Flow battery module operation stability control system

Abstract

The invention belongs to the technical field of flow battery energy storage, and discloses a flow battery module operation stability control system. Comprising a BMS battery system, and an EMS, an SACADA and a PCS which are connected with the BMS battery system; the BMS comprises a battery master controller, a battery cluster controller and an acquisition unit, the battery cluster controller is electrically connected with the liquid path, and the acquisition unit is electrically connected with the electric pile. According to the invention, through multi-sensor data fusion, an adaptive control algorithm and a multi-stage fault response mechanism, all-condition stable operation of the flow battery module is realized.

Description

Technical Field

[0001] This invention belongs to the field of flow battery energy storage technology, specifically relating to a flow battery module operation stability control system. Background Technology

[0002] As a core device for large-scale energy storage, the operational stability of flow batteries is significantly affected by the coupling of electrical control parameters (voltage, current) and physical parameters (temperature, pressure, flow rate). Existing systems suffer from the following technical bottlenecks: 1. Temperature fluctuations cause performance degradation The internal temperature difference of a flow battery stack can reach over 15°C, leading to changes in electrolyte viscosity (±20%), a decrease in ion transport efficiency (reduction of 30%), and accelerated corrosion of electrode materials. For example, vanadium redox flow batteries are prone to vanadium ion precipitation at low temperatures (<5°C) and at high temperatures (>45°C), vanadium ions are easily deposited. 5+ Stability drops sharply.

[0003] 2. Pressure imbalance leads to system failure. Pressure fluctuations in the circulation pipeline (±0.2MPa) may cause electrolyte leakage. Traditional pressure control relies on a single threshold for judgment, resulting in a fault response time >100ms. For example, when the water pump is running dry or the pipeline is blocked, the pressure abnormality cannot be identified in time, leading to localized drying of the fuel cell stack.

[0004] 3. Uneven flow rate causes localized overheating Uneven electrolyte flow distribution can lead to violent local reactions in the fuel cell stack, accelerating the aging of electrode materials. Traditional flow control relies on empirical parameters and cannot dynamically match load changes.

[0005] 4. Lack of fault early warning and health management The existing system lacks the ability to fuse and analyze multi-source data, making it difficult to identify potential faults in advance (such as slight pressure changes in the early stage of electrolyte leakage (<0.05MPa), resulting in high maintenance costs and a high risk of downtime).

[0006] Patent CN104201407A discloses a DCS-based control system for a flow battery system and a flow battery system itself. The control system includes: a data acquisition system connected to at least one of the flow battery systems for collecting operating parameters; and a DCS controller connected to a local monitoring system, the data acquisition system, and at least one flow battery system for controlling the operating state of the flow battery system according to control commands issued by the local monitoring system. The controller also determines whether the operating parameters collected by the data acquisition system are abnormal based on preset judgment conditions and adjusts the operating state of the flow battery system accordingly based on changes in the operating parameters. This invention, based on DCS control technology, allows for a significantly higher maximum number of connected nodes than existing PLC or microcontroller-based control systems, improving data processing and control capabilities. The redundant structure ensures the stable operation and reliability of both the control system and the flow battery system.

[0007] However, the patent does not design an adaptive control algorithm for different situations and does not have a multi-level fault response effect.

[0008] Patent CN108627768A discloses an online SOC detection method for a vanadium redox flow battery system. The method involves placing a porous medium in the pipeline system, measuring the pressure difference across the porous medium and the volumetric flow rate through it in real time, calculating the electrolyte viscosity through the porous medium, and then using offline SOC data along with electrolyte viscosity and temperature data, fitting a black-box model, and calculating the SOC value in real time based on the electrolyte temperature through the porous medium.

[0009] To address the need for real-time online SOC monitoring in vanadium redox flow battery systems, this invention measures the pressure difference and flow rate across a porous medium installed in the pipeline online. Darcy's law is used to obtain the electrolyte viscosity value. Then, through a pre-fitted data model of SOC versus temperature and viscosity, and real-time electrolyte temperature measurements, the online calculation and prediction of the vanadium redox flow battery system's SOC is achieved. The SOC monitoring results can be displayed in real-time through the battery control system. This invention fully utilizes the sensors and data acquisition capabilities essential for the operation of vanadium redox flow battery systems, achieving online SOC monitoring without introducing complex metering instruments and equipment. This significantly improves system stability and reduces system maintenance difficulty and costs.

[0010] However, this patent also lacks adaptive control and multi-level fault response mechanisms, which cannot guarantee the stable operation of the flow battery module. Summary of the Invention

[0011] To overcome the shortcomings of existing technologies, this invention provides a flow battery module operation stability control system, which achieves stable operation of the flow battery module under all operating conditions through multi-sensor data fusion, adaptive control algorithms and multi-level fault response mechanisms.

[0012] The above-mentioned objective of the present invention is achieved through the following technical solution: a flow battery module operation stability control system, including a BMS battery system and an EMS, SACADA, and PCS connected to the BMS battery system; the BMS battery system includes a battery master control, a battery cluster control, and a data acquisition unit, wherein the battery cluster control is electrically connected to the liquid circuit, and the data acquisition unit is electrically connected to the battery stack.

[0013] Furthermore, the data acquisition unit, battery cluster controller, and battery master controller within the BMS battery system are sequentially and electrically connected.

[0014] Furthermore, the main battery control unit includes a PLC, HMI, frame circuit breaker, switch, and gateway; the battery cluster control unit includes an MCU main control board, digital expansion board, analog expansion board, and frequency converter; and the acquisition unit includes a voltage board.

[0015] In a further preferred embodiment of the present invention, the PLC control MCU main control board collects data information from the fuel cell stack and the hydraulic circuit.

[0016] In a further preferred embodiment of the present invention, the HMI is communicatively connected to the PLC to display battery system data.

[0017] In a further preferred embodiment of the present invention, the PLC communicates with the battery cluster control and acquisition unit via a switch to exchange data.

[0018] In a further preferred embodiment of the present invention, the BMS battery system transmits data to EMS, SACADA, and PCS via a gateway.

[0019] In a further preferred embodiment of the present invention, the MCU main control board is communicatively connected to the digital expansion board and the analog expansion board to collect relevant data from the positive electrolyte storage tank and the negative electrolyte storage tank in the liquid circuit.

[0020] In a further preferred embodiment of the present invention, the frequency converter regulates the operating speed of the electrolyte circulation pump in the liquid circuit.

[0021] In a further preferred embodiment of the present invention, the voltage plate collects data from the fuel cell stack, including voltage, leakage signals from the power chamber, temperature signals, pressure signals, and gas concentration signals.

[0022] The advantages of this invention compared to existing technologies are as follows: This invention addresses the problems of coarse temperature control, pressure-flow imbalance, and lack of fault early warning in existing technologies by achieving breakthroughs through multi-parameter collaborative control and intelligent diagnostic technology. The system integrates adaptive temperature regulation, pressure-flow dual closed-loop control, and fault early warning modules, employing algorithms such as fuzzy PID and model predictive control (MPC) to achieve precise control of the stack temperature, reduce flow non-uniformity, and improve the accuracy of critical fault early warning. Through deep integration of hardware and software, this system significantly improves the operational stability of flow batteries, extends cycle life, and provides a reliable electrical control solution for large-scale energy storage applications. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Figure 1 This is a schematic diagram of the operational stability control system for the flow battery module of the present invention; Figure 2 This is a schematic diagram of the operation flow control system for the flow battery module of the present invention. Figure 3 This is a schematic diagram of the fault classification protection strategy of the flow battery module operation stability control system of the present invention. Detailed Implementation

[0024] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.

[0025] Example 1 Flow battery module operation stability control system ( Figure 1 The system includes a Battery Management System (BMS) and connected components such as an EMS, SACADA, and PCS. The BMS includes a main battery controller, a cluster battery controller, and a data acquisition unit. The cluster battery controller is electrically connected to the liquid circuit, and the data acquisition unit is electrically connected to the battery stack. Within the BMS, the data acquisition unit, cluster battery controller, and main battery controller are sequentially interconnected. The main battery controller includes a PLC, HMI, a frame circuit breaker, a switch, and a gateway. The cluster battery controller includes an MCU main control board, a digital expansion board, an analog expansion board, and a frequency converter. The data acquisition unit includes a voltage board.

[0026] The system consists of a liquid acquisition unit, a battery stack acquisition unit, a battery cluster emptying unit, and a battery control unit. The liquid acquisition unit is responsible for monitoring and regulating parameters such as electrolyte flow, temperature, and pressure. It needs to ensure that the electrolyte is evenly distributed throughout the system, preventing leaks or blockages.

[0027] The battery stack data acquisition unit may be involved in real-time monitoring of parameters such as voltage, current, and temperature within the battery stack. The battery stack is the core component of a flow battery, composed of multiple individual cells, and it's crucial to ensure the normal operation of each cell. The battery cluster control unit may be responsible for managing the battery cluster, coordinating the operating states of each stack to ensure the balanced and efficient operation of the entire cluster. The battery master control unit, as the highest level of the entire BMS, is responsible for aggregating data from all lower-level units, performing overall system monitoring, fault diagnosis, and strategy adjustments.

[0028] The implementation of the flow battery module operation stability control system described in this invention is based on the collaborative operation of an embedded BMS controller, multiple sensors, and actuators. During system startup, the electrolyte circulation pump gradually increases its speed via a frequency converter using a ramp-up method (rising from 0Hz to the target frequency of 40Hz within 10 seconds). Simultaneously, the BMS controller verifies the SOC deviation in real time: within 30 seconds, it compares the maximum deviation between the battery voltage and the open-circuit voltage of the battery stack. If the deviation exceeds 0.08V, the startup time is extended to 90 seconds; if it still does not meet the standard, the startup is terminated and an abnormal battery stack voltage is reported. After startup, the system enters the operating mode based on the electrolyte temperature: if the pipeline temperature sensor shows a temperature ≤47.5℃, the DC contactor and circuit breaker are closed, and a charge / discharge permission command is sent to the PCS after a 10-second delay; if the temperature is higher than the threshold, the chiller is activated to continuously cool the battery until the target temperature is reached.

[0029] During charging and discharging operation, the temperature control module dynamically switches control logic according to operating conditions: during charging, if the pipe temperature is ≥20℃, the chiller is activated throughout; if the temperature is <20℃, the heating cable is activated. During discharging or idling, the maximum pipe temperature is used as a reference; the chiller is activated when the temperature is ≥38℃ and shuts off when it is ≤36℃, and this condition must be met continuously for 50 seconds to avoid instantaneous fluctuations. Simultaneously, when the ambient temperature sensor in the power box detects a temperature <5℃, the corresponding heater is automatically activated; it shuts off when the temperature exceeds 10℃. Figure 2 As shown, the pressure and flow control module monitors the pressure of the positive and negative main pipelines in real time. If the pressure is ≥0.16MPa, the pump frequency is preferentially reduced to a safe range, covering the preset flow strategy. Flow regulation is based on the SOC range (0%~100%) and power segmentation (e.g., a fixed frequency of 44 Hz / 43 Hz during charging, and dynamic adjustment of 38 Hz~44 Hz according to SOC during discharging), and combined with ramp changes to reduce the impact of sudden flow changes on the system. Figure 3As shown, the fault classification protection revolves around an early warning layer, a protection layer, and an emergency shutdown. The early warning layer monitors current, voltage, and temperature, triggering a local alarm and uploading it to the monitoring system when limits are exceeded, such as when parameters like the electrolyte circulation pump current or battery module terminal voltage are abnormal. The protection layer executes graded shutdowns when parameters remain abnormal, prioritizing the disconnection of the charging / discharging link and stopping critical equipment, covering various fault scenarios. Emergency shutdown, triggered by an emergency stop signal, simultaneously disconnects the power supply and fluid circulation, i.e., simultaneously sends a shutdown command, disconnects the charging / discharging interlock line, stops the pump, quickly disconnects the DC circuit breaker and contactor, and opens and delays the closing of the electric mixing valve to achieve rapid fault isolation.

[0030] The system includes the following effects: 1. Temperature fluctuation suppression Multi-level temperature monitoring: Deploy a temperature sensor network in electrolyte pipelines, storage tanks and key equipment spaces to collect temperature data in real time; Adaptive temperature control strategy: During charging, the system automatically selects cooling or heating mode based on the comparison between the electrolyte temperature and the preset threshold to ensure that the temperature remains stable within a reasonable range; during discharging / idling, the system dynamically starts and stops the cooling equipment and heating tape to prevent the reaction efficiency from decreasing due to high or low temperatures; during shutdown, the system continuously monitors the tank temperature and activates the heating tape when the temperature is low to prevent the electrolyte from solidifying or deteriorating.

[0031] 2. Dynamic pressure balance Closed-loop pressure control: The pressure sensor provides real-time feedback on the positive and negative pipeline pressures, and automatically adjusts the pump frequency to maintain pressure stability when the pressure exceeds the limit; Differential pressure protection: When the pressure difference between the positive and negative poles exceeds the safety threshold, a shutdown protection is triggered to prevent structural damage or leakage; Dynamic frequency matching: Combines battery state of charge (SOC) and power requirements to optimize pump frequency in real time to balance pressure and flow.

[0032] 3. Precise flow control Tiered flow strategy: In the charging state, the pump frequency is divided into multiple levels according to the power level and SOC range to achieve high-precision flow adaptation; in the discharging state, the low-frequency mode is used in the low SOC range to reduce energy consumption, and the high-frequency mode is switched in the high SOC range to improve cycle efficiency; a ramp transition is used when switching frequencies to avoid the impact of sudden flow changes on the fuel cell stack.

[0033] 4. Fault classification protection Early warning layer: When key parameters (current, voltage, temperature) exceed the limit, a local alarm is triggered and uploaded to the monitoring system; Protection layer: After a continuous anomaly, a tiered shutdown is implemented, prioritizing the disconnection of the charging and discharging links and the shutdown of critical equipment; Emergency shutdown: Upon triggering of the emergency stop signal, power and fluid circulation are simultaneously cut off to ensure rapid isolation of the fault.

[0034] The embodiments described above are merely preferred embodiments of the present invention, and not all feasible embodiments of the present invention. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. A flow battery module operational stability control system, characterized in that, It includes a BMS battery system and EMS, SACADA, and PCS connected to the BMS battery system; the BMS battery system includes a battery master control, a battery cluster control, and a data acquisition unit, wherein the battery cluster control is electrically connected to the liquid circuit, and the data acquisition unit is electrically connected to the battery stack.

2. The flow battery module operation stability control system according to claim 1, characterized in that, The data acquisition unit, battery cluster controller, and battery master controller within the BMS battery system are sequentially and electrically connected.

3. The flow battery module operation stability control system according to claim 2, characterized in that, The main battery control unit includes a PLC, HMI, frame circuit breaker, switch, and gateway; the battery cluster control unit includes an MCU main control board, digital expansion board, analog expansion board, and frequency converter; the acquisition unit includes a voltage board.

4. The flow battery module operation stability control system according to claim 3, characterized in that, The PLC-controlled MCU main control board collects data information from the fuel cell stack and hydraulic circuit.

5. The flow battery module operation stability control system according to claim 3, characterized in that, The HMI is connected to the PLC and displays battery system data.

6. The flow battery module operation stability control system according to claim 3, characterized in that, The PLC communicates with the battery cluster control and acquisition unit via a switch to exchange data.

7. The flow battery module operation stability control system according to claim 3, characterized in that, The BMS battery system sends data to EMS, SACADA, and PCS via a gateway.

8. The flow battery module operation stability control system according to claim 3, characterized in that, The MCU main control board is connected to the digital expansion board and the analog expansion board to collect relevant data from the positive electrolyte storage tank and the negative electrolyte storage tank in the liquid circuit.

9. The flow battery module operation stability control system according to claim 3, characterized in that, The frequency converter regulates the operating speed of the electrolyte circulation pump in the liquid circuit.

10. The flow battery module operation stability control system according to claim 3, characterized in that, The pressure plate collects data from the fuel cell stack, including voltage, leakage signals from the power chamber, temperature signals, pressure signals, and gas concentration signals.

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