the circuit structure of the battery management system provided in this embodiment.

[0063] As shown in the figure, the battery management system includes a microcontroller. The microcontroller is connected to the solar charging circuit, the car alternator charging circuit, the solar charging detection circuit, the car alternator charging detection circuit, and the output port voltage detection circuit through various pins.

[0064] Figure 5 This is a schematic diagram of the power supply circuit structure in the charging module control circuit unit provided in this embodiment.

[0065] like Figure 5 As shown, the power supply circuit in the charging module control circuit unit includes a solar input terminal SE_IN, an automotive alternator input terminal DG_IN, and a battery management system positive input terminal P+. The solar input terminal SE_IN, automotive alternator input terminal DG_IN, and battery management system positive input terminal P+ are connected to the power supply chip U2 via diodes D5, D6, and D7, respectively, as the input signal DC_IN. Diode DZ5, as the input signal terminal DC_IN, serves as a port protection device for the battery management system. The third fuse FU3 is also connected to the power supply chip U2 and outputs a +3.3V power supply.

[0066] Figure 6 This is a schematic diagram of the automotive generator start / stop detection unit provided in this embodiment.

[0067] The charging and discharging circuit of the vehicle energy storage system provided in this embodiment integrates an intelligent monitoring function for the start and stop of the vehicle's alternator (implemented via the ACC port). This function can accurately identify the operating status of the alternator. Specifically, when the alternator is detected to be running, the battery management system automatically adjusts to reduce the charging voltage requirement at the input terminal; conversely, when the alternator is detected to be stopped, the charging voltage requirement at the input terminal is increased accordingly. If the voltage is lower than a set value, charging is not allowed. This controls the vehicle's starter battery to not charge when its voltage is lower than the set value, thereby protecting the starter battery from over-discharge and preventing the vehicle from failing to start due to a depleted starter battery.

[0068] like Figure 6 As shown, the automotive alternator start-stop detection unit performs automotive alternator start-stop voltage detection. After the automotive alternator start-stop interface ACC is connected to the J5 interface, the voltage passes through diode D9, then through a voltage divider circuit composed of resistors R38 and R39, and is filtered by capacitor C40 before being sent to the ACC_ADC port of the microcontroller. DZ6 is a microcontroller port protection device. Based on the voltage value collected by the ACC_ADC port, the microcontroller evaluates whether the output port (the voltage of the automotive alternator start-stop interface ACC) meets the preset charging conditions.

[0069] In this embodiment, an alternator start-stop voltage detection (ACC) is added to the vehicle alternator charging process. If the ACC voltage is lower than the alternator start voltage, it is considered that the alternator has not started. The battery management system will raise the charging voltage at the alternator input port to meet the conditions. Charging is not allowed if the starting battery voltage is within the set value (below 13.3V) to prevent the starting battery from being depleted and causing the car to fail to start.

[0070] Figure 7 This is a schematic diagram of the communication interface structure of the charging and discharging circuit provided in this embodiment.

[0071] like Figure 7 As shown, the communication interface of the charging module control circuit unit is JP1, where pin 1 is the output terminal DC_TX of the charging module, pin 2 is the receiving terminal DC_RX of the charging module, and pin 3 is the ground terminal. The communication interface of the battery management system is JP2, where pin 1 is the receiving terminal BMS_RX of the battery management system, pin 2 is the output terminal BMS_TX of the battery management system, and pin 3 is the ground terminal.

[0072] The automotive generator charging circuit provided in this embodiment also has a dynamic threshold compensation mechanism and an intelligent dynamic voltage compensation mechanism.

[0073] In the dynamic threshold replenishment mechanism, a dual threshold voltage window is set (start threshold 14.2V±0.1V, stop threshold 13.3V±0.1V). This setting not only avoids frequent start-stop cycles but also prevents the starting battery from running out of power. In existing vehicle energy storage systems that require charging from the car's alternator, the alternator is connected in parallel across the starting battery. Therefore, even when the alternator stops working, the vehicle charging system can still detect the voltage (starting battery voltage). In this case, the starting battery charges the vehicle's energy storage system. The conventional method uses voltage detection by the charging management chip, not ADC detection. If voltage is detected, the system will charge the vehicle's energy storage system. Since the normal charging module uses a step-up / step-down converter, the car's starting battery will continuously charge the vehicle's energy storage system until it reaches a voltage that prevents the charging module from working properly, around 6-8V. If the car battery voltage is less than 12V, there is a risk that the car will not be able to start. This embodiment uses a microcontroller ADC module to detect the input, which can accurately determine the voltage at the input terminal.

[0074] Meanwhile, after a normal car start, the alternator begins to work, and the voltage output by the alternator will be above 14.2V. Therefore, setting the threshold at 14.2V can basically ensure that the alternator is in a working state. Setting the stop threshold at 13.3V ensures that the starter battery voltage remains above 13.3V to prevent charging of the vehicle's energy storage system. This ensures the starter battery capacity; basically, with the battery voltage at 13.3V, the battery capacity will be around 80%, preventing the starter battery from running out of power and preventing the car from starting normally. It also extends the lifespan of the car's starter battery.

[0075] The system calculates a 60-second window period fluctuation value > 0.5V and activates reduced-current charging, lowering the charging current to 1A. Simultaneously, it detects the input voltage. If the input voltage is below 13.3V, charging stops; if the charging voltage is above 13.3V, the charging current resumes before the reduced-current charging. This effectively avoids charging hiccups. If the alternator is not working and the car's starting battery has a low charge, the voltage will be pulled down when the battery is amplified externally. When the discharge stops, the voltage will rise back to a higher value, causing the charging module to detect charging conditions intermittently.

[0076] In the intelligent dynamic voltage compensation mechanism, a floating threshold mechanism is established:

[0077] The reference start-up voltage is 14.2V, which is dynamically adjusted by ±0.3V according to the start-up battery SOC.

[0078] When SOC < 30%, the threshold is reduced to 13.9V (emergency power replenishment mode);

[0079] When SOC > 80%, the threshold is raised to 14.5V (energy storage optimization mode).

[0080] In the charging control of the solar charging circuit provided in this embodiment, an intelligent floating threshold (13.6-15V) is set, which is combined with the dynamic adjustment of the SOC of the energy storage system battery pack:

[0081] When SOC < 50%, the MPPT target voltage automatically decreases by 0.5V.

[0082] When there is a sudden change in sunlight, the charging current is adjusted in real time according to the detected voltage. When a sudden drop in solar voltage is detected, the MPPT parameter is dynamically corrected and the charging current is actively reduced.

[0083] When the solar voltage is detected to be below 13V and the charging current is less than 5A, the solar charging mode switches from the original MPPT mode to PWM charging mode, with a low light mode of 0.5-5Hz frequency conversion pulse (pulse width adaptive adjustment).

[0084] This embodiment also provides an on-board energy storage system, which includes an energy storage battery and a charging and discharging circuit for the on-board energy storage system provided in this embodiment.

[0085] According to the charging and discharging circuit and the vehicle-mounted energy storage system provided in this application, charging efficiency is optimized, the battery and vehicle electrical appliances are protected by finely controlling the charging and discharging conditions, and the safe use of the vehicle's starting battery is also ensured. It also integrates a comprehensive management system that combines solar charging, vehicle alternator charging, and a battery management module (BMS), with each module working collaboratively to achieve comprehensive management of the energy storage system.

[0086] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the present invention. Finally, it should be noted that in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0087] The charging and discharging circuit and the vehicle-mounted energy storage system provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A charging and discharging circuit for an on-board energy storage system, characterized in that, The charging and discharging circuit includes a charging module control circuit unit, a discharging module control circuit unit, a charging port insertion detection unit, an automotive alternator start / stop detection unit, and a battery management system. The charging port insertion detection unit is connected to the charging module control circuit unit, the charging module control circuit unit is connected to the battery management system, the battery management system is connected to the discharging module control circuit unit, and the vehicle generator start / stop detection unit is connected to the battery management system; the battery management system controls the charging module control circuit unit and the discharging module control circuit unit to perform charging and discharging.

2. The charging and discharging circuit of the vehicle-mounted energy storage system according to claim 1, characterized in that, The charging module control circuit unit includes a solar charging circuit and a car generator charging circuit. One end of the solar charging circuit and the car generator charging circuit are connected to the charging port insertion detection unit, and the other end is connected to the battery management system.

3. The charging and discharging circuit of the vehicle-mounted energy storage system according to claim 2, characterized in that, The solar charging circuit includes a first fuse FU1, a first transistor QT1, a second transistor QT2, a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6. One end of the first fuse FU1 is connected to the battery management system, and the other end of the first fuse FU1 is connected to the collector of the first transistor QT1. The base of the first transistor QT1 is connected to the battery management system. The emitter of the first transistor QT1 is connected to the base of the second transistor QT2. The collector of the base of the second transistor QT2 is grounded. The emitter of the second transistor QT2 is connected as a node to the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6. The other ends of the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are connected to the gates of the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4, respectively. The drains of the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 are interconnected. The sources of the first switch Q1 and the third switch Q3 are interconnected and connected to the charging port insertion detection unit. The sources of the second switch Q2 and the fourth switch Q4 are interconnected and connected to the battery management system.

4. The charging and discharging circuit of the vehicle-mounted energy storage system according to claim 2, characterized in that, The automotive generator charging circuit includes a second fuse FU2, a fourth transistor QT4, a fifth transistor QT5, a fifth switch Q5, a sixth switch Q6, a seventh switch Q7, an eighth switch Q8, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, and an eleventh resistor R11. One end of the second fuse FU2 is connected to the battery management system, and the other end of the second fuse FU2 is connected to the collector of the fourth transistor QT4. The base of the fourth transistor QT4 is connected to the battery management system, and the emitter of the fourth transistor QT4 is connected to the base of the fifth transistor QT5. The collector of the base of the fifth transistor QT5 is grounded, and the emitter of the fifth transistor QT5 serves as a node connected to the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11. The eighth resistor R8, the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11 are connected to the battery management system. The other ends of resistors R9, R10, and R11 are respectively connected to the gates of the fifth switch Q5, Q6, Q7, and Q8. The drains of the fifth switch Q5, Q6, Q7, and Q8 are interconnected. The sources of the fifth switch Q5 and Q7 are interconnected and connected to the charging port insertion detection unit. The sources of the sixth switch Q6 and Q8 are interconnected and connected to the battery management system.

5. The charging and discharging circuit of the vehicle-mounted energy storage system according to claim 2, characterized in that, The charging port insertion detection unit includes a solar charging detection circuit and an automotive alternator charging detection circuit. One end of the solar charging detection circuit is connected to the solar charging interface, and the other end is connected to the solar charging circuit and the battery management system; one end of the vehicle generator charging detection circuit is connected to the vehicle generator charging interface, and the other end is connected to the vehicle generator charging circuit and the battery management system.

6. The charging and discharging circuit of the vehicle-mounted energy storage system according to claim 5, characterized in that, The solar charging detection circuit includes a positive terminal J1, a negative terminal J4, a diode D1, a first resistor R1, a second resistor R2, a first capacitor C1, and a diode DZ1. The positive terminal J1 is connected to the positive terminal of the solar charging interface, and the negative terminal J4 is connected to the negative terminal of the solar charging interface and marked as GND. The voltage of the solar charging interface flows through the diode D1 and then through the voltage divider circuit composed of the first resistor R1 and the second resistor R2. After being filtered by the first capacitor C1, it is output to the battery management system. The diode DZ1 is a port protection device of the battery management system. The battery management system collects voltage signals.

7. The charging and discharging circuit of the vehicle-mounted energy storage system according to claim 5, characterized in that, The automotive generator charging detection circuit includes a positive interface J2, a negative interface J3, a diode D3, a twelfth resistor R12, a thirteenth resistor R13, a third capacitor C3, and a diode DZ3. The positive terminal J2 is connected to the positive terminal of the car alternator charging interface, and the negative terminal J3 is connected to the negative terminal of the car alternator charging interface and marked as GND. The voltage of the car alternator charging interface flows through the diode D3, then through the voltage divider circuit composed of the twelfth resistor R12 and the thirteenth resistor R13, and is filtered by the third capacitor C3 before being output to the battery management system. The diode DZ3 is a port protection device of the battery management system, and the battery management system collects voltage signals.

8. The charging and discharging circuit of the vehicle-mounted energy storage system according to claim 1, characterized in that, The discharge module control circuit unit includes an output port voltage detection circuit, which is connected to the output terminal of the charging module control circuit unit. The output port voltage detection circuit includes diode D101, resistor R101, resistor R102, capacitor C101, and diode DZ101. The voltage of the battery management system passes through the diode D101, then through the voltage divider circuit composed of resistors R101 and R102, and is filtered by the capacitor C101 before being connected to the voltage acquisition port of the battery management system. The diode D101 is a protection device for the voltage acquisition port of the battery management system, and the battery management system acquires the voltage signal.

9. The charging and discharging circuit of the vehicle-mounted energy storage system according to claim 1, characterized in that, The battery management system includes a microcontroller.

10. A vehicle-mounted energy storage system, characterized in that, The vehicle-mounted energy storage system includes an energy storage battery and a charging and discharging circuit for the vehicle-mounted energy storage system as described in any one of claims 1-9.

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