Distributed flow battery energy storage BMS system based on embedded system

Abstract

The utility model discloses a distributed flow battery energy storage BMS (battery management system) based on an embedded system, which relates to the field of battery energy storage and comprises a main controller, a flow control module, a cooling control module, a pressure control module, a liquid leakage control module, a charge and discharge control module, a balance control module, an alarm output module, an HMI (human-machine interaction) module and a control layer. By collecting the 1 / 2 / 3 temperature, flow, voltage and current of a galvanic pile in a galvanic pile cabinet and the pressure and SOC of a liquid storage tank, communication with a control layer is realized, and the management and control of the alum flow battery are completed. The design and the implementation of the distributed BMS also consider the improvement of the safety performance, and the energy storage capability is greatly improved through the application of a high-precision and high-reliability analog front end (AFE) and a plurality of communication modes.

Description

Technical Field

[0001] The utility model relates to the field of battery energy storage, and more specifically to a distributed flow battery energy storage BMS system based on an embedded system. Background Art

[0002] Electrochemical energy storage is one of the main ways of energy storage. From the perspective of technical routes, lithium-ion batteries and vanadium redox flow batteries are the mainstream. Vanadium redox flow batteries have a series of unique advantages over traditional lithium-ion batteries, such as intrinsic safety, long cycle life, good scalability with decoupled power and capacity, and good energy security. From 2011 to April 2022, a total of 34 energy storage power station explosion incidents occurred globally, among which 32 were lithium batteries, and 1 each for lead-acid batteries and sodium-sulfur batteries; the core of vanadium redox flow batteries lies in their inherent safety, water-based system, and no risk of fire or explosion. Lithium batteries have a short cycle life. The maximum number of cycles for lithium iron phosphate used in energy storage is about 6,000 times, but vanadium redox flow batteries have a very long life, with a cycle number of up to 10,000 - 20,000 times; the power and capacity of all-vanadium redox flow batteries are decoupled, with good scalability. By increasing the electrolyte or replacing the electrolyte, the system operation time can be increased. By replacing the electrolyte, instant recharge can be achieved, similar to refueling a car; lithium batteries cannot do this. Lithium mines are mainly distributed in countries and regions such as South America and Australia, and China's reserves account for only 7%, resulting in an energy crisis. As of the end of 2021, China's vanadium resource reserves ranked first in the world, accounting for about 39% of the global total, and its output accounted for 68% of the global total.

[0003] However, the vanadium redox flow battery has a small energy density, resulting in a large volume and many positions with leakage risks. The operating temperature range is between 5°C and 45°C, and adjustment is required for both too high and too low temperatures. In addition, for accurate monitoring of the energy storage capacity of the vanadium redox flow battery, a good management and control of the vanadium redox flow battery is needed. The energy density of the vanadium redox flow battery is low, only 12 - 40 Wh / kg, mainly restricted by the solubility of vanadium ions and the design of the stack. While lithium batteries are generally 80 - 300 Wh / kg. Therefore, to achieve the same energy storage capacity, the volume of the vanadium redox flow battery is undoubtedly much larger, 3 - 5 times that of lithium batteries; the vanadium redox flow battery system has many vanadium liquid pipelines and large storage tank volumes, and good monitoring of leakage and control of flow rate are required. The operating temperature range of the vanadium redox flow battery is 5°C to 45°C, and adjustment is required for both too high and too low temperatures. Good monitoring and control of the coolant flow rate and adjustment of the electrolyte in the storage tank to maintain it within a certain temperature range are needed. Traditional lithium batteries cannot accurately monitor the energy storage capacity. If the vanadium redox flow battery can be accurately monitored, the battery utilization rate can be improved, and overcharging and over-discharging will not occur.

[0004] Therefore, the utility model proposes a distributed flow battery energy storage BMS system based on an embedded system, which can solve the problems existing in the vanadium redox flow battery itself through the control of the embedded system, accurately measure the energy storage capacity, and complete the detection and control of the distributed vanadium redox flow battery energy storage device. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the utility model discloses a distributed flow battery energy storage BMS system based on an embedded system. Through the control of the embedded system, the problems of large volume and many leakage risk positions caused by the small energy density of the vanadium flow battery can be solved; and the stored energy can be accurately measured to complete the detection and control of the distributed vanadium flow battery energy storage device, with high automation and intelligence.

[0006] In order to achieve the above technical effects, the utility model adopts the following technical solutions:

[0007] A distributed flow battery energy storage BMS system based on an embedded system, the BMS system includes: a main controller and a flow control module, a cooling control module, a pressure control module, a leakage control module, a charge and discharge control module, a balancing control module, an alarm output module and an HMI human-machine interaction module connected to the main controller;

[0008] The main controller is an ARM Cortex-M microcontroller. The main controller is connected to the flow control module, the cooling control module, the pressure control module, the leakage control module, the charge and discharge control module, the balancing control module and the control layer through a CAN bus. The main controller is used for communicating and controlling with each control module. The flow control module is used for controlling the flow rate in the flow battery to achieve energy optimization of the system. The cooling control module is used for controlling the temperature in the flow battery. The pressure control module is used for controlling the pressure in the flow battery. The leakage control module is used for detecting whether there is a leakage phenomenon in the flow battery. The charge and discharge control module is used for controlling the charge and discharge process in the flow battery. The balancing control module is used for balancing the flow rates of each branch pipeline in the battery in the flow battery. The alarm output module and the HMI human-machine interaction module are located outside the system. The alarm output module and the HMI human-machine interaction module are connected to the main controller through an RS232 serial port. The alarm output module is used for abnormal alarm of the flow battery. The HMI human-machine interaction module is used for completing human-machine interaction. The flow control module, the cooling control module, the pressure control module, the leakage control module, the charge and discharge control module, the balancing control module, the alarm output module and the HMI human-machine interaction module are distributed at the lower level of the main controller.

[0009] As a further description of the above technical solution:

[0010] Inside the flow control module, a State of Charge (SOC) sensor for battery state detection is provided. The state of charge detected by the SOC sensor is fed back to the ARM Cortex-M microcontroller via the CAN bus. The ARM Cortex-M microcontroller controls and changes the valve opening of the flow battery to achieve segmented adjustment of the flow rate of the flow battery.

[0011] As a further description of the above technical solution:

[0012] Inside the cooling control module, a temperature sensor is provided to collect the temperatures of the liquid storage tank and the electrolytes flowing in and out of the positive and negative electrodes. A first reference comparator LT6650 is set to compare the collected temperature data with the specified temperature value. The ARM Cortex-M microcontroller controls the cooling system by controlling the output voltage and current of the GPIO input / output ports.

[0013] As a further description of the above technical solution:

[0014] Inside the pressure control module, a pressure sensor is provided to continuously monitor the pressure at the bottom of the storage tank, and a constant-pressure flowmeter is provided to determine the position of the liquid volume in the storage tank. When the pressure reduction exceeds the specified reduction value, it is determined that there is a liquid leak in the storage tank or pipeline. The ARM Cortex-M microcontroller controls the alarm output module via the CAN bus to perform alarm processing.

[0015] As a further description of the above technical solution:

[0016] Inside the liquid leak control module, a flow sensor is provided to perform multiple flow detections on the pipeline, and a second reference comparator LT6650 is set to compare the sum of the flow rates of the main pipeline and the branch pipelines with the set flow rate sum value. When the difference in the flow rate sum exceeds the specified difference value of the flow rate sum, it is determined that there is a liquid leak in the pipeline or the stack. The ARM Cortex-M microcontroller controls the alarm output module via the CAN bus to perform alarm processing.

[0017] As a further description of the above technical solution:

[0018] Inside the charge and discharge control module, a circulation pump is provided. The ARM Cortex-M microcontroller controls the charge and discharge of the flow battery by controlling the switch of the circulation pump.

[0019] As a further description of the above technical solution:

[0020] The internal of the balance control module is equipped with a flow sensor to monitor the flow rates at multiple locations in the pipeline, and a third reference comparator LT6650 is set to compare the flow rate differences of each branch pipeline with the set value of the flow rate difference. When the difference in the flow rate differences exceeds the specified value of the difference in the flow rate differences, the ARM Cortex-M microcontroller realizes the balanced distribution of the electrolyte by adjusting the valve sizes of the branch circuits.

[0021] As a further description of the above technical solution:

[0022] The input end of the alarm output module is provided with an RS232 serial port input interface to receive the control instructions of the ARM Cortex-M microcontroller. The alarm output module automatically stops the operation of the vanadium redox flow battery according to the control instructions of the ARM Cortex-M microcontroller and the degree of exceeding the set value. The input end of the HMI human-machine interaction module is provided with an RS232 serial port input interface to input the set values of the operation mode, voltage, current, temperature, pressure, and SOC, and reads the monitoring and alarm data through the CAN bus. The surface of the HMI human-machine interaction module is provided with an LED touch screen for human-machine interaction.

[0023] In summary, the present utility model discloses a distributed flow battery energy storage BMS system based on an embedded system. The BMS system control of the present utility model can solve the problems existing in the vanadium redox flow battery itself, accurately measure the stored energy, and complete the detection and control of the distributed vanadium redox flow battery energy storage device.

[0024] 1. Collect the data of pressure and flow rate sensors at multiple locations, analyze and process them, alarm when leakage is detected, and at the same time close the circulation pump to reduce the further expansion of leakage and reduce losses.

[0025] 2. Collect the temperatures of the electrolyte flowing in and out of the storage tank, the positive and negative electrodes, compare them with the set values, and control the cooling system to ensure that the operating temperature inside the stack is between 5°C and 45°C.

[0026] 3. By collecting the open-circuit voltage of a single vanadium redox flow battery, the stored energy of the vanadium redox flow battery can be accurately obtained according to a certain calculation.

[0027] 4. Collect the temperature, liquid level, etc. during the operation of the vanadium redox flow battery, compare them with the set values to prevent damage to the battery. Considering the performance and control requirements of the vanadium redox flow battery itself, a charge and discharge BMS system for the vanadium redox flow battery is designed.

[0028] 5. When the vanadium redox flow battery is working, the main work of the control system is to change the opening degree of the valve according to the detected state of charge, adjust the flow rate in sections, and realize the optimization of the system energy. The flow rates of the stacks in the same battery module should be kept consistent, and the flow rate deviation should not exceed ±10%.

[0029] 6. The BMS system has functions of leakage alarm and automatic shutdown; overcurrent and overvoltage alarm functions; short - circuit shutdown and alarm functions; manual and automatic shutdown functions.

[0030] 7. The BMS system has an HMI display function. Brief Description of the Drawings

[0031] Figure 1 It is a schematic diagram of the overall module of a distributed flow - battery energy - storage BMS system based on an embedded system of the present utility model;

[0032] Figure 2 It is a schematic diagram of the module of the cooling control module in a distributed flow - battery energy - storage BMS system based on an embedded system of the present utility model;

[0033] Figure 3 It is a schematic diagram of the module of the pressure control module in a distributed flow - battery energy - storage BMS system based on an embedded system of the present utility model;

[0034] Figure 4 It is a schematic diagram of the module of the leakage control module in a distributed flow - battery energy - storage BMS system based on an embedded system of the present utility model;

[0035] Figure 5 It is a schematic diagram of the module of the equalization control module in a distributed flow - battery energy - storage BMS system based on an embedded system of the present utility model;

[0036] Figure 6 It is a schematic diagram of the process of the flow control module in a distributed flow - battery energy - storage BMS system based on an embedded system of the present utility model;

[0037] Figure 7 It is a schematic diagram of the process of the leakage control module in a distributed flow - battery energy - storage BMS system based on an embedded system of the present utility model;

[0038] Figure 8 It is a schematic diagram of the process of the charge - discharge control module in a distributed flow - battery energy - storage BMS system based on an embedded system of the present utility model.

[0039] Figure 9 It is an illustration diagram of the stack cabinet of a distributed flow - battery energy - storage BMS system based on an embedded system of the present utility model.

[0040] Figure 10 It is an illustration diagram of a distributed flow - battery energy - storage BMS system based on an embedded system of the present utility model. Detailed Description of the Preferred Embodiment

[0041] The following will be combined with the accompanying drawings shown in the embodiments of the present utility model to clearly and completely describe the technical solutions in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model. Figures 1-10 Shown in the figure, a distributed flow battery energy storage BMS system based on an embedded system, the BMS system includes:

[0042] As Figure 1 Shown, a distributed flow battery energy storage BMS system based on an embedded system, the BMS system includes:

[0043] The main controller 1 uses the ARM Cortex-M microcontroller 10 as the main controller and is connected to the flow control module 2, the cooling control module 3, the pressure control module 4, the leakage control module 5, the charge and discharge control module 6, and the equalization control module 7 through the CAN bus 11. The CAN bus is a high-speed and reliable network communication protocol suitable for control systems with high requirements for real-time performance and reliability. The main function of the main controller 1 is to communicate and control with each control module, including: receiving and processing the real-time parameter data reported by each control module (such as flow rate, temperature, pressure, current, voltage, SOC, etc.), sending control instructions to each control module, judging the working state of the control module and making responses, etc. Through the communication method of the CAN bus 11, data sharing and collaborative control among the control modules are realized, improving the reliability and stability of the system.

[0044] The main controller 1 is connected to the following components:

[0045] The flow control module 2 is internally provided with a state of charge (SOC) sensor 12 for battery state detection. The state of charge detected by the SOC sensor 12 for battery state detection is fed back to the ARM Cortex-M microcontroller 10 via the CAN bus 11. The ARM Cortex-M microcontroller 10 controls and changes the valve opening degree of the flow battery to achieve segmented adjustment of the flow rate of the flow battery. According to the state of charge of the flow battery, the ARM Cortex-M microcontroller 10 will control and change the valve opening degree of the flow battery, thereby achieving segmented adjustment of the flow rate of the flow battery. The specific implementation method is that when the state of charge of the flow battery is relatively low, the ARM Cortex-M microcontroller 10 will control a larger valve opening degree, resulting in a larger flow rate, so as to enhance the charging and discharging effects of the battery; while when the state of charge of the flow battery is relatively high, the ARM Cortex-M microcontroller 10 will control a smaller valve opening degree, resulting in a smaller flow rate, so as to avoid overcharging and over-discharging of the battery, protect the battery and extend its service life. By performing segmented adjustment of the flow rate of the flow battery, the energy of the battery can be utilized to the greatest extent, the efficiency and stability of the battery can be improved, the service life of the battery can be extended, and the normal operation of the equipment can be ensured.

[0046] The cooling control module 3 is internally provided with a temperature sensor 13 to collect the temperatures of the liquid storage tank and the electrolytes flowing in and out of the positive and negative electrodes, and a first reference comparator LT6650 14 to compare the collected temperature data with the specified temperature value. The ARM Cortex-M microcontroller 10 controls and realizes the control of the cooling system by controlling the output voltage and current of the GPIO input / output port 15. Under the control of the comparator, the ARM Cortex-M microcontroller 10 can control and realize the control of the cooling system by controlling the output voltage and current of the GPIO input / output port 15. Specifically, if the temperature data collected by the temperature sensor exceeds the specified temperature value, the ARM Cortex-M microcontroller 10 will issue an instruction to control the output voltage and current of the GPIO input / output port 15 to turn on the cooling system so that the flow battery can be cooled in a timely and effective manner. On the contrary, if the temperature data does not exceed the predetermined value, the ARM Cortex-M microcontroller 10 will keep the cooling system in a closed state to save energy and reduce energy consumption.

[0047] The pressure control module 4 is internally equipped with a pressure sensor 16 to monitor the pressure at the bottom of the storage tank in real time, and a constant-pressure flowmeter 17 to judge the position of the liquid volume in the storage tank. When the pressure decreases by more than the specified decrease value, it is judged that there is a liquid leakage in the storage tank or pipeline. The ARM Cortex-M microcontroller 10 controls the alarm output module 8 to perform alarm processing through the CAN bus 11. By monitoring the pressure sensor 16, the pressure control module 4 can judge whether there is a liquid leakage in the storage tank or pipeline. Specifically, if the pressure sensor monitors that the pressure at the bottom of the storage tank decreases by more than the specified decrease value, the pressure control module 4 will judge that there is a liquid leakage in the storage tank or pipeline. Once a liquid leakage occurs, the ARM Cortex-M microcontroller 10 will control the alarm output module 8 to perform alarm processing through the CAN bus 11 to remind the operator to deal with the liquid leakage problem in time. The alarm output module 8 can perform alarm processing through means such as sound, light, and display screen to ensure that the operator obtains the liquid leakage information in the first time, takes appropriate measures, and avoids the impact of liquid leakage on equipment, personnel, and the environment.

[0048] The liquid leakage control module 5 is internally equipped with a flow sensor 18 to detect the flow rate at multiple locations in the pipeline, and a second reference comparator LT6650 19 to compare the sum of the flow rates of the main pipeline and the branch pipelines with the set value of the flow rate sum. When the difference in the flow rate sum exceeds the specified difference value, it is judged that there is a liquid leakage in the pipeline or the fuel cell stack. The ARM Cortex-M microcontroller 10 controls the alarm output module 8 to perform alarm processing through the CAN bus 11. By monitoring the flow sensor 18, the liquid leakage control module 5 can judge whether there is a liquid leakage in the pipeline or the fuel cell stack. Specifically, if the comparator monitors that the difference in the sum of the flow rates of the main pipeline and the branch pipelines exceeds the specified difference value, the liquid leakage control module 5 will judge that there is a liquid leakage in the measured pipeline or the fuel cell stack. Once a liquid leakage occurs, the ARM Cortex-M microcontroller 10 will control the alarm output module 8 to perform alarm processing through the CAN bus 11 to remind the operator to deal with the liquid leakage problem in time. Similar to the pressure control module 4, the alarm output module 8 can perform alarm processing through means such as sound, light, and display screen to ensure that the operator obtains the liquid leakage information in the first time, takes appropriate measures, and avoids the impact of liquid leakage on equipment, personnel, and the environment.

[0049] Charge and discharge control module 6, within which a circulation pump 20 is provided. The ARM Cortex-M microcontroller 10 completes the charge and discharge of the flow battery by controlling the switch of the circulation pump 20. When the flow battery needs to be charged, the ARM Cortex-M microcontroller 10 issues an instruction to control the circulation pump 20 to turn on, so that the electrolyte and the liquid in the liquid storage tank circulate to achieve the purpose of charging. When the flow battery needs to be discharged, the ARM Cortex-M microcontroller 10 issues an instruction to control the circulation pump 20 to turn off, thus stopping the circulation of the liquid and allowing the battery to discharge. The circulation pump 20 plays an important role in the charge and discharge process of the flow battery, effectively regulating the battery capacity and discharge efficiency, and improving the service life and stability of the battery.

[0050] Balancing control module 7, within which a flow sensor 18 is provided to monitor the flow rates at multiple locations in the pipeline, and a third reference comparator LT665021 is set to compare the flow rate differences between the branch pipelines with the set value of the flow rate difference. If the difference in the flow rate differences exceeds the specified value, the ARM Cortex-M microcontroller 10 realizes the balanced distribution of the electrolyte by adjusting the valve sizes of the branch circuits. Through the monitoring of the flow sensor 18, the balancing control module 7 can judge the difference in the flow rates of the branch pipelines. If the comparator monitors that the difference in the flow rate differences between the branch pipelines exceeds the specified difference value, the balancing control module 7 will adjust the valve sizes of the branch circuits to achieve the balanced distribution of the electrolyte, thereby improving the performance and service life of the flow battery. Specifically, when the balancing control module 7 monitors that the difference in the flow rate differences between the branch pipelines exceeds the specified difference value, the ARM Cortex-M microcontroller 10 issues an instruction to control the adjustment of the valve sizes of the branch circuits, thus realizing the balanced distribution of the liquid. In this way, the liquid volume between the branch circuits tends to be evenly distributed, improving the service life and stability of the battery.

[0051] An alarm output module 8 and an HMI human-machine interaction module 9. The input end of the alarm output module 8 is provided with an RS232 serial port input interface 22 to receive the control instructions of the ARM Cortex-M microcontroller 10. The alarm output module 8 automatically stops the operation of the vanadium redox flow battery according to the control instructions of the ARM Cortex-M microcontroller 10 and the degree of exceeding the set value. The input end of the HMI human-machine interaction module 9 is provided with an RS232 serial port input interface 22 to input the set values of the operation mode, voltage, current, temperature, pressure, and SOC, and reads the monitoring and alarm data through the CAN bus 11. The surface of the HMI human-machine interaction module 9 is provided with an LED touch screen for human-machine interaction. The input end of the alarm output module 8 is provided with an RS232 serial port input interface 22 for receiving the control instructions of the ARM Cortex-M microcontroller 10. In actual use, if a fault or abnormal situation occurs in the device, the ARM Cortex-M microcontroller 10 will send control instructions to the alarm output module 8 through the RS232 serial port. The alarm output module 8 automatically stops the operation of the vanadium redox flow battery according to the degree of exceeding the set value to avoid more serious problems or endangering the safety of the device, personnel, and environment. The input end of the HMI human-machine interaction module 9 is also provided with an RS232 serial port input interface 22 for inputting the set values of the operation mode, voltage, current, temperature, pressure, and SOC. At the same time, the HMI human-machine interaction module 9 also reads the monitoring and alarm data through the CAN bus 11 to timely grasp the operation status of the device. Its surface is provided with an LED touch screen, and this screen can be used for human-machine interaction with the device to realize the control and monitoring of the device by the user. Therefore, the HMI human-machine interaction module is crucial for the control and management of the device.

[0052] The main controller 1 is an ARM Cortex-M microcontroller 10. The main controller 1 is connected to the flow control module 2, the cooling control module 3, the pressure control module 4, the leakage control module 5, the charge and discharge control module 6, the balancing control module 7, and the control layer 23 through the CAN bus 11. The main controller 1 is used to communicate with and control each control module. The flow control module 2 is used to control the flow rate in the flow battery to achieve energy optimization of the system. The cooling control module 3 is used to control the temperature in the flow battery. The pressure control module 4 is used to control the pressure in the flow battery. The leakage control module 5 is used to detect whether there is a leakage phenomenon in the flow battery. The charge and discharge control module 6 is used to control the charge and discharge process in the flow battery. The balancing control module 7 is used to balance the flow rate of each branch pipeline in the batteries within the flow battery. The alarm output module 8 and the HMI human-machine interaction module 9 are located outside the system. The alarm output module 8 and the HMI human-machine interaction module 9 are connected to the main controller 1 through the RS232 serial port. The alarm output module 8 is used for abnormal alarm of the flow battery. The HMI human-machine interaction module 9 is used to complete human-machine interaction. The flow control module 2, the cooling control module 3, the pressure control module 4, the leakage control module 5, the charge and discharge control module 6, the balancing control module 7, the alarm output module 8, and the HMI human-machine interaction module 9 are distributed at the lower level of the main controller 1.

[0053] In a specific embodiment, the present utility model practically configures a flow control module, a cooling control module, a pressure control module, a leakage control module, a charge and discharge control module, a balancing control module, an alarm output module, and an HMI module through the main controller. By collecting the temperature, flow rate, voltage, and current of the stack 1 / stack 2 / stack 3 in an electrolyzer cabinet, and the pressure and SOC of the storage tank, and communicating with the control layer 23, the management and control of the vanadium flow battery are completed. Multiple distributed electrolyzer cabinets communicate with the control layer 23 through the BMS system to form a small-scale kilowatt-level or large-scale megawatt-level flow battery energy storage. This distributed flow battery energy storage BMS system replaces the single battery control system BAMS and the large-scale energy control system EMS.

[0054] 1. Flow control module: When the vanadium flow battery is working, the main work of the control system is to change the opening of the valve according to the detected state of charge, and adjust the flow rate in sections to achieve energy optimization of the system. The flow rates of the stacks within the same battery module should be kept consistent, and the flow deviation should not exceed ±10%. The control program is as Figure 6 shown.

[0055] 2. Cooling control module: By controlling the cooling system, ensure that the operating temperature inside the stack is between 25 and 35 °C.

[0056] 3. Pressure control module: By monitoring the pressure at the bottom of the storage tank in real time, it judges the position of the liquid volume in the storage tank. If the pressure reduction exceeds the specified value, it judges that there is liquid leakage in the storage tank or pipeline and performs alarm processing.

[0057] 4. Leakage control module: By detecting the flow rates at multiple points in the pipeline, it compares whether the flow rates of the main pipeline and the branch pipelines are within a certain range. If the difference is too large, it judges that there is liquid leakage in the pipeline or the stack. The control program is as Figure 7 shown.

[0058] 5. Charge and discharge control module: The main task of the design of the vanadium redox flow battery BMS system is to complete the charge and discharge of the vanadium redox flow battery, prevent the temperature, liquid level, etc. from exceeding the set values during the operation of the vanadium redox flow battery. If the operating parameters of the battery exceed the set range, the battery controller will act, take measures to reduce the damage to the battery, and ensure the normal operation of the vanadium redox flow battery. Combining the performance of the vanadium redox flow battery itself and the control requirements, the charge and discharge BMS system of the vanadium redox flow battery is designed, and the flow chart is as Figure 8 shown.

[0059] 6. Balancing control module: By monitoring the flow rates at multiple points in the pipeline, it compares whether the differences in the flow rates of each branch pipeline are within a certain range. If the differences in the flow rates are too large, by adjusting the valve sizes of the branch circuits, the flow rate differences of each branch circuit are controlled within a certain range to achieve the balanced distribution of the electrolyte.

[0060] 7. Alarm output module: It monitors the voltage, current, temperature, pressure, and SOC in real time. If they exceed the normal values, the alarm module will be activated, and the vanadium redox flow battery will be automatically stopped according to the degree of exceeding the set values.

[0061] 8. HMI module: It completes human-machine interaction, inputs the set values of the operating mode, voltage, current, temperature, pressure, and SOC, and reads the monitoring and alarm data.

[0062] The working process of a distributed flow battery energy storage BMS system based on an embedded system is exemplarily described below through specific embodiments. When the present invention is in operation, a distributed flow battery energy storage BMS system based on an embedded system is applied to a 100kW stack cabinet, which consists of 1 set of BMS device, 3 34kW stacks, 2 circulating pumps, 1 liquid cooling system, 4 flow valves, 3 temperature sensors, 2 pressure sensors, 1 positive electrolyte tank, and 1 negative electrolyte tank.

[0063] Four distributed stack cabinets and a 2MW electrolyte storage tank constitute a 0.5MW / 2MWh all-vanadium redox flow battery energy storage system, which has been applied in a wind power project. This all-vanadium redox flow battery energy storage system plays an important role in wind farm supporting. The instability and randomness of wind energy make it difficult for the power grid to maintain stable operation. Functionally, the flow battery energy storage power station can suppress fluctuations, has the ability to dynamically absorb and release power, realizes the smooth output of wind power generation, and can also cut peaks and fill valleys, smooth the output of the wind farm, and reduce its impact on the power grid. In addition, the all-vanadium redox flow battery energy storage system can also improve the reliability and power supply quality of the wind farm, reduce the power grid load fluctuation, and optimize the resource allocation.

[0064] This flow battery energy storage power station also has many highlights in design: such as realizing the standardization of unit design, the modularization of system architecture, and the processization of project implementation; factory prefabrication and on-site skid-mounted assembly, which are convenient for expansion and maintenance; the fast response speed of the energy storage system, which can support the millisecond-level power demand of the park; the electrolyte circulation system adopts multiple control strategies; through the intelligent remote digital monitoring and operation and maintenance platform, the system can realize the intelligent operation control strategies of self-diagnosis, self-recovery, and anti-interference under unattended conditions.

[0065] In the specific implementation manner of the stack cabinet in the present utility model, the positive electrolyte tank and the negative electrolyte tank are a kind of storage containers, which provide positive and negative electrolytes for the entire distributed redox flow battery energy storage BMS system; the BMS device communicates with the liquid flow valve 1, the liquid flow valve 2, the liquid flow valve 3, and the liquid flow valve 4 to control the opening and closing of the 4 liquid flow valves; the BMS device controls the start and stop of the circulation pump 1 and the circulation pump 2, and the circulation pump 2 and the circulation pump 1 provide power for the positive and negative electrolytes; at the same time, the BMS device communicates with the temperature sensor 1, the temperature sensor 2, and the temperature sensor 3 to detect the temperatures of the positive and negative electrolytes. When the temperature is too high, the BMS device starts the liquid cooling system to work, so that the temperatures of the positive and negative electrolytes are maintained at about 25°C; the BMS device communicates with the pressure sensor 1 and the pressure sensor 2 to obtain the pressures on the positive and negative electrolyte pipelines, and then controls the rotation speeds of the circulation pump 1 and the circulation pump 2 through the BMS device to make the pressures on the positive and negative electrolyte pipelines consistent, so that the entire distributed redox flow battery energy storage BMS system works in a safe and reliable environment; the positive and negative electrolytes flow into the stack 1, the stack 2, and the stack 3 to generate an electrochemical reaction, converting the chemical energy of the positive and negative electrolytes into electrical energy to complete the charge and discharge process. See Figure 9 。

[0066] The specific implementation of the distributed flow battery energy storage BMS system of the present utility model is as follows: The power grid is the line for transmitting electricity by the State Grid. After the wind power project generates electricity, it is also connected to the power grid; the energy storage converter PCS controls the charging and discharging processes of the stack cabinets 1, 2, 3, and 4, performs the conversion between alternating current and direct current, and supplies power to the AC load in the event of a power grid outage. It can also charge the stack cabinets 1, 2, 3, and 4 with the excess electric energy generated by wind power to store the electric energy; the stack cabinets 1, 2, 3, and 4 are devices for storing electric energy, storing electric energy when the power supply is sufficient and releasing electric energy when the power is insufficient. There is CAN communication between each stack cabinet; the electrolyte cabinet provides electrolyte for the stack cabinets 1, 2, 3, and 4, converting the chemical energy of the positive and negative electrolytes into electric energy; the industrial display screen can view the operation status of the entire distributed flow battery energy storage BMS system in real time; the management system EMS is a software for managing the distributed flow battery energy storage BMS system. Refer to Figure 10 。

[0067] Although the specific implementation of the present utility model has been described above, those skilled in the art should understand that these specific implementations are merely illustrative. Without departing from the principle and essence of the present utility model, those skilled in the art can make various omissions, substitutions, and changes to the details of the above methods and systems. For example, combining the above method steps so as to perform substantially the same function in a substantially the same way to achieve substantially the same result falls within the scope of the present utility model. Therefore, the scope of the present utility model is only defined by the appended claims.

Claims

1. A distributed flow battery energy storage BMS system based on an embedded system, characterized in that: The BMS system includes: a main controller (1), and a flow control module (2), a cooling control module (3), a pressure control module (4), a leakage control module (5), a charge and discharge control module (6), a balancing control module (7), an alarm output module (8), and an HMI human-machine interaction module (9) connected to the main controller (1); the main controller (1) is connected to the flow control module (2), the cooling control module (3), the pressure control module (4), the leakage control module (5), the charge and discharge control module (6), the balancing control module (7), and a control layer (23) through a CAN bus (11), the main controller (1) is used for communicating and controlling with each control module, the flow control module (2) is used for controlling the flow rate in the flow battery to achieve energy optimization of the system, the cooling control module (3) is used for controlling the temperature in the flow battery, the pressure control module (4) is used for controlling the pressure in the flow battery, the leakage control module (5) is used for detecting whether there is a liquid leakage phenomenon in the flow battery, the charge and discharge control module (6) is used for controlling the charge and discharge process in the flow battery, the balancing control module (7) is used for balancing the flow rate of each branch pipeline in the battery in the flow battery, the alarm output module (8) and the HMI human-machine interaction module (9) are located outside the system, the alarm output module (8) and the HMI human-machine interaction module (9) are connected to the main controller (1) through an RS232 serial port, the alarm output module (8) is used for abnormal alarm of the flow battery, the HMI human-machine interaction module (9) is used for completing human-machine interaction, and the flow control module (2), the cooling control module (3), the pressure control module (4), the leakage control module (5), the charge and discharge control module (6), the balancing control module (7), the alarm output module (8), and the HMI human-machine interaction module (9) are controlled by the main controller (1) to operate in a cycle.

2. The distributed liquid flow battery energy storage BMS system based on an embedded system according to claim 1, wherein: The core component of the main controller (1) is an ARM Cortex-M microcontroller (10). A battery state detection SOC sensor (12) is arranged inside the flow control module (2). The state of charge detected by the battery state detection SOC sensor (12) is fed back to the ARM Cortex-M microcontroller (10) through the CAN bus (11). The ARM Cortex-M microcontroller (10) controls and changes the valve opening degree of the flow battery to achieve segmented adjustment of the flow rate of the flow battery.

3. The distributed liquid flow battery energy storage BMS system based on an embedded system according to claim 1, characterized in that: A temperature sensor (13) is arranged inside the cooling control module (3) to collect the temperatures of the liquid storage tank and the electrolyte flowing in and out of the positive and negative electrodes. A first reference comparator LT6650 (14) is arranged to compare the collected temperature data with the temperature specified value. The ARM Cortex-M microcontroller (10) controls the cooling system by controlling the output voltage and current of the GPIO input and output port (15).

4. The distributed liquid flow battery energy storage BMS system based on an embedded system according to claim 1, wherein: Inside the pressure control module (4), a pressure sensor (16) is provided to monitor the pressure at the bottom of the storage tank in real time, and a constant-pressure flowmeter (17) is provided to judge the position of the liquid volume in the storage tank. When the pressure decrease exceeds the specified decrease value, it is judged that there is liquid leakage in the storage tank or pipeline. The ARM Cortex-M microcontroller (10) controls the alarm output module (8) to perform alarm processing through the CAN bus (11).

5. The distributed liquid flow battery energy storage BMS system based on an embedded system according to claim 1, characterized in that: Inside the liquid leakage control module (5), a flow sensor (18) is provided to detect the flow rate at multiple locations in the pipeline, and a second reference comparator LT6650 (19) is provided to compare the sum of the flow rates in the main pipeline and the branch pipelines with the set value of the flow rate sum. When the difference in the flow rate sum exceeds the specified difference value of the flow rate sum, it is judged that there is liquid leakage in the pipeline or the stack. The ARM Cortex-M microcontroller (10) controls the alarm output module (8) to perform alarm processing through the CAN bus (11).

6. The distributed liquid flow battery energy storage BMS system based on an embedded system according to claim 1, characterized in that: Inside the charge and discharge control module, a circulation pump (20) is provided. The ARM Cortex-M microcontroller (10) controls the charging and discharging of the flow battery by controlling the switch of the circulation pump (20).

7. A distributed flow battery energy storage BMS system based on an embedded system according to claim 1, characterized in that: Inside the equalization control module (7), a flow sensor (18) is provided to monitor the flow rates at multiple locations in the pipeline, and a third reference comparator LT6650 (21) is provided to compare the flow rate difference between each branch pipeline with the set value of the flow rate difference. When the difference in the flow rate difference exceeds the specified difference value of the flow rate difference, the ARM Cortex-M microcontroller (10) realizes the equal distribution of the electrolyte by adjusting the valve size of the branch circuit.

8. A distributed liquid flow battery energy storage BMS system based on an embedded system according to claim 1, characterized in that: At the input end of the alarm output module (8), an RS232 serial port input interface (22) is provided to receive the control instruction of the ARM Cortex-M microcontroller (10). The alarm output module (8) automatically stops the operation of the vanadium flow battery according to the control instruction of the ARM Cortex-M microcontroller (10) and the degree of exceeding the set value. At the input end of the HMI human-machine interaction module (9), an RS232 serial port input interface (22) is provided to input the set values of the operation mode, voltage, current, temperature, pressure, and SOC, and read the monitoring and alarm data through the CAN bus (11). An LED touch screen is provided on the surface of the HMI human-machine interaction module (9) for human-machine interaction.

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