A liquid flow battery energy storage system and control method for electric vehicles

Abstract

The present invention belongs to the technical field of liquid flow battery management, and relates to a liquid flow battery energy storage system and control method on an electric vehicle. The system specifically matches the reference flow rate of the liquid flow battery electrolyte by confirming the current driving state of the target electric vehicle and its response power demand, and corrects it in combination with the safety and effectiveness angles to ensure that the liquid flow battery system can provide the most optimally adapted energy output under safe and stable working conditions. Then, the speed of the built-in circulation pump of the liquid flow battery and the opening and closing degree of the valve are regulated to achieve accurate allocation of the response flow rate of the liquid flow battery electrolyte, and additionally perform capacity recovery operations in the deceleration state to improve the energy utilization efficiency of the electric vehicle. In addition, by identifying whether the built-in liquid storage tank of the current liquid flow battery of the target electric vehicle has excessive liquid height, insufficient liquid height or liquid leakage, corresponding safety processing is performed in a timely manner to ensure the safe and efficient operation of the liquid flow battery system.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid flow battery management, and in particular, relates to a liquid flow battery energy storage system and a control method for an electric vehicle. Background Art

[0002] As an advanced energy storage technology, liquid flow battery works by storing and releasing electrical energy through redox reactions of active substances in the positive and negative electrolytes in the battery stack. As a result, liquid flow batteries have significant advantages in energy density, cycle life, charge and discharge rates, and safety. Especially in the application scenarios of electric vehicles, liquid flow battery energy storage systems can not only significantly improve the cruising range of electric vehicles, but also improve the overall performance and economy of electric vehicles.

[0003] However, in the application scenarios of electric vehicles, the energy storage operation and management of existing flow batteries still have a series of limitations, specifically: 1. The application of existing flow battery energy storage systems has a cognitive limitation, that is, they are too rigidly focused on the literal meaning of charging energy storage, and fail to fully grasp the core value of the dual roles of charging and releasing energy in the application scenarios of electric vehicles. As a result, the flow battery energy storage system lacks a comprehensive, detailed and effective solution in actual applications to fully tap its energy supply potential, limiting the driving performance and user experience of electric vehicles.

[0004] 2. The energy supply power of flow batteries for electric vehicles mainly depends on the internal electrolyte flow rate. Although some existing flow battery energy storage operation management involves energy supply analysis for electric vehicles, the regulation of flow battery electrolyte flow mainly refers to the characteristic curve of technical specifications, and fails to effectively combine the actual internal operation of the flow battery to accurately control the electrolyte flow, resulting in the flow battery's response electrolyte flow not matching when the electric vehicle is driving, affecting the driving experience of the electric vehicle.

[0005] 3. The existing liquid flow battery energy storage operation management lacks an identification mechanism for abnormal liquid level in the liquid storage tank inside the liquid flow battery, which has an adverse impact on the performance and safety of the liquid flow battery. Summary of the invention

[0006] In view of this, in order to solve the problems raised in the above background technology, a liquid flow battery energy storage system and a control method for an electric vehicle are proposed.

[0007] The technical solution adopted by the present invention to solve its technical problems is: in the first aspect, the present invention provides a liquid flow battery energy storage system on an electric vehicle, including: a driving status confirmation module, a reference flow matching module, a response flow acquisition module, a response flow distribution module, a liquid level safety management module and a cloud database.

[0008] The driving status confirmation module is connected to the reference flow matching module, the reference flow matching module is connected to the response flow acquisition module, the response flow acquisition module is connected to the response flow allocation module, the response flow allocation module is connected to the liquid level safety management module, and the cloud database is respectively connected to the driving status confirmation module, the reference flow matching module, and the response flow allocation module.

[0009] The driving state confirmation module is used to confirm the current driving state of the target electric vehicle and its response power demand, wherein the driving state includes acceleration state, constant speed state and deceleration state.

[0010] The reference flow matching module is used to extract the target electric vehicle liquid flow battery electrolyte flow-power characteristic curve pre-stored in the cloud database, and match the reference flow of the corresponding liquid flow battery electrolyte according to the response power demand of the current driving state of the target electric vehicle. .

[0011] The response flow acquisition module is used to collect the current internal operating state of the liquid flow battery of the target electric vehicle, correct the reference flow rate of the liquid flow battery electrolyte matching the current driving state of the target electric vehicle, and obtain the response flow rate of the liquid flow battery electrolyte corresponding to the current driving state of the target electric vehicle.

[0012] The responsive flow allocation module is used to achieve responsive flow allocation of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle by regulating the speed of the built-in circulation pump of the flow battery and the opening and closing degree of the valve. If the current driving state is a deceleration state, an additional energy recovery operation is performed.

[0013] The liquid level safety management module is used to identify whether there is abnormal liquid level performance in the built-in liquid storage tank of the current liquid flow battery of the target electric vehicle, including liquid high exceeding the limit, liquid low exceeding the limit and liquid leakage. If it is identified, the corresponding safety processing is performed.

[0014] The cloud database is used to store the electrolyte flow-power characteristic curve of the target electric vehicle liquid flow battery, store the basic configuration data of the target electric vehicle, store the preset characteristic change curve of the electrolyte flow rate of the target electric vehicle liquid flow battery relative to the speed of the built-in circulation pump based on the opening and closing degrees of the built-in valve, and store the preset characteristic change curve of the electrolyte flow rate of the target electric vehicle liquid flow battery relative to the opening and closing degree of the built-in valve based on the speed of the built-in circulation pump.

[0015] In a second aspect, the present invention provides a method for controlling energy storage of a liquid flow battery on an electric vehicle, comprising: S1. confirming the current driving state of the target electric vehicle and its response power demand, wherein the driving state includes an acceleration state, a constant speed state and a deceleration state.

[0016] S2. Extract the target electric vehicle liquid flow battery electrolyte flow-power characteristic curve pre-stored in the cloud database, and match the reference flow rate of the corresponding liquid flow battery electrolyte according to the response power demand of the current driving state of the target electric vehicle.

[0017] S3. Collect the current internal operating state of the flow battery of the target electric vehicle, correct the reference flow rate of the flow battery electrolyte to match the current driving state of the target electric vehicle, and obtain the response flow rate of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle.

[0018] S4. By regulating the speed of the built-in circulation pump of the liquid flow battery and the opening and closing degree of the valve, the response flow distribution of the liquid flow battery electrolyte corresponding to the current driving state of the target electric vehicle is achieved. If the current driving state is a deceleration state, an additional energy recovery operation is performed.

[0019] S5. Identify whether there is abnormal liquid level in the built-in liquid storage tank of the current liquid flow battery of the target electric vehicle, including liquid high exceeding the limit, liquid low exceeding the limit and liquid leakage. If it is identified, perform corresponding safety processing.

[0020] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: (1) The present invention confirms the current driving state of the target electric vehicle and its response power demand, and specifically matches the corresponding reference flow rate of the flow battery electrolyte, thereby ensuring that the flow battery system can provide appropriate energy output under any operating conditions to meet the power requirements of the electric vehicle.

[0021] (2) The present invention corrects the reference flow rate of the liquid flow battery electrolyte that matches the current driving state of the target electric vehicle from the perspective of safety and effectiveness. When the liquid flow battery is operating safely and with high power matching, the response flow rate of the liquid flow battery electrolyte corresponding to the current driving state of the target electric vehicle is confirmed, thereby ensuring that the liquid flow battery exerts the best power supply performance.

[0022] (3) The present invention controls the rotation speed of the built-in circulation pump of the liquid flow battery and the opening and closing degree of the valve to achieve the responsive flow distribution of the liquid flow battery electrolyte corresponding to the current driving state of the target electric vehicle, thereby ensuring the optimal working state of the liquid flow battery, which not only reduces energy waste but also improves the energy efficiency of the overall system.

[0023] (4) The present invention enables energy recovery operation when the current driving state of the target electric vehicle is a deceleration state, thereby significantly improving energy utilization efficiency and thereby extending the cruising range of the electric vehicle.

[0024] (5) The present invention identifies whether the built-in liquid storage tank of the target electric vehicle's current liquid flow battery has three abnormal liquid level manifestations, namely, liquid over-limit, liquid under-limit, or liquid leakage, and performs corresponding safety processing to keep the electrolyte within a suitable and safe liquid level range, which helps to maintain a stable working environment inside the liquid flow battery and improve the working efficiency and performance stability of the liquid flow battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0026] Figure 1 It is a schematic diagram of module connection of the present invention.

[0027] Figure 2 The figure is a flow chart of the method of the present invention.

[0028] Figure 3 This is a schematic diagram of the reference structure of the electric vehicle of the present invention. DETAILED DESCRIPTION

[0029] 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.

[0030] Reference Figure 1 , 3 As shown, the first aspect of the present invention provides a liquid flow battery energy storage system on an electric vehicle, including: a driving state confirmation module, a reference flow matching module, a response flow acquisition module, a response flow distribution module, a liquid level safety management module and a cloud database.

[0031] The driving status confirmation module is connected to the reference flow matching module, the reference flow matching module is connected to the response flow acquisition module, the response flow acquisition module is connected to the response flow allocation module, the response flow allocation module is connected to the liquid level safety management module, and the cloud database is respectively connected to the driving status confirmation module, the reference flow matching module, and the response flow allocation module.

[0032] The driving state confirmation module is used to confirm the current driving state of the target electric vehicle and its response power demand, wherein the driving state includes an acceleration state, a constant speed state and a deceleration state.

[0033] Specifically, the confirmation of the current driving state of the target electric vehicle and its response power demand includes: sensing the current speed of the vehicle through the onboard sensor of the target electric vehicle; and acceleration , compare the current vehicle acceleration with the preset fluctuation range of the vehicle's uniform speed acceleration. If it is greater than the upper limit of the interval, it is confirmed that the current driving state of the target electric vehicle is an accelerating state. If it is less than the lower limit of the interval, it is confirmed that the current driving state of the target electric vehicle is a decelerating state. If it is within the interval, it is confirmed that the current driving state of the target electric vehicle is a uniform speed state.

[0034] Extract the target electric vehicle basic configuration data stored in the cloud database, including weight , orthographic projection area and basic accessory power , combined with the current speed and acceleration of the target electric vehicle, calculate the current rolling resistance power of the target electric vehicle , air resistance power and inertial power ,Will , , , The power requirement of the target electric vehicle in the current driving state is confirmed by accumulation.

[0035] It should be noted that the above-mentioned preset fluctuation range of the vehicle's uniform acceleration state mainly refers to the acceleration measurement accuracy range specified in the technical specifications of the target electric vehicle's on-board sensor, and the upper and lower limits of this range are used as the upper and lower limits of the preset fluctuation range of the vehicle's uniform acceleration state.

[0036] For example, if the technical specification of the target electric vehicle onboard sensor specifies the acceleration measurement accuracy range of , then the preset fluctuation range of the vehicle's uniform acceleration is set to , the interval units are .

[0037] It should also be noted that the calculation formulas for the current rolling resistance power, air resistance power and inertia power of the above-mentioned target electric vehicle are: , , ,in They are the preset rolling resistance coefficient and air resistance coefficient, is the preset gravity acceleration, is the preset air density.

[0038] The reference flow matching module is used to extract the target electric vehicle liquid flow battery electrolyte flow-power characteristic curve pre-stored in the cloud database, and match the reference flow of the corresponding liquid flow battery electrolyte according to the response power demand of the current driving state of the target electric vehicle. .

[0039] The embodiment of the present invention confirms the current driving state of the target electric vehicle and its response power demand, and specifically matches the corresponding reference flow rate of the flow battery electrolyte, thereby ensuring that the flow battery system can provide appropriate energy output under any operating conditions to meet the power demand of the electric vehicle.

[0040] The response flow acquisition module is used to collect the current internal operating state of the liquid flow battery of the target electric vehicle, correct the reference flow rate of the liquid flow battery electrolyte matching the current driving state of the target electric vehicle, and obtain the response flow rate of the liquid flow battery electrolyte corresponding to the current driving state of the target electric vehicle.

[0041] Specifically, the acquisition of the response flow rate of the electrolyte of the flow battery corresponding to the current driving state of the target electric vehicle includes: collecting the current electrolyte temperature value of the flow battery inside the target electric vehicle; and the cone temperature , analyze the predicted temperature value of the electrolyte inside the flow battery when the reference flow rate of the flow battery matching the current driving state of the target electric vehicle is allocated And the predicted temperature value of the electric cone .

[0042] It should be noted that the above , The specific analysis process is as follows: According to the electrolyte heat balance equation ,in , are the mass and preset specific heat capacity of the electrolyte inside the target electric vehicle flow battery, They are the heat of the electrolyte inside the target electric vehicle entering the liquid flow battery, the heat leaving the liquid flow battery, and the heat loss in the liquid flow battery. The calculation formulas are , , , The preset input power of the built-in electric cone of the target electric vehicle flow battery, is the temperature difference of the electrolyte inside the current flow battery of the target electric vehicle, which can be obtained by collecting the electrolyte temperature values ​​of each node of the pipeline inside the current flow battery of the target electric vehicle for comparison, and by calculating the maximum and minimum temperature differences of the electrolyte between the pipeline nodes. In particular, is the calculated mean value of the electrolyte temperature at each node of the internal pipeline of the current flow battery of the target electric vehicle, Rated heat dissipation efficiency of target electric vehicle flow battery radiator.

[0043] Then by the formula Calculate the predicted temperature value of the electrolyte inside the flow battery when allocating the reference flow rate of the flow battery matching the current driving state of the target electric vehicle, It is the preset reaction residence time of the electrolyte in the flow battery stack.

[0044] According to the electric cone heat balance equation ,in , are the mass and preset specific heat capacity of the target electric vehicle flow battery cone, They are the heat generated by the target electric vehicle flow battery cone, the heat taken away by the electrolyte, and the heat lost by radiation. The calculation formulas are The calculation formula is consistent.

[0045] Then by the formula Calculate the predicted temperature value of the electrolyte inside the flow battery when allocating the reference flow rate of the flow battery matching the current driving state of the target electric vehicle, It is the preset reaction residence time of the electrolyte in the flow battery stack.

[0046] For example, if the current electrolyte temperature value of the flow battery in the target electric vehicle is , the preset specific heat capacity of the electrolyte inside the target electric vehicle flow battery , preset density , target electric vehicle current flow battery internal electrolyte command distribution flow liquid flow , the temperature difference of the electrolyte inside the current flow battery of the target electric vehicle , the preset input power of the built-in electric cone of the target electric vehicle flow battery , the target electric vehicle flow battery radiator rated heat dissipation efficiency , the quality of the electrolyte inside the target electric vehicle flow battery , the preset reaction residence time of the electrolyte in the flow battery stack , , , , according to the formula The predicted temperature value of the electrolyte inside the flow battery is obtained when the reference flow rate of the flow battery matching the current driving state of the target electric vehicle is allocated.

[0047] If the mass and preset specific heat capacity of the target electric vehicle flow battery cone are , , the current internal cone temperature of the target electric vehicle flow battery , then by the formula The predicted temperature value of the electric cone inside the flow battery is obtained when the reference flow rate of the flow battery matching the current driving state of the target electric vehicle is allocated.

[0048] Collect the pipeline pressure values ​​of the electrolyte in and out of the electric cone inside the current flow battery of the target electric vehicle, which are recorded as , the predicted pipeline pressure values ​​of the electrolyte in and out of the electric cone inside the flow battery when the reference flow rate of the flow battery matching the current driving state of the target electric vehicle is analyzed and recorded as ,Depend on The difference is the predicted pipeline pressure difference .

[0049] It should be noted that the above The specific analysis process is as follows: according to the current electrolyte command inside the target electric vehicle flow battery, the flow rate is allocated , according to the formula Analyze the flow rate of the electrolyte inside the current flow battery of the target electric vehicle, where is the preset diameter of the internal pipe of the target electric vehicle flow battery, is the ratio of pi, and then by the formula Analyze the pipeline pressure loss of the electrolyte entering and exiting the electric cone inside the current liquid flow battery of the target electric vehicle, including The preset length of the internal pipes of the target electric vehicle flow battery entering and exiting the electric cone, is the preset density of the electrolyte inside the target electric vehicle flow battery, is the friction factor, and its calculation formula is , The preset roughness of the internal pipes of the target electric vehicle flow battery entering and exiting the electric cone, is the preset viscosity of the electrolyte inside the target electric vehicle's flow battery. Similarly, the corresponding predicted electrolyte flow rate is calculated based on the reference flow rate of the flow battery matching the current driving state of the target electric vehicle. and predicted pipeline pressure loss of electrolyte in and out of the cone , according to the formula , The predicted pipeline pressure values ​​of the electrolyte in and out of the electric cone inside the flow battery are obtained when the reference flow rate of the flow battery matching the current driving state of the target electric vehicle is allocated.

[0050] For example, if the current pressure value of the pipeline for the electrolyte entering and exiting the electric cone in the flow battery of the target electric vehicle is , , target electric vehicle current flow battery internal electrolyte command distribution flow liquid flow , the preset length of the internal pipes of the target electric vehicle flow battery entering and exiting the electric cone , preset diameter , preset roughness value 0.0001, preset density of electrolyte inside target electric vehicle flow battery , preset viscosity , calculate the flow rate of the electrolyte inside the current flow battery of the target electric vehicle: , calculate the pipeline pressure loss of the electrolyte entering and exiting the electric cone inside the current liquid flow battery of the target electric vehicle: , and obtain the friction factor , analyze the pipeline pressure loss of the electrolyte entering and exiting the electric cone inside the current liquid flow battery of the target electric vehicle: Similarly, the reference flow rate of the flow battery matched to the current driving state of the target electric vehicle Calculate the corresponding predicted electrolyte flow rate and predicted pipeline pressure loss of electrolyte in and out of the cone , , , and the predicted pipeline pressure value of the electrolyte in and out of the electric cone inside the flow battery when the reference flow rate of the flow battery matching the current driving state of the target electric vehicle is calculated as follows: , .

[0051] calculate , , The deviation degree of the preset reasonable working range is respectively compared with the deviation degree of the preset reasonable working range, so as to analyze the safety correction compensation flow rate corresponding to the reference flow rate of the flow battery electrolyte matching the current driving state of the target electric vehicle .

[0052] It should be noted that the above , , The calculation process of the deviation degree from the preset reasonable working range corresponding to the above is as follows: extract the upper limit and lower limit of the preset reasonable working range of the electrolyte temperature inside the flow battery, if If it is less than the lower limit of its corresponding preset reasonable working range, The difference is made with the lower limit of the preset reasonable working range, and the ratio of the difference to the lower limit of the preset reasonable working range of the electrolyte temperature inside the flow battery is taken as The degree of deviation from the corresponding preset reasonable working range is a negative value at this time, indicating that the predicted temperature value of the electrolyte inside the flow battery is too low when the reference flow rate of the flow battery matching the current driving state of the target electric vehicle is allocated, which may easily cause the electrolyte viscosity to be too high.

[0053] like If it is greater than the upper limit of its corresponding preset reasonable working range, The difference is made with the upper limit value of the corresponding preset reasonable working range, and the ratio of the difference to the upper limit value of the preset reasonable working range of the electrolyte temperature inside the flow battery is taken as The degree of deviation from the corresponding preset reasonable working range, when the degree of deviation is positive, indicates that when the reference flow rate of the flow battery matching the current driving state of the target electric vehicle is allocated, the predicted temperature of the electrolyte inside the flow battery is too high, which may easily lead to the risk of thermal runaway.

[0054] like If it is within the corresponding preset reasonable working range, it will automatically set The degree of deviation from the corresponding preset reasonable working range is 0, indicating that the predicted temperature value of the electrolyte inside the flow battery is normal when the reference flow rate of the flow battery matching the current driving state of the target electric vehicle is allocated.

[0055] Get it from The degree of deviation from the corresponding preset reasonable working range can be calculated in the same way , The degree of deviation from the corresponding preset reasonable working range.

[0056] Collect the command distribution flow of the target electric vehicle flow battery at each unit time point in the current period and the actual flow rate at each node of the internal pipeline of the flow battery , is the number of each unit time point in the current period, , is the number of each node in the internal pipeline of the flow battery, , calculate the validity correction compensation flow rate corresponding to the reference flow rate of the flow battery electrolyte matching the current driving state of the target electric vehicle .

[0057] It should be noted that the above-mentioned current time period specifically refers to a time period with the current time as the end time and a preset length before the current time.

[0058] right , , The accumulation is performed to obtain the response flow rate of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle.

[0059] Specifically, the The calculation formula is: ,in is a natural constant, The internal safety correction factor of the flow battery is the reference flow rate of the flow battery matching the current driving state of the target electric vehicle, and its value is , , The accumulated values ​​of the deviations from the corresponding preset reasonable working ranges.

[0060] Specifically, the The calculation formula is: ,in is the number of unit time points in the current period, is the number of pipeline nodes inside the flow battery.

[0061] The embodiment of the present invention corrects the reference flow rate of the liquid flow battery electrolyte that matches the current driving state of the target electric vehicle from the perspective of safety and effectiveness, respectively, and confirms the response flow rate of the liquid flow battery electrolyte corresponding to the current driving state of the target electric vehicle when the liquid flow battery is operating safely and with high power matching, thereby ensuring that the liquid flow battery exerts the best power supply performance.

[0062] The responsive flow distribution module is used to achieve responsive flow distribution of the electrolyte of the flow battery corresponding to the current driving state of the target electric vehicle by regulating the rotation speed of the built-in circulation pump of the flow battery and the opening and closing degree of the valve, and if the current driving state is a deceleration state, an additional energy recovery operation is performed.

[0063] Specifically, the regulating the rotation speed and valve opening degree of the built-in circulation pump of the flow battery includes: if the current driving state of the target electric vehicle is a uniform speed state, maintaining the current rotation speed and valve opening degree of the built-in circulation pump of the flow battery.

[0064] If the current driving state of the target electric vehicle is an accelerating state, it is confirmed that the unified control direction of the rotation speed of the built-in circulation pump and the valve opening degree of the flow battery is upward, and the preset characteristic change curve of the electrolyte flow rate relative to the rotation speed of the built-in circulation pump based on the current built-in valve opening degree of the target electric vehicle liquid flow battery pre-stored in the cloud database is extracted, and the corresponding matching built-in circulation pump rotation speed of the response flow rate of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle is retrieved. If the speed of the built-in circulation pump reaches the upper limit threshold and still does not meet the response flow rate of the flow battery electrolyte, the preset characteristic change curve of the electrolyte flow rate relative to the opening degree of the built-in valve based on the upper limit threshold of the built-in circulation pump rotation speed of the target electric vehicle liquid flow battery pre-stored in the cloud database is extracted, and the corresponding matching built-in valve opening degree of the response flow rate of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle is retrieved, so as to realize the upward processing of the rotation speed and valve opening degree of the built-in circulation pump of the flow battery in the current acceleration state.

[0065] If the current driving state of the target electric vehicle is a deceleration state, it is confirmed that the unified control direction of the speed of the built-in circulation pump of the flow battery and the valve opening degree is downward, which is consistent with the acceleration state control analysis method, so as to realize the downward adjustment of the speed of the built-in circulation pump of the flow battery and the valve opening degree in the current deceleration state.

[0066] The embodiment of the present invention controls the rotation speed of the built-in circulation pump of the flow battery and the opening and closing degree of the valve to achieve the responsive flow distribution of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle, thereby ensuring the optimal working state of the flow battery, which not only reduces energy waste but also improves the energy efficiency of the overall system.

[0067] Specifically, the specific execution process of the energy recovery operation includes: transitioning the current target electric vehicle motor drive mode to the electric mode, converting the vehicle kinetic energy in the deceleration state into electrical energy, converting it into direct current through the flow battery inverter and storing it in the flow battery, thereby realizing the energy recovery operation.

[0068] The embodiment of the present invention enables energy recovery operation when the current driving state of the target electric vehicle is a deceleration state, which significantly improves energy utilization efficiency and further extends the cruising range of the electric vehicle.

[0069] The liquid level safety management module is used to identify whether there is abnormal liquid level performance in the built-in liquid storage tank of the current liquid flow battery of the target electric vehicle, including liquid high exceeding the limit, liquid low exceeding the limit and liquid leakage. If it is identified, the corresponding safety processing is performed.

[0070] Specifically, the identification of whether there is abnormal liquid level performance in the built-in liquid storage tank of the current liquid flow battery of the target electric vehicle includes: sensing the current liquid level height of the built-in liquid storage tank of the liquid flow battery of the target electric vehicle through a liquid level sensor arranged in the built-in liquid storage tank of the liquid flow battery of the target electric vehicle; if the current liquid level height is greater than or equal to a preset upper limit warning height of the liquid level of the liquid storage tank, then identifying that the current liquid level exceeds the limit; if the current liquid level height is less than or equal to a preset lower limit warning height of the liquid level of the liquid storage tank, then identifying that the current liquid level is below the limit.

[0071] The liquid level height, outlet flow rate and inlet flow rate of the built-in liquid storage tank of the target electric vehicle flow battery at each unit time point in the current period are collected, and the actual liquid level change rate and reasonable liquid level change rate range of the built-in liquid storage tank of the target electric vehicle flow battery at each unit time point in the current period are calculated. The current liquid leakage risk coefficient of the built-in liquid storage tank of the target electric vehicle flow battery is analyzed, and if it is greater than or equal to the preset liquid leakage risk coefficient warning threshold, it is recognized that there is currently a liquid leakage, otherwise it is recognized that there is no liquid leakage.

[0072] It should be noted that the calculation method of the actual liquid level change rate of the built-in liquid storage tank of the target electric vehicle liquid flow battery in the current period at each unit time point is as follows: subtract the liquid level height at each unit time point of the current period of the built-in liquid storage tank of the target electric vehicle liquid flow battery from the previous unit time point to obtain the liquid level change value at each unit time point of the current period of the built-in liquid storage tank of the target electric vehicle liquid flow battery, and further perform a ratio analysis with the liquid level height at the corresponding unit time point to obtain the actual liquid level change rate of the built-in liquid storage tank of the target electric vehicle liquid flow battery in the current period at each unit time point.

[0073] The calculation method of the reasonable liquid level change rate interval of each unit time point in the current period of the above-mentioned target electric vehicle liquid flow battery built-in liquid storage tank is as follows: according to the cross-sectional area of ​​the technical specifications of the target electric vehicle liquid flow battery built-in liquid storage tank , the difference between the inlet and outlet flow rates of the built-in liquid storage tank of the target electric vehicle liquid flow battery at each unit time point in the current period and The ratio of the value of the built-in liquid storage tank of the target electric vehicle flow battery is used as the reasonable liquid level change rate at each unit time point in the current period , so as to obtain the reasonable liquid level change rate interval of each unit time point in the current period of the built-in liquid storage tank of the target electric vehicle liquid flow battery , is the preset error value.

[0074] Specifically, the corresponding safety processing is executed, and the specific execution process includes: if it is identified that the current liquid height exceeds the limit, the built-in liquid storage tank drainage program of the target electric vehicle liquid flow battery is started until the liquid level height is less than the preset upper limit warning height of the liquid storage tank, and the excess electrolyte is transferred to a spare container.

[0075] If it is identified that the liquid level is currently low, the target electric vehicle flow battery built-in liquid storage tank refilling program is started until the liquid level height is greater than the preset lower limit warning height of the liquid storage tank.

[0076] If a liquid leak is detected, an alarm is triggered immediately and emergency braking is applied to the target battery vehicle.

[0077] The embodiment of the present invention identifies whether the built-in liquid storage tank of the current liquid flow battery of the target electric vehicle has three abnormal liquid level manifestations, namely, liquid over-limit, liquid under-limit or liquid leakage, and performs corresponding safety processing to keep the electrolyte within a suitable and safe liquid level range, which helps to maintain a stable working environment inside the liquid flow battery and improve the working efficiency and performance stability of the liquid flow battery.

[0078] The cloud database is used to store the target electric vehicle liquid flow battery electrolyte flow-power characteristic curve diagram, store the target electric vehicle basic configuration data, store the target electric vehicle liquid flow battery electrolyte flow relative to the built-in circulation pump speed preset characteristic change curve based on the opening and closing degrees of the built-in valve, store the target electric vehicle liquid flow battery electrolyte flow relative to the built-in valve opening and closing degree preset characteristic change curve based on the built-in circulation pump speed.

[0079] The data sources in the cloud database of this embodiment are shown in Table 1 below.

[0080] Table 1 Detailed description of data sources in cloud database

[0081]

[0082] Reference Figure 2 As shown, the second aspect of the present invention provides a method for controlling energy storage of a flow battery on an electric vehicle, comprising: S1. confirming the current driving state of the target electric vehicle and its response power demand, wherein the driving state includes an acceleration state, a constant speed state and a deceleration state.

[0083] S2. Extract the target electric vehicle liquid flow battery electrolyte flow-power characteristic curve pre-stored in the cloud database, and match the reference flow rate of the corresponding liquid flow battery electrolyte according to the response power demand of the current driving state of the target electric vehicle.

[0084] S3. Collect the current internal operating state of the flow battery of the target electric vehicle, correct the reference flow rate of the flow battery electrolyte to match the current driving state of the target electric vehicle, and obtain the response flow rate of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle.

[0085] S4. By regulating the speed of the built-in circulation pump of the liquid flow battery and the opening and closing degree of the valve, the response flow distribution of the liquid flow battery electrolyte corresponding to the current driving state of the target electric vehicle is achieved. If the current driving state is a deceleration state, an additional energy recovery operation is performed.

[0086] S5. Identify whether there is abnormal liquid level in the built-in liquid storage tank of the current liquid flow battery of the target electric vehicle, including liquid high exceeding the limit, liquid low exceeding the limit and liquid leakage. If it is identified, perform corresponding safety processing.

[0087] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A liquid flow battery energy storage system for electric vehicles, characterized in that: The system includes: A driving state confirmation module is used to confirm the current driving state of the target electric vehicle and its response power demand, wherein the driving state includes an acceleration state, a constant speed state and a deceleration state; The reference flow matching module is used to extract the target electric vehicle liquid flow battery electrolyte flow-power characteristic curve pre-stored in the cloud database, and match the reference flow of the corresponding liquid flow battery electrolyte according to the response power demand of the current driving state of the target electric vehicle. ; A response flow acquisition module is used to collect the current internal operating state of the flow battery of the target electric vehicle, correct the reference flow rate of the flow battery electrolyte matching the current driving state of the target electric vehicle, and obtain the response flow rate of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle; The response flow distribution module is used to achieve the response flow distribution of the electrolyte of the flow battery corresponding to the current driving state of the target electric vehicle by regulating the speed of the built-in circulation pump of the flow battery and the opening and closing degree of the valve, and if the current driving state is a deceleration state, an additional energy recovery operation is performed; The liquid level safety management module is used to identify whether there is abnormal liquid level in the built-in liquid storage tank of the current liquid flow battery of the target electric vehicle, including liquid high exceeding the limit, liquid low exceeding the limit and liquid leakage. If it is identified, the corresponding safety processing is performed; The cloud database is used to store the electrolyte flow-power characteristic curve of the target electric vehicle liquid flow battery, store the basic configuration data of the target electric vehicle, store the preset characteristic change curve of the electrolyte flow rate of the target electric vehicle liquid flow battery relative to the speed of the built-in circulation pump based on the opening and closing degrees of the built-in valve, and store the preset characteristic change curve of the electrolyte flow rate of the target electric vehicle liquid flow battery relative to the opening and closing degree of the built-in valve based on the speed of the built-in circulation pump.

2. The electric vehicle flow battery energy storage system according to claim 1, characterized in that: The confirming of the current driving state of the target electric vehicle and its response power demand includes: sensing the speed and acceleration of the current vehicle through the on-board sensor of the target electric vehicle, comparing the current vehicle acceleration with a preset fluctuation range of the vehicle's uniform speed state acceleration, and if it is greater than the upper limit of the range, confirming that the current driving state of the target electric vehicle is an accelerating state; if it is less than the lower limit of the range, confirming that the current driving state of the target electric vehicle is a decelerating state; if it is within the range, confirming that the current driving state of the target electric vehicle is a uniform speed state; Extract the target electric vehicle basic configuration data stored in the cloud database, including weight, orthographic projection area and basic accessory power , combined with the current speed and acceleration of the target electric vehicle, calculate the current rolling resistance power of the target electric vehicle , air resistance power and inertial power ,Will , , , The power requirement of the target electric vehicle in the current driving state is confirmed by accumulation.

3. The electric vehicle flow battery energy storage system according to claim 1, characterized in that: The method of obtaining the response flow rate of the liquid flow battery electrolyte corresponding to the current driving state of the target electric vehicle includes: collecting the current electrolyte temperature value and the electric cone temperature value of the liquid flow battery inside the target electric vehicle, analyzing the predicted temperature value of the electrolyte inside the liquid flow battery when the reference flow rate of the liquid flow battery matching the current driving state of the target electric vehicle is allocated And the predicted temperature value of the electric cone ; Collect the pipeline pressure values ​​of the electrolyte in and out of the electric cone inside the current flow battery of the target electric vehicle, analyze the predicted pipeline pressure values ​​of the electrolyte in and out of the electric cone when the reference flow rate of the flow battery matching the current driving state of the target electric vehicle is allocated, and record them as ,Depend on The difference is the predicted pipeline pressure difference ; calculate , , The deviation degree of the preset reasonable working range is respectively compared with the deviation degree of the preset reasonable working range, so as to analyze the safety correction compensation flow rate corresponding to the reference flow rate of the flow battery electrolyte matching the current driving state of the target electric vehicle ; Collect the command distribution flow of the target electric vehicle flow battery at each unit time point in the current period and the actual flow rate at each node of the internal pipeline of the flow battery , is the number of each unit time point in the current period, , is the number of each node in the internal pipeline of the flow battery, , calculate the validity correction compensation flow rate corresponding to the reference flow rate of the flow battery electrolyte matching the current driving state of the target electric vehicle ; right , , The accumulation is performed to obtain the response flow rate of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle.

4. The electric vehicle flow battery energy storage system according to claim 3, characterized in that: Said The calculation formula is: ,in is a natural constant, The internal safety correction factor of the flow battery is the reference flow rate of the flow battery matching the current driving state of the target electric vehicle, and its value is , , The accumulated values ​​of the deviations from the corresponding preset reasonable working ranges.

5. The electric vehicle flow battery energy storage system according to claim 3, characterized in that: Said The calculation formula is: ,in is the number of unit time points in the current period, is the number of pipeline nodes inside the flow battery.

6. The electric vehicle flow battery energy storage system according to claim 1, characterized in that: The regulating the speed of the internal circulation pump of the flow battery and the valve opening degree includes: if the current driving state of the target electric vehicle is a uniform speed state, maintaining the current speed of the internal circulation pump of the flow battery and the valve opening degree; If the current driving state of the target electric vehicle is an acceleration state, then confirm that the unified control direction of the speed of the built-in circulation pump and the valve opening degree of the flow battery is upward, extract the preset characteristic change curve of the electrolyte flow rate relative to the speed of the built-in circulation pump based on the current built-in valve opening degree of the target electric vehicle flow battery pre-stored in the cloud database, and retrieve the corresponding matching built-in circulation pump speed of the response flow rate of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle. If the speed of the built-in circulation pump reaches the upper limit threshold and still does not meet the response flow rate of the flow battery electrolyte, then extract the preset characteristic change curve of the electrolyte flow rate relative to the built-in valve opening degree based on the speed of the built-in circulation pump as the upper limit threshold of the target electric vehicle flow battery pre-stored in the cloud database, retrieve the corresponding matching built-in valve opening degree of the response flow rate of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle, and realize the upward adjustment of the speed of the built-in circulation pump and the valve opening degree of the flow battery in the current acceleration state; If the current driving state of the target electric vehicle is a deceleration state, it is confirmed that the unified control direction of the speed of the built-in circulation pump of the flow battery and the valve opening degree is downward, which is consistent with the acceleration state control analysis method, so as to realize the downward adjustment of the speed of the built-in circulation pump of the flow battery and the valve opening degree in the current deceleration state.

7. The electric vehicle flow battery energy storage system according to claim 1, characterized in that: The specific execution process of the energy recovery operation includes: transitioning the current target electric vehicle motor drive mode to the electric mode, converting the vehicle kinetic energy in the deceleration state into electrical energy, converting it into direct current through the flow battery inverter and storing it in the flow battery, thereby realizing the energy recovery operation.

8. The electric vehicle flow battery energy storage system according to claim 1, characterized in that: The identifying whether the built-in liquid storage tank of the current liquid flow battery of the target electric vehicle has abnormal liquid level performance includes: sensing the current liquid level height of the built-in liquid storage tank of the liquid flow battery of the target electric vehicle through a liquid level sensor arranged in the built-in liquid storage tank of the liquid flow battery of the target electric vehicle, and if it is greater than or equal to the preset upper limit warning height of the liquid level of the liquid storage tank, identifying that the current liquid level exceeds the limit; if it is less than or equal to the preset lower limit warning height of the liquid level of the liquid storage tank, identifying that the current liquid level is below the limit; The liquid level height, outlet flow rate and inlet flow rate of the built-in liquid storage tank of the target electric vehicle flow battery at each unit time point in the current period are collected, and the actual liquid level change rate and reasonable liquid level change rate range of the built-in liquid storage tank of the target electric vehicle flow battery at each unit time point in the current period are calculated. The current liquid leakage risk coefficient of the built-in liquid storage tank of the target electric vehicle flow battery is analyzed, and if it is greater than or equal to the preset liquid leakage risk coefficient warning threshold, it is recognized that there is currently a liquid leakage, otherwise it is recognized that there is no liquid leakage.

9. The electric vehicle flow battery energy storage system according to claim 1, characterized in that: The specific execution process of executing the corresponding safety processing includes: if it is identified that the current liquid height exceeds the limit, the drainage program of the built-in liquid storage tank of the target electric vehicle liquid flow battery is started until the liquid level height is less than the preset upper limit warning height of the liquid storage tank, and the excess electrolyte is transferred to the spare container; If it is identified that the liquid level is currently low, the target electric vehicle flow battery built-in liquid storage tank refilling program is started until the liquid level height is greater than the preset lower limit warning height of the liquid storage tank; If a liquid leak is detected, an alarm is triggered immediately and emergency braking is applied to the target battery vehicle.

10. A method for controlling energy storage of a flow battery in an electric vehicle, characterized in that: The method includes: S1. Confirm the current driving state of the target electric vehicle and its response power demand, where the driving state includes acceleration state, constant speed state and deceleration state; S2. Extract the target electric vehicle flow battery electrolyte flow-power characteristic curve pre-stored in the cloud database, and match the reference flow rate of the corresponding flow battery electrolyte to the response power demand of the target electric vehicle in the current driving state; S3. Collect the current internal operating state of the flow battery of the target electric vehicle, correct the reference flow rate of the flow battery electrolyte to match the current driving state of the target electric vehicle, and obtain the response flow rate of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle; S4. By regulating the speed of the built-in circulation pump of the flow battery and the opening and closing degree of the valve, the response flow distribution of the flow battery electrolyte corresponding to the current driving state of the target electric vehicle is achieved. If the current driving state is a deceleration state, an additional energy recovery operation is performed; S5. Identify whether there is abnormal liquid level in the built-in liquid storage tank of the current liquid flow battery of the target electric vehicle, including liquid high exceeding the limit, liquid low exceeding the limit and liquid leakage. If it is identified, perform corresponding safety processing.

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