Flow battery charging state monitoring method based on high-frequency isolation technology

Abstract

The invention relates to the technical field of redox flow battery charging, in particular to a redox flow battery charging state monitoring method based on a high-frequency isolation technology, which comprises the following steps: firstly, monitoring the voltage, current, temperature and electrolyte concentration of a battery through a sensor, and analyzing and processing to obtain a comprehensive charging state index; constant-current and constant-voltage charging modes are automatically switched according to the index, constant-current charging needs that the battery voltage is lower than a first threshold value and the temperature is normal, switching to constant-voltage charging needs to meet voltage and current conditions, mode switching adopts a linear interpolation algorithm to adjust current and voltage, transition time can be dynamically adjusted, meanwhile, control logic is designed, and the constant-current and constant-voltage charging modes are designed. The invention further relates to a related system which comprises a sensor, a control module, a power regulation module and a high-frequency isolation module. The method improves the charging efficiency, prolongs the service life of the battery, and enhances the system stability.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid flow battery charging, and in particular to a liquid flow battery charging state monitoring method based on high frequency isolation technology. Background Art

[0002] Flow battery charging is an important technology. With the growth of energy demand and the emphasis on renewable energy storage, flow batteries have attracted widespread attention as a potential energy storage technology. The precise control of the charging mode of flow batteries is crucial to their performance and life. Traditional flow battery charging methods have many shortcomings.

[0003] Among them, during the charging process of the traditional liquid flow battery charging method, due to the complex electromagnetic field in the charging environment and the mutual influence between electrical equipment, the control signal is susceptible to external interference, which leads to untimely and unreasonable mode switching of the battery during the charging mode switching process, further reducing the charging efficiency. In order to solve this technical problem, we provide a liquid flow battery charging status monitoring method based on high-frequency isolation technology. Summary of the invention

[0004] The purpose of the present invention is to provide a method for monitoring the charging state of a flow battery based on high frequency isolation technology to solve the problems raised in the above background technology.

[0005] The present invention isolates external interference and transmits control signals based on high-frequency isolation technology, feeds back the charging status in real time, and then dynamically calculates and adjusts the transition time according to the charging status, so that the charging mode switching is more suitable for the battery.

[0006] To achieve the above object, one of the objects of the present invention is to provide a method for monitoring the charging state of a flow battery based on high frequency isolation technology, comprising the following steps: S1. Real-time monitoring of charging status data of the flow battery by sensors, wherein the charging status data includes battery voltage, current, temperature and electrolyte concentration, and the charging status data is analyzed and processed to calculate a comprehensive charging status index; S2. Automatically switch between constant current charging mode and constant voltage charging mode according to the comprehensive charging state index. When the comprehensive charging state index meets the constant current charging condition, enter the constant current charging mode. When the comprehensive charging state index meets the switching condition, switch from the constant current charging mode to the constant voltage charging mode. In the process of mode switching, a transition algorithm is used to adjust the charging current and voltage. S3. Designing control logic for coordinating the switching of charging modes and the control of the charging process, wherein the control logic includes a state machine design and switching rules; S4. Apply high-frequency isolation technology to transmit the control signal during the charging mode switching, and feed back the real-time charging status to the decision module for adjusting the transition time. The decision module dynamically calculates and adjusts the transition time according to a preset algorithm.

[0007] As a further improvement of the technical solution, the method of analyzing and processing the charging state data in S1 to calculate the comprehensive charging state index is as follows: Monitor and analyze the battery voltage in real time, calculate the voltage change rate, and assign a corresponding first score to the voltage status indicator when the voltage change rate is within a preset first range; Monitor and analyze the battery current, calculate the current change rate, and if the current change rate is within a preset second range, give a second score corresponding to the current state indicator; For the battery temperature, the real-time temperature is compared with the preset temperature threshold range. If the temperature is within the normal temperature threshold range, the temperature status indicator is set to the third score; if the temperature exceeds the normal range but is within the abnormal temperature range, the temperature status indicator is adjusted to the fourth score according to the excess value, wherein the fourth score is less than the third score; if the temperature exceeds the abnormal temperature range, a warning score is given to the temperature status indicator, and the temperature abnormality warning mechanism is triggered; The comprehensive charging state index is calculated by weighted summing the scores of the voltage state index, current state index, temperature state index and electrolyte concentration state index.

[0008] As a further improvement of the technical solution, the constant current charging condition in S2 is that the battery voltage is lower than the first threshold and the battery temperature is within a normal range, specifically including: Monitor the voltage and temperature of the battery in real time, compare its voltage with the preset first threshold, and define the normal temperature range as ; When the temperature values ​​detected by at least 80% of the sensors are within the normal temperature range and the battery voltage is lower than the first threshold, the system determines that the constant current charging condition is met and enters the constant current charging mode; During constant current charging, the battery voltage and temperature are continuously monitored in real time. If the battery voltage rises to 90% of the first threshold or more than 20% of the sensors detect temperature values ​​outside the normal temperature range, the early warning mechanism is activated.

[0009] As a further improvement of the technical solution, when the comprehensive charging state indicator in S2 meets the switching condition, the method for switching from the constant current charging mode to the constant voltage charging mode is as follows: Define the battery voltage upper threshold as , and set a voltage warning range When the real-time monitored battery voltage enters the warning range, it is determined that the battery voltage reaches the upper limit voltage value, where The value of 5%; At the same time, the charging current is monitored in real time. When the current drops to 30% of the current constant current charging value, the current drop condition is met, and in the continuous When the battery voltage is within the voltage warning range and the current drops to a satisfactory condition within a sampling period, it is determined that the switching condition for switching from the constant current charging mode to the constant voltage charging mode is satisfied.

[0010] As a further improvement of the technical solution, after the switching condition is met, the system performs the following operations: Start the preset buffer time During the buffer time, the battery voltage and current are continuously monitored. If the battery voltage exceeds the voltage warning range during this period, the switching operation is suspended, the constant current charging mode is maintained, and the condition judgment is performed again; If the battery voltage is within the voltage warning range and the current drops to meet the conditions within the buffer time, the mode is switched according to the preset transition algorithm and control logic.

[0011] As a further improvement of the technical solution, the transition algorithm is based on a linear interpolation algorithm, which is as follows: When switching from constant current charging mode to constant voltage charging mode, the current in the constant current charging stage is set to , the initial target current in the constant voltage charging phase is , the switching time point is , the scheduled transition time is , during the transition period, for any time , use linear interpolation to calculate the current value ,Right now: ; At the same time, the voltage is linearly interpolated, and the final voltage of the constant current charging stage is set to , the target voltage in the constant voltage charging phase is , then the voltage The calculation formula is: ; The transition time Dynamic adjustment can be performed through high frequency isolation technology.

[0012] As a further improvement of the technical solution, the control logic in S3 is as follows: Three charging states are defined, namely, constant current charging state, constant voltage charging state and mode switching transition state. The system is initially in constant current charging state. When the switching conditions are met, it enters mode switching transition state, and enters constant voltage charging state after the transition is completed. Conversely, if the grid voltage increases or decreases by 10% during the constant voltage charging process, it first enters mode switching transition state from constant voltage charging state, and then returns to constant current charging state. The condition for entering the constant current charging state is that the battery is initially connected and the charging demand is started, and the battery voltage is lower than the preset threshold for starting constant voltage charging. The condition for exiting the constant current charging state and entering the mode switching transition state is that the battery voltage reaches the set upper limit voltage value and the current drops to 30% of the constant current charging value. The condition for entering the constant voltage charging state is the successful completion of the mode switching transition. The condition for exiting the constant voltage charging state is that the charging is completed and the battery temperature exceeds the abnormal temperature range; At the beginning of the transition, the charging current is proportionally reduced and the charging voltage is proportionally increased at the same time, and adjustments are made at fixed time intervals until the current and voltage reach the initial set values ​​of the constant voltage charging mode.

[0013] As a further improvement of the technical solution, the method of dynamically calculating and adjusting the transition time according to a preset algorithm in S4 specifically includes: Define voltage change threshold, current drop threshold, initial transition time, voltage change rate, and current drop ratio; During the transition process, the battery voltage change rate and current drop ratio are continuously monitored. When the voltage change rate is greater than the voltage change threshold and the current drop ratio is less than the current drop threshold, the conditions for triggering the transition time adjustment mechanism are met, and the next step is to calculate the new transition time. The voltage change rate weight factor, the current drop ratio weight factor and the adjustment coefficient are calculated, and a new transition time is calculated based on the adjustment coefficient and the initial transition time.

[0014] Compared with the prior art, the present invention has the following beneficial effects: In the flow battery charging state monitoring method based on high-frequency isolation technology, the high-frequency isolation module is arranged between the control module and the power regulation module to transmit the control signal, effectively isolating interference factors such as external complex electromagnetic fields and mutual influence between electrical equipment, ensuring that the control signal can be transmitted accurately and without error. At the same time, the real-time charging state is fed back to the control module for adjusting the transition time. The control module dynamically calculates and adjusts the transition time according to the preset algorithm and the feedback information, which enables the charging mode switching process to better adapt to the actual state of the battery, avoids inaccurate transition time caused by external interference, reduces energy loss caused by untimely or unreasonable mode switching, and thus improves charging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the overall workflow diagram of the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] Traditional charging methods often lack the ability to accurately monitor and dynamically adjust the charging status, and are unable to automatically optimize the charging mode according to the real-time status of the battery, which can easily lead to problems such as low charging efficiency, overcharging or undercharging, thereby affecting the battery life and performance. At the same time, during the charging process, external interference will affect the accuracy and stability of the charging control signal, resulting in untimely switching of the charging mode, further reducing the charging effect.

[0018] The charging state of a flow battery is a complex process that is affected by the combined effects of battery voltage, current, and temperature. Therefore, these parameters need to be monitored simultaneously to fully understand the battery’s charging state.

[0019] In order to obtain real-time feedback of the charging status, the transition time is dynamically calculated and adjusted according to the charging status, so that the charging mode switching is more suitable for the battery, and the charging mode switching process can better adapt to the actual state of the battery, avoiding inaccurate transition time caused by external interference, reducing energy loss caused by untimely or unreasonable mode switching, thereby improving charging efficiency.

[0020] The following provides a method for monitoring the charging status of flow batteries based on high-frequency isolation technology. Figure 1 As shown, the following steps are included: S1. Real-time monitoring of charging status data of the flow battery by sensors, wherein the charging status data includes battery voltage, current, temperature and electrolyte concentration, and the charging status data is analyzed and processed to calculate a comprehensive charging status index; Each individual parameter can only reflect one aspect of the battery charging state. In order to more accurately evaluate the overall charging state, these parameters need to be considered comprehensively. By assigning scores to different parameters and weighted summing them, the influence of each parameter can be quantified and integrated to obtain an indicator that can comprehensively reflect the battery charging state. A voltage change rate within a certain range may indicate that the battery is in a normal charging stage, while a voltage change rate outside the range may mean that the battery is nearly fully charged or abnormal. Therefore, different scores and threshold ranges are set based on these characteristics to more accurately determine the battery charging status. In S1, the method for analyzing and processing the charging status data and calculating the comprehensive charging status index is as follows: Real-time monitoring and analysis of battery voltage and calculation of voltage change rate can capture the changing trend of battery voltage over time. When the voltage change rate is within a preset first range, a corresponding first score is assigned to the voltage status indicator, thereby realizing a quantitative evaluation of the battery voltage status. Monitor and analyze the battery current, calculate the current change rate, and if the current change rate is within a preset second range, give a second score corresponding to the current state indicator; For the battery temperature, the real-time temperature is compared with the preset temperature threshold range. If the temperature is within the normal temperature threshold range, the temperature status indicator is set to the third score; if the temperature exceeds the normal range but is within the abnormal temperature range, the temperature status indicator is adjusted to the fourth score according to the excess value, wherein the fourth score is less than the third score; if the temperature exceeds the abnormal temperature range, a warning score is given to the temperature status indicator, and the temperature abnormality warning mechanism is triggered; By setting different temperature threshold ranges and assigning different scores according to the temperature range, a more detailed assessment of the battery temperature status can be achieved. The charging system can adjust the charging parameters in real time. When the temperature exceeds the abnormal temperature range, the early warning mechanism is triggered, which can promptly notify the operator or automatically start the corresponding protection measures, thereby extending the battery life.

[0021] The comprehensive charging state index is calculated by weighted summing the scores of the voltage state index, current state index, temperature state index and electrolyte concentration state index.

[0022] S2. Automatically switch between constant current charging mode and constant voltage charging mode according to the comprehensive charging state index. When the comprehensive charging state index meets the constant current charging condition, enter the constant current charging mode. When the comprehensive charging state index meets the switching condition, switch from the constant current charging mode to the constant voltage charging mode. In the process of mode switching, a transition algorithm is used to adjust the charging current and voltage. Battery voltage and temperature are two key factors that affect the battery charging process. In the early stage of charging, when the battery voltage is low and the temperature is relatively stable, the constant current charging mode can charge the battery quickly while preventing the battery from being damaged by excessive voltage or temperature. The constant current charging condition in S2 is that the battery voltage is lower than the first threshold and the battery temperature is within the normal range, specifically including: Use multiple sensors to monitor the voltage and temperature of the battery in real time, compare its voltage with a preset first threshold, and for temperature, determine the temperature value detected by each sensor and judge whether it is within the normal temperature range, and define the normal temperature range as ; When the temperature values ​​detected by at least 80% of the temperature sensors are within the normal temperature range and the battery voltage is lower than the first threshold, the system determines that the constant current charging conditions are met and enters the constant current charging mode. Fast charging can be performed in the initial stage when the battery voltage is low. The requirement that at least 80% of the temperature values ​​detected by the temperature sensors are within the normal range is to avoid the error or abnormality of individual sensors from having too much impact on the overall judgment. The majority principle can improve the accuracy and reliability of the judgment. During constant current charging, the battery voltage and temperature are continuously monitored in real time. If the battery voltage rises to 90% of the first threshold or more than 20% of the sensors detect that the temperature value exceeds the normal temperature range, the early warning mechanism is activated to avoid overcharging and overheating, which can reduce the imbalance of chemical reactions and physical damage inside the battery, thereby extending the battery life; During the charging process of the flow battery, as charging progresses, the battery voltage gradually increases and the current gradually decreases. When the battery voltage is close to being fully charged, in order to avoid overcharging, it is necessary to switch to constant voltage charging mode to maintain the battery voltage stable at an appropriate value. At the same time, the current will further drop to a lower value to ensure that the battery can be charged safely and fully.

[0023] When the comprehensive charging status indicator in S2 meets the switching condition, the method of switching from the constant current charging mode to the constant voltage charging mode is as follows: Define the battery voltage upper threshold as , and set a voltage warning range When the real-time monitored battery voltage enters the warning range, it is determined that the battery voltage reaches the upper limit voltage value, where The value of 5%; By setting the voltage warning range and current drop conditions, the battery can be accurately detected when it is close to full charge, so that the charging mode can be switched in time. At the same time, the charging current is monitored in real time. When the current drops to 30% of the current constant current charging value, the current drop condition is met, and in the continuous In order to avoid misjudgment due to data fluctuations or momentary anomalies within a sampling cycle, when the battery voltage is within the voltage warning range and the current drops to meet the conditions, it is determined that the switching conditions from the constant current charging mode to the constant voltage charging mode are met. The charging mode is reasonably adjusted according to the real-time status of the battery without manual intervention, which improves the automation and intelligence level of the charging process. After the switching conditions are met, the system performs the following operations: Start the preset buffer time , in order to provide an observation and confirmation stage before the formal switching, it is more accurate to judge whether the battery status is really suitable for mode switching, which avoids erroneous switching caused by instantaneous data fluctuations or abnormal conditions, and improves the accuracy of switching decisions. During the buffer time, the battery voltage and current are continuously monitored once a second. If the battery voltage exceeds the voltage warning range during this period, the switching operation is suspended, and the battery voltage is checked again to see if it enters the voltage warning range and whether the current drops to meet the conditions. Only when these conditions are met again and the battery voltage remains stable within the new buffer time, the mode switching will be reconsidered, which helps to maintain the stability of the system and will not cause unstable current and voltage fluctuations in the charging system due to unreasonable switching, ensuring the stable operation of the system in complex environments; If the battery voltage is within the voltage warning range and the current drops to meet the conditions during the buffer time, the battery voltage and current may be affected by a variety of factors. Through further monitoring and judgment during the buffer time, the switching strategy can be flexibly adjusted according to the actual state of the battery to ensure the rationality of the charging mode switching. The mode switching is performed according to the preset transition algorithm and control logic. The transition algorithm is based on the linear interpolation method and is used to achieve a smooth transition between the constant current charging mode and the constant voltage charging mode. The control logic includes the adjustment rules for the charging current and voltage, as well as the coordination and management of the entire switching process. The linear interpolation algorithm can provide a smooth transition between constant current charging mode and constant voltage charging mode. By gradually changing the current and voltage values, it avoids the sudden change of current and voltage at the moment of mode switching, which may damage the battery and affect the battery life and performance. The transition algorithm is based on a linear interpolation algorithm, as follows: When switching from constant current charging mode to constant voltage charging mode, the current in the constant current charging stage is set to , the initial target current in the constant voltage charging phase is , the switching time point is , the scheduled transition time is , in the process of switching from constant current charging mode to constant voltage charging mode, continuous real-time monitoring time , for any time , use linear interpolation to calculate the current value ,Right now: ; At each sampling moment , Substitute the known parameter values ​​into the formula to calculate the corresponding current value. Smooth current and voltage transitions can reduce the impact on the internal structure of the battery and avoid polarization and damage to the battery electrodes due to instantaneous high current or high voltage, thereby extending the battery life. At the same time, linear interpolation is performed on the voltage. Suppose the final voltage of the constant current charging stage is , the target voltage in the constant voltage charging phase is , then the voltage The calculation formula is: ; The battery charging status is monitored and fed back in real time through high-frequency isolation technology. The key parameters such as battery voltage and current are collected by high-frequency isolation sensors and transmitted to the control module. The control module determines whether the transition time needs to be adjusted based on the preset algorithm and the real-time status of the battery. When the battery voltage change rate exceeds the set threshold or the current drop rate is less than the current drop threshold, the transition time is recalculated. , where the transition time Can be dynamically adjusted through high-frequency isolation technology; Since the transition time can be adjusted dynamically, the algorithm can adapt to different types of flow batteries and various charging environments. Whether it is a new battery model or charging under different environmental conditions such as temperature and humidity, a good charging mode switching effect can be achieved by dynamically adjusting the transition time. This charging mode switching method based on linear interpolation algorithm and dynamic adjustment combined with high-frequency isolation technology reflects the intelligence of the charging process. It can automatically adjust the charging mode and transition time according to the real-time status of the battery without manual intervention, thus improving the automation and intelligence level of the charging process. The method of dynamically calculating and adjusting the transition time includes: Define voltage change threshold , Current drop threshold , initial transition time , voltage change rate And the current drop ratio , which can control the charging process more accurately. These thresholds and coefficients are set based on the characteristics of the battery and the charging requirements. In this way, the transition time can be flexibly adjusted according to the actual performance of the battery at different stages, avoiding the charging mode switching too early or too late, thereby improving the charging efficiency and battery life; The voltage change threshold It is 5% of the rated voltage of the battery. When the current drops to 30% of the constant current charging value, the current drop condition is met, that is, , which can make the charging process more in line with the actual charging needs of the battery, and the initial transition time The default transition time set when switching to charging mode, the voltage change rate In order to obtain the value by monitoring the battery voltage in real time and calculating the voltage change per unit time, ; The current drop ratio is calculated by the ratio of the current current value to the constant current charging value; During the transition from constant current charging mode to constant voltage charging mode, the battery voltage change rate and current drop ratio are continuously monitored once per second. and When the conditions for triggering the transition time adjustment mechanism are met, the next step is to calculate the new transition time. Reasonable adjustment of the transition time helps to avoid excessive impact on the battery during the charging mode switching process and reduce the damage to the internal structure of the battery caused by instantaneous current or voltage changes; Calculate the voltage change rate weight factor The voltage change rate weight factor is used to measure the influence of the voltage change rate on the transition time adjustment. When the voltage change rate is twice the threshold, it means that the voltage change is large, which has a greater impact on the adjustment of the transition time. The value will make the effect of the voltage change rate more significant when calculating the adjustment factor; Current drop ratio weight factor The current drop ratio weight factor reflects the effect of the current drop degree on the transition time adjustment. ; When the current drops to half of the constant current charging value, , indicating that the current drop is moderate, which has a certain impact on the transition time. The value of will reflect the influence of the current drop when calculating the adjustment factor. When it is larger, the influence of the current drop degree on the k value will be more obvious when the effects of the voltage change rate and the current drop ratio on the transition time adjustment are comprehensively considered; Adjustment factor , ;in is the weight coefficient, and the new transition time is calculated based on the adjustment coefficient and the initial transition time , ;when hour, , indicating no adjustment, which means that the battery voltage change rate and current drop ratio have not reached the level where the transition time needs to be adjusted. The charging mode can be switched according to the initially set transition time. hour, , indicating that the transition is completed immediately.

[0024] S3. Designing control logic for coordinating the switching of charging modes and the control of the charging process, wherein the control logic includes a state machine design and switching rules; During the charging process of a flow battery, its voltage and current will change as the charging progresses. Defining different charging states and performing state transitions based on changes in battery voltage and current can better adapt to the battery's charging characteristics and ensure the rationality and effectiveness of the charging process; The control logic in S3 is as follows: Three charging states are defined, namely, constant current charging state, constant voltage charging state and mode switching transition state. When the battery is initially connected and the charging demand is started, the control module checks whether the battery voltage is lower than the preset threshold for starting constant voltage charging. If the condition is met, the system enters the constant current charging state; During the constant current charging process, the battery voltage and current are continuously monitored. When the battery voltage reaches the set upper voltage limit and the current drops to 30% of the constant current charging value, the exit condition is determined to be met and the system enters the mode switching transition state. When the mode switching transition is successfully completed, that is, the current and voltage reach the initial setting value of the constant voltage charging mode, the system enters the constant voltage charging state. During the constant voltage charging process, the battery temperature and charging completion status are continuously monitored. When charging is completed or the battery temperature exceeds the abnormal temperature range, the system exits the constant voltage charging state; Through reasonable charging state conversion and smooth mode switching, the impact on the battery can be reduced, and the damage to the internal structure of the battery caused by unreasonable charging mode or sudden current and voltage changes can be avoided, thereby extending the battery life; At the beginning of the transition, the voltage and current are adjusted according to the preset ratio of 5% current reduction and 3% voltage increase every 1 second, and the adjustments are made at fixed time intervals until the current and voltage reach the initial set values ​​of the constant voltage charging mode. This control logic can ensure the stability and reliability of the charging process, reduce the current and voltage fluctuations during the charging process, thereby improving the stability and reliability of the energy storage system and reducing the risk of system failure.

[0025] S4. Apply high-frequency isolation technology to transmit the control signal during the charging mode switching, and feed back the real-time charging status to the decision module for adjusting the transition time. The decision module dynamically calculates and adjusts the transition time according to a preset algorithm.

[0026] The above-mentioned flow battery charging state monitoring method based on high-frequency isolation technology first monitors the battery voltage, current, temperature and electrolyte concentration through sensors, analyzes and processes to obtain a comprehensive charging state index, and automatically switches between constant current and constant voltage charging modes based on the index. Constant current charging requires the battery voltage to be lower than the first threshold and the temperature to be normal. Switching to constant voltage charging requires that the voltage and current conditions are met. The mode switching uses a linear interpolation algorithm to adjust the current and voltage, and the transition time can be dynamically adjusted. At the same time, the control logic is designed, and three charging states and conversion conditions are defined. The present invention also involves related systems, including sensors, controls, power regulation and high-frequency isolation modules. This method improves charging efficiency and battery life and enhances system stability.

[0027] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for monitoring the charging state of a flow battery based on high-frequency isolation technology, characterized in that: The following steps are involved: S1. Real-time monitoring of charging status data of the flow battery by sensors, wherein the charging status data includes battery voltage, current, temperature and electrolyte concentration, and the charging status data is analyzed and processed to calculate a comprehensive charging status index; S2. Automatically switch between constant current charging mode and constant voltage charging mode according to the comprehensive charging state index. When the comprehensive charging state index meets the constant current charging condition, enter the constant current charging mode. When the comprehensive charging state index meets the switching condition, switch from the constant current charging mode to the constant voltage charging mode. In the process of mode switching, a transition algorithm is used to adjust the charging current and voltage. S3. Designing control logic for coordinating the switching of charging modes and the control of the charging process, wherein the control logic includes a state machine design and switching rules; S4. Apply high-frequency isolation technology to transmit the control signal during the charging mode switching, and feed back the real-time charging status to the decision module for adjusting the transition time. The decision module dynamically calculates and adjusts the transition time according to a preset algorithm.

2. The method for monitoring the charging state of a flow battery based on high frequency isolation technology according to claim 1, characterized in that: The method for analyzing and processing the charging state data in S1 to calculate the comprehensive charging state index is as follows: Monitor and analyze the battery voltage in real time, calculate the voltage change rate, and assign a corresponding first score to the voltage status indicator when the voltage change rate is within a preset first range; Monitor and analyze the battery current, calculate the current change rate, and if the current change rate is within a preset second range, give a second score corresponding to the current state indicator; For the battery temperature, the real-time temperature is compared with the preset temperature threshold range. If the temperature is within the normal temperature threshold range, the temperature status indicator is set to the third score; if the temperature exceeds the normal range but is within the abnormal temperature range, the temperature status indicator is adjusted to the fourth score according to the excess value, wherein the fourth score is less than the third score; if the temperature exceeds the abnormal temperature range, a warning score is given to the temperature status indicator, and the temperature abnormality warning mechanism is triggered; The comprehensive charging state index is calculated by weighted summing the scores of the voltage state index, current state index, temperature state index and electrolyte concentration state index.

3. The method for monitoring the charging state of a flow battery based on high frequency isolation technology according to claim 1, characterized in that: The constant current charging condition in S2 is that the battery voltage is lower than the first threshold and the battery temperature is within the normal range, specifically including: Monitor the voltage and temperature of the battery in real time, compare its voltage with the preset first threshold, and define the normal temperature range as ; When the temperature values ​​detected by at least 80% of the sensors are within the normal temperature range and the battery voltage is lower than the first threshold, the system determines that the constant current charging condition is met and enters the constant current charging mode; During constant current charging, the battery voltage and temperature are continuously monitored in real time. If the battery voltage rises to 90% of the first threshold or more than 20% of the sensors detect temperature values ​​outside the normal temperature range, the early warning mechanism is activated.

4. The method for monitoring the charging state of a flow battery based on high frequency isolation technology according to claim 1, characterized in that: When the comprehensive charging state indicator in S2 meets the switching condition, the method for switching from the constant current charging mode to the constant voltage charging mode is as follows: Define the battery voltage upper threshold as , and set a voltage warning range When the real-time monitored battery voltage enters the warning range, it is determined that the battery voltage reaches the upper limit voltage value, where The value of 5%; At the same time, the charging current is monitored in real time. When the current drops to 30% of the current constant current charging value, the current drop condition is met, and in the continuous When the battery voltage is within the voltage warning range and the current drops to a satisfactory condition within a sampling period, it is determined that the switching condition for switching from the constant current charging mode to the constant voltage charging mode is satisfied.

5. The method for monitoring the charging state of a flow battery based on high frequency isolation technology according to claim 4 is characterized in that: After the switching conditions are met, the system performs the following operations: Start the preset buffer time During the buffer time, the battery voltage and current are continuously monitored. If the battery voltage exceeds the voltage warning range during this period, the switching operation is suspended, the constant current charging mode is maintained, and the condition judgment is performed again; If the battery voltage is within the voltage warning range and the current drops to meet the conditions within the buffer time, the mode is switched according to the preset transition algorithm and control logic.

6. The method for monitoring the charging state of a flow battery based on high frequency isolation technology according to claim 5, characterized in that: The transition algorithm is based on a linear interpolation algorithm, as follows: When switching from constant current charging mode to constant voltage charging mode, the current in the constant current charging stage is set to , the initial target current in the constant voltage charging phase is , the switching time point is , the scheduled transition time is , during the transition period, for any time , use linear interpolation to calculate the current value ,Right now: ； At the same time, the voltage is linearly interpolated, and the final voltage of the constant current charging stage is set to , the target voltage in the constant voltage charging phase is , then the voltage The calculation formula is: ； The transition time Dynamic adjustment can be performed through high frequency isolation technology.

7. The method for monitoring the charging state of a flow battery based on high frequency isolation technology according to claim 1, characterized in that: The control logic in S3 is as follows: Three charging states are defined, namely, constant current charging state, constant voltage charging state and mode switching transition state. The system is initially in constant current charging state. When the switching conditions are met, it enters mode switching transition state, and enters constant voltage charging state after the transition is completed. Conversely, if the grid voltage increases or decreases by 10% during the constant voltage charging process, it first enters mode switching transition state from constant voltage charging state, and then returns to constant current charging state. The condition for entering the constant current charging state is that the battery is initially connected and the charging demand is started, and the battery voltage is lower than the preset threshold for starting constant voltage charging. The condition for exiting the constant current charging state and entering the mode switching transition state is that the battery voltage reaches the set upper limit voltage value and the current drops to 30% of the constant current charging value. The condition for entering the constant voltage charging state is the successful completion of the mode switching transition. The condition for exiting the constant voltage charging state is that the charging is completed and the battery temperature exceeds the abnormal temperature range; At the beginning of the transition, the charging current is proportionally reduced and the charging voltage is proportionally increased at the same time, and adjustments are made at fixed time intervals until the current and voltage reach the initial set values ​​of the constant voltage charging mode.

8. The method for monitoring the charging state of a flow battery based on high frequency isolation technology according to claim 1, characterized in that: The method of dynamically calculating and adjusting the transition time according to the preset algorithm in S4 specifically includes: Define voltage change threshold, current drop threshold, initial transition time, voltage change rate, and current drop ratio; During the transition process, the battery voltage change rate and current drop ratio are continuously monitored. When the voltage change rate is greater than the voltage change threshold and the current drop ratio is less than the current drop threshold, the conditions for triggering the transition time adjustment mechanism are met, and the next step is to calculate the new transition time. The voltage change rate weight factor, the current drop ratio weight factor and the adjustment coefficient are calculated, and a new transition time is calculated based on the adjustment coefficient and the initial transition time.

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