Energy storage system and thermal management control system and thermal management control method thereof

Abstract

The invention relates to an energy storage system and a heat management control system thereof and a heat management control method thereof, belongs to the technical field of heat management systems, and designs a reasonable fan control method which is characterized in that according to the change of the maximum temperature, the minimum temperature and the temperature difference of a battery, an existing BMS fan control method is optimized, and the energy storage 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 fans of different battery plug-in boxes is achieved, so that the temperature of the battery plug-in boxes is adjusted, the temperature difference between the battery plug-in boxes is reduced, and then the purposes of improving the reliability of battery operation, achieving energy conservation and emission reduction and prolonging the service life of the battery are achieved.

Description

Technical Field

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

[0002] Due to the very active chemical properties of lithium metal, there are many problems in the processing, storage and use of lithium batteries. 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.

[0003] 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 fan mostly follows the system. When the system starts, the fan turns on, and when the system stops, the fan turns off. There is no special control strategy. Summary of the invention

[0004] The purpose of the present invention is to provide an energy storage system and its thermal management control system and its thermal management control method, 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.

[0005] To achieve the above purpose, the energy storage system thermal management control method of the present invention comprises the following steps:

[0006] 1) Real-time acquisition of the maximum and minimum temperatures within the control range;

[0007] 2) When the temperature difference between the minimum temperature and the maximum temperature is greater than a preset maximum temperature difference value, the fan in the area corresponding to the minimum temperature is turned off to increase the air volume of other fans that are not turned off.

[0008] After turning off the fan, the temperature in this area rises rapidly, and the minimum temperature of the system also rises accordingly. Since some fans are turned off, the air volume of the turned-on fans increases, and the temperature rise in the corresponding battery box slows down. As a result, the maximum temperature in the entire control unit becomes smaller, thereby achieving the effect of reducing the maximum temperature and temperature difference of the battery box.

[0009] This cycle repeats itself, and the system as a whole controls and reduces the temperature difference, and the maximum temperature will also be reduced accordingly, thereby improving the overall reliability of the system.

[0010] Furthermore, in the energy storage system thermal management control method of the present invention, the area is a battery box within a control range, an air conditioner is provided within the control range, the air outlet of the air conditioner is connected to each battery box in a one-to-one correspondence through an air duct, and each battery box is also provided with a fan for exhausting air outwards; in step 2), by turning off the fan of the battery box corresponding to the minimum temperature, the air volume of the fans of other battery boxes is increased when the air volume of the air conditioner is constant.

[0011] Furthermore, in the thermal management control method for the energy storage system of the present invention, after step 2), if the difference between the temperature of the area corresponding to the closed fan and the maximum temperature within the control range is less than a preset minimum temperature difference value, the corresponding closed fan is turned on.

[0012] Furthermore, in the thermal management control method of the energy storage system described in the present invention, if the difference between the temperature of the area corresponding to the turned-off fan and the maximum temperature within the control range is less than a preset minimum temperature difference, and the fan-off state lasts for at least 5 minutes, the corresponding turned-off fan is turned on.

[0013] Furthermore, in the thermal management control method for the energy storage system described in the present invention, in step 1), after collecting the maximum temperature and the minimum temperature within the control range, it is also determined whether the maximum temperature exceeds the preset high temperature start value. If the maximum temperature is higher than the high temperature start value, step 2) is entered; if the maximum temperature is lower than the high temperature start value and the minimum temperature is lower than the preset low temperature start value, the energy storage system is heated.

[0014] 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.

[0015] Furthermore, the energy storage system thermal management control method described in the present invention also starts air conditioning and refrigeration of the energy storage system if the maximum temperature is higher than the high temperature start value.

[0016] Controlling the on and off of the fan also controls the on and off of the air conditioner, improving the efficiency of temperature control.

[0017] Furthermore, the energy storage system thermal management control method described in the present invention turns off the air conditioning refrigeration and all fans if the maximum temperature is below a preset high temperature stop value.

[0018] 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 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.

[0019] Furthermore, in the energy storage system thermal management control method described in the present invention, in step 2), when the temperature difference between the minimum temperature and the maximum temperature is greater than a preset maximum temperature difference value, and the maximum temperature is greater than a preset high temperature setting value, the fan of the area corresponding to the minimum temperature is turned off.

[0020] Furthermore, in the thermal management control method for the energy storage system described in the present invention, if the difference between the temperature of the area corresponding to the turned-off fan and the maximum temperature within the control range is less than a preset minimum temperature difference, and the fan-off state lasts for at least 5 minutes, the turned-off fan is turned on.

[0021] By setting the judgment criteria for both the temperature difference and the maximum temperature at the same time, more precise control of temperature regulation can be achieved.

[0022] Furthermore, in the energy storage system thermal management control method described in the present invention, the heating of the energy storage system includes turning on air conditioning for heating and turning on fans in various areas in batches.

[0023] If multiple 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 fans and prevent overload and malfunction.

[0024] Furthermore, the energy storage system thermal management control method described in the present invention turns off air conditioning heating and all fans when the minimum temperature is greater than the low temperature stop value.

[0025] 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 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.

[0026] A thermal management control system for an energy storage system comprises a processor, wherein the processor is used to execute instructions of the thermal management control method for the energy storage system.

[0027] An energy storage system comprises two or more battery plug-in boxes and the above energy storage system thermal management control system.

[0028] 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 fan on and off. The 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 in the existing battery temperature control system to solve the temperature difference, and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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

[0030] 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.

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

[0032] An embodiment of a thermal management control method for an energy storage system:

[0033] 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 its thermal management control system and its thermal management control method. This control method controls the on and off of all fans in the BMS system.

[0034] 1. Select the temperature control range. In this case, the entire battery stack is selected as the temperature control range;

[0035] 2. Collect the temperature of all battery boxes within the control range, set the high temperature stop value to 24°C, the high temperature preset value to 33°C, the low temperature stop value to 18°C, the low temperature start value to 12°C, the minimum temperature difference value to 5k, the maximum temperature difference value to 8k, and the high temperature start value to 26°C;

[0036] 3. Collect the maximum temperature Tmax and minimum temperature Tmin of all batteries in the system, calculate the corresponding temperature difference, and control the switch of the fan by the change of the system battery temperature.

[0037] S1. Control method when the maximum temperature Tmax of the battery stack rises above 26°C:

[0038] Turn on the air conditioning and cooling, and the BCU turns on the fans in batches:

[0039] (1) When the judgment condition Tmax≥33℃ and the temperature of the non-same plug-in box Tmin≤(Tmax-8k) is met, the system turns off the fan of the plug-in box where the minimum temperature Tmin is located through comparative calculation. After the fan of the plug-in box where the minimum temperature Tmin is located is turned off, the temperature of the plug-in box with the turned-off fan rises rapidly, and the minimum temperature Tmin of the system also rises accordingly. Since some fans are turned off, the air volume of the turned-on fans increases, and the temperature rise in the corresponding battery plug-in box slows down. As a result, the temperature difference in the entire control unit is reduced, improving the uniformity of the battery. When the temperature in the turned-off plug-in box meets the judgment condition Tmin≥(Tmax-5k), the temperature difference between the temperature of the plug-in box with the turned-off fan and the temperature of the plug-in box with the unturned fan is reduced. If the fan off state duration is met at the same time ≥5Min, the turned-off fan is turned on;

[0040] In this embodiment, the total amount of cooling air sent to each battery box is constant. When the exhaust fan or the air supply fan of one or more battery boxes is turned off, the amount of cooling air passing through other battery boxes naturally increases.

[0041] (2) When the judgment condition Tmax ≥ 33°C is not met and the temperature of the same plug-in box Tmin ≤ (Tmax-8k) is not met, it is judged whether the plug-in box temperature meets the condition of Tmax ≤ 24°C. If so, the fan of the plug-in box that meets the judgment condition is turned off, and the air conditioning cooling is turned off.

[0042] S2. Control method when the maximum temperature Tmax of the battery stack is less than 26°C:

[0043] When Tmin≤12℃ is met, the air conditioner starts heating and the BCU turns on the pluggable fans in batches. If the temperature rises to meet Tmin≥18℃, the air conditioner heating is turned off and the pluggable fans are turned off.

[0044] The turned-off fan will remain in the turned-off state for at least 5 minutes. At this time, the temperature of the battery box will rise and the minimum temperature Tmin will be transferred to other battery boxes. Similarly, if the above conditions are met, the fan in the area corresponding to the minimum temperature will be turned off, and the duration will also be ≥5 minutes. The system will proceed in sequence, and the system can have multiple fans in the turned-off state at the same time.

[0045] An embodiment of a thermal management control system for an energy storage system:

[0046] The thermal management control system of the present invention is a system that adopts a thermal management control method of an energy storage system of the present invention. 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.

[0047] An energy storage system embodiment:

[0048] The energy storage system of the present invention is a system that adopts an energy storage system and its thermal management control system and its thermal management control method of the present invention. The energy storage system includes a battery compartment as a control area, an air conditioner and a plurality of battery plug boxes are arranged in the compartment, and an air duct for conveying cold air is arranged between each battery plug box and the air outlet of the air conditioner. Temperature sensors are arranged at different positions in the battery plug box for collecting the temperature of different areas or different single cells; a fan is arranged on the box body and / or in the box body, and the fan can form air flow between the single cells in the box body and inside and outside the box body. In this embodiment, a fan for extracting hot air outward is arranged on each battery plug box. The return air outlet of the air conditioner draws the hot air accumulated in the battery compartment discharged by each battery plug box into the air conditioner for re-cooling, thereby reducing the temperature difference between each battery plug box. The corresponding energy storage system thermal management control method 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: Here are the steps: 1) Real-time acquisition of the maximum and minimum temperatures within the control range; 2) When the temperature difference between the minimum temperature and the maximum temperature is greater than a preset maximum temperature difference value, the fan in the area corresponding to the minimum temperature is turned off to increase the air volume of other fans that are not turned off.

2. The energy storage system thermal management control method according to claim 1, characterized in that: The area is a battery box within a control range, an air conditioner is provided within the control range, an air outlet of the air conditioner is connected to each battery box in a one-to-one correspondence through an air duct, and each battery box is also provided with a fan for exhausting air outwards; in step 2), by turning off the fan of the battery box corresponding to the minimum temperature, the air volume of the fans of other battery boxes is increased when the air volume of the air conditioner is constant.

3. The energy storage system thermal management control method according to claim 1, characterized in that: After step 2), if the difference between the temperature of the area corresponding to the closed fan and the maximum temperature within the control range is less than the preset minimum temperature difference value, the corresponding closed fan is turned on.

4. The energy storage system thermal management control method according to claim 3, characterized in that: If the difference between the temperature of the area corresponding to the turned-off fan and the maximum temperature within the control range is less than the preset minimum temperature difference, and the fan is turned off for at least 5 minutes, the corresponding turned-off fan is turned on.

5. The energy storage system thermal management control method according to claim 1, characterized in that: In step 1), after collecting the maximum temperature and minimum temperature within the control range, it is also determined whether the maximum temperature exceeds the preset high temperature start value. If the maximum temperature is higher than the high temperature start value, step 2) is entered; if the maximum temperature is lower than the high temperature start value and the minimum temperature 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: If the maximum temperature is higher than the high temperature start value, the energy storage system air conditioning and cooling are also turned on.

7. The energy storage system thermal management control method according to claim 3, characterized in that: If the maximum temperature is below the preset high temperature stop value, the air conditioning and all fans are turned off.

8. The energy storage system thermal management control method according to claim 1, characterized in that: In step 2), when the temperature difference between the minimum temperature and the maximum temperature is greater than a preset maximum temperature difference value, and the maximum temperature is greater than a preset high temperature setting value, the fan of the area corresponding to the minimum temperature is turned off.

9. The energy storage system thermal management control method according to claim 3, characterized in that: If the difference between the temperature of the area corresponding to the turned-off fan and the maximum temperature within the control range is less than the preset minimum temperature difference, and the fan is turned off for at least 5 minutes, the turned-off fan is turned on.

10. 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 fans in various areas in batches.

11. The energy storage system thermal management control method according to claim 5, characterized in that: When the minimum temperature is greater than the low temperature stop value, turn off the air conditioning heating and all fans.

12. A thermal management control system for an energy storage system, characterized in that: It comprises a processor, wherein the processor is used to execute instructions for implementing the energy storage system thermal management control method according to any one of claims 1 to 11.

13. An energy storage system, characterized in that: It comprises two or more battery boxes and the energy storage system thermal management control system as claimed in claim 12.

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