Zinc-based flow battery monitoring and control system

Abstract

The present invention relates to a zinc-based liquid flow battery monitoring and control system, comprising: a liquid flow battery controller, an energy recovery device, a voltage regulator, a temperature controller, a heat exchanger, a cold and hot exchange circulation pump, a heat exchange device, a sensor, and a master control switch. The present invention uses sensors to perform real-time detection of multiple physical quantities, such as current, voltage, flow rate, pressure, and temperature, associated with the operating state of the zinc-based liquid flow battery. The liquid flow battery controller performs calculations and analysis, and controls the energy recovery device, voltage regulator, and temperature controller to achieve real-time regulation of physical quantities, such as current, voltage, flow rate, pressure, and temperature, during the operation of the zinc-based liquid flow battery. This allows for refined regulation of the operating state of the zinc-based liquid flow battery, improves the stability and reliability of the liquid flow battery system, and reduces system energy consumption by combining the operation control and maintenance of the liquid flow battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of zinc-based liquid flow batteries, and in particular relates to a zinc-based liquid flow battery monitoring and control system. Background Art

[0002] The transition to low-carbon and zero-carbon energy and the reshaping of a modern energy system are inevitable choices for achieving the UN Sustainable Development Goals and addressing global climate change. New and renewable energy sources are bound to accelerate their integration into the mainstream energy system.

[0003] Liquid flow battery technology has been increasingly valued by countries around the world in recent years due to its advantages such as large energy storage scale, high safety, long charge and discharge cycle life, high cost-effectiveness during the life cycle, low environmental load, recyclable battery materials, and environmental friendliness. It has a huge market prospect.

[0004] The existing monitoring and control systems for flow battery energy storage applications are mostly built with general-purpose controllers, which only detect and control the entire flow battery pack. This has the following problems:

[0005] 1. Insufficient sampling points of the controller. The existing controller only samples the overall parameters of the liquid flow battery pack, without sampling the signals of the battery cells or monitoring various environmental quantities. Therefore, it is impossible to achieve high-precision charge estimation, fault prediction and location, and refined control of the battery status.

[0006] 2. In terms of control, it only realizes the overall control of electric power input and output, lacks the control of battery operating environment parameters, and can only use the shutdown method to deal with battery failure and daily maintenance. Battery maintenance requires additional equipment, which increases the construction cost of the energy storage system.

[0007] 3. It is difficult to coordinate control and maintenance. Battery maintenance requires long periods of downtime, which directly affects the overall operating efficiency of the energy storage system and also increases the cost of system maintenance. Summary of the Invention

[0008] In view of the shortcomings of the prior art described above, the present invention aims to provide a zinc-based flow battery monitoring and control system that enables multi-parameter monitoring of zinc-based flow batteries, including cell voltage monitoring, battery pack total voltage and current monitoring, and electrolyte temperature and flow rate monitoring. Based on this data, the battery's status can be analyzed, including the zinc deposition and zinc shedding status of individual electrodes. Cell balancing control, as well as electrolyte temperature and flow rate control, can also be achieved. These parameter controls enable online maintenance of zinc-based flow batteries. Combined with data analysis and prediction, a rational battery maintenance strategy can be developed, allowing system maintenance to be completed during system operating intervals, thereby reducing maintenance costs.

[0009] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: a zinc-based liquid flow battery monitoring and control system, comprising:

[0010] The flow battery controller is used to obtain the status detection information of the flow battery pack through the sensors installed in the flow battery pack, and analyze the operation of the flow battery pack based on the status detection information; and realize the status control of the flow battery pack through the operation parameter control;

[0011] The main control switch has its input connected to the flow battery pack, the maintenance terminal S1 connected to the voltage regulator, and the battery output terminal S2 connected to the external device to achieve switching between maintenance mode and working mode;

[0012] The voltage regulator has its input side connected to the maintenance terminal of the master switch and its output side connected to the input terminal of the energy recovery device; it is used to adjust the voltage of the flow battery pack to a voltage level acceptable to the input terminal of the energy recovery device;

[0013] The energy recovery device has an input end for receiving electric energy and an output end connected to the temperature control unit; it is used to store part of the electric energy and replenish the electric energy to the temperature control unit when the temperature control unit needs electric energy;

[0014] A temperature control unit is used to obtain electrical energy from an energy recovery device or external devices and regulate the water temperature in the heat exchanger through a temperature feedback closed loop;

[0015] The electrolyte circulation pump is used to directly receive control instructions from the flow battery controller to control the flow rate of the electrolyte.

[0016] The flow battery controller comprises:

[0017] A status detection module is used to collect status detection information of the liquid flow battery pack; it is directly connected to the single electrode in the liquid flow battery pack to detect the voltage of the single flow battery; it is connected to the main output line of the liquid flow battery pack through a voltage sensor to detect the total voltage of the liquid flow battery pack; it is connected to the main output line of the liquid flow battery pack through a current sensor to detect the total current of the liquid flow battery pack;

[0018] A calculation module is used to analyze the state of charge of the battery pack based on the single cell voltage, total voltage and total current obtained by the state detection module;

[0019] an operating parameter control module, configured to perform at least one of battery cell voltage balancing control and battery pack charge and discharge current control;

[0020] The communication module is used to send the status detection information of the liquid flow battery pack and the control parameters in the operation parameter control module to the host computer.

[0021] The temperature control unit includes a temperature controller, a heat exchanger, a heat exchange device connected in sequence, and a cold and hot exchange circulation pump connected to the heat exchanger and the heat exchange device;

[0022] The temperature controller is used to obtain electrical energy from the energy recovery device or external energy to drive the heating and cooling of the heat exchanger. The temperature value is read by the temperature sensor preset in the heat exchange device to form a temperature feedback closed loop to adjust the water temperature in the heat exchanger.

[0023] A heat exchanger for controlling the temperature of the electrolyte through a cold and hot exchange circulation pump and a heat exchange device;

[0024] The heat exchange device is embedded in the electrolyte storage tank in the form of a heat exchange tube to achieve temperature control of the electrolyte;

[0025] The heat exchange circulation pump is connected to the heat exchanger and the heat exchange device to form a water circulation, which is used to adjust the electrolyte temperature.

[0026] A method for monitoring and controlling a zinc-based flow battery comprises the following steps:

[0027] First, the flow battery controller detects the voltage of each battery cell. When the difference between the maximum and minimum voltages exceeds a threshold, and the voltage of any battery cell is non-zero or negative, it is considered that the flow battery has zinc deposition and requires maintenance. The voltage difference threshold is obtained through experiments.

[0028] When the flow battery is in an abnormal state, maintenance will be performed at a later time within the next several cycles:

[0029] When the liquid flow battery pack is allowed to be deeply discharged, the main control switch is first switched to allow the liquid flow battery pack to be connected to the battery output terminal S2 of the main control switch to continue discharging to the outside;

[0030] When the total voltage of the flow battery pack is lower than the minimum threshold voltage of the external device connected to the output line of the flow battery pack and cannot continue to discharge, the flow battery controller controls the main control switch to switch to the maintenance terminal S1 to connect the flow battery pack to the maintenance circuit as maintenance mode; in maintenance mode, the voltage regulator adjusts the total voltage of the flow battery pack to the voltage that the energy recovery device can receive, and the remaining power of the flow battery pack is discharged to the energy recovery device for temporary storage through the voltage regulator;

[0031] When the total voltage of the flow battery pack reaches the lower threshold voltage of the voltage regulator, the discharge is cut off and the flow battery controller continues to discharge the battery cells until each cell of the flow battery pack is completely discharged, completing the entire deep discharge process;

[0032] Then, the master control switch is switched to the battery outlet terminal S2, that is, the operation mode is adjusted.

[0033] A method for monitoring and controlling a zinc-based flow battery comprises the following steps:

[0034] First, the flow battery controller detects the voltage of each battery cell. When the voltage of any battery cell is 0 or negative, it is considered that zinc shedding has occurred inside the battery, causing electrolyte blockage and maintenance is required:

[0035] This is achieved specifically by controlling the temperature controller and the electrolyte circulation pump, including the following steps:

[0036] The temperature controller controls the heat exchanger, temporarily raising the temperature of the electrolyte through the heat exchange device, while increasing the speed of the hot and cold exchange circulation pump to improve the heat exchange efficiency and speed up the temperature increase;

[0037] Control the electrolyte circulation pump to increase the speed and thus increase the electrolyte flow rate;

[0038] Accelerate the removal of electrolyte blockage under the dual effects of temperature and flow rate;

[0039] The battery cell voltage is detected in real time to determine whether the blockage problem has been cleared. If so, the temperature and flow rate are reduced to normal values.

[0040] The present invention has the following beneficial effects and advantages:

[0041] The present invention detects multiple physical quantities of zinc-based liquid flow batteries in real time, and realizes refined and three-dimensional control of zinc-based liquid flow batteries through real-time adjustment of physical quantities such as electrical, temperature, and flow in the zinc-based liquid flow batteries, thereby ensuring the stability and reliability of the liquid flow battery system, and saving system energy consumption by combining the operation control and maintenance of the liquid flow battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 System framework diagram of the present invention.

[0043] Figure 2 Flowchart of the method for controlling zinc deposition problems according to an embodiment of the present invention.

[0044] Figure 3 Flowchart of a method for controlling zinc deposition blockage problems according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0046] The present invention discloses a zinc-based liquid flow battery monitoring and control system, which includes: a liquid flow battery controller, an energy recovery device, a voltage regulator, a temperature controller, a heat exchanger, a cold and hot circulation pump, a heat exchange device, a sensor, and a master control switch.

[0047] The liquid flow battery status detection module in the liquid flow battery controller is connected to the battery cells in the liquid flow battery pack to collect the cell voltage and is connected to the main output line of the battery pack through the voltage / current sensor; the master control switch is a single-pole double-throw switch, which can select the positive pole of the battery to be connected to the positive output line of the battery or the voltage regulator, and the driving end of the master control switch is connected to the I / O module in the liquid flow battery controller; the output end of the voltage regulator is connected to the energy recovery device; the temperature controller is used to control the temperature of the heat exchanger, and finally adjust the temperature of the battery electrolyte through the hot and cold exchange circulation pump; the electrolyte circulation pump, hot and cold exchange circulation pump, temperature controller, energy recovery device, and voltage regulator are all connected to the liquid flow battery controller through a bus. The flow battery controller shown judges the current state of the flow battery by reading parameters such as the voltage of each battery cell in the flow battery pack, the total voltage of the battery pack, the total current of the battery pack, and controls the flow battery pack by adjusting the temperature and flow rate of the flow battery electrolyte in real time, or controls the flow battery system to enter maintenance mode; the flow battery status includes: charge state, battery cell balancing, electrode zinc deposition state, electrode zinc deposition shedding state, and battery state adjustment processing; the maintenance mode includes: deep discharge of the flow battery pack through the voltage regulator, and balancing and deep discharge of the battery cell voltage through the flow battery balancing control module.

[0048] like Figure 1 As shown, a zinc-based liquid flow battery monitoring and control system, the monitoring and control system includes:

[0049] The flow battery controller is responsible for the status detection, data analysis and calculation, operation parameter control, data communication, and system coordination control of the flow battery system.

[0050] The status detection of the liquid flow battery system is divided into two parts. One part is the direct parameter detection of the liquid flow battery pack, which is implemented through the liquid flow battery status detection module inside the controller. The voltage detection channel of the battery detection analog front-end chip in the detection module is directly connected to the liquid flow battery cell electrode for detecting the voltage of the liquid flow battery cell. The total voltage detection channel in the detection module is connected to the total output line of the liquid flow battery pack through a voltage sensor; the total current detection channel is connected to the total output line of the liquid flow battery pack through a current sensor for detecting the overall voltage and current of the battery pack. The other part of the system status detection is the detection of the parameters of each component device in the system. This part of the data is obtained from each device by the controller through the system bus module via the internal bus.

[0051] Data analysis and calculations are performed by the controller's computing module, which uses system status parameters and various algorithms to determine system operating conditions. These analyses primarily include battery pack state of charge estimation, remaining battery life estimation, zinc deposition and zinc shedding fault prediction, and system maintenance requirements.

[0052] The operating parameter control of zinc-based flow batteries involves both electrical and environmental parameter control. Electrical parameter control primarily involves cell voltage balancing and battery pack charge / discharge current control. Cell voltage balancing is accomplished by the flow battery balancing control module within the controller, which uses active and passive balancing to maintain uniform cell voltages. Battery pack charge / discharge current control is accomplished by the controller sending parameters to an external charger / discharger via a communication module.

[0053] Data communication allows the controller to send system status information to external upper-level controllers and control devices, such as chargers and PCS, through the communication module. The upper-level controller can also send control information to the flow battery controller based on the overall energy scheduling situation to complete system control.

[0054] Intra-system coordinated control means that the controller can control the parameters of other devices in the system according to the control strategy to achieve the purpose of system-level control.

[0055] The voltage and current sensors are connected to the battery main output line, converting the total voltage and total current signals of the battery pack into low-level systems that can be received by the controller, while also having the function of signal isolation.

[0056] The common end of the single-pole double-throw master control switch is connected to the positive terminal of the battery pack, one end (S1) is connected to the voltage regulator, and the other end (S2) is connected to the positive terminal of the battery main output line. It is mainly used for switching the battery pack connection topology.

[0057] The voltage regulator's input is connected to the master switch, and its output is connected to the energy recovery device. Its primary function is to adjust the voltage of the flow battery stack to a voltage level acceptable to the energy recovery device's input. The voltage regulator consists of a step-up / step-down module, a monitoring module, and a protection module.

[0058] The energy harvester's input connects to the voltage regulator's output to receive power, while its output connects to the system's electrical devices, including a temperature controller. Its primary function is to temporarily store some of the power, allowing it to be replenished when needed. The energy harvester consists of an internal energy storage module, an output voltage regulator module, a control module, and a protection module.

[0059] The temperature controller is used to obtain electrical energy from the energy recovery device or the outside to drive the heating and cooling in the heat exchanger, and reads the temperature value through the temperature sensor preset in the heat exchange device to form a temperature feedback closed loop to adjust the water temperature in the heat exchanger; the heat exchanger is used to control the temperature of the electrolyte through the heat exchange circulation pump and the heat exchange device; the heat exchange device is embedded in the electrolyte storage tank in the form of a heat exchange tube to achieve temperature control of the electrolyte; the heat exchange circulation pump is connected to the heat exchanger and the heat exchange device to form a water circulation, which is used to adjust the temperature of the electrolyte.

[0060] The electrolyte circulation pump constitutes the electrolyte flow rate regulation part of the system. The electrolyte circulation pump directly receives the control instructions of the flow battery controller to adjust the output to achieve the purpose of controlling the flow rate of the electrolyte.

[0061] During zinc-based flow battery operation, the flow battery controller uses the flow battery status detection module to monitor real-time flow battery status data, including individual battery cell voltage, total battery pack voltage, and total battery pack current. The calculation module then processes this information in real time. This data processing provides further status information, including battery pack state of charge estimation, remaining battery life estimation, zinc deposition and zinc shedding fault prediction, and system maintenance requirements.

[0062] The flow battery controller can report status information to the station control layer controller in real time through the communication module. The communication module can be equipped with a module that supports the physical layer interface of multiple data buses such as Ethernet, RS485 bus, CAN bus, etc. according to the data interface requirements of the station control layer. 4G / 5G communication module can also be optionally installed to realize remote data monitoring.

[0063] The flow battery controller can control the system components according to the state of the zinc-based flow battery. The specific control measures are as follows:

[0064] like Figure 2 As shown, the liquid flow battery controller first detects the voltage of each battery cell. When the difference between the maximum voltage and the minimum voltage exceeds the threshold, and the voltage of any battery cell is not 0 or is negative, it is considered that the liquid flow battery has a zinc deposition problem and needs maintenance.

[0065] Furthermore, the threshold value of the voltage difference is obtained through experiments.

[0066] When the flow battery is in an abnormal state, maintenance will be performed at a later time within the next several cycles:

[0067] When the liquid flow battery pack is allowed to be deeply discharged, the main control switch is first switched to allow the liquid flow battery pack to be connected to the battery output terminal S2 of the main control switch to continue discharging to the outside;

[0068] When the total voltage of the flow battery pack is lower than the minimum threshold voltage of the external device connected to the output line of the flow battery pack and cannot continue to discharge, the flow battery controller controls the main control switch to switch to the maintenance terminal S1 to connect the flow battery pack to the maintenance circuit as maintenance mode; in maintenance mode, the voltage regulator adjusts the total voltage of the flow battery pack to the voltage that the energy recovery device can receive, and the remaining power of the flow battery pack is discharged to the energy recovery device for temporary storage through the voltage regulator;

[0069] When the total voltage of the flow battery pack reaches the lower threshold voltage of the voltage regulator, the discharge is cut off and the flow battery controller continues to discharge the battery cells until each cell of the flow battery pack is completely discharged, completing the entire deep discharge process;

[0070] Then, the master control switch is switched to the battery outlet terminal S2, that is, the operation mode is adjusted.

[0071] like Figure 3 As shown, the flow battery controller first detects the voltage of each battery cell. When the voltage of any battery cell is 0 or negative, it is considered that zinc shedding has occurred inside the battery, causing electrolyte blockage, and maintenance is required:

[0072] This is achieved specifically by controlling the temperature controller and the electrolyte circulation pump, including the following steps:

[0073] The temperature controller controls the heat exchanger, temporarily raising the temperature of the electrolyte through the heat exchange device, while increasing the speed of the hot and cold exchange circulation pump to improve the heat exchange efficiency and speed up the temperature increase;

[0074] Control the electrolyte circulation pump to increase the speed and thus increase the electrolyte flow rate;

[0075] Accelerate the removal of electrolyte blockage under the dual effects of temperature and flow rate;

[0076] The battery cell voltage is detected in real time to determine whether the blockage problem has been cleared. If so, the temperature and flow rate are reduced to normal values.

Claims

1. Zinc-based flow battery monitoring and control system, characterized in that: include: A flow battery controller, configured to obtain status detection information of the flow battery pack through sensors provided in the flow battery pack, and analyze the operation of the flow battery pack based on the status detection information; The state control of the flow battery pack is achieved through operating parameter control; The main control switch has its input connected to the flow battery pack, its maintenance end connected to the voltage regulator, and its battery output end connected to external equipment to achieve switching between maintenance mode and working mode; The voltage regulator has an input side connected to the maintenance terminal of the master control switch and an output side connected to the input terminal of the energy recovery device; Used to adjust the voltage of the flow battery group to a voltage level acceptable to the input end of the energy recovery device; An energy recovery device, the input end of which is used to receive electrical energy, and the output end of which is connected to the temperature controller; Used to save part of the electrical energy and replenish it when the temperature controller needs electrical energy; A temperature controller is used to obtain electrical energy from an energy recovery device or external sources and regulate the water temperature in the heat exchanger through a temperature feedback closed loop; An electrolyte circulation pump is used to directly receive control instructions from the flow battery controller to control the flow rate of the electrolyte; When the total voltage of the flow battery pack is lower than the minimum threshold voltage of the external device connected to the output line of the flow battery pack and cannot continue to discharge, the flow battery controller controls the main control switch to switch to the maintenance end to connect the flow battery pack to the maintenance circuit as maintenance mode; in maintenance mode, the voltage regulator adjusts the total voltage of the flow battery pack to the voltage that the energy recovery device can receive, and the remaining power of the flow battery pack is discharged to the energy recovery device for temporary storage through the voltage regulator; When the total voltage of the flow battery pack reaches the lower threshold voltage of the voltage regulator, the discharge is cut off and the flow battery controller continues to discharge the battery cells until each cell of the flow battery pack is completely discharged, completing the entire deep discharge process; Then, switch the master switch to the battery outlet terminal, that is, adjust to the working mode; The flow battery controller detects the voltage of each battery cell. If the voltage of any battery cell is 0 or negative, it is considered that zinc shedding has occurred inside the battery, causing electrolyte blockage. Maintenance is required, including the following steps: The temperature controller controls the heat exchanger, temporarily raising the temperature of the electrolyte through the heat exchange device, while increasing the speed of the hot and cold exchange circulation pump to improve the heat exchange efficiency and speed up the temperature increase; Control the electrolyte circulation pump to increase the speed and thus increase the electrolyte flow rate; Accelerate the removal of electrolyte blockage under the dual effects of temperature and flow rate; The battery cell voltage is detected in real time to determine whether the blockage problem has been cleared. If so, the temperature and flow rate are reduced to normal values.

2. The zinc-based flow battery monitoring and control system according to claim 1, characterized in that: The flow battery controller comprises: A status detection module is used to collect status detection information of the liquid flow battery pack; it is directly connected to the single electrode in the liquid flow battery pack to detect the voltage of the single flow battery; it is connected to the main output line of the liquid flow battery pack through a voltage sensor to detect the total voltage of the liquid flow battery pack; it is connected to the main output line of the liquid flow battery pack through a current sensor to detect the total current of the liquid flow battery pack; A calculation module is used to analyze the state of charge of the battery pack based on the single cell voltage, total voltage and total current obtained by the state detection module; an operating parameter control module, configured to perform at least one of battery cell voltage balancing control and battery pack charge and discharge current control; The communication module is used to send the status detection information of the liquid flow battery pack and the control parameters in the operation parameter control module to the host computer.

3. The zinc-based flow battery monitoring and control system according to claim 1, characterized in that: The temperature controller includes a temperature controller, a heat exchanger, a heat exchange device, and a cold and hot exchange circulation pump connected to the heat exchanger and the heat exchange device. The temperature controller is used to obtain electrical energy from the energy recovery device or external energy to drive the heating and cooling of the heat exchanger. The temperature value is read by the temperature sensor preset in the heat exchange device to form a temperature feedback closed loop to adjust the water temperature in the heat exchanger. A heat exchanger for controlling the temperature of the electrolyte through a cold and hot exchange circulation pump and a heat exchange device; The heat exchange device is embedded in the electrolyte storage tank in the form of a heat exchange tube to achieve temperature control of the electrolyte; The heat exchange circulation pump is connected to the heat exchanger and the heat exchange device to form a water circulation, which is used to adjust the electrolyte temperature.

4. A method for monitoring and controlling a zinc-based flow battery, the method being applied to the zinc-based flow battery monitoring and control system according to claim 1, characterized in that: The following steps are involved: The flow battery controller detects the voltage of each battery cell. When the difference between the maximum and minimum voltages exceeds a threshold, and the voltage of any battery cell is not zero or is negative, it is considered that the flow battery has zinc deposition problems and requires maintenance. The voltage difference threshold is obtained through experiments. When the flow battery is in an abnormal state, maintenance will be performed at a later time within the next several cycles: When the liquid flow battery pack is allowed to be deeply discharged, the main control switch is first switched to enable the liquid flow battery pack to be connected to the battery output terminal of the main control switch to continue discharging to the outside.

Images