A battery thermal management system

Abstract

The present application relates to the technical field of new energy vehicles, and specifically relates to a battery thermal management system. Through the combination of a multi-channel switch and a bidirectional DC-DC converter, the system can flexibly adjust the functional distribution of the energy storage units, enabling the system to dynamically adjust the configuration of the thermal management power supply units and the key energy storage units according to actual needs and working conditions, thereby improving the adaptability and resource utilization efficiency of the system. Each energy storage unit is equipped with an independent heating / cooling module, and a differentiated thermal management strategy is adopted, enabling the system to accurately control each energy storage unit according to its specific conditions. By logically dividing the functional units, the system can more reasonably allocate energy resources. The thermal management power supply units are specifically used to support thermal management functions, while the key energy storage units ensure the power supply needs of the main loads, effectively preventing mutual interference between thermal management needs and main load needs, and improving the stability and reliability of the system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy vehicles, in particular to a battery thermal management system. BACKGROUND

[0002] With the rapid development of electric vehicles and new energy technologies, the performance and life of the battery as a key component directly affect the efficiency and reliability of the entire system. Traditional battery management systems usually adopt a unified management strategy, which is difficult to meet the differentiated needs under complex working conditions, resulting in the battery performance not being fully utilized, the service life being shortened, and even safety hazards existing.

[0003] In the prior art, the battery thermal management system usually includes a dedicated independent battery to power the thermal management module. This makes the system have low integration and low energy utilization efficiency. Although using an independent battery to power the thermal management module improves reliability, it increases the complexity, weight and cost of the system. At the same time, the thermal management, energy recovery, battery management and other subsystems often operate independently, lacking effective coordination mechanisms. This not only leads to the inability to effectively share and optimize the use of energy between the main battery pack and the thermal management battery, reducing overall energy efficiency, but also makes it difficult to achieve overall optimization of the system.

[0004] In view of the above problems, there is an urgent need for an advanced battery thermal management system that can overcome the limitations of existing technology and achieve more efficient, intelligent and integrated battery management. SUMMARY

[0005] To solve the above problems, the present application discloses a battery thermal management system.

[0006] The present application discloses a battery thermal management system, comprising:

[0007] The battery pack includes a plurality of energy storage units with consistent physical properties, each of which is electrically connected to a busbar and a bidirectional DC-DC converter through a multi-channel switch. Each channel of the multi-channel switch is a bidirectional switch, and a plurality of energy storage units are logically divided into a plurality of functional units.

[0008] The thermal management module includes a heating / cooling module corresponding to each energy storage unit, which is used to independently control each heating / cooling module according to the differentiated thermal management strategy.

[0009] The power supply management module is electrically connected to the battery pack and the thermal management module, and is used to control the adjustment of the functional units in the battery pack according to the feedback information of the battery pack and the thermal management module.

[0010] The adjustment includes: the battery pack is logically divided into at least a thermal management power supply unit and a key energy storage unit; for the energy storage unit designated as belonging to the thermal management power supply unit, the power supply management module enables its connection with the bidirectional DC-DC converter;

[0011] For the energy storage unit designated as belonging to the key energy storage unit, the power supply management module enables its connection with the busbar.

[0012] Wherein, the power supply management module realizes the series-parallel configuration of multiple energy storage units by controlling the multi-channel switch and the bidirectional DC-DC converter, including:

[0013] Series mode: multiple energy storage units are connected in series through the multi-channel switch, and the total output voltage is adjusted by the bidirectional DC-DC converter;

[0014] Parallel mode: multiple energy storage units are connected in parallel through the multi-channel switch, and the total output current is adjusted by the bidirectional DC-DC converter.

[0015] In addition, the system further comprises a road condition detection unit, and the thermal management module adjusts the temperature of each functional unit according to the real-time driving road condition detected by the road condition detection unit, specifically including:

[0016] When it is detected that the vehicle is in uphill or high-speed driving state, the temperature of the key energy storage unit is actively lowered to ensure its stability under the condition of continuous high-power discharge.

[0017] In the above scheme, the heating / cooling module includes a thermoelectric refrigeration sheet and a heating film, and both are integrated on the same heat dissipation substrate to realize bidirectional temperature regulation function.

[0018] The total number N of energy storage units required by the thermal management power supply unit is determined by the following formula:

[0019] N = ceil(V / v) * ceil(P / (V * i)) * (1 + S);

[0020] Wherein, V is the required total voltage, P is the required total power, v is the rated voltage of a single energy storage unit, i is the maximum discharge current of a single energy storage unit, ceil() is the upward rounding function, and S is the safety factor calculated by the following formula:

[0021] S = max(0, (Pr - Pa) / Pa + k * (1 - e));

[0022] wherein Pr is the power required by the system, Pa is the power currently configured to be provided, k is an adjustable weight coefficient ranging from 0 to 1, and e is the energy conversion efficiency of the system.

[0023] The weight coefficient k is associated with the working mode of the thermal management module, and specifically includes:

[0024] When the thermal management module is in the cooling mode, k = k cool * (1 + P cool / P cool max) ;

[0025] When the thermal management module is in the heating mode, k = k heat * (1 + P heat / P heat max) ;

[0026] When the thermal management module is in the standby mode, k = k standby ;

[0027] wherein k cool, k heat, and k standby are preset basic weight values, P cool and P heat are the current cooling and heating powers, and P cool max and P heat max are the maximum cooling and heating powers.

[0028] The scheme of the present application can flexibly adjust the functional distribution of the energy storage units through the combination of multi-channel switches and bidirectional DC-DC converters, so that the system can dynamically adjust the configuration of the thermal management power supply unit and the key energy storage unit according to actual needs and working conditions, thereby improving the adaptability and resource utilization efficiency of the system. Each energy storage unit is equipped with an independent heating / cooling module, and a differentiated thermal management strategy is adopted, so that the system can accurately control each energy storage unit according to its specific conditions, which not only helps to prolong the battery life, but also improves the energy efficiency and safety of the entire system. By logically dividing the functional units, the system can more reasonably allocate energy resources. The thermal management power supply unit is specifically used to support the thermal management function, and the key energy storage unit guarantees the power supply demand of the main load, which can effectively prevent the mutual interference between the thermal management demand and the main load demand, and improves the stability and reliability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 FIG. 1 is an architectural diagram of a battery thermal management system in Embodiment 1 of the present application;

[0030] Figure 2 FIG. 5 is a connection diagram of the energy storage units, busbars, and bidirectional DC-DC converters in the present application;

[0031] Figure 3 FIG. 6 is a connection mode diagram of the functional units in the present application. DETAILED DESCRIPTION

[0032] In order to make the inventive objectives, characteristics and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the embodiments described below are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application. The principles and characteristics of the present application are described below with reference to the drawings, and the examples are used to explain the present application, but not to limit the scope of the present application.

[0033] The term “comprising” and other similar expressions in the description and claims of the present application and the above drawings means covering the non-exclusive inclusion, such as the process, method or system, device including a series of steps or units, which is not limited to the listed steps or units.

[0034] Embodiment 1: As shown in a battery thermal management system, comprising: Figures 1-2

[0035] The battery pack 100 comprises a plurality of energy storage units with consistent physical characteristics, each of the energy storage units is electrically connected to a bus bar and a bidirectional DC-DC converter through a multi-channel switch, each channel of the multi-channel switch is a bidirectional switch, and the plurality of energy storage units are logically divided into a plurality of functional units.

[0036] In a possible implementation, each energy storage unit is equipped with a three-channel switch, including three bidirectional channels: 1. Connecting the bus bar; 2. Connecting the bidirectional DC-DC converter; 3. Self-isolation channel. Each channel includes a bidirectional switch element, which can be composed of a solid-state relay, a MOSFET or other suitable switching device. The bidirectional DC-DC converter can use a buck-boost structure. The channel connecting the bus bar: the channel directly connects the energy storage unit and the main bus bar of the system, and when the channel is opened, the energy storage unit can directly power or charge the system. The self-isolation channel is a switching channel connected to the multi-channel switch, which will isolate the energy storage unit from the entire system when disconnected. When the energy storage unit needs to be maintained, replaced, or a fault is detected, after disconnecting this channel, the energy storage unit is disconnected from all other circuits to ensure safety and continuous operation of the system.

[0037] The thermal management module 200 comprises heating / cooling modules 210 respectively arranged corresponding to each energy storage unit, for independently controlling each heating / cooling module according to a differentiated thermal management strategy; wherein each energy storage unit is equipped with an independent thermoelectric cooler (TEC) and a heating film.

[0038] ​The power supply management module 300 is electrically connected with the battery pack and the thermal management module, respectively, for controlling the adjustment of the functional units in the battery pack according to the feedback information of the battery pack and the thermal management module; the power supply management module can specifically use a processing module containing an ARM / X86 chip;

[0039] The adjustment includes that the battery pack is logically divided into at least a thermal management power supply unit and a key energy storage unit; for the energy storage unit designated as belonging to the thermal management power supply unit, the power supply management module enables the connection of the energy storage unit with the bidirectional DC-DC converter;

[0040] For the energy storage unit designated as belonging to the key energy storage unit, the power supply management module enables the connection of the energy storage unit with the busbar.

[0041] Suppose the battery pack is composed of 20 lithium ion battery units, and the default configuration is that 15 units are used as key energy storage units and 5 units are used as thermal management power supply units. The dynamic adjustment threshold is that when the environmental temperature is <0°C or >40°C, the number of thermal management power supply units is increased to 8.

[0042] Cyclic use: the thermal management power supply units are rotated every 24 hours to balance the use.

[0043] The differentiated thermal management strategy can include:

[0044] Key energy storage unit: kept in the optimal temperature range of 20-30°C;

[0045] Thermal management power supply unit: allows a wider temperature range (15-35°C), and these units are preferentially used for system thermal management.

[0046] When the system starts, the power supply management module reads the state of each unit, divides the functional units according to the preset strategy and the current state, controls the multi-channel switch to connect the corresponding units to the busbar or the DC-DC converter, continuously monitors the state of all units including voltage, current, temperature, etc., independently controls the heating / cooling module of each unit according to the thermal management strategy, and periodically (e.g. every 5 minutes) evaluates the system state and adjusts the functional unit division if necessary.

[0047] Through logical division and dynamic adjustment of functional units, the system can optimize resource allocation according to real-time demand. This flexibility enables the system to maintain high efficiency under different working conditions, improving overall energy utilization. Independent heating / cooling modules allow the system to accurately manage the temperature of each energy storage unit. This not only prolongs the battery life, but also improves the charging and discharging efficiency, especially in extreme temperature environments.

[0048] The power supply management module controls a multi-channel switch and a bidirectional DC-DC converter to achieve series-parallel configuration of multiple energy storage units, including:

[0049] Series mode: Multiple energy storage units are connected sequentially through a multi-channel switch, and the total output voltage is regulated by a bidirectional DC-DC converter;

[0050] Parallel mode: Multiple energy storage units are connected in parallel through a multi-channel switch, and the total output current is regulated by a bidirectional DC-DC converter.

[0051] like Figure 3 As shown, specifically, each energy storage unit requires at least three bidirectional switches: S1: connected to the positive terminal of the DC-DC converter circuit; S2: connected to the negative terminal of the DC-DC converter circuit; S3: connected to the positive terminal of the next energy storage unit.

[0052] When configured in parallel:

[0053] S1 of all units is closed (connected to the positive line of the DC-DC converter line).

[0054] S2 of all units is closed (connected to the negative line of the DC-DC converter line);

[0055] S3 of all units is disconnected (to prevent short circuits between units);

[0056] When configured in series:

[0057] The S1 terminal of the first unit is closed (connected to the positive line of the DC-DC converter circuit).

[0058] The last unit's S2 is closed (connected to the negative line of the DC-DC converter circuit).

[0059] The S3 of all intermediate units is closed (forming a series chain);

[0060] All other switches remain off.

[0061] Dynamic series-parallel configuration enables the system to operate over a wide range of voltage and current requirements, adapting to various load demands. This flexibility allows the same hardware to be applied to multiple scenarios, improving system versatility and cost-effectiveness.

[0062] In the above scheme, the heating / cooling module includes a thermoelectric cooling chip and a heating film, and the two are integrated on the same heat dissipation substrate to achieve bidirectional temperature regulation function.

[0063] The heat dissipation substrate is made of a metal material (such as aluminum alloy) with good thermal conductivity, serving as the installation basis for the thermoelectric cooling sheet and the heating film. The thermoelectric cooling sheet is a semiconductor cooling sheet of appropriate specifications, fixed on one side of the heat dissipation substrate through welding or thermal conductive glue. The cold end of the cooling sheet faces the controlled object, and the hot end is in close contact with the substrate. The heating film is a flexible electrothermal film, fixed on the other side of the heat dissipation substrate through pasting or pressing. Thermal conductive silicone grease is applied between the heating film and the substrate to improve heat conduction efficiency. A temperature sensor is installed on the surface of the heat dissipation substrate to monitor the module temperature in real time. The heating and cooling functions are integrated in a compact module. When cooling is needed, the thermoelectric cooling sheet is started; when heating is needed, the heating film is started. Through the adjustment of the control circuit, precise bidirectional temperature regulation function can be realized. The heat dissipation substrate plays a role in heat transfer and dissipation in this process, helping to improve the thermal efficiency of the entire module.

[0064] In an embodiment, the total number of energy storage units N required by the thermal management power supply unit is determined by the following formula:

[0065] N = ceil(V / v) * ceil(P / (V * i)) * (1 + S);

[0066] where V is the total voltage required, P is the total power required, v is the rated voltage of a single energy storage unit, i is the maximum discharge current of a single energy storage unit, ceil() is the ceiling function, and S is the safety factor, calculated by the following formula:

[0067] S = max(0, (Pr - Pa) / Pa + k * (1 - e));

[0068] where Pr is the power required by the system, Pa is the power that the current configuration can provide, k is an adjustable weight coefficient ranging from 0 to 1, and e is the energy conversion efficiency of the system.

[0069] The weight coefficient k is associated with the working mode of the thermal management module, specifically including:

[0070] When the thermal management module is in cooling mode, k = k_cool * (1 + P_cool / P_cool_max);

[0071] When the thermal management module is in heating mode, k = k_heat * (1 + P_heat / P_heat_max);

[0072] When the thermal management module is in standby mode, k = k_standby;

[0073] where k_cool, k_heat, k_standby are preset base weight values, P_cool and P_heat are current cooling and heating power, P_cool_max and P_heat_max are maximum cooling and heating power.

[0074] For example, assume the parameters of the thermal management system are as follows:

[0075] System requirements: V = 48V (total voltage required), P = 1000W (total power required), Pr = 1100W (power required by the system);

[0076] Energy storage unit parameters: v = 3.7V (rated voltage of a single energy storage unit), i = 2A (maximum discharge current of a single energy storage unit);

[0077] System parameters: e = 0.9 (energy conversion efficiency of the system);

[0078] k_cool = 0.3, k_heat = 0.4, k_standby = 0.1 (base weight values)

[0079] P_cool_max = 800W, P_heat_max = 600W (maximum cooling and heating power)

[0080] Calculation process:

[0081] Calculate the power that the current configuration can provide:

[0082] Pa = V * i * floor(V / v) = 48 * 2 * floor(48 / 3.7) = 48 * 2 * 12 =1152W

[0083] Assume the system is currently in cooling mode, and the cooling power P_cool = 600W

[0084] k = k_cool * (1 + P_cool / P_cool_max) = 0.3 * (1 + 600 / 800) =0.525

[0085] Calculate the safety factor S:

[0086] S = max(0, (Pr - Pa) / Pa + k * (1 - e))

[0087] = max(0, (1100 - 1152) / 1152 + 0.525 * (1 - 0.9))

[0088] = max(0, -0.0451 + 0.0525) = 0.0074

[0089] Calculate the total number of energy storage units required N:

[0090] N = ceil(V / v) * ceil(P / (V * i)) * (1 + S)

[0091] = ceil(48 / 3.7) * ceil(1000 / (48 * 2)) * (1 + 0.0074)

[0092] = 13 * 11 * 1.0074 = 144.06

[0093] Upward rounding, final N = 145.

[0094] The method of this embodiment takes into account the real-time working state of the system (cooling, heating or standby), dynamically adjusts the number of energy storage units by adjusting the weight coefficient k. Ensures that the system has enough power supply in different working modes. By introducing the safety factor S, the difference between power demand and actual supply, as well as the influence of energy conversion efficiency, is considered in the calculation. Helps to prevent power shortage of the system in high load conditions. Using the upward rounding function ensures that the number of energy storage units always meets or slightly exceeds the demand, avoiding the risk of power shortage. By considering the energy conversion efficiency e of the system, the required number of energy storage units can be more accurately estimated, avoiding resource waste caused by over-provisioning. According to different working modes (cooling, heating, standby), automatically adjust the configuration to ensure that the system maintains optimal performance in various situations.

[0095] Embodiment 3: In addition, the system also includes a road condition detection unit, and the thermal management module adjusts the temperature of each functional unit according to the real-time driving road condition detected by the road condition detection unit, specifically including:

[0096] When it is detected that the vehicle is in an uphill or high-speed driving state, the temperature of the key energy storage unit is actively lowered to ensure its stability under continuous high-power discharge conditions.

[0097] The road condition detection unit includes GPS, acceleration sensor and inclination sensor; for real-time monitoring of vehicle position, speed, acceleration and road slope information. Then transmit the collected data to the power supply management module for processing to calculate the current real-time road condition information.

[0098] The power supply management module implements differentiated thermal management strategies for each functional unit based on the output of the road condition detection unit, the strategy includes:

[0099] When the vehicle is detected to be in uphill or high-speed driving state, the temperature of the key energy storage unit is actively lowered to ensure its stability under continuous high-power discharge conditions; the cooling temperature can be 3-5°C lower than the normal temperature, or a hierarchical cooling strategy can be adopted to adjust the cooling intensity according to the slope or speed.

[0100] The key energy storage unit is also preferentially subjected to cooling management to cope with the rapid temperature rise during high-power discharge; the preferential cooling can adopt a liquid cooling or forced air cooling system, and the cooling system is started in real time when the high-power discharge demand is detected (such as sudden acceleration), and the cooling intensity is adjusted in proportion to the discharge power.

[0101] The technical means disclosed in the present application scheme is not limited to the technical means disclosed in the above-mentioned embodiments, but also includes the technical solutions composed of any combination of the above technical features. It should be pointed out that for ordinary skilled persons in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, which are also considered as the protection scope of the present application.

Claims

1. A battery thermal management system, characterized by, The system comprises: a battery pack comprising a plurality of energy storage units with consistent physical properties, each of the energy storage units being electrically connected to a bus bar and a bidirectional DC-DC converter through a multi-channel switch, each channel of the multi-channel switch being a bidirectional switch, and the plurality of energy storage units being logically divided into a plurality of functional units; a thermal management module comprising heating / cooling modules respectively arranged for each energy storage unit, for independently controlling each heating / cooling module according to a differentiated thermal management strategy; a power supply management module electrically connected to the battery pack and the thermal management module, for controlling the adjustment of the functional units in the battery pack according to the feedback information of the battery pack and the thermal management module; the adjustment comprises: logically dividing the battery pack into at least thermal management power supply units and key energy storage units; for the energy storage units designated as thermal management power supply units, the power supply management module enables the connection of the energy storage units to the bidirectional DC-DC converter; for the energy storage units designated as key energy storage units, the power supply management module enables the connection of the energy storage units to the bus bar; the power supply management module realizes the series-parallel configuration of the plurality of energy storage units by controlling the multi-channel switch and the bidirectional DC-DC converter, including: series mode: connecting the plurality of energy storage units in series through the multi-channel switch, and adjusting the total output voltage by using the bidirectional DC-DC converter; parallel mode: connecting the plurality of energy storage units in parallel through the multi-channel switch, and adjusting the total output current by using the bidirectional DC-DC converter.

2. The battery thermal management system of claim 1, wherein, The system further comprises a road condition detection unit, and the thermal management module adjusts the temperature of each functional unit according to the real-time driving road condition detected by the road condition detection unit, specifically including: when it is detected that the vehicle is in an uphill or high-speed driving state, the temperature of the key energy storage unit is actively lowered to ensure its stability under the condition of continuous high-power discharge.

3. The battery thermal management system of claim 1 or 2, wherein, The heating / cooling module comprises a thermoelectric refrigeration sheet and a heating film, and both are integrated on the same heat dissipation substrate to realize the function of bidirectional temperature regulation.

4. The battery thermal management system of claim 1, wherein, The required total number N of energy storage units for the thermal management power supply unit is determined by the following formula: N = ceil(V / v) * ceil(P / (V*i)) * (1+S); wherein V is the required total voltage, P is the required total power, v is the rated voltage of a single energy storage unit, i is the maximum discharge current of a single energy storage unit, ceil() represents the upward rounding function, and S is a safety factor calculated by the following formula: S = max(0, (Pr-Pa) / Pa+k*(1-e)); wherein Pr is the required power of the system, Pa is the power that can be provided by the current configuration, k is an adjustable weight coefficient, and its range is 0-1; and e is the energy conversion efficiency of the system.

5. The battery thermal management system of claim 4, wherein, The weight coefficient k is associated with the working mode of the thermal management module, specifically including: when the thermal management module is in a cooling mode, k = k_cool*(1+P_cool / P_cool_max); when the thermal management module is in a heating mode, k = k_heat*(1+P_heat / P_heat_max). ​ ​ k=k_standby when the thermal management module is in standby mode; wherein k_cool, k_heat, k_standby are preset base weight values, P_cool and P_heat are current cooling and heating powers respectively, and P_cool_max and P_heat_max are maximum cooling and heating powers.

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