A sodium electric energy storage system suitable for low temperature environments

Abstract

The application discloses a sodium electric energy storage system suitable for a low-temperature environment and relates to the technical field of electric energy storage equipment. A plurality of sodium electric PACKs are arranged in a single row to form a battery cluster, and a temperature sensor is arranged in each sodium electric PACK; a liquid cooling unit is arranged close to the side wall of a box body in the electric control area; a heater is arranged on the side of a liquid cooling pipeline close to the liquid outlet position of the upper layer of the liquid cooling unit; a three-level BMS control module is arranged in a control cabinet and is in communication connection with an external EMS / PCS; a fire control cabinet is arranged on the side, away from the energy storage area, of the control cabinet; and the fire control cabinet is interconnected with the three-level BMS control module through RS485. By adopting sodium ion batteries as the energy storage main body of the PACK unit, the sodium electric energy storage system can have good working performance at low temperatures; by adopting a three-level BMS temperature control strategy, the sodium electric energy storage system can complete energy storage before the arrival of low temperatures through the rapid response control of the system and the instruction of the PCS, so that the normal power supply is not affected at excessively low temperatures, the safety of the system is improved, and the use cost is reduced.

Description

Technical Field

[0001] This utility model relates to a sodium-ion energy storage system suitable for low-temperature environments, and belongs to the field of energy storage equipment technology. Background Technology

[0002] In order to obtain a more stable power supply in areas with relatively scarce power or high power demand, energy storage systems are usually used for output. Existing energy storage systems mostly use lithium batteries for energy storage and use.

[0003] However, traditional lithium batteries suffer from performance degradation, low charge and discharge efficiency, and insufficient safety in low-temperature environments, which limits their application in cold regions. At the same time, low temperatures lead to a decrease in energy density, affecting the normal operation of the battery, and there is also a high risk of thermal runaway during normal use. In addition, traditional lithium batteries require an additional heating system outside the system to be used in low-temperature environments, which increases the footprint of the equipment and the overall cost of use. Utility Model Content

[0004] The purpose of this invention is to address the deficiencies or shortcomings of existing technologies by providing a sodium-ion battery energy storage system suitable for low-temperature environments. By using sodium-ion batteries as the main energy storage unit of the PACK, it can maintain good performance at low temperatures. It also employs a three-level BMS temperature control strategy and has a built-in heating device. Through rapid system response control, the PCS is instructed to complete energy storage before the onset of low temperatures, thus avoiding disruption to normal power supply at excessively low temperatures. This also improves system safety and reduces operating costs.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: It includes a housing 1, internal mounting columns 2, and a base 3. A plurality of internal mounting columns 2 are matrixed on the base 3 and disposed within the housing 1. The base 3 is provided with a plurality of partition plates that divide the housing 1 into an energy storage area and an electrical control area. A plurality of sodium battery packs 4 are stacked on the internal mounting columns 2. A single row of sodium battery packs 4 forms a battery cluster. A temperature control valve box 13 is provided at the bottom of each battery cluster and connected to each sodium battery pack 4 via a pipeline. A temperature and humidity sensor is provided within the energy storage area, and each sodium battery pack 4 integrates a temperature control valve. The electrical control area includes a temperature sensor. A liquid cooling unit 6 is installed near the side wall of the enclosure 1. The liquid cooling unit 6 is connected to the battery cluster via a liquid cooling pipe 7. A heater 12 is installed next to the liquid cooling pipe 7 near the upper liquid outlet of the liquid cooling unit 6. A control cabinet 10 is also installed in the electrical control area and is connected to the battery cluster, the liquid cooling unit 6, and the heater 12. A three-level BMS control module 101 is installed in the control cabinet 10 and communicates with the external EMS / PCS. A fire control cabinet 11 is installed on the side of the control cabinet 10 away from the energy storage area. The fire control cabinet 11 is interconnected with the three-level BMS control module 101 via RS485.

[0006] Furthermore, a fire-fighting pipe 1101 is provided on the inner mounting column 2, and the fire-fighting pipe 1101 is arranged along the sodium battery PACK 4. At the same time, the fire-fighting pipe 1101 is connected to the fire control cabinet 11.

[0007] Furthermore, the three-level BMS control module 101 has a three-layer hierarchical structure, consisting of a BMS three-level main control unit 1011, a BMS two-level control board 1012, and a BMS one-level signal acquisition terminal 1013, from top to bottom.

[0008] Furthermore, the BMS three-level main control unit 1011 is equipped with a communication module 1014 for connection with an external EMS, an AI prediction chip 1015 for temperature and internal resistance data analysis, and a display screen for displaying system status. The BMS three-level main control unit 1011 is powered by DC 24V.

[0009] Furthermore, the BMS secondary control board 1012 includes a CAN bus concentrator 1016 connected to the communication module 1014, and a temperature gradient analysis module 1017 connected to the AI ​​prediction chip 1015. The temperature gradient analysis module 1017 is also connected to the liquid cooling unit 6.

[0010] Furthermore, the BMS primary signal acquisition terminal 1013 is equipped with a voltage acquisition line and a temperature acquisition line. The voltage acquisition line is connected to the sodium battery PACK4 and the CAN bus concentrator 1016, and the temperature acquisition line is connected to the temperature gradient analysis module 1017.

[0011] Furthermore, a dehumidifier is installed below the heater 12, and the dehumidifier is electrically connected to the humidity sensor.

[0012] Furthermore, the AI ​​prediction chip 1015, through the BMS three-level main control unit 1011, links the PCS to increase the SOC to over 80%, and the BMS two-level control board 1012 automatically limits the discharge rate to ≤0.3C when it detects -10℃.

[0013] Furthermore, the bottom of the sodium battery PACK4 is fitted with a PTC heating element that is connected to the heater 12 circuitry, and the bottom of the sodium battery PACK4 housing is fitted with a liquid cooling plate 14.

[0014] After adopting the above technical solution, the beneficial effects of this utility model are as follows: by using sodium-ion batteries as the energy storage body of the PACK unit, it can have good working performance at low temperatures, and adopt a three-level BMS temperature control strategy. At the same time, the chamber is equipped with a heating device. Through the system's rapid response control, the PCS is instructed to complete energy storage before the arrival of low temperatures, avoiding the impact on normal power supply at excessively low temperatures, improving system safety, and reducing operating costs. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 yes Figure 1 Second angle view;

[0018] Figure 3 This is a schematic diagram of the assembly structure of part of the sodium battery PACK4 of this utility model;

[0019] Figure 4 This is a top view of the internal structure of this utility model;

[0020] Figure 5 This is a communication topology diagram of the three-level BMS control module 101 in this utility model;

[0021] Figure 6 This is a schematic diagram of the hierarchical structure of the three-level BMS control module 101 in this utility model.

[0022] Explanation of reference numerals in the attached diagram: 1. Enclosure; 2. Internal mounting column; 3. Base; 4. Sodium battery pack; 6. Liquid cooling unit; 7. Liquid cooling pipeline; 8. Branch pipeline; 9. Quick-connect coupling; 10. Control cabinet; 11. Fire control cabinet; 12. Heater; 13. Temperature control valve box; 14. Liquid cooling plate; 101. Cabinet door; 102. Ventilation grille; 1011. BMS Level 3 main control unit; 1012. BMS Level 2 control board; 1013. BMS Level 1 signal acquisition terminal; 1014. Communication module; 1015. AI prediction chip; 1016. CAN bus concentrator; 1017. Temperature gradient analysis module. Detailed Implementation

[0023] See Figures 1-6As shown, the technical solution adopted in this specific embodiment is as follows: It includes a housing 1, internal mounting columns 2, and a base 3. A plurality of internal mounting columns 2 are arranged in a matrix on the base 3 and are disposed inside the housing 1. A plurality of partition plates are provided on the base 3 to divide the housing 1 into an energy storage area and an electrical control area. A plurality of cabinet doors 101 are provided on the housing 1 to facilitate operation and maintenance of the equipment. A plurality of sodium battery packs 4 are stacked on the internal mounting columns 2. A plurality of sodium battery packs 4 in a single row form a battery cluster. A temperature control valve box 13 is provided at the bottom of each battery cluster and is connected to each sodium battery pack 4 through a pipeline. Each sodium battery pack 4 is provided with a temperature and humidity sensor on the outside and a temperature sensor integrated inside. The electrical control area is located near the side wall of the housing 1. A liquid cooling unit 6 is installed, which is connected to the battery cluster via liquid cooling pipes 7. A heater 12 is installed next to the liquid cooling pipes 7 near the upper liquid outlet of the liquid cooling unit 6. A control cabinet 10 is also installed in the electrical control area, which is connected to the battery cluster, liquid cooling unit 6, and heater 12. A three-level BMS control module 101 is installed in the control cabinet 10 and communicates with the external EMS / PCS. A fire control cabinet 11 is installed on the side of the control cabinet 10 away from the energy storage area. The fire control cabinet 11 is interconnected with the three-level BMS control module 101 via RS485. When the detected temperature is greater than 80°C, the pipeline valves are automatically opened to control thermal runaway. In this embodiment, a partitioned energy storage device is provided, in which the tank is divided into two sections by a partition plate. The main areas are divided into an energy storage area and an electrical control area. The electrical control area is further divided into a liquid cooling area, a heating control area, and a system control area via partitions. In this embodiment, a sodium-ion battery pack is used. Compared to traditional lithium-ion batteries, sodium-ion batteries have better low-temperature stability and safety, and lower material costs. Each sodium-ion battery pack unit is vertically stacked to form a battery cluster. In this example, there are nine battery clusters arranged in two rows. Temperature and humidity sensors are installed in the energy storage area, each corresponding to a row of battery clusters and located at the center of the middle battery cluster. Temperature sensors are also integrated inside the sodium-ion battery packs for real-time monitoring of the internal temperature of individual packs. A liquid cooling unit is installed in the liquid cooling area, and a liquid cooling system is installed on the side of the liquid cooling unit. Both the inlet and outlet of the battery pack are connected to liquid cooling pipes. Each battery cluster also has a temperature control valve box at its bottom. After branching out from the liquid cooling unit, each row of battery clusters branches off into a main pipe, with branch pipes 8 on the main pipe. The bottom of the sodium battery pack 4 is fitted with a PTC heating element that is electrically connected to the heater 12. A liquid cooling plate 14 is located at the bottom of the sodium battery pack 4 housing. The branch pipes 8 connect to the liquid cooling plate interface at the bottom of the sodium battery pack via quick-connect couplings 9. The temperature control valve box is communicatively connected to each sodium battery pack, and each sodium battery pack has a control valve that controls the inlet and outlet. The temperature control valve box controls each control valve, thereby effectively controlling the coolant flow rate. Furthermore…Although sodium-ion batteries operate relatively stably at low temperatures, their energy density can still decrease in extreme environments. Therefore, this embodiment employs a combination of a heater and a PTC heating element. The heater acts as the control unit, sending a control command to the PTC heating element upon receiving a heating signal. The PTC heating element, located inside the sodium-ion battery pack, heats the bottom of the casing through a thermally conductive layer. At -40°C, the temperature rises to -8°C in 35 minutes, allowing the sodium-ion battery pack to quickly recover its energy density in low-temperature environments and ensuring stable output.

[0024] Specifically, this embodiment mainly uses a three-level BMS control module to interconnect and control the entire system. It monitors the internal temperature of the PACK through an internal temperature sensor, and coordinates with the liquid cooling unit and fire control cabinet to control the temperature and thermal runaway of the battery cluster. It also controls the power through interconnection with the external EMS / PCS. This is a smart control strategy that actively raises the battery state of charge (SOC) to above the safety threshold through the collaborative work of the three-level control architecture of the BMS and the PCS.

[0025] The three-level BMS control module 101 has a three-layer hierarchical structure, consisting of a BMS three-level main control unit 1011, a BMS two-level control board 1012, and a BMS one-level signal acquisition terminal 1013 from top to bottom. The BMS one-level monitors the voltage of individual cells (sampling accuracy ±2mV); the BMS two-level manages the battery clusters through the CAN bus; and the BMS three-level integrates environmental data and transmits prediction commands to the EMS through the communication network port.

[0026] Specifically, the BMS level 3 main control unit 1011 is equipped with a communication module 1014 connected to the external EMS, an AI prediction chip 1015 for temperature and internal resistance data analysis, and a display screen for displaying system status. The BMS level 3 main control unit 1011 is powered by DC 24V. In this embodiment, the AI ​​prediction chip analyzes meteorological data and historical operating conditions to decide whether to increase the SOC. The communication module sends instructions to the PCS. After receiving the BMS level 3 instructions, the PCS switches to constant power charging mode and increases the SOC from the current value to ≥80% within a specified time (e.g., 2 hours).

[0027] The BMS secondary control board 1012 includes a CAN bus concentrator 1016 connected to a communication module 1014, and a temperature gradient analysis module 1017 connected to an AI prediction chip 1015. The temperature gradient analysis module 1017 is also connected to the liquid cooling unit 6. It manages the battery clusters through the CAN bus, summarizes the cluster-level status (such as average SOC and temperature gradient), and identifies low-temperature risk areas. During charging, the PCS synchronously receives temperature / internal resistance data from the BMS secondary feedback and dynamically adjusts the current (current limit ≤0.5C at low temperatures).

[0028] The BMS primary signal acquisition terminal 1013 is equipped with voltage acquisition lines and temperature acquisition lines. The voltage acquisition line is connected to the sodium battery PACK4 and the CAN bus concentrator 1016, and the temperature acquisition line is connected to the temperature gradient analysis module 1017. It collects cell voltage (±2mV accuracy) and temperature data in real time and detects the increase in battery internal resistance (if the internal resistance suddenly increases by more than 20% at low temperature and the temperature is less than ℃, it triggers temperature control to heat the battery, reduce the electrolyte viscosity, thereby reducing the internal resistance. Under the linkage effect, it limits the discharge rate and SOC increase, which can improve the capacity retention rate. At -3℃, the traditional energy storage system without three-level linkage will have its battery resistance increase and its capacity decrease significantly when the low temperature is not resolved in time. It usually drops to about 38%, which is a common problem in the industry. However, in this embodiment, the battery capacity retention rate can be maintained at 82% through the three-level linkage strategy, thereby eliminating the risk of local overheating and reducing the fire linkage trigger rate).

[0029] Taking the current SOC of the energy storage system at 45% as an example, the BMS level 3 main control unit analyzes and predicts the arrival of a cold wave through the AI ​​prediction chip. It sends a command to the PCS through the communication module, specifying that the SOC should be increased from the current value to 80% within 2 hours. The PCS responds to the command, switches the charging mode and provides feedback that the lower current limit has been dynamically adjusted to 0.4C. At this time, the BMS level 2 control board continuously monitors and removes the charging limit, sending a control signal to the heater to control the PTC heating element to heat. When the SOC is ≥ 80%, charging stops. Under this linkage mechanism, prediction-decision-execution are integrated into battery management, fundamentally solving the capacity decay and safety risks caused by low temperature.

[0030] More specifically, the internal mounting column 2 is equipped with a fire-fighting pipe 1101, which runs along the sodium battery PACK 4. The fire-fighting pipe 1101 is connected to the fire control cabinet 11. Specifically, the fire-fighting pipe and the liquid cooling pipe can be run in parallel and connected to the fire-fighting pipe connection port on the sodium battery PACK panel. In the event of thermal runaway, the three-level linkage system can promptly trigger the fire-fighting system to start working, thereby effectively controlling the thermal runaway situation.

[0031] More specifically, a dehumidifier is installed below the heater 12. The dehumidifier is electrically connected to the temperature and humidity sensor. In this embodiment, a dehumidifier is also installed to prevent excessive humidity due to internal temperature differences in low-temperature areas. A ventilation grille 102 is installed on the side of the housing near the liquid cooling unit. The air outlet of the dehumidifier is connected to the ventilation grille through a pipe, sharing the ventilation area with the liquid cooling unit. Dehumidification is performed when the humidity sensor detects excessive humidity. Specifically, a three-stage dehumidification mechanism is adopted: when the RH is 55%-60%, low-power dehumidification is used for preventative dehumidification to maintain stable humidity; when the RH is >60%, the dehumidifier operates at full power to force dehumidification to <50%RH; when the RH is >75%, the BMS three-level linkage fire protection module is pre-activated for explosion protection.

[0032] More specifically, the BMS three-level main control unit 1011, in conjunction with the PCS, increases the SOC to above 80%. When the BMS secondary control board 1012 detects -10℃, it automatically limits the discharge rate to ≤0.3C. In this embodiment, to ensure stable battery power supply and prevent battery damage, the SOC value is set to above 80%. -10℃ is the inflection point where ionic conductivity drops sharply (a drop of >70%). Below this temperature, the internal resistance increases irreversibly. As long as the three-level linkage mechanism is triggered, a command is sent to the PCS to increase the SOC to above 80%, and the heating mechanism raises the temperature to reduce the battery's internal resistance. In addition, the BMS secondary control board sets the ambient temperature to -10℃. Upon reaching the detection value, it automatically limits the discharge rate. The sodium battery's maximum discharge rate at -20℃ is approximately 0.35C. The 0.3C setting reserves a 10% safety margin, ensuring the normal operation of the sodium battery, preventing sodium deposition risk, reducing the rate of capacity decay per cycle, and extending the service life of the sodium battery.

[0033] The working principle of this utility model is as follows: When the energy storage system is running, the three-level BMS control module 101 in the control cabinet 10 performs three-level division of labor and linkage. The BMS level one signal acquisition terminal 1013 collects individual cell voltage (±2mV accuracy) and temperature data in real time and detects the increase in battery internal resistance. The BMS level two control board 1012 manages the battery clusters through the CAN bus, summarizes the cluster-level status (such as SOC average value, temperature gradient), and identifies low-temperature risk areas. The BMS level three main control unit 1011 analyzes meteorological data and historical operating conditions through the AI ​​prediction chip 1015 to decide whether to... To increase the SOC, the communication module 1014 sends instructions to the PCS. The entire process is a prediction-decision-execution process. During the prediction or monitoring process, when the temperature difference between the center and the edge of the energy storage area exceeds 8 degrees, the partition liquid cooling is activated to make the temperature of the entire energy storage area uniform. When the ambient temperature drops to -10℃, the heater 12 is activated. The heater 12 controls the PTC heating element 14 to heat up. The humidity sensor monitors the sodium battery PACK4 in real time. Dynamic constant temperature is achieved through system control to ensure that the energy storage system can still operate normally under low temperature conditions.

[0034] The above description is only used to illustrate the technical solution of this utility model and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A sodium-ion battery energy storage system suitable for low-temperature environments, comprising a housing (1), internal mounting columns (2), and a base (3), wherein a plurality of internal mounting columns (2) are matrixed on the base (3) and disposed within the housing (1), and a plurality of partition plates are provided on the base (3) to divide the housing (1) into an energy storage area and an electrical control area, characterized in that: Several sodium battery packs (4) are stacked on the inner mounting column (2). Several sodium battery packs (4) in a single row form a battery cluster. A temperature control valve box (13) is set at the bottom of each battery cluster and is connected to each sodium battery pack (4) through a pipeline. A temperature and humidity sensor is set in the energy storage area, and a temperature sensor is integrated inside each sodium battery pack (4). A liquid cooling unit (6) is set near the side wall of the box (1) in the electrical control area. The liquid cooling unit (6) is connected to the battery cluster through a liquid cooling pipeline (7). A heater (12) is installed next to the liquid cooling pipe (7) at the upper liquid outlet of the chiller unit (6). A control cabinet (10) is also installed in the electrical control area and connected to the battery cluster, the liquid chiller unit (6), and the heater (12). A three-level BMS control module (101) is installed in the control cabinet (10) and communicates with the external EMS / PCS. A fire control cabinet (11) is installed on the side of the control cabinet (10) away from the energy storage area. The fire control cabinet (11) is interconnected with the three-level BMS control module (101) via RS485.

2. The sodium-ion battery energy storage system suitable for low-temperature environments according to claim 1, characterized in that: The internal mounting column (2) is provided with a fire-fighting pipeline (1101), and the fire-fighting pipeline (1101) is arranged along the sodium battery PACK (4). At the same time, the fire-fighting pipeline (1101) is connected to the fire control cabinet (11).

3. The sodium-ion battery energy storage system suitable for low-temperature environments according to claim 1, characterized in that: The three-level BMS control module (101) has a three-layer hierarchical structure, consisting of a BMS three-level main control unit (1011), a BMS two-level control board (1012), and a BMS one-level signal acquisition terminal (1013) from top to bottom.

4. A sodium-ion battery energy storage system suitable for low-temperature environments according to claim 3, characterized in that: The BMS three-level main control unit (1011) is equipped with a communication module (1014) for connection with an external EMS, an AI prediction chip (1015) for temperature and internal resistance data analysis, and a display screen for displaying system status. The BMS three-level main control unit (1011) is powered by DC 24V.

5. A sodium-ion battery energy storage system suitable for low-temperature environments according to claim 3, characterized in that: The BMS secondary control board (1012) includes a CAN bus concentrator (1016) connected to a communication module (1014), and also includes a temperature gradient analysis module (1017) connected to an AI prediction chip (1015). The temperature gradient analysis module (1017) is also connected to the liquid cooling unit (6).

6. A sodium-ion battery energy storage system suitable for low-temperature environments according to claim 3, characterized in that: The BMS primary signal acquisition terminal (1013) is equipped with a voltage acquisition line and a temperature acquisition line. The voltage acquisition line is connected to the sodium battery PACK (4) and the CAN bus concentrator (1016), and the temperature acquisition line is connected to the temperature gradient analysis module (1017).

7. A sodium-ion battery energy storage system suitable for low-temperature environments according to claim 1, characterized in that: A dehumidifier is installed below the heater (12), and the dehumidifier is electrically connected to the temperature and humidity sensor.

8. A sodium-ion battery energy storage system suitable for low-temperature environments according to claim 4, characterized in that: The AI ​​prediction chip (1015) is linked with the PCS through the BMS three-level main control unit (1011) to increase the SOC to more than 80%. When the BMS two-level control board (1012) detects that the temperature is -10℃, it automatically limits the discharge rate to ≤0.3C.

9. A sodium-ion battery energy storage system suitable for low-temperature environments according to claim 1, characterized in that: The sodium battery PACK (4) has a PTC heating element that is connected to the heater (12) circuit at the bottom of the inner shell and a liquid cooling plate (14) at the bottom of the sodium battery PACK (4) shell.

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