Edge control based vanadium redox flow battery management system

Abstract

This disclosure relates to an edge-controlled vanadium redox flow battery management system, which features high integration and improved control accuracy. The system includes an edge controller integrating an Ethernet interface, an RS485 interface, and a CAN interface; at least one analog signal acquisition unit, connected to the edge controller via the RS485 interface, for converting acquired analog signals into digital signals; the edge controller controls the frequency converters of the positive and negative electrode circulation pumps via the CAN interface, and connects to a power conversion unit and a battery equalizer via the Ethernet interface; the edge controller is configured to execute: a first control flow, for adjusting the speed of the negative electrode circulation pump based on a preset target flow rate value and a real-time flow rate value in the negative electrode main pipeline; and a second control flow, for adjusting the speed of the positive electrode circulation pump based on a preset target pressure difference value between the positive and negative electrode main pipelines and a real-time pressure difference value.

Description

Technical Field

[0001] This disclosure relates to the field of vanadium redox flow battery technology, and more specifically, to a vanadium redox flow battery management system based on edge control. Background Technology

[0002] Vanadium redox flow batteries have demonstrated unique advantages in the field of large-scale energy storage due to their high safety, long cycle life, capacity and power decoupling design, and environmental friendliness.

[0003] Currently, there are two technical approaches to the hardware of vanadium redox flow battery management systems: one is centralized PLC control, which uses existing controllers for programming; the other is using embedded control boards as the hardware of the control system. However, the following drawbacks exist: the PLC centralized control method has low integration, requires multiple expansion modules, has cumbersome wiring, and is relatively expensive; the embedded control board as the hardware of the control system has poor hardware compatibility, requires frequent switching of environments during debugging, and has insufficient resistance to environmental interference.

[0004] Moreover, most current electrolyte circulation pumps use segmented frequency control, which has low control precision and can easily cause excessive voltage difference between the positive and negative electrodes of the fuel cell stack. Long-term operation can affect the life of the fuel cell stack diaphragm, and untimely flow response can also lead to energy waste. Summary of the Invention

[0005] The purpose of this disclosure is to provide an edge-controlled vanadium redox flow battery management system to solve the technical problems of low control integration and low control accuracy of electrolyte circulation pump in vanadium redox flow batteries.

[0006] To achieve the above objectives, this disclosure provides an edge-controlled all-vanadium redox flow battery management system, comprising: An edge controller, which integrates an Ethernet interface, an RS485 interface, and a CAN interface; At least one analog signal acquisition unit is communicatively connected to the edge controller via the RS485 interface, and is used to convert the acquired analog signals into digital signals; The edge controller controls the inverters of the positive and negative circulating pumps through the CAN interface, and connects to the power conversion unit and battery equalizer through the Ethernet interface. The edge controller is configured to perform: The first control process is used to adjust the rotation speed of the negative electrode circulation pump according to the preset target value of the negative electrode main pipeline flow and the real-time flow value. The second control process is used to adjust the rotation speed of the positive electrode circulation pump according to the preset target value of the pressure difference between the positive and negative electrode main pipelines and the real-time pressure difference value.

[0007] Optionally, the edge controller is configured to: The positive electrode circulation pump is controlled to operate at a first initial frequency, and the negative electrode circulation pump is controlled to operate at a second initial frequency higher than the first initial frequency; When the frequency of the positive electrode circulation pump reaches the first initial frequency, the second control process is executed: the frequency of the positive electrode circulation pump is adjusted to a set value based on the first pressure difference target value, while the frequency of the negative electrode circulation pump remains unchanged; When the second control process causes the pressure difference between the positive and negative main pipelines to reach the first pressure difference target value, the first control process is executed: the frequency of the negative circulating pump is adjusted to the first flow target value as the set value, and the set value of the second control process is switched to the second pressure difference target value. The setpoint of the first control flow is set to the second flow target value, and the setpoint of the second control loop is switched to the third pressure difference target value, so that the system enters standby mode.

[0008] Optionally, the all-vanadium redox flow battery management system includes multiple parallel battery management subsystems. The first CAN interface of the edge controller is connected to the frequency converters of the positive and negative circulation pumps of the first battery management subsystem, and the second CAN interface of the edge controller is connected to the frequency converters of the positive and negative circulation pumps of the second battery management subsystem.

[0009] Optionally, the second control process causes the pressure difference between the positive and negative electrode main pipelines to reach the first pressure difference target value, including: The multiple real-time pressure difference values ​​collected continuously are equal to the first pressure difference target value.

[0010] Optionally, a timer is started during the process of adjusting the frequency of the negative electrode circulation pump to a set value with a first flow target value; When the duration of the timing reaches the preset delay threshold and the real-time flow rate and the real-time pressure difference do not exceed their respective preset protection thresholds, the setpoint of the first control flow is set to the second flow rate target value, and the setpoint of the second control loop is switched to the third pressure difference target value, so that the vanadium redox flow battery management system enters the standby state.

[0011] Optionally, both the first control flow and the second control flow adopt a control structure that combines feedforward and feedback; In this process, the feedforward channel of the first control flow calculates the first feedforward amount based on the set value of the flow rate, and the feedback channel of the first control flow uses a PI controller to calculate the first feedback amount based on the flow rate error. The first feedforward amount and the first feedback amount are superimposed and then output to the frequency converter of the negative electrode circulating pump. The feedforward channel of the second control process calculates the second feedforward quantity based on the set value of the pressure difference, and the feedback channel of the second control process uses a PI controller to calculate the second feedback quantity based on the pressure difference error. The second feedforward quantity and the second feedback quantity are superimposed and output to the frequency converter of the positive electrode circulation pump.

[0012] Optionally, it is detected whether the real-time flow rate value is within the preset error range of the second flow rate target value, and whether the real-time pressure difference value is less than or equal to 10 kPa. If so, it is determined that the vanadium redox flow battery management system enters the standby state.

[0013] Optionally, the edge controller is further configured to: In response to a shutdown command, switch the state of the negative pressure valve; Execute the third control process: Adjust the frequency of the negative electrode circulation pump to make the pressure reach the preset shutdown pressure target value; Simultaneously execute the second control process: using the fourth pressure difference target value as the set value, adjust the frequency of the positive electrode circulation pump; When the pressure of the negative electrode main pipeline reaches the shutdown pressure target value and the pressure difference between the positive and negative electrode main pipelines is less than the preset pressure threshold, the frequency of the positive electrode circulation pump and the negative electrode circulation pump is controlled to decrease to zero at a preset decreasing rate. Turn off the positive circulation pump and the negative circulation pump.

[0014] Optionally, the all-vanadium redox flow battery management system presets a multi-level alarm threshold for the pressure difference between the positive and negative electrode main circuits; The edge controller is also configured to: When the real-time pressure difference exceeds the alarm threshold of any level, the corresponding alarm operation is triggered.

[0015] Optionally, the edge controller is further configured to: Monitor the state of charge (SOC) value of each battery management subsystem and the real-time charge / discharge status of the power conversion unit; When the power conversion unit is in a charging state and the SOC difference between any two battery management subsystems is greater than a first preset difference, the battery equalizer is controlled to discharge the subsystem with the higher SOC value. When the power conversion unit is in a discharging state and the SOC difference between any two subsystems is greater than a second preset difference, the battery equalizer is controlled to charge the subsystem with the lower SOC value.

[0016] The above technical solution utilizes an integrated edge controller to directly connect to other devices via standard Ethernet, CAN, and RS485 digital buses, eliminating cumbersome wiring and resulting in high integration. The edge controller aggregates data from other connected devices, enabling multi-source information fusion processing for more accurate control. Furthermore, the digital bus transmission boasts strong anti-interference capabilities, fundamentally solving the problems of high attenuation and susceptibility to interference in long-distance analog signal transmission, thus improving overall system reliability. Additionally, flow control is delegated to the negative electrode pump, while pressure difference control is delegated to the positive electrode pump. A rationally optimized circulating pump control strategy is developed, dynamically adjusting the circulating pump speed through these two control processes to extend the fuel cell stack diaphragm life and avoid energy waste.

[0017] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a battery system provided in an embodiment of the present disclosure.

[0019] Figure 2 A schematic diagram of the structure of an edge-controlled vanadium redox flow battery management system provided in an embodiment of this disclosure.

[0020] Figure 3 A flowchart of a control method based on an edge controller provided in an embodiment of this disclosure.

[0021] Figure 4 A flowchart of another edge controller-based control method provided in an embodiment of this disclosure.

[0022] Figure 5 This is a schematic diagram of the negative electrode main pipeline flow control loop provided in an embodiment of this disclosure.

[0023] Figure 6 This is a schematic diagram of the positive electrode main pipeline pressure difference control loop provided in an embodiment of this disclosure.

[0024] Figure 7 A flowchart of another edge controller-based control method provided in this disclosure embodiment.

[0025] Figure 8 This is a block diagram of an edge-controlled vanadium redox flow battery management device provided in an embodiment of the present disclosure.

[0026] Figure 9 This is a block diagram of an electronic device provided in an embodiment of the present disclosure. Detailed Implementation

[0027] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0028] It should be noted that all actions involving the acquisition of signals, information, or data in this disclosure are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with authorization from the owner of the relevant device.

[0029] The operational efficiency of a vanadium redox flow battery system is highly dependent on the precision and reliability of its control system. Its electrochemical characteristics necessitate real-time coordination of multiple modules, including the electrolyte circulation pump and SOC system equalization control, while simultaneously addressing performance degradation caused by operating condition fluctuations, environmental interference, and long-term charge-discharge cycles. Furthermore, it must meet stringent industrial safety standards, efficient human-machine interface requirements, and compatibility requirements for future capacity expansion. Existing PLC centralized control or embedded control board hardware structures cannot meet the integrated control needs of vanadium redox flow battery systems. Moreover, the electrolyte circulation pump often employs segmented frequency control, which not only fails to protect the lifespan of the stack diaphragm but also wastes electrical energy.

[0030] In view of the aforementioned technical background and application requirements, embodiments of this disclosure propose a vanadium redox flow battery management system based on edge control technology. This system deeply integrates the distributed processing capabilities of edge computing, and by deploying an edge controller with multi-protocol interfaces locally, it achieves real-time monitoring and control of the vanadium redox flow battery stack status, electrolyte parameters, and energy conversion process, significantly improving the accuracy and response efficiency of battery management. Compared to traditional battery management architectures relying on centralized PLC control, this system solves the problems of high hardware platform development costs and cumbersome wiring. Compared to battery management architectures using embedded control boards, this system has stronger anti-interference capabilities.

[0031] This disclosure provides an edge-controlled all-vanadium redox flow battery management system, including: An edge controller that integrates an Ethernet interface, an RS485 interface, and a CAN interface; At least one analog signal acquisition unit is connected to the edge controller via an RS485 interface to convert the acquired analog signals into digital signals; The edge controller controls the inverters of the positive and negative circulating pumps via the CAN interface, and connects to the power conversion unit and battery equalizer via the Ethernet interface. The edge controller is configured to execute: The first control process is used to adjust the speed of the negative electrode circulation pump according to the preset target value of the negative electrode main pipeline flow and the real-time flow value. The second control process is used to adjust the speed of the positive electrode circulation pump based on the preset target value of the pressure difference between the positive and negative electrode main pipelines and the real-time pressure difference value.

[0032] Figure 1 This is a schematic diagram of a battery system provided in an embodiment of this disclosure. Figure 1 As shown, the battery system is centered around a 500kW battery system and is connected to a 400V AC bus via a power conversion unit (PCS) to achieve charging and discharging. The battery system includes components such as a 400V AC bus, an energy storage AC converter (PCS), the battery system, a distribution cabinet, a BMS (Battery Management System), a SOC equalizer, and a switching cabinet.

[0033] In the battery system provided in this embodiment, the BMS uses an edge controller as its core processor. Unlike existing PLC control or embedded control boards, the edge controller achieves high integration and accurate control through multiple interfaces.

[0034] Figure 2 This is a schematic diagram of the structure of a vanadium redox flow battery management system based on edge control, provided in an embodiment of this disclosure. Figure 2 As shown, the edge controller (H1500) connects to the upper-layer system via multiple Ethernet interfaces (Eth1~Eth4) using different protocols. For example, the Modbus TCP protocol is used to connect the human-machine interface (HMI) and the PCS to realize parameter setting and power command issuance; the dual Ethernet ports (Eth3~Eth4) use the IEC-104 protocol to connect to the energy management system (EMS) to achieve reliable communication with the grid dispatching system.

[0035] The edge controller also connects to the frequency converters via multiple CAN interfaces (CAN1, CAN2). For example, the controller's CAN1 and CAN2 interfaces are connected to the frequency converters of subsystem one and subsystem two, respectively. The positive and negative circulation pumps of each subsystem are driven by independent frequency converters, which receive speed commands from the controller via the CANOpen protocol.

[0036] The edge controller also connects to other devices via multiple RS485 interfaces (485-1 to 485-4). For example, the edge controller connects analog signal acquisition units from two subsystems (such as...) via RS485-1 to 485-1. Figure 2The data acquisition units (1 to m) are analog signal acquisition units responsible for collecting analog signals such as temperature, pressure, and gas concentration, and converting them into digital signals. The edge controller is connected to electricity meters 1 to n via a 485-3 circuit; these meters are used to measure electricity consumption. The edge controller is also connected to flow meters 1 to i via a 485-4 circuit; these flow meters provide digital signals of the main pipeline flow. These devices communicate with the edge controller via the stable Modbus RTU protocol, forming a data sensing network.

[0037] The edge controller can also connect to local storage devices via a USB interface to record system operation logs and historical data, such as by inserting a USB flash drive.

[0038] In this embodiment of the disclosure, the first control flow and the second control flow are control algorithms running in the edge controller.

[0039] The first control flow is a flow loop in the negative electrode main pipeline, and its control objective is the flow rate of the negative electrode electrolyte in the main pipeline. Specifically, the edge controller internally sets the target flow rate value and receives data from the flow meter (e.g., ...). Figure 2 The real-time flow value of the flow meter i) connected to the RS485 bus is compared with the flow value. The algorithm calculates the control command and sends it to the frequency converter of the negative circulation pump via the CAN bus to adjust the pump speed, so that the actual flow rate accurately follows the set flow target value.

[0040] The second control process is a pressure difference loop between the positive and negative electrode main pipelines. Its control objective is to maintain the pressure difference between the positive and negative electrode electrolyte main pipelines within a set safe range. Specifically, the edge controller sets the target pressure difference value, receives pressure values ​​from the positive and negative electrode pressure sensors, and then calculates the difference in real time. The algorithm adjusts the frequency converter of the positive electrode circulation pump based on the deviation.

[0041] The above technical solution utilizes an integrated edge controller to directly connect to other devices via standard Ethernet, CAN, and RS485 digital buses, eliminating cumbersome wiring and resulting in high integration. The edge controller aggregates data from other connected devices, enabling multi-source information fusion processing for more accurate control. Furthermore, the digital bus transmission boasts strong anti-interference capabilities, fundamentally solving the problems of high attenuation and susceptibility to interference in long-distance analog signal transmission, thus improving overall system reliability. Additionally, by delegating flow control to the negative pump and pressure difference control to the positive pump, a rationally optimized circulating pump control strategy is developed. This dynamically adjusts the circulating pump speed through two control processes to extend the fuel cell stack diaphragm life and avoid energy waste.

[0042] In some feasible embodiments, such as Figure 3 As shown, the edge controller is configured as follows: Step S31: Control the positive electrode circulation pump to operate at a first initial frequency, and control the negative electrode circulation pump to operate at a second initial frequency higher than the first initial frequency.

[0043] Step S32: When the frequency of the positive electrode circulation pump reaches the first initial frequency, execute the second control process: adjust the frequency of the positive electrode circulation pump to the first pressure difference target value as the set value, and keep the frequency of the negative electrode circulation pump unchanged.

[0044] Step S33: When the second control process causes the pressure difference between the positive and negative main pipelines to reach the first pressure difference target value, execute the first control process: adjust the frequency of the negative circulating pump with the first flow target value as the set value, and at the same time switch the set value of the second control process to the second pressure difference target value.

[0045] Step S34: Set the setpoint of the first control flow to the second flow target value, and switch the setpoint of the second control loop to the third pressure difference target value, so that the system enters standby mode.

[0046] The first initial frequency is 25Hz, the second initial frequency is 30Hz, and the preset ramp rate is 5Hz / second; the first pressure difference target value is 0kPa, the second pressure difference target value is 8kPa, and the third pressure difference target value is 5kPa; the first flow rate target value is 25m³ / h, and the second flow rate target value is 36m³ / h.

[0047] In step S31, for example, the first initial frequency is 25Hz and the second initial frequency is 30Hz. The edge controller sends commands to the two inverters via the CAN bus: the positive pump starts at 25Hz and the negative pump starts at a higher frequency of 30Hz, both accelerating at a gentle ramp (e.g., 5Hz / second). The negative side is typically the main circulation path for the electrolyte; allowing it to establish flow rate more quickly helps to rapidly fill the pipes, remove air bubbles, and provide an initial flow and pressure foundation for the entire battery system.

[0048] In step S32, the edge controller continuously monitors the feedback frequency of the positive electrode pump. Once it reaches the preset first initial frequency, it locks the current frequency of the negative electrode pump to keep it constant, and simultaneously activates the second control process (i.e., the pressure difference loop), setting the target of the second control process to the first pressure difference target value (usually 0 kPa). During this stage, only the positive electrode pump is regulated. The regulation task of the positive electrode pump is to quickly adjust its own speed to bring the pressure of the positive electrode main pipeline towards the negative electrode side until the pressure difference between the two sides approaches zero.

[0049] It should be noted that by eliminating the static pressure difference across the fuel cell stack diaphragm before introducing significant flow changes, a better initial start-up environment is provided for the fuel cell stack diaphragm, thereby extending its service life.

[0050] Step S33 introduces flow control based on the pressure control in step S32. The edge controller switches to the first control flow (or activates the flow loop) and starts adjusting the negative electrode pump with a first flow target value (e.g., 25 m³ / h). Simultaneously, the target value of the second control flow (i.e., the pressure difference loop) is switched from 0 kPa to a second pressure difference target value (e.g., 8 kPa). In this way, the vanadium redox flow battery management system enters a dual-loop collaborative working mode: the flow loop drives the negative electrode pump to achieve a flow rate of 25 m³ / h, while the pressure difference loop drives the positive electrode pump to maintain a small pressure difference environment.

[0051] After step S33 stabilizes the flow rate and differential pressure, the system proceeds to step S34, where the setpoint of the first control flow is smoothly increased from 25 m³ / h to the second flow rate target value of 36 m³ / h, and the differential pressure loop target is adjusted from 8 kPa to 5 kPa. These values ​​are the operating condition setpoints when the system is running normally. Those skilled in the art can design them according to actual needs, and this disclosure does not impose any restrictions on them.

[0052] At this point, the all-vanadium redox flow battery management system has sufficient fluid circulation capability to quickly respond to charge and discharge commands, while maintaining a low differential pressure environment that is friendly to the battery stack and achieving low pumping power consumption.

[0053] The above technical solution first balances the pressure, then controls the flow rate, and only increases it to the set value for normal system operation after the flow rate and pressure difference stabilize. This ensures uniform fluid distribution inside the fuel cell stack during startup, effectively avoiding electrolyte leakage and diaphragm deformation caused by sudden pressure changes or uneven flow. Moreover, the startup process does not directly reach the maximum flow rate, but first uses a lower flow rate (25 m³ / h) to meet basic circulation and heat exchange, and then increases it to the standby flow rate (36 m³ / h) after stabilization, avoiding energy waste caused by operating at high power too early.

[0054] In some embodiments, the vanadium redox flow battery management system includes multiple parallel battery management subsystems. The first CAN interface of the edge controller is connected to the inverters of the positive and negative circulation pumps of the first battery management subsystem, and the second CAN interface of the edge controller is connected to the inverters of the positive and negative circulation pumps of the second battery management subsystem.

[0055] Continue to refer to Figure 1 Subsystem 1 is equivalent to the first battery management subsystem, and subsystem 2 is equivalent to the second battery management subsystem. Each subsystem includes an independent electrolyte circulation loop, specifically including positive and negative electrode stacks, circulation pumps, storage tanks, and pipelines, which are electrically connected in parallel to the DC bus.

[0056] The edge controller (H1500) provides multiple independent CAN channels. CAN1 bus serves subsystem one, connecting inverters 1 and 2 within it, which drive the positive and negative pumps respectively. CAN2 bus connects inverters 3 and 4 in subsystem two. Each CAN bus is an independent communication network, using the CANopen protocol, with each inverter on the bus acting as a node with an independent address.

[0057] This design simplifies system expansion by requiring only the CAN interface on the edge controller for each new subsystem. Furthermore, the control program can be reused for new subsystems, reducing the complexity and cost of system upgrades. Independent CAN channels ensure uninterrupted communication between subsystems; a pump or inverter failure in one subsystem will not affect others. This also allows maintenance personnel to quickly pinpoint the malfunctioning CAN bus, thereby reducing troubleshooting time and improving system maintainability and availability.

[0058] In some embodiments, the second control process enables the pressure difference between the positive and negative main pipelines to reach a first pressure difference target value, including: multiple real-time pressure difference values ​​collected continuously are equal to the first pressure difference target value.

[0059] Specifically, the pressure difference between the positive and negative main pipelines reaching the first pressure difference target value does not mean that the sampled value at a certain instant equals the target value. Rather, it means that the real-time pressure difference values ​​obtained in multiple consecutive sampling cycles are equal to the first pressure difference target value, so that the system can operate smoothly and avoid misjudging the target state due to instantaneous fluctuations.

[0060] In some feasible embodiments, during the process of adjusting the frequency of the negative electrode circulation pump with the first flow target value as the setpoint, a timer is started; if the timer duration reaches a preset delay threshold and the real-time flow value and the real-time pressure difference value do not exceed their respective preset protection thresholds, the setpoint of the first control flow is set to the second flow target value, and the setpoint of the second control loop is switched to the third pressure difference target value, causing the vanadium redox flow battery management system to enter a standby state. The delay threshold can be set to 20 seconds.

[0061] In other words, this embodiment incorporates a time-delay observation into the first control flow of step S33 mentioned above. When the system begins to adjust the frequency of the negative electrode circulating pump to the first target flow rate (25 m³ / h), an internal timer is started to continuously monitor the real-time flow rate and the pressure difference between the positive and negative electrode main pipelines. During the timer period, both the real-time flow rate and the real-time pressure difference must remain within the set protection thresholds to confirm that the system is operating normally. The protection thresholds can be set according to actual needs; for example, the real-time flow protection threshold can be set to 30 m³ / h, and the pressure difference protection threshold can be set to 0.15 MPa. Only when both remain within the time-delay thresholds are the system considered stable.

[0062] In some feasible embodiments, both the first control flow and the second control flow adopt a control structure combining feedforward and feedback. Specifically, the feedforward channel of the first control flow calculates a first feedforward quantity based on the set value of the flow rate, and the feedback channel of the first control flow uses a PI controller to calculate a first feedback quantity based on the flow rate error. The first feedforward quantity and the first feedback quantity are superimposed and output to the inverter of the negative circulating pump. The feedforward channel of the second control flow calculates a feedforward quantity based on the set value of the pressure difference, and the feedback channel of the second control flow uses a PI controller to calculate a feedback quantity based on the pressure difference error. The second feedforward quantity and the second feedback quantity are superimposed and output to the inverter of the positive circulating pump.

[0063] Taking the first control flow (i.e., the flow loop) as an example, the feedback channel continuously calculates the error between the flow setpoint and the actual flow value from the flow meter. The PI controller performs PI calculations on this error to obtain the feedback quantity. The feedforward channel is a predictive control based on models or experience. It directly calculates the control quantity in advance based on changes in the setpoint without obtaining the error. For example, when the flow target switches from 25 m³ / h to 36 m³ / h, the feedforward channel can calculate the frequency increment of the inverter based on system characteristics (such as the relationship between pump flow and frequency, pipeline characteristics, etc.). This increment is added to the feedback quantity output by the feedback channel, and together they act on the inverter to achieve rapid response and precise adjustment.

[0064] The above technical solution combines feedforward and feedback, achieving control accuracy exceeding that of traditional single feedback or simple segmented control. Specifically, simple feedback control requires waiting for an error to occur before adjustment begins, resulting in a slow response. In contrast, the feedforward channel drives the pump to adjust rapidly when a command to change the target value is issued, thus shortening the response time of parameters such as flow rate and pressure to the setpoint, allowing the system to reach a stable state more quickly. While maintaining rapid response, PI feedback ensures the accuracy and stability of the adjustment, effectively suppressing overshoot and oscillation.

[0065] In some embodiments, the condition for determining that the vanadium redox flow battery management system enters the standby state is: whether the real-time flow value is within the preset error range of the second flow target value, and whether the real-time pressure difference is less than or equal to 10 kPa. If so, the vanadium redox flow battery management system enters the standby state.

[0066] This embodiment uses dual judgment conditions to ensure that the system only enters standby mode when both the flow rate and pressure difference meet the set thresholds, thus ensuring stable system operation.

[0067] In some feasible embodiments, such as Figure 4 As shown, the edge controller is also configured as follows: Step S41: In response to the shutdown command, switch the state of the negative pressure valve.

[0068] Step S42: Execute the third control process: Adjust the frequency of the negative electrode circulation pump to make the pressure reach the preset shutdown pressure target value.

[0069] Step S43: Simultaneously execute the second control process: using the fourth pressure difference target value as the set value, adjust the frequency of the positive electrode circulation pump.

[0070] Step S44: When the pressure of the negative electrode main pipeline reaches the shutdown pressure target value and the pressure difference between the positive and negative electrode main pipelines is less than the preset pressure threshold, control the frequency of the positive electrode circulation pump and the negative electrode circulation pump to decrease to zero at a preset decreasing rate.

[0071] Step S45: Turn off the positive and negative circulation pumps.

[0072] The preset shutdown pressure target value can be set to 60 kPa, the fourth pressure difference target value can be set to 0 kPa, the preset pressure threshold can be set to 3 kPa, and the preset descent ramp rate can be set to 5 Hz / second.

[0073] Similar to the startup process, the shutdown process also involves a smooth decrease in frequency. Specifically, the first step involves operating the negative pressure valve to change the system's pressure relief. The second step activates the third control process, targeting the negative main pipeline pressure. This process is set to a higher shutdown pressure target value (e.g., 60 kPa) to increase system pressure. Simultaneously, the second control process (pressure differential loop) is initiated, but its target is set to a fourth pressure differential target value (typically 0 kPa). During this stage, the two pumps work together again: the negative pump works to increase pressure, while the positive pump reduces its frequency based on pressure differential feedback to maintain pressure balance and prevent electrolyte backflow. When the system pressure stabilizes at the shutdown target value and the pressure difference between the positive and negative main pipelines approaches zero, the system no longer maintains pressure. Instead, it controls the frequency of both pumps to decrease to zero at a synchronized, gradual ramp rate (e.g., 5 Hz / second), and then executes the shutdown command. This ramp-down is to allow for a smooth release of fluid momentum.

[0074] This design actively raises the system pressure to a higher value (e.g., 60 kPa) before stopping the pump. Utilizing the residual pressure, more electrolyte is pushed back from the complex flow channels and pipelines inside the fuel cell stack to the main storage tank after the pump stops. This reduces the amount of electrolyte remaining in the stack. In low-temperature environments, this effectively reduces the risk of localized electrolyte oversaturation and crystallization. During long-term static storage, it also mitigates potential corrosion of local materials by the electrolyte, improving system restart performance and long-term reliability. Furthermore, the shutdown process is not a direct shutdown; instead, a second control procedure is initiated to ensure that the pressure on both sides of the fuel cell stack diaphragm remains dynamically balanced during the overall system pressure increase. This prevents pressure increases on one side (usually the negative electrode side due to the pressure target) from causing compressive or tensile stress on the diaphragm, thus protecting the fuel cell stack diaphragm.

[0075] The following is combined Figure 5 and Figure 6 The two control loops provided in the embodiments of this disclosure are further described.

[0076] like Figure 5 As shown, this embodiment of the present disclosure provides a flow control loop for the negative electrode main circuit.

[0077] The control objective of the negative electrode main pipeline flow control loop is to ensure that the flow rate of the negative electrode main pipeline closely follows the setpoint, so as to ensure that the stack receives a stable electrolyte supply.

[0078] according to Figure 5 The direction of the middle arrow is explained: 1. Setpoint Input: The value given by the edge controller based on the current startup state of the system, which can be set to 25m³ / h.

[0079] 2. Reference value calculation: Receive the set value, process the set value, such as adding a slope change rate limit to ensure a smooth transition of the target value, and output the flow target reference signal (AQref).

[0080] 3. Feedforward control: Based on the calculated AQref, a basic control quantity (such as the basic frequency of the frequency converter) is estimated.

[0081] 4. Feedback Comparison and Error Generation: The target reference signal is compared with the negative main pipeline flow feedback (AQreal), and the error Err = AQref - AQreal is calculated.

[0082] 5. PI Controller: Receives the flow error signal Err. The P (proportional) element outputs control action proportional to the magnitude of the error; the I (integral) element accumulates historical errors. The control output of the PI controller is used to correct deviations that the feedforward control failed to fully compensate for.

[0083] 6. Negative system input: The fast predictive control input output from the feedforward channel is added to the deviation correction control input output from the PI controller to obtain the final control command, which is then sent to the actuator.

[0084] 7. Actuator: The pump and pipeline together constitute the controlled mechanism. Control commands are first converted into a given signal (such as a frequency command) to the frequency converter. The frequency converter drives the motor of the negative pole pump, adjusting its output flow rate by changing the pump's speed.

[0085] 8. Negative main pipeline flow rate: The flow meter measures this value in real time and uses it as an AQreal feedback signal, which is then sent back to the input for comparison.

[0086] like Figure 6 As shown, this embodiment of the present disclosure provides a pressure difference control loop for the positive electrode main pipeline. The control objective of the pressure difference control loop for the positive and negative electrode main pipelines is to maintain the pressure difference between the positive and negative electrode main pipelines at a set value, thereby protecting the fuel cell stack diaphragm.

[0087] according to Figure 6 The direction of the middle arrow is explained: 1. Setpoint Input: The value given by the edge controller based on the current startup state of the system, which can be set to 0 kPa.

[0088] 2. Reference value calculation: Similar to the flow loop, this step processes the set value and outputs a smoothed pressure difference target reference signal (APref).

[0089] 3. Feedforward control: The positive pump frequency value is estimated based on the calculated APref for rapid coarse adjustment.

[0090] 4. Feedback Comparison and Error Generation: Compare APref with the pressure difference feedback of the positive and negative main pipelines, and generate a pressure difference error signal Err = APref - APreal.

[0091] 5. PI Controller: Receives the pressure difference error signal Err. The P (proportional) element outputs control action proportional to the magnitude of the error; the I (integral) element accumulates historical errors. The control output of the PI controller is used to correct deviations that the feedforward control failed to fully compensate for.

[0092] 6. Actuator: The action of the positive pump changes the pressure in the positive main pipeline. The positive and negative pressures are measured simultaneously and subtracted to obtain the real-time pressure difference feedback value.

[0093] During system operation, two loops work simultaneously: the flow loop acts as the main loop, controlling the negative electrode pump to ensure the total amount of electrolyte required for the reaction; the pressure differential loop acts as the auxiliary loop, controlling the positive electrode pump to ensure the fluid pressure balance within the fuel cell stack. The edge controller sets matching target values ​​for both, enabling the system to balance flow and pressure differential requirements, thereby extending diaphragm life and improving energy efficiency.

[0094] In some embodiments, the vanadium redox flow battery management system presets multi-level alarm thresholds for the pressure difference between the positive and negative electrode main circuits; the edge controller is also configured to trigger the alarm operation corresponding to any level when the real-time pressure difference exceeds the alarm threshold of any level.

[0095] For example, the positive and negative pole differential pressure protection values ​​can be set (18 kPa for level 3 alarm, 21 kPa for level 2 alarm, and 25 kPa for level 1 alarm), and the positive and negative pole main pipeline flow difference can also be set as protection (8 kPa for level 3 alarm). 3 / h, Level 2 alarm 10m 3 / h, Level 1 alarm 12m 3 ( / h). Different alarm levels correspond to different alarm actions. For example, a level 1 alarm will light up a light to alert the user, a level 2 alarm will issue an audible and visual warning and reduce the pump speed, and a level 3 alarm will automatically shut down the machine and lock the system.

[0096] In some embodiments, such as Figure 7 As shown, the edge controller is also configured as follows: Step S71: Monitor the state of charge (SOC) value of each battery management subsystem and the real-time charging and discharging status of the power conversion unit.

[0097] Step S72: When the power conversion unit is in a charging state and the SOC difference between any two battery management subsystems is greater than the first preset difference, control the battery equalizer to discharge the subsystem with the higher SOC value.

[0098] Step S73: When the power conversion unit is in a discharging state and the SOC difference between any two subsystems is greater than the second preset difference, control the battery equalizer to charge the subsystem with the lower SOC value.

[0099] Specifically, the edge controller continuously monitors the state of charge (SOC) of each parallel battery management subsystem and the real-time charging and discharging status of the power conversion unit through a communication network (such as CAN or internal bus), and determines whether to trigger the equalization strategy based on the preset SOC difference threshold.

[0100] Among them, the polling time, starting SOC difference, and stopping SOC difference can be set on the touch screen.

[0101] Scenario 1: The PCS is charging the entire battery pack. If an imbalance in State of Charge (SOC) is detected between subsystems (the difference exceeds a threshold), the edge controller commands the equalizer to discharge the subsystem with the higher SOC. Note that this subsystem is simultaneously receiving charge from the PCS, so the net charging current of the high-SOC subsystem equals the charging current provided by the PCS minus the current discharged by the equalizer, resulting in a slower SOC rise rate. Meanwhile, the low-SOC subsystem receives a relatively larger share of the charge.

[0102] Scenario 2: The PCS is drawing power from the battery pack and discharging. If a significant difference in State of Charge (SOC) is detected between subsystems, the edge controller commands the equalizer to charge the subsystem with the lower SOC. This low-SOC subsystem is simultaneously discharging through the PCS, so its net discharge current equalizes the discharge current drawn by the PCS minus the current charged by the equalizer, resulting in a slower rate of SOC decline. Meanwhile, the high-SOC subsystem contributes relatively more discharge energy.

[0103] In traditional low-SOC charging equalization methods, if low-SOC cells are additionally charged during PCS charging, the cell will experience a current exceeding the sum of the PCS charging current and the equalizer charging current. This total current may exceed the design limits of the fuel cell stack, bus, or components, leading to overheating, damage, or even safety accidents. However, this embodiment ensures that the equalization current always offsets the main power current. Therefore, regardless of whether the PCS is charging or discharging, the absolute value of the total current flowing into the subsystem is less than the current generated by the PCS.

[0104] Based on the same technical concept, this disclosure also provides an edge-controlled all-vanadium redox flow battery management device, such as... Figure 8 As shown, it includes: System startup control module 801, used to execute the system startup program; includes: The positive electrode circulation pump is controlled to operate at a first initial frequency, and the negative electrode circulation pump is controlled to operate at a second initial frequency higher than the first initial frequency; When the frequency of the positive electrode circulation pump reaches the first initial frequency, the second control process is executed: the frequency of the positive electrode circulation pump is adjusted to the set value of the first pressure difference target value, while the frequency of the negative electrode circulation pump remains unchanged. When the second control process causes the pressure difference between the positive and negative main pipelines to reach the first pressure difference target value, the first control process is executed: the frequency of the negative circulating pump is adjusted to the first flow target value as the set value, and the set value of the second control process is switched to the second pressure difference target value. Set the setpoint of the first control flow to the second flow target value, and switch the setpoint of the second control loop to the third pressure difference target value, so that the system enters standby mode.

[0105] It also includes a system shutdown control module 802, used to execute system shutdown procedures; including: In response to a shutdown command, switch the state of the negative pressure valve; Execute the third control process: Adjust the frequency of the negative electrode circulation pump to make the pressure reach the preset shutdown pressure target value; Simultaneously execute the second control process: using the fourth pressure difference target value as the set value, adjust the frequency of the positive electrode circulation pump; When the pressure in the negative electrode main pipeline reaches the shutdown pressure target value and the pressure difference between the positive and negative electrode main pipelines is less than the preset pressure threshold, the frequency of the positive electrode circulation pump and the negative electrode circulation pump is controlled to decrease to zero at a preset decreasing rate. Turn off both the positive and negative circulation pumps.

[0106] It also includes a leveling control module 803, used to execute the SOC automatic leveling program, specifically including: Monitor the state of charge (SOC) value of each battery management subsystem and the real-time charging and discharging status of the power conversion unit; When the power conversion unit is in a charging state and the SOC difference between any two battery management subsystems is greater than the first preset difference, the battery equalizer is controlled to discharge the subsystem with the higher SOC value. When the power conversion unit is in a discharging state and the SOC difference between any two subsystems is greater than the second preset difference, the battery equalizer is controlled to charge the subsystem with the lower SOC value.

[0107] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0108] like Figure 9 As shown, the electronic device 900 may include a processor 901 and a memory 902. The electronic device 900 may also include one or more of a multimedia component 903, an input / output (I / O) interface 904, and a communication component 905.

[0109] The processor 901 controls the overall operation of the electronic device 900 to complete all or part of the aforementioned steps. The memory 902 stores various types of data to support the operation of the electronic device 900. This data may include, for example, instructions for any application or method operating on the electronic device 900, and application-related data such as sensor data, alarm records, etc. The memory 902 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The multimedia component 903 may include a screen and an audio component. The screen may be, for example, a touchscreen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signals may be further stored in memory 902 or transmitted via communication component 905. The audio component also includes at least one speaker for outputting audio signals. I / O interface 904 provides an interface between processor 901 and other interface modules, such as a keyboard, mouse, buttons, etc. These buttons may be virtual or physical buttons. Communication component 905 is used for wired or wireless communication between the electronic device 900 and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, 4G, NB-IoT, eMTC, or other 5G, or a combination thereof, is not limited here. Therefore, the corresponding communication component 905 may include: a Wi-Fi module, a Bluetooth module, an NFC module, etc.

[0110] In an exemplary embodiment, the electronic device 900 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the methods described above.

[0111] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided, which, when executed by a processor, implement the aforementioned steps. For example, the computer-readable storage medium may be the aforementioned memory 902 including program instructions, which may be executed by the processor 901 of the electronic device 900 to complete the aforementioned steps.

[0112] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0113] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0114] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. An edge control based vanadium redox flow battery management system, characterized in that, include: An edge controller, which integrates an Ethernet interface, an RS485 interface, and a CAN interface; At least one analog signal acquisition unit is communicatively connected to the edge controller via the RS485 interface, and is used to convert the acquired analog signals into digital signals; The edge controller controls the inverters of the positive and negative circulating pumps through the CAN interface, and connects to the power conversion unit and battery equalizer through the Ethernet interface. The edge controller is configured to perform: The first control process is used to adjust the rotation speed of the negative electrode circulation pump according to the preset target value of the negative electrode main pipeline flow and the real-time flow value. The second control process is used to adjust the rotation speed of the positive electrode circulation pump according to the preset target value of the pressure difference between the positive and negative electrode main pipelines and the real-time pressure difference value.

2. The edge control based vanadium redox flow battery management system of claim 1, wherein, The edge controller is configured to: The positive electrode circulation pump is controlled to operate at a first initial frequency, and the negative electrode circulation pump is controlled to operate at a second initial frequency higher than the first initial frequency; When the frequency of the positive electrode circulation pump reaches the first initial frequency, the second control process is executed: the frequency of the positive electrode circulation pump is adjusted to a set value based on the first pressure difference target value, while the frequency of the negative electrode circulation pump remains unchanged; When the second control process causes the pressure difference between the positive and negative main pipelines to reach the first pressure difference target value, the first control process is executed: the frequency of the negative circulating pump is adjusted to the first flow target value as the set value, and the set value of the second control process is switched to the second pressure difference target value. The setpoint of the first control flow is set to the second flow target value, and the setpoint of the second control loop is switched to the third pressure difference target value, so that the system enters standby mode.

3. The edge control based vanadium redox flow battery management system of claim 2, wherein, The vanadium redox flow battery management system includes multiple parallel battery management subsystems. The first CAN interface of the edge controller is connected to the frequency converters of the positive and negative circulation pumps of the first battery management subsystem, and the second CAN interface of the edge controller is connected to the frequency converters of the positive and negative circulation pumps of the second battery management subsystem.

4. The edge control based vanadium redox flow battery management system of claim 2, wherein, The second control process enables the pressure difference between the positive and negative electrode main pipelines to reach the first pressure difference target value, including: The multiple real-time pressure difference values ​​collected continuously are equal to the first pressure difference target value.

5. The edge control based vanadium redox flow battery management system of claim 2, wherein, During the process of adjusting the frequency of the negative electrode circulation pump to a set value based on the first flow target value, a timer is started; When the duration of the timing reaches the preset delay threshold and the real-time flow rate and the real-time pressure difference do not exceed their respective preset protection thresholds, the setpoint of the first control flow is set to the second flow rate target value, and the setpoint of the second control loop is switched to the third pressure difference target value, so that the vanadium redox flow battery management system enters the standby state.

6. The edge control based vanadium redox flow battery management system of claim 2, wherein, Both the first control flow and the second control flow adopt a control structure that combines feedforward and feedback; In this process, the feedforward channel of the first control flow calculates the first feedforward amount based on the set value of the flow rate, and the feedback channel of the first control flow uses a PI controller to calculate the first feedback amount based on the flow rate error. The first feedforward amount and the first feedback amount are superimposed and then output to the frequency converter of the negative electrode circulating pump. The feedforward channel of the second control process calculates the second feedforward quantity based on the set value of the pressure difference, and the feedback channel of the second control process uses a PI controller to calculate the second feedback quantity based on the pressure difference error. The second feedforward quantity and the second feedback quantity are superimposed and output to the frequency converter of the positive electrode circulation pump.

7. The edge control based vanadium redox flow battery management system of claim 2, wherein, The system detects whether the real-time flow rate value is within the preset error range of the second flow rate target value and whether the real-time pressure difference is less than or equal to 10 kPa. If so, it determines that the vanadium redox flow battery management system enters the standby state.

8. The edge control based vanadium redox flow battery management system of claim 2, wherein, The edge controller is also configured to: In response to a shutdown command, switch the state of the negative pressure valve; Execute the third control process: Adjust the frequency of the negative electrode circulation pump to make the pressure reach the preset shutdown pressure target value; Simultaneously execute the second control process: using the fourth pressure difference target value as the set value, adjust the frequency of the positive electrode circulation pump; When the pressure of the negative electrode main pipeline reaches the shutdown pressure target value and the pressure difference between the positive and negative electrode main pipelines is less than the preset pressure threshold, the frequency of the positive electrode circulation pump and the negative electrode circulation pump is controlled to decrease to zero at a preset decreasing rate. Turn off the positive circulation pump and the negative circulation pump.

9. The edge control based vanadium redox flow battery management system of claim 8, wherein, The vanadium redox flow battery management system has preset multi-level alarm thresholds for the pressure difference between the positive and negative electrode main circuits. The edge controller is also configured to: When the real-time pressure difference exceeds the alarm threshold of any level, the corresponding alarm operation is triggered.

10. The edge control based vanadium redox flow battery management system of claim 3, wherein, The edge controller is also configured to: Monitor the state of charge (SOC) value of each battery management subsystem and the real-time charge / discharge status of the power conversion unit; When the power conversion unit is in a charging state and the SOC difference between any two battery management subsystems is greater than a first preset difference, the battery equalizer is controlled to discharge the subsystem with the higher SOC value. When the power conversion unit is in a discharging state and the SOC difference between any two subsystems is greater than a second preset difference, the battery equalizer is controlled to charge the subsystem with the lower SOC value.

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