A battery pack cooling control circuit, a pulse cooling control circuit, and a control method

Abstract

The application discloses a battery pack cooling control circuit, a pulse cooling control circuit and a control method, and is applied to the technical field of battery pack cooling control, and comprises a controller, a first cooling control unit, a second cooling control unit and a battery management system, wherein the first cooling control unit comprises a first power supply, a first triode, a first resistor and a first load; the second cooling control unit comprises a second power supply, a second triode, a second load and a second resistor; through the double-path independent design of the first cooling control unit and the second cooling control unit, the battery pack is cooled in combination with the battery management system, the power consumption of the battery pack for additional cooling in the fast charging process is greatly reduced, and the cooling effect is provided.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle cooling control technology, and in particular to a battery pack cooling control circuit, a pulse cooling control circuit, and a control method. Background Technology

[0002] With the technological iteration of electric vehicles, fast charging is currently the mainstream energy replenishment technology. Current technological directions are divided into cell-level design, overall battery pack system design, and BMS (Battery Management System) design. At the cell level, optimized material design enables it to withstand the large amounts of heat generated by internal and external circuits during high-current charging. The BMS mainly consists of passive and active protection. Passive protection involves monitoring cell temperature rise during charging; when overheating is detected, feedback is sent to the vehicle, and charging is stopped. Active protection involves controlling the vehicle's thermal management system to cool the cells within the battery pack when overheating is detected. The turbulence effect generated by pulsed cooling fluid during flow creates a differential velocity, and the temperature gradient within the pipe generates a large turbulent temperature boundary layer. This phenomenon increases the heat exchange rate of the pipe walls, thereby improving the heat exchange rate between the cooling surface and the object.

[0003] Fast charging generates a significant amount of heat in the battery cells, impacting battery lifespan and potentially leading to dangerous events like thermal runaway when heat accumulates to a certain level. Therefore, maintaining a comfortable temperature for the battery cells during fast charging is a major technological hurdle. Secondly, during supercharging, the heat generated by the entire battery pack exceeds that of the vehicle under driving conditions. Relying solely on vehicle-side thermal management to cool the battery pack is insufficient to support future high-rate charging requirements. Therefore, controlling pulse water cooling and implementing various forms of pulse cooling during the charging process are key issues that need to be addressed. Summary of the Invention

[0004] To address the aforementioned technical problems, embodiments of the present invention provide a battery pack cooling control circuit, a pulse cooling control circuit, and a control method to solve the technical problems in the prior art where the cooling effect is poor and the battery cannot be cooled down quickly during the charging process of electric vehicles.

[0005] A first aspect of this invention provides a battery pack cooling control circuit, the circuit including a controller, a first cooling control unit, a second cooling control unit, and a battery management system, wherein...

[0006] The first cooling control unit includes: a first power supply, a first transistor, a first resistor, and a first load, wherein the positive terminal of the first power supply is connected to the first end of the first resistor, the second end of the first resistor is connected to the emitter of the first transistor, the collector of the first transistor is connected to the first end of the first load, the second end of the first load is connected to the negative terminal of the first power supply, and the base of the first transistor is connected to the controller.

[0007] The second cooling control unit includes: a second power supply, a second transistor, a second load, and a second resistor, wherein the positive terminal of the second power supply is connected to the first end of the second resistor, the second end of the second resistor is connected to the emitter of the second transistor, the first end of the second load is connected to the collector of the second transistor, the second end of the second load is connected to the negative terminal of the second power supply, and the base of the second transistor is connected to the controller.

[0008] The controller communicates with the battery management system.

[0009] In one possible implementation of the first aspect, the second cooling control unit further includes a third resistor, wherein,

[0010] The first end of the third resistor is connected to the collector of the second transistor, and the second end of the third resistor is connected to the negative terminal of the second power supply.

[0011] One possible implementation of the first aspect also includes:

[0012] The combiner module is used to combine the cooling medium provided by the first load and the cooling medium provided by the second load.

[0013] In one possible implementation of the first aspect, the controller, the first cooling control unit, and the second cooling control unit are installed at the charging pile end or the vehicle end.

[0014] A second aspect of the present invention provides a battery pack pulse cooling control circuit, including a battery pack cooling control circuit and a capacitor, wherein,

[0015] The battery pack cooling control circuit is as described in the first aspect of the battery pack cooling control circuit.

[0016] The first terminal of the capacitor is connected to the collector of the second transistor, and the second terminal of the capacitor is connected to the negative terminal of the second power supply.

[0017] A third aspect of this invention provides a method for cooling an electric vehicle battery pack. This method is implemented using a battery pack cooling control circuit as described in the first aspect of this invention, or using a battery pack pulse cooling control circuit as described in the second aspect of this invention, and includes:

[0018] The temperature of the battery pack after being cooled for a first preset time under charging or discharging conditions is obtained, and the temperature after the first cooling is obtained.

[0019] Determine whether the temperature after the first cooling is greater than the first temperature threshold. If it is greater, send a first control signal to the controller to make the controller close the first transistor, so that the first power supply drives the first load to cool the battery pack. Obtain the battery pack temperature after the first load has been driven to cool the battery pack for a preset time, and obtain the second cooling temperature.

[0020] Determine whether the temperature after the second cooling is greater than or equal to the first temperature threshold. If it is still greater than the first temperature threshold, send a second control signal to the controller to make the controller close the second transistor, so that the second power supply drives the second load to cool the battery pack according to the preset duty cycle input pulse power.

[0021] The battery pack temperature is obtained after the second load performs pulse cooling on the battery pack for a preset time. The third cooled temperature is obtained. If the third cooled temperature is less than the first temperature threshold and greater than the second temperature threshold, the battery pack is cooled until the battery pack temperature is less than the second temperature threshold, and then the cooling is stopped.

[0022] In one possible implementation of the third aspect, before obtaining the temperature after the first cooling, the following is included:

[0023] The temperature of the battery pack is obtained after a second preset time of charging or discharging, and the current temperature is obtained.

[0024] Determine whether the current temperature is less than the first temperature threshold and greater than the second temperature threshold. If so, open the valve of the bottom liquid cooling plate of the battery pack to cool the battery pack and obtain the temperature of the battery pack during the preset cooling time period, wherein the second temperature threshold is less than the first temperature threshold.

[0025] The temperature rise rate is calculated based on the temperature of the battery pack during a preset cooling period. When the temperature rise rate is greater than 0, the valve of the top liquid cooling plate of the battery pack is opened.

[0026] In one possible implementation of the third aspect, the second power source drives the second load to cool the battery pack according to a preset duty cycle input pulse power, including:

[0027] Determine whether the battery pack is in charging or discharging mode. If it is in charging mode, the second power supply outputs pulse power according to the first preset duty cycle to drive the second load to perform pulse cooling on the battery pack.

[0028] If the battery is in discharge mode, the second power supply outputs pulse power according to the second preset duty cycle to drive the second load to perform pulse cooling on the battery pack.

[0029] In one possible implementation of the third aspect, after obtaining the temperature after the first cooling, it further includes:

[0030] If the temperature after the first cooling is greater than the first temperature threshold, a third control signal is sent to the controller to make the controller close the first transistor, so that the first power supply outputs power according to the preset frequency pulse signal to drive the first load to cool the battery pack.

[0031] In one possible implementation of the third aspect, pulse cooling includes rectangular pulse cooling or sawtooth pulse cooling.

[0032] The technical solution of this invention has the following advantages:

[0033] The battery pack cooling control circuit provided by this invention comprises a controller, a first cooling control unit, a second cooling control unit, and a battery management system. The first cooling control unit includes a first power supply, a first transistor, a first resistor, and a first load. The second cooling control unit includes a second power supply, a second transistor, a second load, and a second resistor. By adopting a dual-path independent design of the first and second cooling control units, combined with the battery management system to cool the battery pack, the power consumption of additional cooling during fast charging is greatly reduced, thus providing a cooling effect.

[0034] The battery pack pulse cooling control circuit provided by the present invention, by adding a capacitor in parallel to the first cooling control unit, can convert the rectangular power wave output by the first cooling control unit and the second cooling control unit into a sawtooth power wave, thereby improving the cooling effect and reducing the pressure in the flow channel.

[0035] The electric vehicle battery pack cooling control method provided by this invention utilizes the battery management system to collect the temperature of the battery pack during cooling. If the temperature is greater than a first temperature threshold, the first cooling control unit is controlled to cool the battery pack. If the temperature of the battery pack is still greater than the first temperature threshold after cooling, the second cooling control unit is controlled to cool it, thereby outputting pulse power to pulse cool the battery pack. This method achieves differential water flow and increases turbulence, which can greatly improve the heat exchange of the cooling medium and improve the cooling effect of the battery pack. Attached Figure Description

[0036] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a circuit diagram of the battery pack cooling control circuit in an embodiment of the present invention;

[0038] Figure 2 This is a connection diagram of the vehicle and charging pile cooling systems for the battery pack cooling control circuit in an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the vehicle and charging pile layout of the battery pack cooling control circuit in an embodiment of the present invention;

[0040] Figure 4 This is a diagram illustrating the cooling cycle system architecture of the battery pack cooling control circuit in an embodiment of the present invention.

[0041] Figure 5 This is a diagram showing the dual-power rectangular pulse cooling power of the battery pack cooling control circuit in this embodiment of the invention.

[0042] Figure 6 This is a single-power-supply cooling circuit for the battery pack cooling control circuit in this embodiment of the invention;

[0043] Figure 7 This is a diagram of the single-supply rectangular pulse cooling power of the battery pack cooling control circuit in an embodiment of the present invention.

[0044] Figure 8 This is a circuit diagram of the battery pack pulse cooling control circuit in an embodiment of the present invention;

[0045] Figure 9 This is a dual-power sawtooth cooling power diagram of the battery pack pulse cooling control circuit in an embodiment of the present invention;

[0046] Figure 10 This is a single-power sawtooth pulse cooling circuit diagram of the battery pack pulse cooling control circuit in an embodiment of the present invention;

[0047] Figure 11 This is a single-supply sawtooth cooling power diagram of the battery pack pulse cooling control circuit in an embodiment of the present invention;

[0048] Figure 12 This is a flowchart of the electric vehicle battery pack cooling control method in an embodiment of the present invention;

[0049] Figure 13 This is a flowchart of the dual-power pulse cooling control method for electric vehicle battery pack cooling control under charging conditions in an embodiment of the present invention.

[0050] Figure 14 This is a flowchart illustrating the dual-power pulse cooling control method for the electric vehicle battery pack under driving conditions in an embodiment of the present invention.

[0051] Figure 15This is a flowchart of the single-power-source pulse cooling control method for the electric vehicle battery pack under charging conditions in an embodiment of the present invention.

[0052] Figure 16 This is a flowchart illustrating the single-power-source pulse cooling control method for the electric vehicle battery pack cooling control under driving conditions, as described in this embodiment of the invention.

[0053] The attached diagram is labeled as follows: 1. Charging pile; 2. High-voltage charging cable; 3. Cooling pipe; 4. Vehicle end; 43. Bottom liquid cooling plate; 44. Top liquid cooling plate; 45. Vehicle end cooling system connection connector; 46. Vehicle end charging connector; 47. Charging end cooling system connection connector; 100. Controller; 200. First cooling control unit; 300. Second cooling control unit; 400. Battery management system; 21. First power supply; 41. First transistor; 61. First resistor; 31. First load; 22. Second power supply; 42. Second transistor; 32. Second load; 62. Second resistor; 63. Third resistor; 50. Busbar module; 70. Capacitor. Detailed Implementation

[0054] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] In the description of this invention, it should be noted that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0056] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can also refer to the internal connection of two components; it can be a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0057] The battery pack cooling control circuit provided in this embodiment of the invention, such as Figure 1 As shown, it includes a controller 100, a first cooling control unit 200, a second cooling control unit 300, and a battery management system 400, wherein,

[0058] The first cooling control unit 200 includes: a first power supply 21, a first transistor 41, a first resistor 61, and a first load 31. The positive terminal of the first power supply 21 is connected to the first end of the first resistor 61, the second end of the first resistor 61 is connected to the emitter of the first transistor 41, the collector of the first transistor 41 is connected to the first end of the first load 31, the second end of the first load 31 is connected to the negative terminal of the first power supply 21, and the base of the first transistor 41 is connected to the controller 100.

[0059] The second cooling control unit 300 includes: a second power supply 22, a second transistor 42, a second load 32, and a second resistor 62. The positive terminal of the second power supply 22 is connected to the first terminal of the second resistor 62, the second terminal of the second resistor 62 is connected to the emitter of the second transistor 42, the first terminal of the second load 32 is connected to the collector of the second transistor 42, the second terminal of the second load 32 is connected to the negative terminal of the second power supply 22, and the base of the second transistor 42 is connected to the controller 100.

[0060] The controller 10 is connected in communication with the battery management system.

[0061] In this embodiment, a complete cooling cycle system is formed by connecting the vehicle's cooling system and the charging station's cooling system. The connection diagram of the vehicle and charging station cooling systems is shown below. Figure 2 and Figure 3 As shown, from Figure 2 and Figure 3 As can be seen, the vehicle end 4 and the charging pile 1 are connected by cooling pipes 3 and high-voltage charging cables 2. The battery pack in the vehicle end 4 is equipped with a bottom liquid cooling plate 43 on the top and a top liquid cooling plate 44 on the bottom. The cooling pipes are equipped with a vehicle end cooling system connection connector 45, a vehicle end charging connector 46, and a charging end cooling system connection connector 47.

[0062] A corresponding battery pack cooling control circuit is designed for this cooling cycle system to control the system. When the battery pack is in driving mode, the battery management system collects its temperature information and sends a control signal to the vehicle controller. The vehicle controller then controls the vehicle-side cooling cycle system to cool the battery pack. When the battery pack is charging, the battery management system collects its temperature information and sends a control signal to the charging station. The charging station's control unit then controls the cooling cycle system to cool the battery pack. The cooling cycle system architecture diagram is shown below. Figure 4 As shown, the charging pile's control unit communicates with the battery management system and the vehicle controller. By receiving signals from the battery management system, it controls the charging unit and the cooling unit to adjust the flow rate of the cooling medium.

[0063] The battery pack cooling control circuit has dual power supplies: a first power supply 21 and a second power supply 22, which power two loads respectively. Specifically, the battery pack cooling control circuit includes a controller 100, a first cooling control unit 200, a second cooling control unit 300, and a battery management system 400. The first power supply 21 is located in the first cooling control unit. The first cooling control unit also includes a first transistor 41, a first resistor 61, and a first load 31. The connections between the components are as follows: the positive terminal of the first power supply 21 is connected to the first end of the first resistor 61, the second end of the first resistor 61 is connected to the emitter of the first transistor 41, the collector of the first transistor 41 is connected to the first end of the first load 31, the second end of the first load 31 is connected to the negative terminal of the first power supply 21, and the base of the first transistor 41 is connected to the controller 100. When only the first power supply 21 is working, a continuous and stable power output is generated, and the flow rate of the cooling medium is also stable.

[0064] The second power supply 22 is located in the second cooling control unit 300, which also includes a second transistor 42, a second load 32, and a second resistor 62. The connections between these components are as follows: the positive terminal of the second power supply 22 is connected to the first end of the second resistor 62; the second end of the second resistor 62 is connected to the emitter of the second transistor 42; the first end of the second load 32 is connected to the collector of the second transistor 42; the second end of the second load 32 is connected to the negative terminal of the second power supply 22; and the base of the second transistor 42 is connected to the controller 100. When the second power supply 22 intermittently supplies power via the switching of the second transistor 42, it can work in conjunction with the first power supply 21 to generate rectangular pulse-type power, such as... Figure 5 As shown, the flow rate of the cooling medium is affected by the power to generate a pulsed flow state. During the process of cooling the fluid in the form of pulses, the heat transfer effect of the boundary layer can be effectively improved, the heat transfer rate can be increased, and the cooling can be accelerated.

[0065] When fluid is cooled in a pulsed manner, a velocity difference is created between the high and low flow rates during the pulse. The two fluids exert forces on each other. Due to the high specific heat capacity, the temperature of the fluid in the center is low, while the temperature of the fluid in contact with the top and bottom liquid cooling plates is high, creating a temperature gradient. Therefore, under the action of the pulse, the high-velocity fluid impacts the low-velocity fluid, mixing temperatures and effectively improving the temperature uniformity within the container. Water has a thermal conductivity of 0.6 W / (m·K), while aluminum has a thermal conductivity of 237 W / (m·K). During the cooling heat exchange process, the bottleneck lies in the slow thermal conductivity of liquid cooling. Therefore, pulsed cooling can bring the coolant in the low-temperature central zone into contact with the channel wall. Due to the increased temperature difference, its heat transfer effect is further increased compared to the traditional cooling scheme under a stable flow rate.

[0066] It should be noted that the first transistor 41 and the second transistor 42 function as transistors, and can achieve a pulse effect by changing the voltage through the P wave output by the battery management system.

[0067] It should be noted that the battery pack cooling control circuit can also power the cooling circulation system using only one power source. For example... Figure 6 As shown, Figure 6 This is a single-supply cooling circuit. The cooling cycle system receives power from only one power source, providing the maximum continuous power, at which point the cooling medium flow rate also reaches its maximum. The MCU in the battery management system outputs a P-wave signal, which is transmitted to the controller 100 via a CAN signal. This controller then controls the second transistor 42 to change the power level, achieving a rectangular pulse cooling effect, such as... Figure 7 As shown, this method can reduce energy consumption while maximizing the heat exchange of the cooling medium.

[0068] In one embodiment, the second cooling control unit 300 further includes a third resistor 63, wherein,

[0069] The first end of the third resistor 63 is connected to the collector of the second transistor 42, and the second end of the third resistor 63 is connected to the negative terminal of the second power supply 22.

[0070] In this embodiment, a third resistor 63 is also connected in parallel in the second cooling control unit 300 to control the magnitude of the current flowing into the second load 32, thereby adjusting the peak value of the rectangular pulse.

[0071] It should be noted that the third resistor 63 is a variable resistor, and its resistance value can be dynamically adjusted.

[0072] In one embodiment, a junction module 50 is used to combine the cooling medium provided by the first load 31 and the cooling medium provided by the second load 32.

[0073] In this embodiment, the battery pack cooling control circuit also includes a combiner module 50, which can combine the cooling medium provided by the first load 31 and the cooling medium provided by the second load 32. Specifically, when the first power supply 21 is working, the second power supply 22 is also turned on. The second power supply 22 generates intermittent flow rates by supplying power to the second load 32, thereby achieving pulse cooling rectangular pulses or sawtooth pulses in the combiner module.

[0074] In one embodiment, the controller 100, the first cooling control unit 200, and the second cooling control unit 300 are installed at the charging pile end or the vehicle end.

[0075] In this embodiment, the controller 100, the first cooling control unit 200, and the second cooling control unit 300 can be installed at the charging pile end or the vehicle end. If installed at the charging pile end, the controller 100 is the controller of the charging pile; if installed at the vehicle end, the controller 100 is the vehicle controller.

[0076] To solve the same technical problem, the battery pack pulse cooling control circuit provided in the embodiments of the present invention, such as... Figure 8 As shown, the battery pack cooling control circuit and capacitor 70, wherein,

[0077] The battery pack cooling control circuit is as described in this embodiment.

[0078] The first end of capacitor 70 is connected to the collector of the second transistor 42, and the second end of capacitor 70 is connected to the negative terminal of the second power supply 22.

[0079] In this embodiment, based on the battery pack cooling control circuit, a capacitor 70 is connected in parallel in the second cooling control unit 300. This converts the rectangular wave into a sawtooth-shaped power wave. The cooling circulation system, under the influence of power, generates a sawtooth-shaped flow state, which is similar to the effect of rectangular pulse cooling, but reduces the pressure in the flow channel. Specifically, the first end of the capacitor 70 is connected to the collector of the second transistor 42, and the second end of the capacitor 70 is connected to the negative terminal of the second power supply 22.

[0080] A sawtooth power diagram is shown below. Figure 9 As shown, since the rectangular pulse method is suitable for the commercial vehicle end where the cold plate has a large pressure load, a capacitor is introduced into the second cooling control unit 300 to generate a sawtooth pulse, which is suitable for cold plates that can withstand large pressure loads in a short time.

[0081] It should be noted that connecting a capacitor 70 in parallel with the second cooling control unit 300 can be used in both dual-power supply cooling cycle system scenarios and single-power supply cooling cycle system scenarios, such as... Figure 10 As shown, Figure 10 This is a single-supply sawtooth pulse cooling circuit. A capacitor is connected in parallel or an inductor is connected in series with a single-supply cooling circuit to generate sawtooth pulse cooling, improving heat exchange efficiency. Its power schematic diagram is shown below. Figure 11 As shown.

[0082] To solve the same technical problem, the present invention provides a method for cooling control of an electric vehicle battery pack, the method being as follows: Figure 12 As shown, Figure 12 The flowchart shows a method for cooling control of an electric vehicle battery pack, including steps S121 to S124, each of which is detailed below:

[0083] S121. Obtain the temperature of the battery pack after it has been cooled for a first preset time under charging or discharging conditions, and obtain the temperature after the first cooling.

[0084] In this embodiment, the battery management system collects the temperature of the battery pack after it has been cooled for a first preset time under charging or discharging conditions, thus obtaining the first cooled temperature. This can be understood as the battery pack cooling process being divided into charging and operating conditions. Under charging conditions, the cooling process is as follows: Figure 13 As shown, during the initial charging phase, the battery management system monitors the temperature of the entire battery pack in real time. If the detected temperature of the battery pack exceeds the second temperature threshold, cooling of the battery pack begins and the temperature of the battery pack is continuously monitored to obtain the first cooled temperature. The first preset cooling time can be understood as a fixed duration (e.g., 1s, 5s, 10s, etc.) manually set when collecting the first cooled temperature, and can be set according to actual needs.

[0085] Under operating conditions, during the driving phase, the cooling process is as follows: Figure 14 As shown, the battery management system adopts the same strategy as the above charging conditions, namely, monitoring the temperature of the entire battery pack. If the temperature of the battery pack is detected to be greater than the second temperature threshold, the battery pack is cooled and the temperature of the battery pack is continuously monitored to obtain the first cooled temperature.

[0086] In one embodiment, before obtaining the first cooled temperature, the process includes:

[0087] The temperature of the battery pack is obtained after a second preset time of charging or discharging, and the current temperature is obtained.

[0088] Determine whether the current temperature is less than the first temperature threshold and greater than the second temperature threshold. If so, open the valve of the bottom liquid cooling plate of the battery pack to cool the battery pack and obtain the temperature of the battery pack during the preset cooling time period, wherein the second temperature threshold is less than the first temperature threshold.

[0089] The temperature rise rate is calculated based on the temperature of the battery pack during a preset cooling period. When the temperature rise rate is greater than 0, the valve of the top liquid cooling plate of the battery pack is opened.

[0090] In this embodiment, during the initial charging phase, the battery management system monitors the temperature of the entire battery pack in real time to obtain the current temperature. When the current temperature of the battery pack is low, i.e., below the second temperature threshold, the battery management system controls the three-way valve to close and simultaneously sends a signal to the charging pile, preventing cooling from being activated. If the current temperature is greater than the second temperature threshold but less than the first temperature threshold, a signal is sent to activate the battery pack liquid cooling plate. Specifically, the valve of the bottom liquid cooling plate of the battery pack is activated to cool the battery pack. During cooling, the temperature of the battery pack is monitored in real time. If the temperature rise rate of the battery pack is detected to be greater than 0 and the battery voltage has not reached the charging cutoff voltage, the valve of the top liquid cooling plate of the battery pack is activated, allowing both the bottom and top liquid cooling plates to cool the battery pack simultaneously.

[0091] If it is in the operating condition, the battery management system will operate in the same way as in the charging condition when driving, which will not be repeated here. The difference is that the battery management system will input the signal to the vehicle.

[0092] It should be noted that the second temperature threshold is less than the first temperature threshold. The second preset cooling time can be understood as follows: when the battery pack is in the initial stage of charging or after a time set by the driver (e.g., 1s, 5s, 10s, etc.), it can be set according to actual needs.

[0093] S122. Determine whether the temperature after the first cooling is greater than the first temperature threshold. If it is greater, send a first control signal to the controller to make the controller close the first transistor, so that the first power supply drives the first load to cool the battery pack. Obtain the battery pack temperature after the first load has been driven to cool the battery pack for a preset time, and obtain the second cooling temperature.

[0094] In this embodiment, regardless of whether it is in charging or driving mode, if the temperature after the first cooling is greater than the first temperature threshold, the battery management system sends a first control signal to the controller 100. After the controller 100 closes the first transistor 41, the first power supply 21 starts to work and drives the first load 61 to cool the battery pack. After a certain period of time, that is, after the preset cooling time, the battery management system re-detects the temperature to obtain the temperature after the second cooling.

[0095] It should be noted that the first control signal refers to the control signal issued by the battery management system to the first transistor 41 or the second transistor 42 in the battery pack cooling control circuit with dual power supplies.

[0096] S123. Determine whether the temperature after the second cooling is greater than or equal to the first temperature threshold. If it is still greater than the first temperature threshold, send a second control signal to the controller so that the controller closes the second transistor and the second power supply drives the second load to cool the battery pack according to the preset duty cycle input pulse power.

[0097] In this embodiment, after obtaining the second cooled temperature, when the cooling system is powered by a dual power supply, if the second cooled temperature is greater than the first temperature threshold, the battery management system outputs via CAN to the charging pile or vehicle, causing the charging pile or vehicle to close the second transistor 42 and supply power through the second power supply 62. Specifically, the switching frequency of the second transistor 42 is output according to a preset duty cycle, so that the second power supply 62 generates an intermittent flow rate through the power supply to the second load 32 to achieve pulse cooling (rectangular pulse or sawtooth pulse) in the busbar module.

[0098] In one embodiment, driving a second load to cool the battery pack by inputting pulse power with a preset duty cycle from a second power source includes:

[0099] Determine whether the battery pack is in charging or discharging mode. If it is in charging mode, the second power supply outputs pulse power according to the first preset duty cycle to drive the second load to perform pulse cooling on the battery pack.

[0100] If the battery is in discharge mode, the second power supply outputs pulse power according to the second preset duty cycle to drive the second load to perform pulse cooling on the battery pack.

[0101] In this embodiment, if the battery pack is in charging mode, the second power supply outputs pulse power according to the first preset duty cycle to drive the second load to perform pulse cooling on the battery pack, wherein the first preset duty cycle is set to 0% to 70%.

[0102] If in discharge mode, the second power supply outputs pulse power according to the second preset duty cycle to drive the second load to pulse cool the battery pack, wherein the second preset duty cycle is set to 20% to 80%.

[0103] In one embodiment, after obtaining the first cooled temperature, the method further includes:

[0104] If the temperature after the first cooling is greater than the first temperature threshold, a third control signal is sent to the controller to make the controller close the first transistor, so that the first power supply outputs power according to the preset frequency pulse signal to drive the first load to cool the battery pack.

[0105] In this embodiment, after obtaining the first cooled temperature, a single power supply can be used to power the cooling system. Specifically, when in a charging state, such as... Figure 15 As shown, if the temperature after the first cooling is greater than the first temperature threshold, the battery management system outputs a P-wave signal to the charging pile to control the change amplitude of the second transistor 42, thereby achieving single-power-pulse cooling.

[0106] When in motion, such as Figure 16As shown, if the temperature after the first cooling is greater than the first temperature threshold, the battery management system outputs a P-wave signal to the vehicle to control the change amplitude of the second transistor 42, thereby achieving single-power-pulse cooling.

[0107] It should be noted that the third control signal can be understood as a signal that enables the controller to close the first transistor, so that the first power supply outputs power according to the preset frequency pulse signal to drive the first load to cool the battery pack. The preset frequency pulse signal can be understood as a P-wave signal.

[0108] In one embodiment, pulse cooling includes rectangular pulse cooling or sawtooth pulse cooling.

[0109] In this embodiment, pulse cooling includes rectangular pulse cooling or sawtooth pulse cooling. Rectangular pulse cooling is achieved through dual power supplies in the battery pack cooling control circuit, or it can be achieved by the battery management system outputting a P-wave signal to the vehicle to control the amplitude of the second transistor 42 in the single power supply cooling circuit.

[0110] Sawtooth pulse cooling can be achieved by connecting a capacitor 70 in parallel in the second cooling control unit 300 to convert a rectangular wave into a sawtooth power wave. Alternatively, it can be achieved by connecting a capacitor in parallel or an inductor in series to a single-power-supply cooling circuit to generate sawtooth pulse cooling.

[0111] S124. Obtain the battery pack temperature after the second load performs pulse cooling on the battery pack for a preset time, and obtain the third cooled temperature. If the third cooled temperature is less than the first temperature threshold and greater than the second temperature threshold, continue cooling the battery pack until the battery pack temperature is less than the second temperature threshold, and then stop cooling.

[0112] In this embodiment, regardless of whether it is charging or driving, after the second power supply 62 generates intermittent flow rates to supply power to the second load 32 to achieve pulse cooling in the combiner module, the temperature of the battery pack is continuously monitored to obtain the third cooled temperature. If the third cooled temperature is less than the first temperature threshold, the next step is to determine whether it is less than the second temperature threshold. If it is still greater than the second temperature threshold, pulse cooling of the battery pack continues. If it is less than the second temperature threshold, a signal to shut down the bottom liquid cooling plate and the top liquid cooling plate is output, and the power supply to the cooling system at the vehicle end or the charging pile end is shut down.

[0113] After a certain period of time, the battery management system re-checks the battery pack temperature to determine whether the vehicle is powered off, the battery voltage has reached the charging cutoff state of charge (SOC), or charging has been manually stopped. If not, the battery pack temperature is re-evaluated. If so, the entire battery pack stops supplying power.

[0114] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A battery pack cooling control circuit, characterized in that, It includes a controller (100), a first cooling control unit (200), a second cooling control unit (300), and a battery management system (400), wherein, The first cooling control unit (200) includes: a first power supply (21), a first transistor (41), a first resistor (61), and a first load (31), wherein the positive terminal of the first power supply (21) is connected to the first end of the first resistor (61), the second end of the first resistor (61) is connected to the emitter of the first transistor (41), the collector of the first transistor (41) is connected to the first end of the first load (31), the second end of the first load (31) is connected to the negative terminal of the first power supply (21), and the base of the first transistor (41) is connected to the controller (100). The second cooling control unit (300) includes: a second power supply (22), a second transistor (42), a second load (32), and a second resistor (62), wherein the positive terminal of the second power supply (22) is connected to the first end of the second resistor (62), the second end of the second resistor (62) is connected to the emitter of the second transistor (42), the first end of the second load (32) is connected to the collector of the second transistor (42), the second end of the second load (32) is connected to the negative terminal of the second power supply (22), and the base of the second transistor (42) is connected to the controller (100). The controller (100) is communicatively connected to the battery management system.

2. The battery pack cooling control circuit as described in claim 1, characterized in that, The second cooling control unit (300) also includes a third resistor (63), wherein, The first end of the third resistor (63) is connected to the collector of the second transistor (42), and the second end of the third resistor (63) is connected to the negative terminal of the second power supply (22).

3. The battery pack cooling control circuit as described in claim 1, characterized in that, Also includes: A junction module (50) is used to combine the cooling medium provided by the first load (31) and the cooling medium provided by the second load (32).

4. The battery pack cooling control circuit as described in claim 1, characterized in that, The controller (100), the first cooling control unit (200), and the second cooling control unit (300) are installed at the charging pile end or the vehicle end.

5. A battery pack pulse cooling control circuit, characterized in that, Includes battery pack cooling control circuitry and capacitor (70), wherein, The battery pack cooling control circuit is as described in any one of claims 1-4. The first end of the capacitor (70) is connected to the collector of the second transistor (42), and the second end of the capacitor (70) is connected to the negative terminal of the second power supply (22).

6. A method for cooling control of an electric vehicle battery pack, characterized in that, Implemented by the battery pack cooling control circuit as described in any one of claims 1-4, or by the battery pack pulse cooling control circuit as described in claim 5, comprising: The temperature of the battery pack after being cooled for a first preset time under charging or discharging conditions is obtained, and the temperature after the first cooling is obtained. Determine whether the first cooled temperature is greater than a first temperature threshold. If it is, send a first control signal to the controller to make the controller close the first transistor, so that the first power supply drives the first load to cool the battery pack. Obtain the battery pack temperature after the first load has been driven to cool the battery pack for a preset time, and obtain the second cooled temperature. Determine whether the second cooled temperature is greater than or equal to the first temperature threshold. If it is still greater than the first temperature threshold, send a second control signal to the controller to make the controller close the second transistor and make the second power supply drive the second load to cool the battery pack according to a preset duty cycle input pulse power. The battery pack temperature is obtained after the second load performs pulse cooling on the battery pack for a preset time. The third cooled temperature is obtained. If the third cooled temperature is less than the first temperature threshold and greater than the second temperature threshold, the battery pack is cooled until the temperature of the battery pack is less than the second temperature threshold, and then the cooling is stopped.

7. The electric vehicle battery pack cooling control method as described in claim 6, characterized in that, Before reaching the temperature after the first cooling, the following are included: The temperature of the battery pack is obtained after a second preset charging or discharging time, and the current temperature is obtained. Determine whether the current temperature is less than the first temperature threshold and greater than the second temperature threshold. If so, open the valve of the bottom liquid cooling plate of the battery pack to cool the battery pack and obtain the temperature of the battery pack during the cooling preset time period, wherein the second temperature threshold is less than the first temperature threshold. The temperature rise rate is calculated based on the temperature of the battery pack during a preset cooling time period. When the temperature rise rate is greater than 0, the valve of the top liquid cooling plate of the battery pack is opened.

8. The electric vehicle battery pack cooling control method as described in claim 6, characterized in that, The step of driving the second load to cool the battery pack by inputting pulse power according to a preset duty cycle includes: Determine whether the battery pack is in a charging or discharging state. If it is in a charging state, then make the second power supply output pulse power according to the first preset duty cycle to drive the second load to pulse cool the battery pack. If in discharge mode, the second power supply outputs pulse power according to the second preset duty cycle to drive the second load to pulse cool the battery pack.

9. The electric vehicle battery pack cooling control method as described in claim 6, characterized in that, After obtaining the temperature after the first cooling, the process also includes: If the temperature after the first cooling is greater than the first temperature threshold, a third control signal is sent to the controller to make the controller close the first transistor, so that the first power supply outputs power according to a preset frequency pulse signal to drive the first load to cool the battery pack.

10. The electric vehicle battery pack cooling control method as described in claim 8, characterized in that, The pulse cooling includes rectangular pulse cooling or sawtooth pulse cooling.

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