Capacitance-based battery charging voltage regulation system and method of regulating

Abstract

This invention relates to the field of lithium battery charging control technology, specifically to a capacitor-based battery charging voltage regulation system and method. The system includes a power generation module, a main relay, a control module, and a lithium battery pack. A capacitor regulation branch is connected in parallel across the main relay. The capacitor regulation branch includes a capacitor relay JDQ1, a capacitor bank, a resistor bank, a discharge branch, and a current-conducting branch. This application connects the capacitor regulation branch in parallel across the main relay, forming a dual-path architecture for direct charging and voltage regulation. The capacitor bank adopts a design of parallel connection within the module and series connection between modules, ensuring voltage adaptability while allowing the voltage to be quickly boosted by the power generation module. The current-limiting branch of the resistor bank achieves instantaneous current limiting during charging through a series-parallel combination. The diode in the current-conducting branch enables unidirectional current conduction, and the discharge branch provides a dedicated discharge path for the capacitor bank. All branches cooperate with each other to ensure the stability and safety of the voltage regulation process.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery charging control, and particularly to a battery charging voltage regulation system based on capacitance and its regulation method. Background Art

[0002] In the vehicle-mounted scenario, the charging power source of the lithium battery mainly comes from the vehicle-mounted generator. The output voltage of the generator is easily affected by factors such as engine speed and instantaneous changes in vehicle loads, resulting in fluctuations. If there is no precise charging voltage regulation mechanism, the charging voltage of the lithium battery is extremely likely to exceed the rated charging threshold, which will cause the aging of the battery cells and the attenuation of the capacity. In severe cases, it will also cause safety hazards such as bulging and leakage. At the same time, the battery management system (BMS) supporting the vehicle-mounted lithium battery has multiple protection and self-locking mechanisms to ensure the safety of the battery cells. When the lithium battery is in a low-temperature environment or encounters abnormal working conditions such as high-voltage charging, the BMS will trigger the self-locking protection and directly cut off the charging and discharging circuit of the lithium battery, resulting in the lithium battery being unable to accept charging or discharge. This will not only affect the normal use of the vehicle-mounted lithium battery system, but also cause the power supply interruption of the vehicle-mounted electrical system due to the inability of the lithium battery to supplement the discharge when the vehicle-mounted generator power supply is insufficient, seriously affecting the normal operation of the vehicle. Therefore, the precise voltage regulation of the charging process of the vehicle-mounted lithium battery and the avoidance of the BMS self-locking risk under abnormal working conditions are the core keys in the design of the vehicle-mounted lithium battery system.

[0003] At present, the conventional schemes for regulating the charging voltage of vehicle-mounted lithium batteries mainly include three types: resistor step-down voltage regulation, switch tube circuit voltage regulation, and generator excitation regulation. All of them have obvious technical defects and are difficult to adapt to the actual working conditions of vehicles. The resistor step-down voltage regulation scheme has a simple structure but high energy consumption, serious heat generation, and low voltage regulation accuracy, which is likely to trigger the BMS self-locking due to high-voltage charging. The switch tube circuit voltage regulation scheme has a relatively high regulation accuracy, but the circuit structure is complex, the cost of the core components is high, the failure probability is high under the harsh working conditions of vehicles, and the voltage adaptability to low-temperature working conditions is poor, which is likely to trigger the BMS low-temperature self-locking. The generator excitation regulation scheme regulates the voltage from the source, but has a slow response speed, cannot cope with sudden voltage fluctuations, is likely to have regulation lag resulting in short-term high-voltage charging of the lithium battery, and has a complex control logic and poor generator compatibility, and cannot solve the BMS self-locking problem under low-temperature working conditions.

[0004] In addition, the existing technical schemes all have the pain points of conflicts between lithium battery charging protection, avoidance of BMS self-locking and vehicle load power supply: if the connection between the generator and the lithium battery is cut off to prevent overcharging, the vehicle load will lose power supply; if the connection is maintained to ensure continuous power supply, it is likely to trigger the BMS self-locking due to voltage fluctuations, resulting in double interruption of the charging and discharging of the lithium battery and loss of the emergency power supply function, and it is difficult to achieve a balance between the safety protection of the lithium battery and the stable power supply of the vehicle system. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a battery charging voltage regulation system and regulation method based on capacitors. This system can accurately control the charging voltage to avoid BMS self-locking caused by high voltage charging, adapt to the use requirements of low temperature conditions, and ensure stable power supply to vehicle loads while cutting off the effective charging of lithium batteries.

[0006] This invention is achieved through the following technical solution: a capacitor-based battery charging voltage regulation system, including a power generation module, a main relay, a control module, and a lithium battery pack. The positive terminal of the power generation module is electrically connected to the positive terminal of the lithium battery pack through the main relay. The negative terminals of the lithium battery pack and the power generation module are connected to a common ground terminal, forming a direct charging link between the power generation module and the lithium battery pack. A capacitor regulation branch is connected in parallel across the two ends of the main relay. The capacitor regulation branch includes a capacitor relay JDQ1, a capacitor bank, a resistor bank, a discharge branch, and a current-conducting branch. The capacitor relay JDQ1, capacitor bank, and resistor bank are connected in series to form the main capacitor regulation path. The capacitor relay JDQ1 is electrically connected to the positive terminal of the lithium battery bank. The control module is electrically connected to the capacitor relay JDQ1 and the main relay respectively. The control module controls the on / off state of the capacitor relay JDQ1 and the main relay. The discharge branch is electrically connected to the capacitor bank and is used to discharge the capacitor bank. The current-conducting branch is used to achieve directional conduction and reverse blocking of current in the circuit.

[0007] The capacitor bank includes several capacitor modules, each of which contains multiple capacitors connected in parallel, and the capacitor modules are connected in series.

[0008] The resistor group includes several current-limiting branches; Each of the current-limiting branches includes at least two resistors connected in series, and the resistors at corresponding series positions in each of the current-limiting branches are connected in parallel. One end of the capacitor bank is connected in series with the resistor bank.

[0009] The discharge branch includes a number of discharge resistors corresponding to the capacitor modules. The discharge resistors are connected in series and in parallel with the corresponding capacitors in the corresponding capacitor modules.

[0010] The capacitor module includes two capacitors. The first capacitor module includes capacitors C1 and C2 connected in parallel, and the second capacitor module includes capacitors C3 and C4 connected in parallel. Capacitors C1 and C3 are connected in series, and capacitors C2 and C4 are connected in series.

[0011] There are three current-limiting branches. The first current-limiting branch includes resistors R1 and R2 connected in series, the second current-limiting branch includes resistors R3 and R4 connected in series, and the third current-limiting branch includes resistors R5 and R6 connected in series. The resistor R3 is connected in parallel with resistors R1 and R5, the resistor R4 is connected in parallel with resistors R2 and R6, the resistors R1 and R2 are connected in series, the resistors R3 and R4 are connected in series, and the resistors R5 and R6 are connected in series. The resistor R2 is connected in series with the capacitor C1, and the resistor R6 is connected in series with the capacitor C2.

[0012] The discharge branch includes resistors R7 and R8 connected in series, resistor R7 is connected in parallel with capacitor C2, and resistor R8 is connected in parallel with capacitor C4.

[0013] The current-conducting branch includes diode D1 and diode D2. The anode of diode D1 is electrically connected to capacitor relay JDQ1, and the cathode of diode D1 is electrically connected to the positive terminal of the power generation module. The anode of diode D2 is electrically connected to the positive terminal of the power generation module, and the cathode of diode D2 is electrically connected to capacitor C2.

[0014] The capacitor-based battery charging voltage regulation method, applied to the aforementioned capacitor-based battery charging voltage regulation system, includes the following steps: During normal charging: the control module controls the main relay to close and the capacitor relay JDQ1 to open, the capacitor regulation branch is in an open circuit state, and the electrical energy output by the power generation module is directly delivered to the lithium battery pack through the main relay to realize the normal charging of the lithium battery pack by the power generation module. The control module collects the voltage signal of the lithium battery pack in real time and continuously monitors whether its charging voltage reaches the preset charging threshold. If it does, it enters the capacitor adjustment stage; otherwise, it continues the normal charging stage. Capacitor voltage regulation stage: When the lithium battery pack voltage is detected to reach the preset charging threshold, the capacitor relay JDQ1 is closed to connect the capacitor pack to the circuit, the main relay is disconnected, the power generation module stops directly charging the lithium battery pack, and instead charges the capacitor pack. The power generation module raises the voltage of the capacitor bank. When the combined voltage of the capacitor bank and the lithium battery bank is equal to the output voltage of the power generation module, the charging current decreases to zero, and the power generation module stops charging, thereby regulating the charging voltage of the lithium battery bank. During the power supply maintenance phase: the main relay is disconnected, the capacitor regulation branch is turned on, and the power generation module directly supplies power to the external load; if the power generation module is insufficient, the lithium battery pack provides external power through the capacitor relay JDQ1 and diode D1.

[0015] The electrical energy stored in the capacitor bank is released through the discharge branch.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This application connects a capacitor regulation branch in parallel across the main relay to form a dual-path architecture for direct charging and voltage regulation. The capacitor bank adopts a design of parallel connection within the module and series connection between modules, which ensures voltage adaptability and allows the voltage to be quickly boosted by the power generation module. The current limiting branch of the resistor bank achieves instantaneous current limiting during charging through a combination of series and parallel connections. The diode in the current guiding branch enables unidirectional current conduction, while the discharge branch provides a dedicated discharge path for the capacitor bank. All branches cooperate with each other to ensure the stability and safety of the voltage regulation process.

[0017] This application leverages the rapid charging and discharging characteristics of capacitor banks. By balancing the combined voltage of the lithium battery pack and capacitor bank with the generator output voltage, the charging voltage is locked at the rated threshold, and the charging current can be quickly reduced to zero, thus preventing overcharging of the lithium battery at its source. At the same time, it can respond instantly to sudden fluctuations in generator voltage caused by changes in engine speed and vehicle load, solving the problem of lag in traditional excitation regulation schemes. This effectively prevents cell aging and capacity decay, avoids safety hazards such as lithium battery bulging and leakage, and extends the service life of lithium batteries.

[0018] This application system adopts a minimalist circuit design with no complex core electronic components, making it suitable for harsh operating conditions such as low temperatures and vibrations in vehicles. It avoids BMS low-temperature self-locking triggered by poor low-temperature compatibility. Through precise voltage regulation, directional current conduction, and active discharge reset of the capacitor bank, it avoids problems such as high-voltage charging, abnormal current, and voltage drift, thus preventing BMS high-voltage self-locking from the source and ensuring the normal operation of lithium battery charging and discharging functions throughout the process, avoiding dual interruption of charging and discharging caused by self-locking.

[0019] The core components used in this application mainly include basic components such as relays, capacitor banks, diodes, and resistor banks. It abandons the complex voltage regulation and excitation regulation modules of traditional solutions, resulting in low component costs and low failure probability under harsh vehicle operating conditions. There are no high-power energy-consuming components, solving the problems of high energy consumption and severe heat generation in traditional resistor voltage reduction solutions. The control logic is simple, the generator is highly compatible, and there is no need for complex program calculations and parameter debugging, which greatly improves the practicality of the system.

[0020] This application adopts a timing control strategy of first closing the capacitor relay and then cutting off the main relay. While cutting off the direct charging circuit of the lithium battery pack to prevent overcharging, it maintains the circuit path, solving the core contradiction of traditional solutions where cutting off the circuit results in power loss due to overcharging and maintaining power supply triggers self-locking. It designs a dual-path power supply mode with generator main power supply and lithium battery emergency power supply. When the generator power supply is insufficient, the lithium battery can be accurately replenished through a dedicated path to ensure the continuous stability of the vehicle's power system and avoid power interruption affecting the normal operation of the vehicle.

[0021] This application also sets up an independent discharge branch, which can quickly release the energy of the capacitor bank to achieve reset, avoid component aging and voltage drift caused by the capacitor bank being charged for a long time, and ensure the system's cyclic voltage regulation accuracy; through the segmented current limiting and directional conduction component design, the component workload is reduced, the probability of failure is reduced, the overall service life of the system is extended, and the maintenance and replacement costs of the vehicle lithium battery system are significantly reduced. Attached Figure Description

[0022] Figure 1 This is the circuit diagram of this application.

[0023] In the diagram: 1. Power generation module; 2. Main relay; 3. Control module; 4. Lithium battery pack. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention 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 the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1 Reference Figure 1 A capacitor-based battery charging voltage regulation system includes a power generation module 1, a main relay 2, a control module 3, and a lithium battery pack 4. The positive terminal of the power generation module 1 is electrically connected to the positive terminal of the lithium battery pack 4 through the main relay 2. The negative terminals of the lithium battery pack 4 and the power generation module 1 are connected to a common ground terminal, forming a direct charging link from the power generation module 1 to the lithium battery pack 4. A capacitor regulation branch is connected in parallel across the two ends of the main relay 2. The capacitor regulation branch includes a capacitor relay JDQ1, a capacitor bank, a resistor bank, a discharge branch, and a current-conducting branch. The capacitor relay JDQ1, capacitor bank, and resistor bank are connected in series to form the main capacitor regulation path. The capacitor relay JDQ1 is electrically connected to the positive terminal of the lithium battery bank 4. The control module 3 is electrically connected to the capacitor relay JDQ1 and the main relay 2 respectively. The control module 3 controls the on / off state of the capacitor relay JDQ1 and the main relay 2. The discharge branch is electrically connected to the capacitor bank and is used to discharge the capacitor bank. The current-conducting branch is used to achieve directional conduction and reverse blocking of current in the circuit.

[0026] The capacitor bank includes several capacitor modules, each of which contains multiple capacitors connected in parallel. The capacitor modules are connected in series, thus forming a capacitor bank structure with parallel connections within modules and series connections between modules.

[0027] The resistor group includes several current-limiting branches; Each of the current-limiting branches includes at least two resistors connected in series, and the resistors at corresponding series positions in each of the current-limiting branches are connected in parallel. One end of the capacitor bank is connected in series with the resistor bank.

[0028] The discharge branch includes a number of discharge resistors corresponding to the capacitor modules. The discharge resistors are connected in series and in parallel with the corresponding capacitors in the corresponding capacitor modules.

[0029] Example 2 In this embodiment, the power generation module 1 uses a vehicle-mounted 24V generator, whose positive terminal is connected to an external load to supply power to the load. The control module 3 is a CPU, which is used to collect the voltage signal of the lithium battery pack 4 in real time and compare it with a preset threshold. Based on the comparison result, it outputs high and low level signals to control the on and off of the main relay 2 and the capacitor relay JDQ1.

[0030] like Figure 1 As shown, this embodiment specifically sets up two capacitor modules. The first capacitor module includes capacitors C1 and C2 connected in parallel, and the second capacitor module includes capacitors C3 and C4 connected in parallel. Capacitors C1 and C3 are connected in series, and capacitors C2 and C4 are connected in series. This achieves series connection between the capacitor modules, thereby forming a charging and discharging capacitor structure with a series-parallel combination of capacitors. Connecting capacitors in parallel can increase the capacitance, while connecting capacitor modules in series can improve the overall withstand voltage of the capacitor bank. In actual use, the number of capacitor modules and the number of capacitors in each capacitor module can be adaptively adjusted according to the actual operating voltage and capacitance requirements.

[0031] Reference Figure 1 In this embodiment, there are three current limiting branches. The first current limiting branch includes resistors R1 and R2 connected in series, the second current limiting branch includes resistors R3 and R4 connected in series, and the third current limiting branch includes resistors R5 and R6 connected in series. The resistor R3 is connected in parallel with resistors R1 and R5, resistor R4 is connected in parallel with resistors R2 and R6, resistors R1 and R2 are connected in series, resistors R3 and R4 are connected in series, and resistors R5 and R6 are connected in series, thus forming a series-parallel combined network.

[0032] The resistor R2 is connected in series with the capacitor C1, and the resistor R6 is connected in series with the capacitor C2.

[0033] The purpose of setting resistors in series is to increase the equivalent resistance value of the branch, thereby achieving the current limiting function of the circuit and preventing excessive current from damaging the components. The purpose of setting current limiting branches in parallel is to increase the overall power capacity of the resistor network, improve heat dissipation, prevent individual resistors from being overloaded or overheated and burned out, and ensure long-term stable operation of the circuit.

[0034] The discharge branch includes resistors R7 and R8 connected in series, resistor R7 is connected in parallel with capacitor C2, and resistor R8 is connected in parallel with capacitor C4.

[0035] The current-conducting branch includes diode D1 and diode D2. The anode of diode D1 is electrically connected to capacitor relay JDQ1, and the cathode of diode D1 is electrically connected to the positive terminal of power generation module 1. The anode of diode D2 is electrically connected to the positive terminal of power generation module 1, and the cathode of diode D2 is electrically connected to capacitor C2.

[0036] Example 3 Based on Embodiment 1 and / or Embodiment 2, this embodiment proposes a capacitor-based battery charging voltage regulation method. Its core is to achieve precise regulation of the lithium battery pack charging voltage by switching and coordinating the direct charging link and the capacitor regulation branch, combined with the parallel connection within the capacitor pack module and the series connection between modules, thus avoiding overcharging. Simultaneously, through the synergistic effect of the discharge branch and the current-conducting branch, it ensures directional current conduction and safe capacitor discharge. Control module 3 is the core control unit throughout the process, precisely controlling the on / off timing of the main relay 2 and the capacitor relay JDQ1 based on the voltage signal of the lithium battery pack 4. The specific adjustment method is as follows: During normal direct charging: Control module 3 controls the main relay 2 to close and the capacitor relay JDQ1 to open, the capacitor regulation branch is in an open circuit state, and the electrical energy output by the power generation module 1 is directly delivered to the lithium battery pack 4 through the main relay 2 (direct charging link) to realize the normal charging of the lithium battery pack 4 by the power generation module 1. During this stage, the current output from the positive terminal of the power generation module 1 flows directly to the positive terminal of the lithium battery pack 4 through the closed main relay 2. The negative terminal of the lithium battery pack 4 and the negative terminal of the power generation module 1 are connected to the common ground terminal, forming a complete charging circuit, realizing the direct charging of the lithium battery pack 4 by the power generation module 1, and replenishing the lithium battery pack with electrical energy. The control module 3 collects the voltage signal of the lithium battery pack 4 in real time and continuously monitors whether its charging voltage reaches the preset charging threshold. When the voltage of the lithium battery pack 4 reaches the preset charging threshold, it enters the capacitor voltage regulation stage. If it does not reach the threshold, it continues the normal charging stage.

[0037] Capacitor voltage regulation stage: When the voltage of lithium battery pack 4 reaches the preset charging threshold, the capacitor relay JDQ1 is closed, connecting the capacitor pack to the circuit, and the main relay 2 is disconnected. The power generation module 1 stops directly charging the lithium battery pack and starts charging the capacitor pack instead. Utilizing the structural characteristics of the series-parallel combination of capacitor packs, the power generation module 1 quickly raises the voltage of the capacitor pack. When the combined voltage of the capacitor pack and lithium battery pack 4 is basically equal to the output voltage of the power generation module 1, the charging current decreases to zero, and the power generation module 1 stops charging, thus realizing the regulation of the charging voltage of the lithium battery pack.

[0038] Specifically, when the control module 3 detects that the voltage of the lithium battery pack 4 reaches the preset voltage regulation threshold, it triggers the voltage regulation action to prevent the lithium battery pack from being overcharged due to continuous charging by the power generation module. At this time, the control module 3 first controls the capacitor relay JDQ1 to close, so that the capacitor regulation branch is connected to the circuit, and then controls the main relay 2 to open, cutting off the direct charging link. This control of closing before opening can prevent the voltage from changing suddenly due to the instantaneous circuit break, thereby triggering the lithium battery BMS self-locking protection.

[0039] After the capacitor relay JDQ1 closes, the initial voltage of the capacitor bank is much lower than the output voltage of the generator module 1, resulting in a large voltage difference in the circuit. Initially, the circuit is in a high-current charging state: the large current output from the positive terminal of the generator module 1 flows directly to the capacitor bank through diode D2, forming a fast charging path. Utilizing the directional conduction characteristic of diode D2, the large current directly charges the capacitor bank, achieving a rapid increase in capacitor voltage. As the capacitor bank voltage continues to rise, the voltage difference between the generator module and the capacitor bank gradually decreases, and the charging current decreases accordingly, entering a stable charging stage: at this point, the charging current decreases, and the current no longer charges directly through diode D2. The current-limiting branch of the resistor group begins to fully utilize its current-limiting function, avoiding unnecessary energy consumption in the low-current stage, while simultaneously stabilizing the charging voltage of the capacitor bank and preventing voltage fluctuations.

[0040] This application utilizes a combination of initial high-current direct charging and subsequent current-limiting and stabilizing charging. The power generation module 1 can quickly raise the voltage of the capacitor bank, ultimately making the combined voltage of the lithium battery pack 4 and the capacitor bank essentially equal to the output voltage of the power generation module. According to the principle of circuit voltage balance, the voltage difference in the charging circuit disappears at this point, the charging current decreases to zero, and the power generation module stops charging the lithium battery pack. This achieves precise locking of the lithium battery pack charging voltage, thus achieving the purpose of voltage regulation to prevent overcharging and avoiding the lithium battery pack 4 from triggering the BMS self-locking protection due to high-voltage charging.

[0041] The preset charging threshold is the threshold for the rated charging voltage of the lithium battery. It can be adjusted according to the lithium battery model, operating conditions and low temperature environment adaptation requirements to avoid triggering the lithium battery BMS self-locking protection under low temperature and high pressure conditions.

[0042] After the main relay 2 is disconnected and the capacitor regulation branch is turned on, the system enters the power supply maintenance phase.

[0043] During the power supply maintenance phase: the power generation module 1 directly supplies power to external loads (such as vehicle electrical systems); if the power supply from the power generation module 1 is insufficient, such as a sudden increase in load power, the lithium battery pack 4 can supplement power through the capacitor relay JDQ1 and diode D1 to ensure the stable operation of the electrical system.

[0044] The electrical energy stored in the capacitor bank is released through the discharge branch. Specifically, when the system returns to a normal charging phase (e.g., when the lithium battery bank voltage drops, the control module controls the main relay to close and the capacitor relay to open) or when the capacitor bank voltage is too high, the discharge branch automatically starts to release the stored electrical energy from the capacitor bank, restoring its voltage to its initial state. Figure 1 As shown, in this embodiment, the electrical energy stored in the capacitor bank is quickly consumed through resistors R7 and R8, and the voltage returns to its initial state, preparing for the next voltage regulation operation.

[0045] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the content of the present invention under the concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A capacitor-based battery charging voltage regulation system, comprising a power generation module (1), a main relay (2), a control module (3), and a lithium battery pack (4), wherein the positive terminal of the power generation module (1) is electrically connected to the positive terminal of the lithium battery pack (4) via the main relay (2), and the negative terminals of the lithium battery pack (4) and the power generation module (1) are connected to a common ground terminal, forming a direct charging link between the power generation module (1) and the lithium battery pack (4), characterized in that, The main relay (2) has a capacitor adjustment branch connected in parallel at both ends. The capacitor adjustment branch includes a capacitor relay JDQ1, a capacitor group, a resistor group, a discharge branch, and a current-conducting branch. The capacitor relay JDQ1, capacitor group and resistor group are connected in series to form the main capacitor regulation path. The capacitor relay JDQ1 is electrically connected to the positive terminal of the lithium battery pack (4). The control module (3) is electrically connected to the capacitor relay JDQ1 and the main relay (2) respectively. The control module (3) controls the on / off state of the capacitor relay JDQ1 and the main relay (2). The discharge branch is electrically connected to the capacitor bank and is used to discharge the capacitor bank. The current-conducting branch is used to achieve directional conduction and reverse blocking of current in the circuit.

2. The capacitor-based battery charging voltage regulation system according to claim 1, characterized in that, The capacitor bank includes several capacitor modules, each of which contains multiple capacitors connected in parallel, and the capacitor modules are connected in series.

3. The capacitor-based battery charging voltage regulation system according to claim 2, characterized in that, The resistor group includes several current-limiting branches; Each of the current-limiting branches includes at least two resistors connected in series, and the resistors at corresponding series positions in each of the current-limiting branches are connected in parallel. One end of the capacitor bank is connected in series with the resistor bank.

4. The capacitor-based battery charging voltage regulation system according to claim 3, characterized in that, The discharge branch includes a number of discharge resistors corresponding to the capacitor modules. The discharge resistors are connected in series and in parallel with the corresponding capacitors in the corresponding capacitor modules.

5. The capacitor-based battery charging voltage regulation system according to claim 4, characterized in that, The capacitor module includes two capacitors. The first capacitor module includes capacitors C1 and C2 connected in parallel, and the second capacitor module includes capacitors C3 and C4 connected in parallel. Capacitors C1 and C3 are connected in series, and capacitors C2 and C4 are connected in series.

6. The capacitor-based battery charging voltage regulation system according to claim 5, characterized in that, There are three current-limiting branches. The first current-limiting branch includes resistors R1 and R2 connected in series, the second current-limiting branch includes resistors R3 and R4 connected in series, and the third current-limiting branch includes resistors R5 and R6 connected in series. The resistor R3 is connected in parallel with resistors R1 and R5, the resistor R4 is connected in parallel with resistors R2 and R6, the resistors R1 and R2 are connected in series, the resistors R3 and R4 are connected in series, and the resistors R5 and R6 are connected in series. The resistor R2 is connected in series with the capacitor C1, and the resistor R6 is connected in series with the capacitor C2.

7. The capacitor-based battery charging voltage regulation system according to claim 6, characterized in that, The discharge branch includes resistors R7 and R8 connected in series, resistor R7 is connected in parallel with capacitor C2, and resistor R8 is connected in parallel with capacitor C4.

8. The capacitor-based battery charging voltage regulation system according to claim 7, characterized in that, The current-carrying branch includes diode D1 and diode D2. The anode of diode D1 is electrically connected to capacitor relay JDQ1, and the cathode of diode D1 is electrically connected to the positive terminal of power generation module (1). The anode of diode D2 is electrically connected to the positive terminal of the power generation module (1), and the cathode of diode D2 is electrically connected to capacitor C2.

9. A capacitor-based battery charging voltage regulation method, characterized in that, The battery charging voltage regulation system based on capacitors according to any one of claims 1-8 includes the following steps: Normal charging phase: The control module (3) controls the main relay (2) to close and the capacitor relay JDQ1 to open. The capacitor regulation branch is in the open circuit state. The electrical energy output by the power generation module (1) is directly transmitted to the lithium battery pack (4) through the main relay (2) to realize the normal charging of the lithium battery pack (4) by the power generation module (1). The control module (3) collects the voltage signal of the lithium battery pack (4) in real time and continuously monitors whether its charging voltage reaches the preset charging threshold. If it does, it enters the capacitor adjustment stage; otherwise, it continues the normal charging stage. Capacitor voltage regulation stage: When the voltage of the lithium battery pack (4) reaches the preset charging threshold, the capacitor relay JDQ1 is closed to connect the capacitor pack to the circuit, the main relay (2) is cut off, the power generation module (1) stops directly charging the lithium battery pack and instead charges the capacitor pack. The power generation module (1) raises the voltage of the capacitor bank. When the combined voltage of the capacitor bank and the lithium battery bank (4) is equal to the output voltage of the power generation module (1), the charging current decreases to zero, and the power generation module (1) stops charging, thereby realizing the regulation of the charging voltage of the lithium battery bank. During the power supply maintenance phase: the main relay (2) is disconnected, the capacitor regulation branch is turned on, and the power generation module (1) directly supplies power to the external load; If the power generation module (1) is insufficient, the lithium battery pack (4) will supply power to the outside through the capacitor relay JDQ1 and diode D1.

10. The battery charging voltage regulation method based on capacitor according to claim 9, characterized in that, The electrical energy stored in the capacitor bank is released through the discharge branch.

Images