Direct current charging and discharging control system and control method

Abstract

The invention discloses a direct current charging and discharging control system and method, and relates to the technical field of battery charging and discharging, and the system comprises the steps: monitoring the input and output voltage and current, the battery state parameters and the environment temperature in real time; judging whether the charging and discharging control mode is a charging mode, a discharging mode or a mixed mode according to the analysis result; if the charging mode is determined, the charging current is dynamically adjusted based on a self-adaptive closed-loop control unit; if a discharging mode is determined, dynamically distributing a discharging current based on a load grading strategy and the residual electric quantity of the battery; and if it is judged that the mode is the mixed mode, charging and discharging parallel control is carried out through the dynamic power distribution unit. The technical problems that in the prior art, a charging and discharging control strategy is single, complex and changeable working conditions cannot be adapted, and key parameters are difficult to accurately monitor in real time to achieve efficient battery management are solved, and the technical effects of improving the energy utilization efficiency and enhancing the equipment operation stability and reliability are achieved.

Description

Technical Field

[0001] The present application relates to the technical field related to battery charging and discharging, and specifically to a direct current charging and discharging control system and control method. Background Art

[0002] As a key energy storage component, efficient management of battery charging and discharging processes is crucial. Traditional charging and discharging control methods often employ fixed strategies that are unable to adapt to the complex and changing real-world operating environment. In real-world applications, the input and output voltages and currents of devices fluctuate constantly due to various factors. Battery status parameters such as state of charge and health are also constantly changing. Furthermore, ambient temperature significantly impacts battery performance and charge and discharge efficiency. Without accurate, real-time monitoring of these critical parameters, effective control of the battery charging and discharging process is difficult to achieve.

[0003] Therefore, in the current related technologies, there are technical problems such as a single charging and discharging control strategy, an inability to adapt to complex and changing working conditions, and difficulty in real-time and accurate monitoring of key parameters to achieve efficient battery management. Summary of the Invention

[0004] This application solves the technical problems in the prior art of a single charging and discharging control strategy, which cannot adapt to complex and changeable working conditions, and is difficult to accurately monitor key parameters in real time to achieve efficient battery management by providing a DC charging and discharging control system and control method. It achieves the technical effect of improving energy utilization efficiency and enhancing equipment operation stability and reliability.

[0005] The present application provides a direct current charge and discharge control system, which includes: a real-time charge and discharge data acquisition module for monitoring the input and output voltage and current, battery status parameters and ambient temperature in real time; a charge and discharge control mode judgment module for analyzing the voltage, the current, the battery status parameters and the ambient temperature, and traversing and matching in a preset strategy library based on the analysis results to determine whether the charge and discharge control mode is a charging mode, a discharging mode or a mixed mode; a charging current adjustment module for dynamically adjusting the charging current based on an adaptive closed-loop control unit if it is determined to be the charging mode; a discharge current distribution module for dynamically distributing the discharge current based on a load classification strategy and the remaining battery power if it is determined to be the discharging mode; and a charge and discharge parallel control module for performing charge and discharge parallel control through a dynamic power distribution unit if it is determined to be the mixed mode.

[0006] In a possible implementation, the DC charge and discharge control system further performs the following processing: the battery status parameters include battery state of charge SOC, state of health SOH, internal resistance, battery temperature and cycle number.

[0007] In a possible implementation, the DC charge and discharge control system also performs the following processing: in the constant current charging stage, variable gain PID control is adopted to dynamically adjust the PID parameters according to the battery temperature and the internal resistance; in the constant voltage charging stage, model predictive control MPC is introduced to optimize the charging time with the goal of minimizing the battery polarization effect; if it is detected that the health state SOH decays beyond a preset threshold, it automatically switches to the repair charging mode.

[0008] In a possible implementation, the DC charge and discharge control system further performs the following processing: setting a dynamic discharge current upper limit according to the battery state of charge SOC and the health state SOH, wherein the SOC stratification threshold is dynamically adjusted with the SOH value, including a first SOC threshold and a second SOC threshold; when the battery state of charge SOC is lower than the first SOC threshold, starting a graded load reduction strategy to reduce the power supply priority of non-critical loads; when the battery state of charge SOC is lower than the second SOC threshold, triggering a deep protection strategy to cut off non-critical loads and activate the backup power supply; if the battery temperature during the discharge process exceeds the safety threshold, introducing temperature-current coupling control to reduce the discharge current.

[0009] In a possible implementation, the DC charge and discharge control system further performs the following processing: the system includes a DC charge and discharge equipment component, wherein the DC charge and discharge equipment component includes a metal casing frame, input and output copper bars, a contactor shunt, a DC meter, an isolating switch, a lightning protection device, a DCDC module, a module compartment, a protection circuit and an intelligent control unit; the intelligent control unit performs charge and discharge control according to preset battery parameters, wherein the intelligent control unit includes a charge and discharge mode switching unit and an abnormality detection unit; the intelligent control unit is also used to realize parallel control of multiple modules.

[0010] In a possible implementation, the DC charge and discharge control system further performs the following processing: when an external power supply is detected, seamless switching to charging mode is achieved through a bidirectional DC-DC converter; when the external power supply is disconnected, the discharge mode is switched and the transient power gap is compensated by a supercapacitor.

[0011] In a possible implementation, the DC charge and discharge control system further performs the following processing: obtaining real-time power demand through the IoT communication module and dynamically generating a load scheduling sequence; detecting critical loads according to the load scheduling sequence and determining abnormal battery status; and automatically switching to a backup battery pack if the battery is abnormal.

[0012] The present application also provides a DC charging and discharging control method, which includes: real-time monitoring of input and output voltage and current, battery status parameters and ambient temperature; analyzing the voltage, current, battery status parameters and ambient temperature, and traversing and matching in a preset strategy library based on the analysis results to determine whether the charging and discharging control mode is a charging mode, a discharging mode or a mixed mode; if it is determined to be the charging mode, dynamically adjusting the charging current based on an adaptive closed-loop control unit; if it is determined to be the discharging mode, dynamically allocating the discharge current based on a load classification strategy and the remaining battery power; if it is determined to be the mixed mode, performing charging and discharging parallel control through a dynamic power allocation unit.

[0013] This application proposes a DC charge-discharge control system and control method that monitors input and output voltage and current, battery status parameters, and ambient temperature in real time. Based on the analysis results, the control mode is determined to be charging mode, discharging mode, or a mixed mode. If the control mode is determined to be charging mode, the charging current is dynamically adjusted based on an adaptive closed-loop control unit. If the control mode is determined to be discharging mode, the discharge current is dynamically allocated based on the load classification strategy and the remaining battery charge. If the control mode is a mixed mode, parallel charging and discharging control is performed through a dynamic power allocation unit. This solves the technical problems in the prior art of single charge-discharge control strategies, the inability to adapt to complex and changing operating conditions, and the difficulty in accurately monitoring key parameters in real time to achieve efficient battery management. This achieves the technical effect of improving energy utilization efficiency and enhancing the stability and reliability of equipment operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the accompanying drawings of the embodiments of the present disclosure are briefly introduced below. Flowcharts are used in this application to illustrate the operations performed by the systems according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in precise order. Instead, various steps may be processed in reverse order or simultaneously as needed. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0015] Figure 1 A schematic diagram of the structure of a DC charging and discharging control system provided in an embodiment of the present application.

[0016] Figure 2 A flow chart of a DC charge and discharge control method provided in an embodiment of the present application.

[0017] Description of reference numerals: real-time charge and discharge data acquisition module 10 , charge and discharge control mode determination module 20 , charge current adjustment module 30 , discharge current distribution module 40 , charge and discharge parallel control module 50 . DETAILED DESCRIPTION

[0018] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below.

[0019] In order to make the purpose, technical solutions and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limiting this application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0020] In the following description, reference is made to “some embodiments”, which describes a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict, and the terms “first\second” involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. The terms “including” and “having” and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or modules that are not clearly listed or that are inherent to these processes, products, or devices. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used herein are for the purpose of describing the embodiments of this application only.

[0021] The embodiment of the present application provides a DC charge and discharge control system, such as Figure 1 As shown, the system includes:

[0022] The real-time charge and discharge data acquisition module 10 is used to monitor the input and output voltage and current, battery status parameters and ambient temperature in real time.

[0023] Furthermore, the specific configuration of the real-time charge and discharge data acquisition module 10 also includes that the battery status parameters include battery state of charge SOC, state of health SOH, internal resistance, battery temperature and cycle number.

[0024] Preferably, the real-time charge and discharge data acquisition module is responsible for collecting and monitoring data related to the battery charge and discharge process. Through specific sensors or circuits, the voltage and current values of the power input to the battery and the battery output to the load during the charge and discharge process are measured in real time, which can reflect key information such as the power size of the charge and discharge, energy transmission efficiency, etc. For example, when charging, monitoring the input voltage and current can understand the power provided by the charger to the battery. When discharging, monitoring the output voltage and current can understand the status of the battery powering external devices. Real-time monitoring of battery status parameters includes battery state of charge (SOC), state of health (SOH), internal resistance, battery temperature, and cycle count. Specifically, the battery state of charge (SOC) reflects the current remaining power of the battery, similar to the fuel gauge of a fuel car, expressed as a percentage. By monitoring the SOC in real time, it is possible to understand how long the battery can support the operation of the device, which also helps to control the charge and discharge process and avoid damage to the battery caused by overcharging or over-discharging.

[0025] Preferably, the battery state of health (SOH) is used to assess the overall performance and aging of the battery. The SOH gradually decreases with battery use and cycle count, which can help users predict the remaining service life of the battery and determine whether the battery needs to be replaced. The battery internal resistance is used to reflect battery performance and changes with battery aging and usage conditions. The magnitude of the internal resistance affects the battery's charge and discharge efficiency, heat generation, and output power. Real-time monitoring of the internal resistance can promptly detect potential problems within the battery, such as electrode aging and electrolyte drying. The battery generates heat during the charge and discharge process. Excessive high or low temperatures will have an adverse effect on the battery's performance and life. The number of complete charge and discharge cycles experienced by the battery is recorded. The number of cycles is closely related to the degree of battery aging. Generally speaking, as the number of cycles increases, the battery's performance will gradually decrease. By monitoring the number of cycles, the battery's life status can be better understood. The ambient temperature has a significant impact on the battery's performance and charge and discharge efficiency. Under different ambient temperatures, the battery's chemical reaction rate, internal resistance and other characteristics will change. For example, in a low temperature environment, the battery's charging efficiency will decrease, while in a high temperature environment, the battery may face the risk of overheating and even shorten its service life.

[0026] The charge and discharge control mode judgment module 20 is used to analyze the voltage, the current, the battery status parameters and the ambient temperature, and traverse the matching in the preset strategy library according to the analysis results to determine whether the charge and discharge control mode is the charging mode, the discharging mode or the mixed mode.

[0027] Preferably, the main function of the charge and discharge control mode judgment module is to accurately judge which charge and discharge control mode the current battery should be in based on the multi-dimensional data such as voltage, current, battery status parameters and ambient temperature monitored in real time, by matching and analyzing with various strategies in the preset strategy library. Specifically, the voltage, current, battery status parameters and ambient temperature are analyzed. When the input current is monitored to be greater than zero and the battery state of charge (SOC) is lower than the set full charge threshold, and the battery voltage is within the normal charging voltage range, the impact of the ambient temperature on the charging efficiency and the impact of the battery health state (SOH) on the charging acceptance are considered, and it is judged that the battery may be in the charging state. Similarly, for the judgment of the discharge mode, when the output current is greater than zero and the battery SOC is higher than the set cut-off discharge threshold, and the voltage and current required by the load match the capacity that the battery can provide, the battery may be in the discharge state. The preset strategy library is a collection of strategies developed based on battery characteristics, different application scenarios, and a large amount of experimental data. For example, there are different charging and discharging strategies for different types of batteries (such as lithium-ion batteries, lead-acid batteries, etc.); there are corresponding temperature compensation strategies for different operating ambient temperature ranges; there are different charging and discharging current limit strategies for different battery health states, etc.; the strategies in the strategy library usually exist in the form of conditional judgment statements. For example, when the battery SOC is lower than 20% and the ambient temperature is between 20℃-30℃, the constant current charging mode is adopted, and the charging current is set to a specific value until the battery voltage reaches the set upper limit value, and then it switches to the constant voltage charging mode until the battery is fully charged.

[0028] Preferably, the charge and discharge control mode judgment module will traverse and match the analysis results with the strategies in the preset strategy library one by one, and check in turn whether the current data meets the conditions of the strategy. If all the conditions of a strategy are met, then the current charge and discharge control mode can be judged according to the strategy. For example, if the data meets the condition that "when the battery SOC is lower than 80%, the input current is greater than zero, and the ambient temperature is within the allowable charging temperature range, the charging mode is adopted", then the module judges that it is currently in the charging mode; if the data meets the condition that "when the battery SOC is higher than 20%, the output current is greater than zero, and the load demand matches the battery output capacity, the discharge mode is adopted", then it is judged to be the discharge mode; and when there are input current and output current at the same time, and the battery status and environmental conditions meet a specific hybrid mode strategy, such as charging the battery at the same time during the braking energy recovery process of the electric vehicle, and the battery discharges the drive motor during the vehicle driving process, the module judges it to be a hybrid mode.

[0029] The charging current adjustment module 30 is configured to dynamically adjust the charging current based on the adaptive closed-loop control unit if the charging mode is determined to be the charging mode.

[0030] Preferably, after determining that it is in charging mode, the charging current adjustment module dynamically adjusts the charging current based on the adaptive closed-loop control unit, wherein the adaptive closed-loop control unit is the core of the module and works based on the feedback control principle. Specifically, during the charging process, various real-time data related to charging are continuously obtained, such as the battery voltage, current, temperature, state of charge (SOC), state of health (SOH), etc., and then the actual data is compared with the pre-set target value. According to the deviation generated by the comparison, the control unit will automatically calculate and adjust the charging current so that the battery charging process is as close to the ideal state as possible, and can adapt to the changes of the battery in different stages and different working conditions.

[0031] Preferably, in the initial stage of charging, when the battery SOC is low, the battery can withstand a large charging current. At this time, the adaptive closed-loop control unit will provide a relatively large charging current according to a preset strategy to achieve fast charging and shorten the charging time. As the charging process progresses, the battery SOC gradually increases. In order to avoid overcharging and ensure the safety and life of the battery, the control unit will gradually reduce the charging current. For example, when the battery SOC reaches 80%-90%, the charging current will significantly decrease, entering the so-called "trickle charging" stage to slowly and steadily fill the battery. The optimal charging temperature range of the battery is usually within a certain range (such as 20°C-30°C). If the ambient temperature is low, the internal resistance of the battery will increase and the charging efficiency will decrease. At this time, if a normal charging current is used, the charging speed may be too slow or even unable to charge normally. The adaptive closed-loop control unit will appropriately increase the charging current according to the real-time monitored battery temperature to improve the charging efficiency. On the contrary, if the battery temperature is too high, in order to prevent the battery from overheating and causing safety problems and accelerating battery aging, the control unit will reduce the charging current and may also activate heat dissipation measures to reduce the battery temperature.

[0032] Preferably, as the battery is used and the number of cycles increases, the performance of the battery will gradually decline, and the maximum charging current it can withstand will also decrease accordingly. The adaptive closed-loop control unit will evaluate the battery's SOH in real time and dynamically adjust the charging current based on the evaluation results. For batteries in poor health, a smaller charging current will be used for charging to protect the battery and extend its service life. During the charging process, the battery voltage will continue to rise. When the battery voltage approaches its charge cut-off voltage, in order to avoid overcharging, the adaptive closed-loop control unit will quickly reduce the charging current. For example, for lithium-ion batteries, when the battery voltage reaches its specified charge cut-off voltage (such as 4.2V), the charging current will gradually decrease from a larger value to a very small value until the battery is fully charged.

[0033] Furthermore, the specific configuration of the charging current adjustment module 30 also includes: in the constant current charging stage, variable gain PID control is adopted to dynamically adjust the PID parameters according to the battery temperature and the internal resistance; in the constant voltage charging stage, model predictive control MPC is introduced to optimize the charging time with the goal of minimizing the battery polarization effect; if it is detected that the health state SOH decays beyond a preset threshold, it automatically switches to the repair charging mode.

[0034] Preferably, PID (proportional-integral-differential) control is a common feedback control algorithm that adjusts the control variable by calculating the proportional (P), integral (I), and differential (D) terms of the error (the difference between the set value and the actual value) to make the system output as close to the set value as possible. Specifically, in the constant current charging stage, the set goal is to keep the charging current constant, while the variable gain PID control dynamically adjusts the three parameters of the PID controller (proportional coefficient, integral coefficient, and differential coefficient) according to the real-time status of the battery (such as battery temperature and internal resistance) to achieve more precise control. In low temperature environments, the internal resistance of the battery increases and the chemical reaction rate slows down. In order to achieve the set charging current, it may be necessary to increase the proportional coefficient of the PID controller to speed up the response speed. At the same time, the integral coefficient and differential coefficient should be appropriately adjusted to avoid overshoot or oscillation in the system. In high temperature environments, the performance of the battery will be affected, and it may be necessary to reduce the proportional coefficient to prevent excessive charging current from damaging the battery. When the internal resistance increases, it means that the chemical reaction inside the battery may be hindered to a certain extent. At this time, it is necessary to adjust the PID parameters so that the charging current can better adapt to the changes in the battery. For example, increase the integral coefficient to eliminate the steady-state error caused by the change in internal resistance.

[0035] Preferably, model predictive control (MPC) is a model-based optimization control strategy that predicts the future output of the system and solves the optimal control sequence online based on certain optimization objectives and constraints. During the constant voltage charging stage, the goal is to minimize the battery polarization effect while maintaining a constant battery voltage, thereby optimizing the charging time. Specifically, during the charging process, polarization occurs inside the battery, which manifests as an increase in battery voltage and a decrease in charging efficiency. The polarization effect will extend the charging time and may also affect the battery life. By introducing model predictive control, the polarization of the battery in the future can be predicted based on the mathematical model and real-time status of the battery, and the polarization effect can be minimized by adjusting the charging current. MPC continuously optimizes the control sequence of the charging current online, so that the battery can approach the full charge state as quickly as possible during the constant voltage charging stage, while avoiding the influence of overcharging and polarization effects. That is, according to the battery status and optimization objectives, the optimal charging current at the current moment is calculated and adjusted in the next control cycle until the battery is fully charged.

[0036] Preferably, when the battery's state of health (SOH) decay is detected to exceed a preset threshold, the system automatically switches to a repair charging mode. The preset threshold is set based on the battery type and usage requirements. When the SOH falls below this threshold, it indicates that the battery's performance has seriously degraded and requires repair. Specifically, the repair charging mode typically uses special charging strategies, such as pulse charging and intermittent charging, to improve the battery's internal state, reduce polarization and internal resistance, and increase battery capacity and performance. Through repair charging, the battery's service life can be extended and its reliability and safety can be improved.

[0037] The discharge current distribution module 40 is configured to dynamically distribute the discharge current based on the load classification strategy and the remaining battery capacity if the discharge mode is determined to be the discharge mode.

[0038] Preferably, after determining that the discharge mode is in progress, the discharge current distribution module dynamically distributes the discharge current based on the load classification strategy and the remaining battery power. Specifically, the loads are divided into different levels according to factors such as the importance of different loads, power requirements, and requirements for power supply stability. For example, core loads that are critical to the normal operation of the equipment (such as control systems, safety equipment, etc.) can be classified as high-level loads, while some non-critical auxiliary loads (such as entertainment equipment, some lighting equipment, etc.) can be classified as low-level loads. During the discharge process, priority is given to ensuring the power supply of high-level loads, which means that when the battery power is limited, the current demand of high-level loads will be met first to ensure the basic functions and safe operation of the equipment. For example, in electric vehicles, even if the battery power is low, priority will be given to ensuring the normal power supply of key loads such as the drive system and braking system to ensure the driving safety of the vehicle. The discharge current is distributed according to a certain ratio or rule based on the load level and actual demand. For high-level loads, a relatively large current will be allocated to ensure their normal operation. For low-level loads, an appropriate current will be allocated based on the remaining power and the demand of the high-level loads. For example, when the battery has sufficient remaining power, the low-level load can obtain relatively more current to meet its normal operation. However, when the battery is insufficient, the current of the low-level load will be appropriately reduced to prioritize the power supply of the high-level load.

[0039] Preferably, the remaining power of the battery is monitored in real time to accurately obtain the current state of charge (SOC) information of the battery, and then the distribution of the discharge current is dynamically adjusted according to the changes in the load demand and the remaining power of the battery. Specifically, when the remaining power of the battery is large, the discharge current of the low-level load can be appropriately increased to make full use of the battery energy and meet the working needs of more loads; and when the remaining power of the battery gradually decreases, the current distribution of the low-level load will be gradually reduced, and even the power supply of some low-level loads will be cut off when necessary to ensure that the high-level load can obtain sufficient power to maintain the basic operation of the equipment. By dynamically distributing the discharge current through the load classification strategy and combining the remaining power of the battery, it is possible to reasonably utilize the battery energy, improve the battery utilization efficiency and the overall performance of the equipment, and also help to extend the service life of the battery while ensuring the normal operation of the key functions of the equipment.

[0040] Furthermore, the specific configuration of the discharge current distribution module 40 also includes setting a dynamic discharge current upper limit according to the battery state of charge SOC and the health state SOH, wherein the SOC stratification threshold is dynamically adjusted with the SOH value, including a first SOC threshold and a second SOC threshold; when the battery state of charge SOC is lower than the first SOC threshold, a graded load reduction strategy is started to reduce the power supply priority of non-critical loads; when the battery state of charge SOC is lower than the second SOC threshold, a deep protection strategy is triggered to cut off non-critical loads and activate the backup power supply; if the battery temperature during the discharge process exceeds the safety threshold, temperature-current coupling control is introduced to reduce the discharge current.

[0041] Preferably, the battery state of charge (SOC) reflects the current remaining power of the battery, while the state of health (SOH) reflects the overall performance and aging of the battery. Generally speaking, as the battery is used and ages (i.e., the SOH decreases), the actual available capacity of the battery will decrease, which means that at the same SOC, the energy that the battery can provide and its sustainable discharge capacity will also change; by setting different SOC thresholds, the battery discharge process is divided into different stages so that different control strategies can be adopted, that is, divided into two key dividing points: the first SOC threshold and the second SOC threshold. For example, the first SOC threshold may be set to 30%, and the second SOC threshold may be set to 10%.

[0042] Preferably, when the battery state of charge (SOC) is lower than the first SOC threshold, it indicates that the battery power is relatively low. At this time, a hierarchical load reduction strategy is initiated, that is, based on the concept of load classification, by reducing the power supply priority of non-critical loads and reducing the current distribution of these loads, the normal operation of critical loads is prioritized. For example, when the battery power drops below the first SOC threshold, the power supply priority of non-critical loads such as monitoring equipment or auxiliary communication equipment that do not require high real-time performance will be reduced, and the operating frequency may be reduced or some non-essential functions may be suspended to save power. When the battery state of charge (SOC) is lower than the second SOC threshold, the battery power is already at a very low level. In order to protect the battery and ensure the minimum operating requirements of critical equipment, a deep protection strategy needs to be triggered. At this time, the power supply to non-critical loads is cut off to minimize the discharge current of the battery, and at the same time, the backup power supply (if equipped) is activated to provide power support for critical loads.

[0043] Preferably, during battery discharge, if the battery temperature exceeds a safety threshold, it indicates that the chemical reaction inside the battery may be too intense or the heat dissipation may be poor, which can seriously affect the battery's performance and lifespan and may even cause safety issues. Therefore, a temperature-current coupled control mechanism is introduced to dynamically adjust the discharge current based on changes in battery temperature to maintain the battery temperature within a safe range. Specifically, through a feedback control system, when the temperature exceeds the safety threshold, the system automatically detects the temperature change and calculates the required discharge current value based on a preset control algorithm. Generally speaking, the higher the temperature, the greater the required discharge current reduction. For example, when the battery temperature exceeds the safety threshold by 5°C, the discharge current may be reduced by 20%; if the temperature continues to rise, the discharge current will be further reduced. In this way, the battery temperature is controlled within a safe range while ensuring that the battery can provide the required power to the greatest extent possible under the premise of safety.

[0044] The charge and discharge parallel control module 50 is configured to perform charge and discharge parallel control through a dynamic power distribution unit if the hybrid mode is determined.

[0045] Preferably, the charge and discharge parallel control module performs charge and discharge parallel control through the dynamic power allocation unit when it is determined to be in the mixed mode. Specifically, it monitors the voltage, current, power and other parameters of the charging and discharging circuits, as well as the battery's SOC, SOH, temperature and other status information in real time, and then formulates a reasonable power allocation strategy based on the battery status. For example, when the system needs to power an external load and there is a power supply to charge the battery, it is necessary to comprehensively consider the battery's charging requirements (such as the current SOC, whether it is close to full charge, etc.), the load's power requirements and the power supply capacity of the power supply. If the battery SOC is low and the load power demand is not particularly large, a portion of the power may be allocated to battery charging first to increase the battery's power; if the load is a critical load and the power demand is large, the charging power may be appropriately reduced to prioritize the power supply to the load.

[0046] Preferably, the charging and discharging power is dynamically adjusted based on real-time monitoring information and the established power allocation strategy. For example, if the battery temperature rises too quickly during charging, the charging power may be reduced while the discharging power is appropriately increased to allow the battery to reach a balance during the charging and discharging process, allowing it to continue to supply power to the load while also controlling the battery temperature. Alternatively, when the load power suddenly increases, the charging power is dynamically reduced, and more power is allocated to the discharge circuit to meet the load's needs. Ensure that the charging and discharging processes are coordinated to avoid conflicts or mutual interference between the two. For example, appropriate isolation devices and control switches are provided in the charging and discharging circuits to precisely control the direction and magnitude of the current according to the power allocation instructions, allowing the charging and discharging processes to proceed simultaneously without interfering with each other. At the same time, the characteristics and limitations of the charging and discharging equipment, such as the maximum output power of the charger and the maximum charge and discharge current of the battery, must also be taken into account. During the control process, ensure that these limitations are not exceeded to ensure the safe and stable operation of the equipment.

[0047] Furthermore, the DC charge and discharge control system also includes a DC charge and discharge equipment component, wherein the DC charge and discharge equipment component includes a metal casing frame, input and output copper bars, a contactor shunt, a DC meter, an isolating switch, a lightning protection device, a DCDC module, a module compartment, a protection circuit and an intelligent control unit; the intelligent control unit performs charge and discharge control according to preset battery parameters, wherein the intelligent control unit includes a charge and discharge mode switching unit and an abnormality detection unit; the intelligent control unit is also used to realize parallel control of multiple modules.

[0048] Preferably, the metal outer shell frame is used to protect the internal electrical components, provide mechanical support and physical protection, and prevent external mechanical damage, dust, moisture, etc. from affecting the internal components of the device. At the same time, it can also play a certain electromagnetic shielding role, reduce the impact of external electromagnetic interference on the device, and prevent the electromagnetic interference generated by the device itself from affecting other devices; the input and output copper busbars have good conductivity and mechanical strength, and can carry a large current, input the electric energy of the external power supply into the device for charging, or output the electric energy stored in the battery to the load through the copper busbar; the contactor shunt is used to control the on and off of the circuit, realize the control and switching of the charging and discharging process, and is also used to measure the current in the circuit. By measuring the voltage drop across the shunt, the current in the circuit is calculated according to Ohm's law, and current data is provided to the intelligent control unit for charging and discharging control; the DC meter is used to measure the DC circuit Voltage, current and other parameters display the operating status of the equipment in real time; the isolating switch can isolate the equipment from the power supply or load during equipment maintenance or troubleshooting to ensure the safety of operators; the lightning protection device is used to protect the equipment from overvoltage such as lightning strikes. When a lightning strike or other overvoltage phenomenon occurs, the lightning protection device can quickly conduct and introduce the overvoltage into the ground to protect the electrical components inside the equipment from damage; the DCDC module is a DC-DC converter used to realize the conversion between DC power of different voltage levels. During the charging and discharging process, it can convert the input DC voltage into the appropriate voltage value according to the battery voltage and load requirements to meet the requirements of battery charging and load power supply; the module compartment is the installation space for each module inside the equipment, providing a place for fixing and protecting each module; the module compartment is the installation space for each module inside the equipment, providing a place for fixing and protecting each module.

[0049] Preferably, the intelligent control unit pre-stores various battery-related parameters, such as the battery's rated voltage, rated capacity, charge cut-off voltage, and discharge cut-off voltage. During the charge and discharge process, the intelligent control unit monitors the battery's state parameters (such as voltage, current, SOC, SOH, etc.) in real time and compares them with the preset battery parameters. Based on the comparison results, the intelligent control unit controls components such as contactors to achieve precise control of the charge and discharge process. For example, when the battery voltage reaches the charge cut-off voltage, the intelligent control unit controls the contactor to disconnect the charging circuit and stop charging; when the battery voltage drops to the discharge cut-off voltage, the intelligent control unit controls the contactor to disconnect the discharge circuit to prevent the battery from over-discharging. The charge and discharge mode switching unit is responsible for switching between charge mode, discharge mode, and mixed mode. Based on the real-time monitored system status and battery status, it determines which charge and discharge mode should be currently in, and switches the mode by controlling the corresponding circuit components. For example, when an external power source is connected and the battery needs to be charged, the charge and discharge mode switching unit controls the device to enter charge mode; when the battery needs to power a load, it switches to discharge mode; when both charge and discharge are required, it switches to mixed mode and coordinates the charge and discharge process. The abnormality detection unit is used to monitor the operating status of the equipment and the status of the battery in real time, and detect whether there are any abnormal conditions. Abnormal conditions may include overvoltage, undervoltage, overcurrent, short circuit, high battery temperature, abnormal battery SOC, etc. Once an abnormal condition is detected, the abnormality detection unit will immediately issue an alarm and take corresponding measures, such as cutting off the circuit, starting the protection circuit, etc., to ensure the safety of the equipment and battery.

[0050] Preferably, the intelligent control unit can realize parallel control of multiple modules, specifically including current sharing control (ensuring uniform current distribution between the modules in parallel, by monitoring the current of each module and adjusting the output of the module according to a certain control algorithm, so that the output current of each module is as equal as possible to achieve current sharing operation), synchronous control (ensuring that the modules in parallel operate synchronously during the charging and discharging process, that is, the intelligent control unit coordinates the control signals of each module to achieve synchronous operation between modules. For example, during the charging process, each module can start charging and end charging at the same time; during the discharging process, it can supply power to the load at the same time, and the output voltage and current remain consistent) and fault handling (when a module in parallel fails, the intelligent control unit can detect the fault in time and take corresponding measures, for example, isolating the faulty module to prevent the fault from affecting the normal operation of other modules, and issuing an alarm to notify the operator to perform maintenance; at the same time, the intelligent control unit can also adjust the operating parameters of other normal modules to compensate for the loss of the faulty module to ensure the normal operation of the entire system).

[0051] Furthermore, the specific configuration of the charge and discharge mode switching unit includes: when it is detected that the external power supply is connected, seamless switching to the charging mode is achieved through the bidirectional DC-DC converter; when the external power supply is disconnected, the discharge mode is switched and the transient power gap is compensated by the supercapacitor.

[0052] Preferably, the bidirectional DC-DC converter is used to realize bidirectional transmission and voltage conversion of direct current power. When it is detected that an external power source is connected, the power of the external power source can be transmitted to the battery at an appropriate voltage and current for charging according to the state of the battery (such as the battery state of charge SOC, battery voltage, etc.) and the parameters of the external power source (such as voltage, power, etc.). Specifically, in the process of switching from other modes (such as discharge mode or standby mode) to charging mode, there will be no obvious interruption or abnormality in the operation of the system. Through rapid response and precise control, the bidirectional DC-DC converter can quickly adjust its working state at the moment of detecting the connection of the external power source and start transmitting the power of the external power source to the battery without affecting other loads connected to the system (if any).

[0053] Preferably, when the external power supply is disconnected, the system needs to quickly switch from charging mode or other modes to discharging mode to meet the power demand of the load. At this time, the bidirectional DC-DC converter will change its working direction, convert the electric energy stored in the battery into a suitable voltage and current, and output it to the load. The switching process is fast and stable to ensure that the load can continue to obtain power supply and will not have abnormal operation due to the switching of the power supply. Specifically, at the moment when the external power supply is disconnected, due to the relatively slow response speed of the battery, there may be a short-term power shortage, resulting in fluctuations in the voltage or current of the load, that is, a transient power gap. Supercapacitors have the characteristics of fast charging and discharging and can provide a large current in a short time. Therefore, when the external power supply is detected to be disconnected, the system immediately starts the supercapacitor and uses the electric energy stored in the supercapacitor to compensate for the transient power gap and maintain the normal operation of the load. As the battery gradually enters the discharge state, it can stably provide the required power. The supercapacitor will stop discharging at the appropriate time and charge as needed for the next use.

[0054] Furthermore, the specific configuration of the abnormality detection unit also includes obtaining real-time power demand through the IoT communication module and dynamically generating a load scheduling sequence; detecting key loads according to the load scheduling sequence and judging the abnormal state of the battery; if the battery is abnormal, automatically switching to the backup battery pack.

[0055] Preferably, the IoT (Internet of Things) communication module is a key component for the device to interact with the outside world for data, and can be connected to the IoT network through various communication protocols (such as Wi-Fi, Bluetooth, 4G / 5G, etc.). Specifically, the IoT communication module can receive real-time power demand information, and then dynamically generate a load scheduling sequence based on the acquired real-time power demand information, which determines the power supply priority and power supply time arrangement of each load in different time periods. For example, when the battery power is limited, the power supply of key loads (such as security monitoring equipment, emergency lighting, etc.) will be prioritized, while for some non-critical loads (such as landscape lighting, entertainment equipment, etc.), their power supply time may be appropriately adjusted or their power supply priority may be lowered, or even the power supply may be temporarily cut off according to the power demand and battery status. The load scheduling sequence will be continuously adjusted as the real-time power demand changes to achieve reasonable allocation and efficient utilization of battery energy.

[0056] Preferably, by analyzing the load scheduling sequence, the critical load is accurately identified, and the various status parameters of the battery (such as battery state of charge SOC, state of health SOH, battery voltage, current, temperature, etc.) are combined to determine whether the battery is in an abnormal state. For example, if the battery SOC is found to drop sharply suddenly, or the battery voltage is lower than the normal range, or the battery temperature is too high, it may be a sign of battery abnormality. If the operation of the critical load is abnormal (such as sudden power outage, performance degradation, etc.), and the load itself is not faulty, it may also indicate that there is a problem with the battery, and then determine whether the battery is in an abnormal state. If it is determined that the battery is in an abnormal state, the automatic switching mechanism is immediately started to automatically control the relevant circuit switches or relays and other components to switch the power supply from the abnormal battery pack to the backup battery pack to ensure the continued normal operation of the critical load.

[0057] In the above, refer to Figure 1 A DC charge and discharge control system according to an embodiment of the present invention is described in detail. Figure 2 A DC charge and discharge control method according to an embodiment of the present invention is described. A DC charge and discharge control method, such as Figure 2 As shown, the method includes: real-time monitoring of input and output voltage and current, battery status parameters and ambient temperature; analyzing the voltage, current, battery status parameters and ambient temperature, traversing and matching in a preset strategy library according to the analysis results, and judging whether the charge and discharge control mode is a charge mode, a discharge mode or a mixed mode; if it is determined to be the charge mode, dynamically adjusting the charge current based on an adaptive closed-loop control unit; if it is determined to be the discharge mode, dynamically allocating the discharge current based on a load classification strategy and the remaining battery power; if it is determined to be the mixed mode, performing charge and discharge parallel control through a dynamic power allocation unit.

[0058] In a possible implementation, the DC charge and discharge control method further includes: the battery status parameters include battery state of charge SOC, state of health SOH, internal resistance, battery temperature and cycle number.

[0059] In one possible implementation, the DC charging and discharging control method further includes: in the constant current charging stage, variable gain PID control is adopted to dynamically adjust the PID parameters according to the battery temperature and the internal resistance; in the constant voltage charging stage, model predictive control MPC is introduced to optimize the charging time with the goal of minimizing the battery polarization effect; if it is detected that the health state SOH decays beyond a preset threshold, it automatically switches to the repair charging mode.

[0060] In one possible implementation, the DC charge and discharge control method further includes: setting a dynamic discharge current upper limit according to the battery state of charge SOC and the health state SOH, wherein the SOC stratification threshold is dynamically adjusted with the SOH value, including a first SOC threshold and a second SOC threshold; when the battery state of charge SOC is lower than the first SOC threshold, starting a graded load reduction strategy to reduce the power supply priority of non-critical loads; when the battery state of charge SOC is lower than the second SOC threshold, triggering a deep protection strategy to cut off non-critical loads and activate the backup power supply; if the battery temperature during the discharge process exceeds the safety threshold, introducing temperature-current coupling control to reduce the discharge current.

[0061] In one possible implementation, the DC charge and discharge control method further includes: a DC charge and discharge equipment assembly, wherein the DC charge and discharge equipment assembly includes a metal housing frame, input and output copper bars, a contactor shunt, a DC meter, an isolating switch, a lightning protection device, a DCDC module, a module compartment, a protection circuit, and an intelligent control unit; the intelligent control unit performs charge and discharge control according to preset battery parameters, wherein the intelligent control unit includes a charge and discharge mode switching unit and an abnormality detection unit; and the intelligent control unit is further used to implement parallel control of multiple modules.

[0062] In one possible implementation, the DC charge and discharge control method further includes: when an external power supply is detected to be connected, seamlessly switching to a charging mode through a bidirectional DC-DC converter; when the external power supply is disconnected, completing the discharge mode switching and compensating for the transient power gap through a supercapacitor.

[0063] In one possible implementation, the DC charging and discharging control method further includes: obtaining real-time power demand through an IoT communication module and dynamically generating a load scheduling sequence; detecting critical loads according to the load scheduling sequence and determining abnormal battery status; and automatically switching to a backup battery pack if the battery is abnormal.

[0064] A DC charge and discharge control system provided by an embodiment of the present invention can execute a DC charge and discharge control method provided by any embodiment of the present invention, and has functional modules and beneficial effects corresponding to the execution method.

[0065] Although the present application makes various references to certain modules in the system according to the embodiments of the present application, any number of different modules may be used and run on the user terminal and / or server, and the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other and are not used to limit the scope of protection of the present invention.

[0066] The above specific embodiments do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application shall be included within the scope of protection of this application.

Claims

1. A DC charge and discharge control system, characterized in that: The system comprises: Real-time charge and discharge data acquisition module, used to monitor input and output voltage and current, battery status parameters and ambient temperature in real time; a charge and discharge control mode determination module, configured to analyze the voltage, the current, the battery status parameters, and the ambient temperature, and perform matching in a preset strategy library based on the analysis results to determine whether the charge and discharge control mode is a charge mode, a discharge mode, or a mixed mode; a charging current adjustment module, configured to dynamically adjust the charging current based on an adaptive closed-loop control unit if the charging mode is determined to be the charging mode; A discharge current distribution module, configured to dynamically distribute the discharge current based on a load classification strategy and the remaining battery capacity if the discharge mode is determined to be the discharge mode; The charge and discharge parallel control module is used to perform charge and discharge parallel control through the dynamic power allocation unit if it is determined to be the mixed mode.

2. A DC charge and discharge control system according to claim 1, characterized in that: The battery status parameters include battery state of charge (SOC), state of health (SOH), internal resistance, battery temperature, and cycle count.

3. A DC charge and discharge control system according to claim 2, characterized in that: The adaptive closed-loop control unit comprises: During the constant current charging stage, variable gain PID control is adopted to dynamically adjust PID parameters according to the battery temperature and the internal resistance; During the constant voltage charging phase, model predictive control (MPC) is introduced to optimize the charging time with the goal of minimizing the battery polarization effect. If it is detected that the health state SOH decays beyond a preset threshold, the system automatically switches to the repair charging mode.

4. A DC charge and discharge control system according to claim 2, characterized in that: The steps performed by the discharge current distribution module include: Setting a dynamic discharge current upper limit according to the battery state of charge (SOC) and the state of health (SOH) stratification, wherein the SOC stratification threshold is dynamically adjusted with the SOH value, including a first SOC threshold and a second SOC threshold; When the battery state of charge (SOC) is lower than the first SOC threshold, the hierarchical load reduction strategy is activated to reduce the power supply priority of non-critical loads; When the battery state of charge (SOC) is lower than the second SOC threshold, the deep protection strategy is triggered to cut off non-critical loads and activate the backup power supply; If the battery temperature during the discharge process exceeds the safety threshold, temperature-current coupling control is introduced to reduce the discharge current.

5. A DC charge and discharge control system according to claim 1, characterized in that: The system also includes a DC charging and discharging equipment assembly, wherein the DC charging and discharging equipment assembly includes a metal housing frame, input and output copper bars, a contactor shunt, a DC meter, an isolating switch, a lightning protection device, a DCDC module, a module compartment, a protection circuit and an intelligent control unit; The intelligent control unit performs charge and discharge control according to preset battery parameters, wherein the intelligent control unit includes a charge and discharge mode switching unit and an abnormality detection unit; The intelligent control unit is also used to realize parallel control of multiple modules.

6. A DC charge and discharge control system according to claim 5, characterized in that: The steps performed by the charge and discharge mode switching unit include: When an external power source is detected, the device switches seamlessly to charging mode via a bidirectional DC-DC converter. When the external power supply is disconnected, the discharge mode is switched and the transient power gap is compensated by the supercapacitor.

7. A DC charge and discharge control system according to claim 5, characterized in that: The steps performed by the anomaly detection unit include: Obtain real-time power demand through the IoT communication module and dynamically generate load scheduling sequences; detecting critical loads according to the load scheduling sequence and determining abnormal battery status; If the battery fails, it will automatically switch to the backup battery pack.

8. A DC charge and discharge control method, characterized in that: The method is applied to a DC charging and discharging control system according to any one of claims 1 to 7, and the method comprises: Real-time monitoring of input and output voltage and current, battery status parameters and ambient temperature; Analyze the voltage, the current, the battery status parameter, and the ambient temperature, and traverse and match in a preset strategy library according to the analysis results to determine whether the charge and discharge control mode is a charge mode, a discharge mode, or a mixed mode; If it is determined to be the charging mode, dynamically adjusting the charging current based on the adaptive closed-loop control unit; If it is determined to be the discharge mode, the discharge current is dynamically allocated based on the load classification strategy and the remaining battery power; If it is determined to be the mixed mode, the dynamic power distribution unit is used to perform parallel control of charging and discharging.

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