Low-temperature automatic heating control system for energy storage battery

Abstract

The utility model discloses a low-temperature automatic heating control system for an energy storage battery. The low-temperature automatic heating control system comprises a battery module, a battery management system, a heating relay, a circuit breaker, a main relay, a plurality of heating film temperature sensors, a plurality of battery cell temperature sensors and a plurality of heating films, the heating films are tightly attached to the upper and lower surfaces of the battery module, the heating film temperature sensors are tightly attached to the surfaces of the heating films, the battery cell temperature sensors are uniformly dispersed in the battery module, and the heating film temperature sensors and the battery cell temperature sensors are connected to the battery management system; the circuit breaker is connected to the two ends of the battery module and is connected with the negative electrode of the heating film; one end of the heating relay is connected with the positive electrode of the heating film, and the other end of the heating relay is connected with the Pack + end; one end of the main relay is connected with the circuit breaker, and the other end of the main relay is connected with the Pack + end; the main relay, the heating relay and the circuit breaker are all connected to a battery management system; the battery management system is used for controlling switching on and switching off of the main relay, the circuit breaker and the heating relay.

Description

Technical Field

[0001] This utility model belongs to the field of energy storage lithium batteries or lithium battery applications, and specifically relates to a low-temperature automatic heating control system for energy storage batteries. Background Technology

[0002] Lithium-ion batteries, as a representative product of new energy, play a crucial role in many fields, such as mobile phone batteries in communications, power battery packs for electric vehicles in transportation, and photovoltaic integrated battery packs for drones in transportation. With the development of technology, the energy density of lithium-ion batteries has significantly improved, leading to widespread development in industries such as power storage and backup power. However, due to the electrochemical characteristics of lithium ions, the performance of lithium-ion batteries deteriorates sharply in high-latitude and cold environments, resulting in rapid capacity decay, insufficient output power, charging difficulties, and shortened lifespan. This greatly limits the application scenarios of lithium-ion batteries, preventing their benefits from reaching photovoltaic energy storage users in cold regions.

[0003] To address these issues, the market typically adds a heating film to lithium batteries to improve their performance in low-temperature environments. While this method partially solves the problem of batteries failing to function properly at low temperatures, traditional heating solutions lack automatic control, leading to low energy utilization, overheating, and prolonged high battery temperatures, which can cause short circuits and other abnormalities. Therefore, this solution cannot effectively and promptly control risks, instead adding many potential safety hazards to the use of lithium batteries. Utility Model Content

[0004] Purpose of the utility model: In order to solve the safety hazards caused by using heating film to heat lithium batteries, this utility model proposes a low-temperature automatic heating control system for energy storage batteries.

[0005] Technical solution: A low-temperature automatic heating control system for energy storage batteries, comprising: a battery module, a battery management system, a heating relay, a circuit breaker, a main relay, multiple heating film temperature sensors, multiple cell temperature sensors, and multiple heating films; the power supply of the battery management system is connected in parallel to both ends of the circuit breaker, and if the circuit breaker is opened, the battery management system is also completely de-energized.

[0006] The heating film is attached to the upper and lower surfaces of the battery module, and the heating film temperature sensor is attached to the surface of the heating film to collect the surface temperature of the heating film. The cell temperature sensor is evenly distributed in the battery module to collect the battery module temperature. Both the heating film temperature sensor and the cell temperature sensor are connected to the battery management system.

[0007] The circuit breaker is connected to both ends of the battery module and to the negative electrode of the heating film;

[0008] One end of the heating relay is connected to the positive electrode of the heating film, and the other end is connected to the Pack+ terminal;

[0009] One end of the main relay is connected to the circuit breaker, and the other end is connected to the Pack+ terminal;

[0010] The main relay, heating relay, and circuit breaker are all connected to the battery management system.

[0011] The battery management system is used to control the closing and opening of the main relay, the closing and opening of the circuit breaker, and the closing and opening of the heating relay.

[0012] Furthermore, the circuit breaker is connected to both ends of the battery module and to the negative terminal of the heating film, specifically including:

[0013] Pin 1 of the circuit breaker is connected to the positive terminal of the battery module and exits from pin 2 of the circuit breaker;

[0014] The circuit breaker's pin 3 is connected to the negative terminal of the battery module and makes contact with pin 4 of the circuit breaker; the circuit breaker's pin 3 is also connected to the negative terminal of the heating film.

[0015] Furthermore, one end of the main relay is connected to the circuit breaker, and the other end is connected to the Pack+ terminal. The specific connection includes:

[0016] Pin 2 of the circuit breaker is connected to one end of the main relay, and the other end of the main relay is connected to the Pack+ terminal.

[0017] The circuit breaker's pin 4 is connected to the Pack- terminal.

[0018] Furthermore, the main relay, heating relay, and circuit breaker are all connected to the battery management system, specifically including:

[0019] The HV pin of the battery management system is connected to one pin of the main relay, and the I_GND pin of the battery management system is connected to the negative terminal of the battery module. When the circuit breaker is closed, the battery management system is used to detect the voltage Vbat of the battery module.

[0020] The HV1 pin of the battery management system is connected to the two pins of the main relay, and the I_GND pin of the battery management system is connected to the negative terminal of the battery module. When the circuit breaker is closed, it is used to detect the external voltage Vpack.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0022] (1) This utility model not only has a more efficient heating logic, but can also automatically judge and heat in a low-temperature environment, effectively solving the problem of performance degradation of lithium batteries in a low-temperature environment and greatly improving the utilization rate of battery energy.

[0023] (2) This utility model uses a relay as a control device, which has a higher isolation level, can withstand greater power, and has stronger impact resistance compared to a MOSFET.

[0024] (3) This utility model can greatly enhance the stability of the battery pack, greatly avoid the risks to the battery caused by abnormal situations such as heating film failure and short circuit, and ensure the user's power safety. Attached Figure Description

[0025] Figure 1 This is a schematic diagram showing the placement of the heating film and the heating film temperature sensor of this utility model.

[0026] Figure 2 This is a schematic diagram of the circuit principle of an automatic heating control system for low temperature energy storage batteries according to the present invention.

[0027] Figure 3 This is a schematic diagram illustrating the working process of a low-temperature automatic heating control method for energy storage batteries according to this utility model. Detailed Implementation

[0028] The technical solution of this utility model will now be further described in conjunction with the accompanying drawings and embodiments.

[0029] This embodiment proposes a low-temperature automatic heating control system for energy storage batteries, aiming to improve the shortcomings of existing heating schemes, perfect the low-temperature automatic heating mechanism of energy storage battery packs, and extend the service life of battery packs in low-temperature environments. Figure 2 As shown, it mainly includes: a battery module (BAT Model), a battery management system (BMS), a heating relay (PTC Relay), a circuit breaker, a main relay, at least two heating film temperature sensors (T_P), at least two cell temperature sensors (T_C), and multiple heating film PTCs. The main relay, heating relay (PTC Relay), and circuit breaker are all connected to the BMS to enable the BMS to control the heating film PTCs, achieving high-efficiency heating of the battery module (BAT Model). The BMS should have a 20W load capacity to drive the control devices.

[0030] Each heating film PTC is tightly attached to the upper and lower surfaces of the battery module (BAT Model); such as Figure 1As shown, the heating film temperature sensor T_P is attached tightly to the surface of the heating film PTC, as close as possible to the center of the heating film PTC. The cell temperature sensors T_C should be evenly distributed throughout the battery module BAT Model. The heating film PTC temperature and battery module BAT Model temperature data collected by the heating film temperature sensor T_P and the cell temperature sensor T_C will be transmitted to the battery management system BMS in real time, providing accurate judgment basis for the heating logic.

[0031] The circuit breaker (Breaker) is connected to both ends of the battery module (BAT Model) and controls the outputs of the positive (Battery+) and negative (Battery-) terminals of the battery module (BAT Model) as well as the negative terminal of the heating film (PTC). The main relay (Main Relay) is connected in series in the positive circuit, after the circuit breaker (Breaker), to control the output of the PACK+. The heating relay (PTC Relay) is connected in series in the positive circuit, after the main relay (Main Relay), to control the positive terminal of the heating film (PTC). The positive terminal of the heating film (PTC) is connected in series to the front end of the heating relay (PTC Relay), and its negative terminal is connected in series to the front end of the circuit breaker (Breaker), so that the corresponding relays are closed and connected to both ends of the battery module (BAT Model) and the PACK.

[0032] The specific connections are as follows: The positive terminal (Battery+) of the battery module (BAT Model) is connected to pin 1 of the circuit breaker (Breaker). From pin 2 of the circuit breaker, it is connected to pin 1 of the main relay (Main Relay). Finally, pin 2 of the main relay (Main Relay) is connected to the PACK+ terminal. The negative terminal (Battery-) of the battery module (BAT Model) is connected to pin 3 of the circuit breaker (Breaker), and from pin 4 of the circuit breaker, it is connected to the PACK- terminal.

[0033] The positive terminals of multiple heating PTCs are connected to one pin of the heating relay PTC Relay, and then from the second pin of the heating relay PTC Relay to the second pin of the main relay Main Relay, which is connected to the Pack+ terminal. The negative terminal of the heating PTC is connected to the third pin of the circuit breaker Breaker, and then from the fourth pin of the circuit breaker Breaker to the Pack- terminal.

[0034] Each heating film temperature sensor T_P is connected to the battery management system (BMS). In each battery pack's low-temperature heating circuit, at least two cell temperature sensors T_C are connected to the BMS. The heating film temperature sensor T_P is used to collect the surface temperature of the heating film PTC, and the cell temperature sensor T_C is used to collect the surface temperature of the cell.

[0035] The Battery Management System (BMS) has its HV pin connected to one pin of the Main Relay, and its I_GND pin connected to the negative terminal (Battery-) of the Battery Module (BAT Model). When the Circuit Breaker (Breaker) closes, this pin is used to detect the voltage Vbat of the BAT Model. The BMS's HV1 pin is connected to the second pin of the Main Relay, and its I_GND pin is connected to the negative terminal (Battery-) of the BAT Model. When the Circuit Breaker (Breaker) closes, this pin is used to detect the external voltage Vpack of the battery pack. The BMS also uses commands to control the opening and closing of the Main Relay, the opening and closing of the Circuit Breaker (Breaker), and the opening and closing of the PTC Heating Relay (PTCRelay).

[0036] The working process of the control system proposed in this embodiment is as follows:

[0037] Set two heating temperature thresholds. Heating temperature threshold one should be determined based on the lower limit of the cell's charging temperature. For example, if the lower limit is 0℃, it is recommended to set heating temperature threshold one between 0 and 20℃. It is not recommended to set heating temperature threshold one below the lower limit of the cell's charging temperature. Heating temperature threshold two should be determined based on the lower limit of the cell's discharging temperature. For example, if the lower limit is -20℃, it is recommended to set heating temperature threshold two between -20℃ and 0℃. It is not recommended to set heating temperature threshold two below the lower limit of the cell's discharging temperature.

[0038] like Figure 3 As shown, the Battery Management System (BMS) determines whether the temperature of the Battery Module (BAT) is lower than the heating temperature threshold.

[0039] If the temperature of the battery module (BAT Model) is less than the heating threshold, then:

[0040] The main relay is disconnected. When the battery management system (BMS) detects that the external voltage Vpack of the battery pack is within the voltage range that the heating film PTC can withstand, the main relay remains disconnected, and the heating relay PTCRelay is closed. The heating film PTC receives the external voltage Vpack of the battery pack, and then heats the battery module (BAT Model).

[0041] Alternatively, the main relay can be disconnected. When the battery management system (BMS) detects that the external voltage Vpack of the battery pack is lost and the temperature of the battery module BAT Model is greater than the heating temperature threshold, the main relay closes and the heating relay PTC Relay closes. The heating film PTC receives the voltage Vbat of the battery module BAT Model and then heats the battery module BAT Model.

[0042] Alternatively, the main relay can be disconnected, and if the external voltage Vpack of the battery pack detected by the battery management system (BMS) is higher than the voltage range that the heating film PTC can withstand after the main relay is disconnected, then the main relay will remain disconnected, and the heating relay PTC Relay will remain disconnected.

[0043] If the temperature of the battery module BAT Model is greater than or equal to the heating threshold, the main relay closes, the heating relay PTC closes, the heating film PTC receives the voltage Vbat of the battery module BAT Model, and the battery module BAT Model begins to heat up.

[0044] If a discharge request is received during the heating process described above, and the temperature of the battery module (BAT Model) exceeds the heating threshold two, the PTC relay is disconnected, the PTC is de-energized, and heating of the battery module (BAT Model) ceases. Simultaneously, the main relay is closed to control the battery pack discharge.

[0045] If no discharge request is received during the above heating process, and the temperature of the battery module BAT Model is greater than the heating threshold two, then the heating film PTC will continue to heat the battery module BAT Model, and the battery pack will remain prohibited from charging and discharging.

[0046] If no discharge request is received during the above heating process, and the temperature of the battery module (BAT Model) is greater than heating threshold 2 but less than heating threshold 1, then the heating film PTC will continue to heat the battery module (BAT Model), allowing the battery pack to discharge and prohibiting the battery pack from charging.

[0047] When the Battery Management System (BMS) detects that the cell temperature has reached the heating cutoff temperature, heating ends, the heating relay (PTC Relay) disconnects, the heating film (PTC) loses power, and heating of the battery module (BAT Model) fails. If the external load is not removed and the external voltage (Vpack) of the battery pack is within the heating film's voltage tolerance range, the main relay disconnects for 1 minute. If the temperatures collected by the heating film temperature sensor (T_P) and the cell temperature sensor (T_C) rise instead of falling, a fault is determined to be a sticking fault in the heating film relay (PTC Relay). The fault information is written to and saved in the BMS, and the circuit breaker (Breaker) is simultaneously disconnected. If the temperatures collected by the heating film temperature sensor (T_P) and the cell temperature sensor (T_C) drop normally 1 minute after the main relay disconnects, the heating film relay (PTC Relay) is determined to have disconnected normally.

[0048] During the heating process, the battery management system (BMS) collects the heating film PTC temperature and the cell temperature in real time through the heating film temperature sensor T_P and the cell temperature sensor T_C, and determines whether the difference between the heating film temperature and the battery module temperature is greater than the set threshold.

[0049] If yes, the heating film PTC function is determined to be faulty, the heating film relay PTC Relay is disconnected, and the fault information is written to and saved in the battery management system (BMS). If no, the heating film PTC is determined to be working normally.

[0050] In this embodiment, the power supply of the battery management system (BMS) should be connected in parallel to both ends of the circuit breaker (Breaker). If the circuit breaker (Breaker) is disconnected, the battery management system (BMS) should also be completely powered off to minimize the power loss of the battery module (BAT Model). At the same time, the battery management system (BMS) should have fast data processing capabilities, a certain degree of anti-interference capability, and a lower operating temperature limit that is higher than the lower limit of the cell discharge temperature.

[0051] If the heating relay PTC Relay in this embodiment becomes stuck, the battery management system (BMS) should promptly report the corresponding fault and save it. At the same time, it should turn off the heating mode, disconnect the battery module (BAT Model) from the external load, and remind the user to check the heating relay PTC Relay the next time the battery is turned on.

[0052] It should be noted that the above content describes a low-temperature automatic heating system for energy storage batteries. This system is an optimization of traditional heating methods, which greatly improves the efficiency of battery pack heating, the stability of battery pack use, and the consistency of battery capacity.

Claims

1. A low-temperature automatic heating control system for energy storage batteries, characterized in that: include: The battery module includes a battery management system, a heating relay, a circuit breaker, a main relay, multiple heating film temperature sensors, multiple cell temperature sensors, and multiple heating films. The power supply of the battery management system is connected in parallel to both ends of the circuit breaker. If the circuit breaker is opened, the battery management system will also be completely de-energized. The heating film is attached to the upper and lower surfaces of the battery module, and the heating film temperature sensor is attached to the surface of the heating film to collect the surface temperature of the heating film. The cell temperature sensor is evenly distributed in the battery module to collect the battery module temperature. Both the heating film temperature sensor and the cell temperature sensor are connected to the battery management system. The circuit breaker is connected to both ends of the battery module and to the negative electrode of the heating film; One end of the heating relay is connected to the positive electrode of the heating film, and the other end is connected to the Pack+ terminal; One end of the main relay is connected to the circuit breaker, and the other end is connected to the Pack+ terminal; The main relay, heating relay, and circuit breaker are all connected to the battery management system.

2. The low-temperature automatic heating control system for energy storage batteries according to claim 1, characterized in that: The circuit breaker is connected to both ends of the battery module and to the negative terminal of the heating film. The specific connection includes: Pin 1 of the circuit breaker is connected to the positive terminal of the battery module and exits from pin 2 of the circuit breaker; The circuit breaker's pin 3 is connected to the negative terminal of the battery module and makes contact with pin 4 of the circuit breaker; the circuit breaker's pin 3 is also connected to the negative terminal of the heating film.

3. The low-temperature automatic heating control system for energy storage batteries according to claim 2, characterized in that: One end of the main relay is connected to the circuit breaker, and the other end is connected to the Pack+ terminal. The specific connection includes: Pin 2 of the circuit breaker is connected to one end of the main relay, and the other end of the main relay is connected to the Pack+ terminal. The circuit breaker's pin 4 is connected to the Pack- terminal.

4. The low-temperature automatic heating control system for energy storage batteries according to claim 1, characterized in that: The main relay, heating relay, and circuit breaker are all connected to the battery management system, specifically including: The HV pin of the battery management system is connected to one pin of the main relay, and the I_GND pin of the battery management system is connected to the negative terminal of the battery module. When the circuit breaker is closed, the battery management system is used to detect the voltage Vbat of the battery module. The HV1 pin of the battery management system is connected to the two pins of the main relay, and the I_GND pin of the battery management system is connected to the negative terminal of the battery module. When the circuit breaker is closed, it is used to detect the external voltage Vpack.

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