Energy storage system and thermal management control method thereof

Abstract

The invention relates to an energy storage system and a heat management control method thereof, and belongs to the technical field of heat management systems, a reasonable cooling fan control method is designed, the temperatures of all areas are collected, then sorting is conducted, a plurality of cooling fans with the low temperature sorting are turned off, the existing BMS fan control method is optimized, and the heat management efficiency is improved. Under the condition that any structure of the system is not changed and any cost is not increased, real-time accurate control over on and off of cooling fans of different battery boxes is achieved, so that the temperature of the battery boxes is adjusted, the temperature difference between the battery boxes is reduced, and the purposes of improving the operation reliability of the battery, achieving energy conservation and emission reduction and prolonging the service life of the battery are achieved.

Description

Technical Field

[0001] The invention relates to an energy storage system and a thermal management control method thereof, belonging to the technical field of thermal management systems. Background Art

[0002] Lithium battery refers to a battery containing lithium in the electrochemical system. Lithium batteries can be roughly divided into two types, lithium metal batteries and lithium ion batteries. Lithium metal batteries are usually non-rechargeable and contain metallic lithium. Lithium ion batteries do not contain metallic lithium and are rechargeable.

[0003] Due to the very active chemical properties of lithium metal, the processing, storage and use of lithium batteries face many problems. The lithium battery energy storage system requires high reliability and long life operation, which places very stringent requirements on the battery working environment. In addition, the operating performance of lithium batteries depends largely on the battery temperature and the temperature difference between batteries. The current air cooling technology is a very mature temperature control method, but the ability to control temperature difference is insufficient. Under some working conditions, the battery temperature is very high (>15k), which seriously affects the battery performance.

[0004] The existing technology changes the temperature difference by designing a very complex air duct system, including cluster top air ducts, cluster inner air ducts, adding cluster top fans, etc., but the improvement on the temperature difference is very limited and increases the manufacturing cost; and the current control of the battery box cooling fan mostly follows the system. When the system starts, the cooling fan turns on, and when the system stops, the cooling fan turns off. There is no special control strategy. Summary of the invention

[0005] The purpose of the present invention is to provide an energy storage system and a thermal management control method thereof, so as to solve the problems of high cost and complex structure caused by the existing battery temperature control system relying on complex air duct design to solve the temperature difference.

[0006] To achieve the above object, a thermal management control method for an energy storage system of the present invention is characterized by:

[0007] Collect the temperature of all areas within the control range in real time;

[0008] The temperatures of each area form a temperature set of the energy storage system, and the temperature set is sorted according to the temperature values;

[0009] When the set conditions are met, the cooling fans of the areas corresponding to the set number of temperatures with the lowest temperature concentration are turned off, so that the speeds of other cooling fans that are not turned off are increased;

[0010] If the difference between the temperature of the area corresponding to the turned-off cooling fan and the highest temperature of the current temperature set is less than a preset minimum temperature difference value, the corresponding turned-off cooling fan is turned on.

[0011] By sorting the temperature values, some areas with lower temperatures are screened out, and the cooling fans in the screened out areas are turned off. At this time, the temperature of the area where the cooling fans are turned off rises rapidly, and the minimum temperature of the system also rises accordingly. Since some cooling fans are turned off, the air volume of the turned-on cooling fans increases, and the temperature rise in the corresponding battery box slows down, thereby achieving the effect of reducing the temperature difference of the battery box and improving the overall reliability of the system.

[0012] Furthermore, a thermal management control method for an energy storage system described in the present invention is characterized in that the temperatures of all areas within the control range are collected in real time, and the minimum value of the readings of all temperature sensors in the corresponding area is used as the temperature of the area.

[0013] Using the minimum value of the regional temperature sensor as the temperature of the region can better reflect the temperature difference between this region and the region with the maximum temperature of the entire battery box, and can more accurately select which area's cooling fan needs to be regulated.

[0014] Furthermore, a thermal management control method for an energy storage system described in the present invention is characterized in that the set condition is that the highest temperature of the temperature concentration is greater than a high temperature preset value.

[0015] Furthermore, a thermal management control method for an energy storage system described in the present invention is characterized in that the temperatures of all temperature sensors in the control area are also collected to determine whether the maximum value of the collected temperatures exceeds a preset high-temperature start value; if the maximum value is higher than the high-temperature start value, the air conditioning is turned on to determine whether the set conditions are met.

[0016] Furthermore, a thermal management control method for an energy storage system described in the present invention is characterized in that if the maximum value is lower than the high temperature start value and the lowest temperature of the temperature set is lower than a preset low temperature start value, the energy storage system is heated.

[0017] This means that temperature control is no longer simply dependent on turning the system on and off, but rather has different temperature control strategies in different temperature ranges, making temperature control more precise.

[0018] Furthermore, a thermal management control method for an energy storage system described in the present invention is characterized in that heating of the energy storage system includes turning on air conditioning for heating and turning on cooling fans in various areas in batches.

[0019] If multiple cooling fans are turned on at the same time, the system workload may increase. Turning them on in batches is to reduce the load on the power supply when turning on the cooling fans to prevent overload and malfunction.

[0020] Furthermore, a thermal management control method for an energy storage system described in the present invention is characterized in that when the lowest temperature of the temperature set is greater than a low temperature stop value, the air conditioning heating and all cooling fans are turned off.

[0021] At this time, the overall temperature of the system is in a suitable range and does not need to be regulated by air conditioning or cooling fans, achieving the effect of energy saving and emission reduction, and also improving the life of the battery, allowing it to operate for a long time.

[0022] Furthermore, the energy storage system thermal management control method described in the present invention is characterized in that if the maximum temperature is below a preset high temperature stop value, the air conditioning refrigeration and all cooling fans are turned off.

[0023] Combining the control of the cooling fan with the control of the air conditioner can achieve better temperature control. At this time, the overall temperature of the system is in a suitable range, and there is no need to control it through the air conditioner or cooling fan, which achieves the effect of energy saving and emission reduction, and also improves the life of the battery, allowing it to run for a long time.

[0024] Furthermore, a thermal management control method for an energy storage system described in the present invention is characterized in that the set number is a set percentage of the total number of cooling fans.

[0025] A set percentage of cooling fans is always turned off, which ensures the number of cooling fans turned off, making this method more stable.

[0026] An energy storage system described in the present invention is characterized in that the energy storage system is used to execute instructions for implementing the above-mentioned thermal management control method.

[0027] Without increasing costs (additional fans, complex air ducts, etc.) or changing any system structure, the temperature difference of the batteries in the entire system can be significantly reduced by optimizing the BMS fan control strategy and accurately controlling the on and off of the cooling fan. The cooling fan and air conditioner can be turned off when the temperature is appropriate, thereby achieving energy conservation and emission reduction and increasing the long life of the battery. The entire method improves on the existing technology, simplifies the complex air ducts designed for the temperature difference in the existing battery temperature control system, and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of a thermal management control method for an energy storage system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0030] Method Example:

[0031] The present invention designs a reasonable cooling fan control strategy and controls the on and off of cooling fans of different battery boxes in real time according to the battery temperature change, thereby adjusting the battery box temperature and reducing the temperature difference between the battery boxes.

[0032] like Figure 1 As shown in the flow chart of the thermal management control method for an energy storage system in an embodiment of the present invention, in order to achieve the above purpose, the technical solution provided by the present invention is an energy storage system and a thermal management control method thereof. This control method controls the turning on and off of the cooling fans in all areas through the BMS control system.

[0033] In this embodiment, the battery stack includes a plurality of plug-in boxes, each plug-in box or a plurality of plug-in boxes corresponds to an area, and each area is provided with one or more cooling fans for dissipating heat from the area through gas circulation.

[0034] 1. Select the temperature control range. In this case, the entire battery stack is selected as the temperature control range, and the temperature of all plug-in boxes within the control range is collected in real time;

[0035] 2. Select the minimum temperature Tmin of each plug-in box as the temperature of each area. The temperatures of all areas form the temperature set Tn of the energy storage system. Sort the temperature set Tn from small to large according to the value;

[0036] 3. Set the high temperature preset value to 33°C, the high temperature start value to 26°C, the high temperature stop value to 24°C, the low temperature start value to 12°C, the low temperature stop value to 18°C, the minimum temperature difference value to 5K, the maximum value of the temperature set to Tnmax, and the minimum value of the temperature set to Tnmin;

[0037] 4. When the highest temperature Tnmax of the temperature set Tn is higher than the high temperature preset value, the cooling fans of the area corresponding to a part of the temperature of the temperature set are turned off for a period of time to increase the speed of other cooling fans that are not turned off.

[0038] S1. Control method when the maximum temperature of all plug-in boxes rises to more than 26°C:

[0039] Turn on the air conditioning and cooling, and the BCU turns on the pack cooling air in batches:

[0040] (1) There are multiple temperature sensors in the plug-in box. In this case, the minimum temperature Tmin is selected to represent the temperature of the plug-in box. All the temperature sensors of the plug-in boxes are sorted and sorted in real time from low to high according to the plug-in box units. When Tnmax in the control unit range is greater than the high temperature preset value of 33°C, the cooling fans of 20% of the total number of plug-ins are turned off, and the shutdown time is greater than or equal to 3 minutes. After turning off some cooling fans, the temperature of the plug-in box with the cooling fans turned off rises rapidly, and the minimum temperature of the temperature set Tn also rises accordingly. Since some cooling fans are turned off, the air volume of the turned-on cooling fans increases, and the temperature rise in the corresponding battery box slows down. As a result, the maximum temperature difference in the entire control unit becomes smaller. When the temperature in the turned-off plug-in box meets the judgment condition ΔT≤5K, ΔT refers to the difference between the temperature of the area corresponding to the turned-off cooling fan and the highest temperature of the current temperature set Tn. At this time, the system temperature difference has dropped to a reasonable range, so the corresponding turned-off cooling fan is turned on;

[0041] (2) When the judgment condition Tnmax ≥ 33°C is not met, it is judged whether the temperature of the plug-in box meets the condition Tnmax ≤ 24°C. If so, it is considered that the temperature in the corresponding area is appropriate and the air conditioner and cooling fan do not need to work. The cooling fan of the plug-in box in the corresponding area that meets the judgment condition is turned off, and the air conditioner cooling is turned off.

[0042] S2. Control method when the maximum temperature of all plug-in boxes is less than 26℃:

[0043] When Tnmin≤12℃ is met, the air conditioner in the corresponding area starts heating, and the BCU turns on the cooling fans of the plug-in boxes in batches. If the temperature rises to meet Tnmin≥18℃, the air conditioner heating in the corresponding area is turned off, and the cooling fans of the plug-in boxes are turned off.

[0044] System Example:

[0045] The energy storage system of the present invention adopts an energy storage system and a thermal management control method thereof of the present invention. The energy storage system includes a battery box body and a plurality of single cells arranged in the box body. Temperature sensors are arranged at different positions in the battery box for collecting the temperatures of different areas or different single cells. A cooling fan is arranged on the box body and / or in the box body. The cooling fan can form air flow between the single cells in the box body and inside and outside the box body, thereby reducing the temperature difference in the battery box and dissipating heat. The corresponding thermal management control method of the energy storage system has been introduced clearly enough in the method embodiment and will not be repeated here.

Claims

1. A thermal management control method for an energy storage system, characterized in that: Collect the temperature of all areas within the control range in real time; The temperatures of each area form a temperature set of the energy storage system, and the temperature set is sorted according to the temperature values; When the set conditions are met, the cooling fans of the areas corresponding to the set number of temperatures with the lowest temperature concentration are turned off, so that the speeds of other cooling fans that are not turned off are increased; If the difference between the temperature of the area corresponding to the turned-off cooling fan and the highest temperature of the current temperature set is less than a preset minimum temperature difference value, the corresponding turned-off cooling fan is turned on.

2. The energy storage system thermal management control method according to claim 1, characterized in that: The temperature of all areas within the control range is collected in real time, and the minimum value of all temperature sensor readings in the corresponding area is taken as the temperature of the area.

3. The energy storage system thermal management control method according to claim 2, characterized in that: The setting condition is that the highest temperature in the temperature concentration is greater than the high temperature preset value.

4. The energy storage system thermal management control method according to claim 1, characterized in that: The temperatures of all temperature sensors in the control area are also collected to determine whether the maximum value of the collected temperatures exceeds a preset high-temperature start value. If the maximum value is higher than the high-temperature start value, the air conditioning is turned on and it is determined whether the set conditions are met.

5. The energy storage system thermal management control method according to claim 4, characterized in that: If the maximum value is lower than the high temperature start value, and the lowest temperature of the temperature set is lower than the preset low temperature start value, the energy storage system is heated.

6. The energy storage system thermal management control method according to claim 5, characterized in that: The heating of the energy storage system includes turning on the air conditioner for heating and turning on the cooling fans in each area in batches.

7. The energy storage system thermal management control method according to claim 6, characterized in that: When the lowest temperature of the temperature set is greater than the low temperature stop value, the air conditioning heating and all cooling fans are turned off.

8. The energy storage system thermal management control method according to claim 4, characterized in that: If the maximum temperature is below the preset high temperature stop value, the air conditioning and cooling and all cooling fans are turned off.

9. The energy storage system thermal management control method according to claim 1, characterized in that: The set number is a set percentage of the total number of cooling fans.

10. An energy storage system, characterized in that: The energy storage system is used to execute instructions for implementing the thermal management control method according to any one of claims 1 to 9.

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