Zinc-based flow battery controller and control method

Abstract

The application discloses a zinc-based flow battery controller and control method, which comprises the following steps: collecting the state detection information of the zinc-based flow battery fed back by each functional board, including voltage state information, discharge current state information, electrolyte temperature state information and electrolyte flow rate state information of a heat exchange circulating pump; according to the voltage state information, the discharge current state information and the electrolyte temperature state information of the flow battery module obtained by the state detection unit, performing battery pack equalization discharge analysis, battery pack state of charge estimation, battery remaining life estimation, zinc deposition fault prediction and zinc shedding fault prediction; when the battery voltage is unbalanced, controlling the discharge parameters to perform at least one of active equalization discharge and passive equalization discharge of the flow battery module; when the zinc deposition fault occurs, controlling the heat exchange rate of the heat exchange circulating pump and the electrolyte temperature parameter in the heat exchange tank to heat the electrolyte, so as to realize zinc deposition reduction of the zinc-based flow battery; and uploading the analysis, estimation and prediction results to a host computer.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery control, and particularly relates to a zinc-based flow battery controller and a control method. BACKGROUND

[0002] Under the background of current energy transformation and climate change response, energy storage battery technology plays an increasingly key role. As an emerging energy storage technology, zinc-based flow batteries are considered one of the most promising technologies in grid-level energy storage solutions due to their high energy density, low cost, and environmental friendliness. Compared with traditional lithium-ion batteries, zinc-based flow batteries have significant advantages in safety, cost, and cycle life, especially in large-scale energy storage applications such as renewable energy generation and grid stability control, showing great application potential.

[0003] Although zinc-based flow batteries have the above advantages, they still face some technical challenges in commercialization and large-scale deployment. The most important problem is the uneven voltage between battery cells, which can lead to reduced charging and discharging efficiency and shortened battery life. The uneven voltage of battery cells is mainly caused by differences in materials and processes during manufacturing, as well as performance degradation due to uneven electrochemical reaction kinetics during long-term operation. In addition, during the charging and discharging process of zinc-based flow batteries, uneven deposition and peeling of zinc can occur due to the reaction kinetics between the electrode and the electrolyte, further exacerbating the inconsistency of cell performance. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a zinc-based flow battery controller. Through advanced hardware design and intelligent software algorithms, not only can the battery cell voltage be monitored and adjusted, but also the battery data can be processed and analyzed in real time to achieve optimal management of the battery state.

[0005] The technical scheme adopted by the application to achieve the above-mentioned purpose is:

[0006] The zinc-based flow battery controller comprises a main board and at least one functional board sequentially connected thereto; the main board and the functional board, and adjacent functional boards are connected through a board card connector;

[0007] The main board comprises a core processor and a communication interface, a backplane bus controller, a memory, a clock module, and a power module connected thereto respectively;

[0008] The communication interface is used for the core processor to connect the battery and the upper computer for data transmission and communication;

[0009] The power module is connected to the core processor through an isolation circuit and is used to provide power to other electronic components on the main board;

[0010] The backplane bus controller is connected with the core processor and the board connector through the bus interface to perform data transmission.

[0011] The memory is used to store the collected battery state information and the output operation control parameters.

[0012] The clock module provides a system clock for the core processor.

[0013] The power module is used to convert an external power supply into power for the mainboard and the functional boards through a step-down chip.

[0014] The board connector is used to transmit feedback data and control data between the core processor and the functional boards.

[0015] The functional board comprises a functional board processor, a backplane bus controller and various functional modules connected therewith, the functional board processor is connected with the zinc-based flow battery through the various functional modules to collect battery state information and output operation control parameters, and the zinc-based flow battery is detected and controlled.

[0016] The functional modules comprise a flow battery single cell voltage detection module, a single cell voltage equalization module and an electrolyte temperature control module.

[0017] The flow battery single cell voltage detection module is used to convert analog signals collected by a sensor into digital signals through an analog front end (AFE) chip.

[0018] Further, the flow battery single cell voltage detection module comprises an input protection circuit, a filter, a preamplifier and an AFE chip, which is used to convert analog signals collected by a sensor into digital signals.

[0019] The single cell voltage equalization module adopts at least one of active equalization and passive equalization, the passive equalization is used to realize energy equalization between battery single cells through a resistance energy dissipation mode, and the active equalization is used to realize energy equalization between battery single cells through energy transfer.

[0020] Further, the passive equalization comprises a bleeder loop formed by a switch tube and a bleeder resistor connected across the detection port of each battery single cell, and the switch tube is controlled to be turned on and turned off by the AFE to realize control of energy release of the corresponding battery to achieve equalization.

[0021] Further, the active equalization comprises a switch array and a flying capacitor arranged at both ends of the battery module, the switch array is controlled to be connected to the flying capacitor to receive high-voltage battery energy and transfer the energy to a low-voltage battery to realize battery voltage equalization.

[0022] The electrolyte temperature control unit comprises a temperature controller, a heater, a heat exchange circulating pump and a heat exchanger connected in sequence.

[0023] A temperature controller receives temperature control parameters of the mainboard core processor, drives the heater to heat, and reads temperature values through the temperature sensor preset in the heater to form a temperature feedback closed loop to adjust the temperature of the heat conduction medium in the heater.

[0024] The heater controls the temperature of the heat conduction medium in the box through the resistance wire.

[0025] The heat exchange circulating pump is arranged on the pipeline between the heater and the heat exchanger, and is used for adjusting the efficiency of temperature conduction.

[0026] The heat exchanger is a heat exchange pipe closely wound in the heat exchange tank, and the heat exchange pipe heats the electrolyte stored in the heat exchange tank.

[0027] The zinc-based flow battery control method comprises the following steps:

[0028] The state detection information of the zinc-based flow battery fed back by each functional board is collected, including voltage state information, discharge current state information, electrolyte temperature state information, and electrolyte flow rate state information of the heat exchange circulating pump.

[0029] According to the voltage state information, the discharge current state information and the electrolyte temperature state information of the flow battery module obtained by the state detection unit, the battery pack equalization discharge analysis, the battery pack state of charge estimation, the battery remaining life estimation, the zinc deposition fault prediction and the zinc shedding fault prediction are performed.

[0030] When the battery voltage is unbalanced, at least one of the active equalization discharge and the passive equalization discharge of the flow battery module is controlled; when the zinc deposition fault occurs, the heat exchange rate of the heat exchange circulating pump and the electrolyte temperature parameter in the heat exchange tank are controlled to heat the electrolyte, so that the zinc deposition of the zinc-based flow battery is reduced; and the results of the analysis, estimation and prediction are uploaded to the upper computer.

[0031] The method comprises creating a plurality of task threads, including at least one of a data acquisition task, a device control task, a wireless communication task, data storage, energy consumption monitoring, an alarm task and a fault diagnosis task.

[0032] The data acquisition obtains the working voltage, current and temperature of the battery in real time through I2C and SPI bus protocols.

[0033] The communication task establishes a wireless communication channel through a TCP protocol, encapsulates data through an MQTT protocol and sends the data to a cloud server, and through a data retransmission mechanism and a channel communication quality evaluation mechanism, the stability and continuity of the data are ensured.

[0034] The present application has the following advantages and benefits:

[0035] 1.The controller is capable of multi-parameter online monitoring and analysis of the operating state of the zinc-based flow battery, effectively solving the problem of uneven voltage of the battery monomer, and improving the performance and operating life of the battery pack.

[0036] 2.The method of the present application evaluates and predicts the state of zinc deposition, and adjusts the zinc deposition accordingly, effectively solving the problem of battery performance degradation caused by uneven and peeling of the battery.

[0037] 3.The controller of the present application is designed by modular design method, which is convenient to expand and can be applied to different specifications of the battery stack. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The zinc-based flow battery controller of the present application is a block diagram.

[0039] Figure 2 The flow battery monomer voltage detection module of the embodiment of the present application is a block diagram.

[0040] Figure 3 The flow battery monomer equalization module function block diagram of the embodiment of the present application.

[0041] Figure 4 The electrolyte temperature control unit function block diagram of the embodiment of the present application.

[0042] Figure 5 The software flow chart of the zinc-based flow battery of the embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation method of the present application will be described in detail below. In the following description, a lot of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, therefore the present application is not limited by the specific implementation disclosed below.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application.

[0045] The present application proposes a zinc-based flow battery controller. Through advanced hardware design and intelligent software algorithm, not only the battery monomer voltage can be monitored and adjusted, but also the battery data can be processed and analyzed in real time, realizing the optimal management of the battery state.

[0046] Firstly, such as Figure 1 As shown, this embodiment of the invention provides a zinc-based flow battery controller, which consists of a motherboard and multiple function boards. The motherboard includes: a core processor and peripheral modules, a memory, a clock module, a communication interface, a control bus interface, a power module, and a motherboard backplane bus controller. The function boards are packaged separately according to their functions, and basically include: a board processor, a function board backplane bus controller, and other modules for realizing the detection and control of the zinc-based flow battery. The other modules mainly include a flow battery cell voltage detection module, a cell voltage equalization module, a digital input module, and a digital output module.

[0047] The clock module uses an RTC clock chip. Communication interfaces include wired or wireless interfaces such as RS485, RS232, CAN, Ethernet, and USB debugging interfaces. Memory utilizes various formats, such as EEPROM, SDRAM, and eMMC. The core processor is an MCU processor. The power supply module employs an isolation scheme, converting the external +12V power supply to +5V and +3.3V to provide power to various functional modules on the motherboard.

[0048] The peripheral modules include power interface circuits and isolation circuits.

[0049] The motherboard and function boards are cascaded via board connectors, which include a backplane bus for data communication and power supply lines. The motherboard has one connector for connecting to the first function board; each function board has two connectors: one for connecting to the previous board and one for connecting to the next board. The controller can be expanded using this cascading method to accommodate different flow battery sizes.

[0050] The zinc-based flow battery controller comprises two parts: detection and control. Detected quantities include: individual cell voltage, total battery voltage, total battery current, electrolyte temperature, and electrolyte flow rate. Controlled quantities include: individual cell balancing, battery pack balancing, electrolyte temperature, and electrolyte flow rate.

[0051] The voltage detection of the flow battery cell, such as Figure 2As shown, the signal first passes through the input protection circuit, which includes overvoltage protection and ESD protection for module back-end device protection. The analog signal collected by the battery voltage may contain some unnecessary noise and interference, and a filter is added to filter the analog signal to improve the signal-to-noise ratio of the analog signal. The preamplifier realizes the amplification of the analog signal to improve the sensitivity and resolution of the analog signal. The filtered and amplified signal enters the analog front-end (AFE) chip, and the analog signal is converted into a digital signal by the built-in ADC (analog-to-digital converter). The AFE chip uses a dynamic sampling scheme to adjust the sampling rate according to the signal change rate. Finally, the AFE chip sends the digital signal to the processor for digital signal processing. The processor can perform various algorithm processing on the digital signal, such as filtering, FFT (Fast Fourier Transform), signal analysis, etc. The digital signal processed by the AFE chip can be output to the board processor in various ways.

[0052] There will be certain differences in the production process of zinc-based flow batteries, such as different flatness of electrode plates, flow channel design and processing technology, etc., resulting in poor consistency of zinc-based flow battery monomers. The use scene is that the active material deposition is different, and there is a certain voltage difference between the monomer batteries after several cycles, affecting the overall charge and discharge efficiency and life of the battery pack. Therefore, a monomer battery equalization module needs to be set in the zinc-based flow battery controller. The implementation scheme of the equalization function is divided into two kinds, active equalization and passive equalization. As shown in Figure 3 Since the AFE chip has a passive equalization controller, passive equalization is achieved in the detection module.

[0053] The principle of passive equalization is to use resistance to dissipate energy, according to the single string battery voltage data, the energy of the higher voltage battery in the battery pack is discharged in the form of resistance, so that the energy of the high voltage battery and the low voltage battery is equal, and the consistency of the battery is realized. The specific implementation is to cross-connect the switch tube and the bleeder resistor on the detection port of each battery monomer to form a bleeder loop, and the switch tube is controlled by the AFE. When the AFE chip detects that the voltage of a certain battery monomer is too high, the corresponding battery bleeder switch tube is opened to release energy to achieve the purpose of equalization.

[0054] The active balancing is an equalization achieved by energy transfer. The voltage data of each string of batteries is detected, and the energy of the battery with high voltage is transferred to the battery with low voltage, which almost realizes lossless energy transfer. Since the single cell voltage platform of zinc-based flow battery is low, it is more appropriate to use a flying capacitor as an energy transfer medium. The specific implementation is to use a switch array to connect each battery monomer to the flying capacitor. When a battery monomer with high voltage is detected, the microcontroller controls the switch array to connect the battery monomer with high voltage to the flying capacitor. Since the battery voltage is higher than the capacitor voltage, the battery charges the capacitor. After charging is completed, the switch array is controlled to connect the battery monomer with low voltage in the battery pack to the flying capacitor. At this time, the battery voltage is lower than the capacitor voltage, and the capacitor charges the battery. It is equivalent to transferring part of the energy of the highest voltage monomer to the lowest voltage monomer. Repeating several times will make the battery voltage balanced.

[0055] The electrolyte temperature control is completed by an independent temperature control unit, and temperature control is achieved by controlling the temperature control unit and the electrolyte circulating pump, as shown in Figure 4 The temperature control unit adjusts the electrolyte temperature by controlling the heat transfer medium and the heat exchange efficiency. Specifically, by controlling the hot water tank to increase the hot water temperature, and increasing the speed of the heat exchange circulating pump to increase the heat exchange efficiency.

[0056] The flow rate control is achieved by the controller controlling the bus to drive the electrolyte circulating pump.

[0057] The data analysis and calculation are made by the controller based on the state parameters of the system and various algorithms to judge the operation of the system, which is responsible for the calculation module in the controller. The data analysis and calculation mainly include: battery pack state of charge estimation, battery remaining life estimation, zinc deposition fault prediction, zinc shedding fault prediction, system maintenance requirements, etc.

[0058] The second aspect, as shown in Figure 5 The method for realizing the zinc-based flow battery controller is as follows:

[0059] When the program is initialized, multiple task threads are created, including but not limited to data acquisition tasks, device control tasks, wireless communication tasks, data storage, energy consumption monitoring, alarm tasks, and fault diagnosis tasks, etc.

[0060] Take the schematic flowchart in the figure as an example for illustration.

[0061] 1. Data acquisition and control tasks.

[0062] 1) The main processor drives the voltage sampling chip, temperature sampling chip, and current sampling device through I2C, SPI, and other bus protocols to obtain the working voltage, current, and temperature of the battery in real time.

[0063] 2) The collected voltage and current data are processed, integrated, etc. to comprehensively determine whether zinc deposition or blockage occurs in the battery;

[0064] 3) When it is determined that zinc deposition or blockage occurs, an external discharge device needs to be turned on to artificially intervene in discharging the battery during a non-working period of the battery;

[0065] 4) When the voltage reaches a threshold or exceeds a specified duration, the discharge device is immediately turned off.

[0066] The purpose of this task is to determine the occurrence of zinc deposition in real time, and then accelerate the dissolution of the deposition by artificial intervention to ultimately improve the service life of the battery.

[0067] 5) The battery temperature is monitored in real time, and when the battery temperature is abnormal, a temperature regulating device is turned on. When the temperature returns to normal, the related device is turned off. The temperature is artificially adjusted to ensure stable battery performance.

[0068] 2. Communication task

[0069] 1) According to the use scenario, wired communication and wireless communication can be selected. This example uses a more extensive wireless communication mode as an example.

[0070] 2) The main processor directly controls the communication chip through the SPI bus or USART;

[0071] 3) After successful driving, a wireless communication channel is established using the TCP protocol;

[0072] 4) After encapsulating the data using the MQTT protocol, the data is sent to the cloud server;

[0073] 5) A data retransmission mechanism and channel communication quality evaluation mechanism are designed in the task. When multiple sending fails or the channel communication quality is poor, the processor will cache the data and actively disconnect the old connection with the cloud server and create a new connection.

[0074] 6) When the communication is restored, the chip continues to send the cached data. The stability and continuity of the data are ensured.

[0075] 3. Data storage task

[0076] 1) The processor creates an SD card driver;

[0077] 2) After successfully identifying the SD card, a file is created in the SD card to save real-time collected data;

[0078] 3) If the data is successfully written, the data in the write cache is updated, and the next write is waited;

[0079] 4) If the data write fails, check the SD card drive state, file open state, etc. in turn. Find the exception and re-initialize the corresponding link.

[0080] The above is only the preferred embodiment of the present application, and does not limit the present application. Any simple modification, change and equivalent structure change of the above embodiment according to the technical essence of the present application are still within the protection scope of the technical solution of the present application.

Claims

1. A zinc-based flow battery controller, characterized by, The main board and at least one functional board sequentially connected with the main board; the main board and the functional board and adjacent functional boards are connected through the board card connector; The main board includes a core processor and a communication interface, a backplane bus controller, a memory, a clock module and a power module connected with the core processor respectively; The communication interface is used for the core processor to connect the battery and the upper computer for data transceiving communication; The power module is connected with the core processor through an isolation circuit and is used for providing power for other electronic components on the main board; The backplane bus controller is connected with the core processor and the board card connector through a control bus interface for data transmission; the memory is used for storing the collected battery state information and the output running control parameters; The clock module provides a system clock for the core processor; The power module adopts a step-down chip to convert an external power supply to provide power for the main board and the functional board; The board card connector is used for transmitting feedback data and control data between the core processor and the functional boards; The functional board includes a functional board card processor, a backplane bus controller and various functional modules connected with the functional board card processor, the functional board card processor is connected with the zinc-based flow battery through the various functional modules to collect battery state information and output running control parameters; The zinc-based flow battery is detected and controlled; The functional modules include a flow battery single cell voltage detection module, a single cell voltage equalization module and an electrolyte temperature control module; The flow battery single cell voltage detection module adopts an analog front end (AFE) chip to convert analog signals collected by a sensor into digital signals; The electrolyte temperature control unit includes a temperature controller, a heater, a heat exchange circulating pump and a heat exchanger connected in sequence; the temperature controller receives temperature control parameters of the core processor of the main board, drives the heater to heat and reads temperature values through a temperature sensor preset in the heater to form a temperature feedback closed loop to adjust the temperature of a heat conduction medium in the heater; the heater controls the temperature of the heat conduction medium in the box through a resistance wire; the heat exchange circulating pump is arranged on a pipeline between the heater and the heat exchanger and is used for adjusting the temperature conduction efficiency; the heat exchanger is a heat exchange pipe tightly wound in a heat exchange tank, and the heat exchange pipe heats electrolyte stored in the heat exchange tank; When the battery voltage is unbalanced, at least one of active equalization discharge and passive equalization discharge of the flow battery module is controlled according to the discharge parameters; when zinc deposition failure occurs, the heat exchange rate of the heat exchange circulating pump and the electrolyte temperature parameters in the heat exchange tank are controlled to heat the electrolyte, so that the zinc-based flow battery is reduced in zinc deposition; and the results of analysis, estimation and prediction are uploaded to the upper computer.

2. The zinc-based flow battery controller of claim 1, wherein, The single cell voltage equalization module adopts at least one of active equalization and passive equalization; the passive equalization realizes energy equalization between the battery single cells through resistance dissipation; and the active equalization realizes energy equalization between the battery single cells through energy transfer.

3. The zinc-based flow battery control method of claim 1, wherein, The method includes the following steps: Collecting state detection information of the zinc-based flow battery fed back by the functional boards, including voltage state information, discharge current state information, electrolyte temperature state information and electrolyte flow rate state information of the heat exchange circulating pump; According to the voltage state information, the discharge current state information and the electrolyte temperature state information of the flow battery module obtained by the state detection unit, the battery pack equalization discharge analysis, the battery pack state of charge estimation, the battery remaining life estimation, the zinc deposition fault prediction and the zinc shedding fault prediction are performed. When the battery voltage is unbalanced, at least one of the active equalization discharge and the passive equalization discharge of the flow battery module is controlled by controlling the discharge parameters; when the zinc deposition fault occurs, the heat exchange rate of the heat exchange circulating pump and the electrolyte temperature parameter in the heat exchange tank are controlled to heat the electrolyte, so as to reduce the zinc deposition of the zinc-based flow battery; and the results of the analysis, estimation and prediction are uploaded to the upper computer.

4. The zinc-based flow battery control method of claim 3, wherein, The method comprises creating a plurality of task threads, including at least one of a data acquisition task, a device control task, a wireless communication task, a data storage, an energy consumption monitoring, an alarm task and a fault diagnosis task.

5. The zinc-based flow battery control method of claim 3 or 4, wherein, The data acquisition obtains the working voltage, current and temperature of the battery in real time through I2C and SPI bus protocols.

6. The zinc-based flow battery control method of claim 3 or 4, wherein, The communication task establishes a wireless communication channel through a TCP protocol, encapsulates the data through an MQTT protocol and sends the data to a cloud server, and through a data retransmission mechanism and a channel communication quality evaluation mechanism, the stability and continuity of the data are ensured.

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