Battery energy storage system and temperature adjusting method thereof

Abstract

The invention belongs to the technical field of battery energy storage, and discloses a battery energy storage system and a temperature adjusting method thereof, the battery energy storage system comprises a plurality of single batteries, and each single battery comprises a single cell, a solid-state thermal transistor and a bidirectional power switch; the solid-state thermal transistor is arranged on the single cell, two ends of the solid-state thermal transistor are respectively connected with a positive electrode and a negative electrode of the single cell, and the bidirectional power switch is connected in parallel with the solid-state thermal transistor. According to the battery energy storage system, the solid-state thermal transistor is arranged on the single cell of each single battery, and the temperature of the single battery can be adjusted in real time by controlling the solid-state thermal transistor, so that the temperature self-adaptive adjustment of the battery energy storage system is realized; auxiliary heating and ventilation power equipment is not needed, the temperature of each single battery cell is maintained in a temperature interval with the highest operation efficiency, heat management energy consumption is low, the occupied space of battery energy storage system equipment is small, the overall investment cost of the equipment is low, and battery operation can resist high and low temperature.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery energy storage, and particularly relates to a battery energy storage system and a temperature regulation method thereof. Background Art

[0002] A battery energy storage system is composed of multiple single cells connected in series and parallel. During operation, a large amount of heat will be generated. If heat dissipation cannot be carried out in time, it will affect the safety and operation efficiency of the battery energy storage system. Similarly, under low-temperature conditions, if the ambient temperature of the battery energy storage system is too low, it will also lead to very low operation efficiency or even inability to start the system operation.

[0003] In view of the above situation, the commonly used solution in the prior art is to integrate the battery energy storage system in a container and adjust the temperature of the environment where the battery energy storage system is located through an industrial air conditioner. The existing temperature regulation methods for battery energy storage systems have the following problems:

[0004] 1. The energy consumption of the energy storage power station is large; 2. The occupied space of the energy storage system is large; 3. The investment cost of auxiliary equipment such as heating, ventilation, and power is high; 4. The existing air conditioning system in the battery container has inaccurate control accuracy of the ambient temperature of the battery system and a large error. Summary of the Invention

[0005] In view of the above problems, the present invention provides a battery energy storage system and a temperature regulation method thereof, adopting the following technical solutions:

[0006] A battery energy storage system includes a plurality of single cells, and each single cell includes a monomer cell, a solid-state thermal transistor, and a bidirectional power switch;

[0007] Wherein, the solid-state thermal transistor is arranged on the monomer cell, and two ends of the solid-state thermal transistor are respectively connected to the positive electrode and the negative electrode of the monomer cell, and the bidirectional power switch is connected in parallel with the solid-state thermal transistor.

[0008] Further, the solid-state thermal transistor includes a lower electrode plate, a solid electrolyte layer, a semiconductor heat conduction layer, and an upper electrode plate which are sequentially stacked from bottom to top.

[0009] Further, the lower electrode plate of each solid-state thermal transistor is in contact with the surface of the monomer cell.

[0010] Further, the positive electrode of the monomer cell is connected to the upper electrode plate through a first connecting wire, the negative electrode of the monomer cell is connected to the lower electrode through a second connecting wire, and one end of the bidirectional power switch is connected to the first connecting wire and the other end is connected to the second connecting wire.

[0011] Further, the material of the semiconductor heat conduction layer is strontium cobaltate.

[0012] Further, the battery energy storage system includes a plurality of serially connected battery packs, each of the battery packs includes a plurality of parallel-connected cell strings, each of the cell strings includes a plurality of serially connected single cells, and the solid-state thermal transistors are provided on multiple sides of the single cell cores of each of the single cells.

[0013] Further, each of the single cells further includes a temperature sensor, each of the temperature sensors is communicatively connected to the battery management system, and the temperature sensor is configured to send the temperature of the single cell core collected to the battery management system.

[0014] Further, the bidirectional power switches of each of the single cells are connected to the battery management system, and the battery management system is configured to adjust the surface temperature of each of the single cell cores in real time through the solid-state thermal transistors according to the temperature of each of the single cell cores, so that the temperature of the battery energy storage system is within a set temperature.

[0015] The present invention also provides a temperature regulation method for the battery energy storage system as described above, including the following steps:

[0016] Obtain the temperature of the single cell core of each single cell;

[0017] According to the temperature of each single cell core, adjust the surface temperature of each single cell core in real time through the solid-state thermal transistors, so that the temperature of the battery energy storage system is within a set temperature.

[0018] Further, adjusting the surface temperature of each single cell core in real time through the solid-state thermal transistors according to the temperature of each single cell core includes the following steps:

[0019] Control the direction of the voltage applied to the solid-state thermal transistor through the bidirectional power switch, change the thermal conductivity of the solid-state thermal transistor to make the single cell core release heat or store heat, and dynamically adjust the surface temperature of each single cell core in real time.

[0020] Advantages of the present invention:

[0021] 1. By providing solid-state thermal transistors on the single cell cores of each single cell, the present invention can realize real-time temperature regulation of the single cell through control of the solid-state thermal transistors, thereby realizing adaptive temperature regulation of the battery energy storage system.

[0022] 2. The present invention does not require auxiliary heating, ventilation and power equipment, enables the temperature of each single cell core to be maintained in the temperature range of the highest operating efficiency, has low thermal management energy consumption, small floor space for the battery energy storage system equipment, low overall investment cost of the equipment, and can achieve high and low temperature resistance of the battery operation.

[0023] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the structure particularly pointed out in the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 Shows a schematic structural diagram of a single cell according to an embodiment of the present invention;

[0026] Figure 2 Shows a schematic installation diagram of a solid-state thermal transistor and a bidirectional power switch according to an embodiment of the present invention;

[0027] Figure 3 Shows a schematic structural diagram of a battery energy storage system with series and parallel connection of single-cell battery cores after covering a solid-state thermal transistor according to an embodiment of the present invention;

[0028] Figure 4 Shows a schematic main flow diagram of a temperature regulation method for a battery energy storage system according to an embodiment of the present invention;

[0029] Figure 5 Shows a schematic detailed flow diagram of a temperature regulation method for a battery energy storage system according to an embodiment of the present invention.

[0030] In the figure: 1, single-cell battery core; 2, solid-state thermal transistor; 3, bidirectional power switch; 4, lower electrode plate; 5, solid-state electrolyte layer; 6, semiconductor heat conduction layer; 7, upper electrode plate; 8, first connection line; 9, second connection line; 10, wire. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first", "second", etc. in this application are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances for the embodiments of the present application described herein.

[0033] The present invention provides a battery energy storage system and its temperature regulation method. By dynamically and real-time adjusting the surface heat dissipation performance and heat preservation performance of each single cell in the battery energy storage system, the temperature of each single cell is maintained within the temperature range of the highest operating efficiency. The temperature regulation method of the battery energy storage system of the present invention does not require auxiliary heating, ventilation, and power equipment, and can solve the problems brought by the current thermal management of the battery energy storage system.

[0034] As Figure 1 shown, a battery energy storage system includes a plurality of series-parallel connected single cells, and each single cell includes a single cell core 1, a solid-state thermal transistor 2, and a bidirectional power switch 3.

[0035] Among them, the solid-state thermal transistor 2 is arranged on the single cell core 1. For example, each solid-state thermal transistor 2 includes a lower electrode plate 4, a solid-state electrolyte layer 5, a semiconductor heat conduction layer 6, and an upper electrode plate 7 that are stacked in sequence from bottom to top. For example, the lower electrode plate 4 of each solid-state thermal transistor 2 is in contact with the surface of the single cell core 1.

[0036] For example, the material of the semiconductor heat conduction layer 6 is strontium cobaltate (SrCoO x )(abbreviation: SCO), and SCO has the characteristic of variable thermal conductivity. By covering a solid-state electrolyte layer 5 on the surface of SCO and applying voltages above and below their combination through the single cell core 1, the redox reaction of SCO can be made to occur.

[0037] The working principle of the solid-state thermal transistor 2: When an external voltage is applied to the solid-state thermal transistor 2 to cause an oxidation reaction in the semiconductor heat conduction layer 6, the single-atom arrangement inside its material becomes more orderly, resulting in a significant increase in the thermal conductivity of the semiconductor heat conduction layer 6, which can increase to multiple times the original value and become a good conductor of heat; when an external voltage is applied to the solid-state thermal transistor 2 to cause a reduction reaction in the semiconductor heat conduction layer 6, the single-atom arrangement inside its material becomes more disordered, resulting in a significant decrease in the thermal conductivity of the semiconductor heat conduction layer 6, or even becoming a thermal insulator. Therefore, through the characteristic of variable thermal conductivity of the semiconductor heat conduction layer 6, real-time thermal management can be provided for the single cell core 1 in the battery energy storage system, achieving the purpose of rapid heat release and heat storage in the environment around the cell core.

[0038] As Figure 2 shown, both ends of the solid-state thermal transistor 2 are respectively connected to the positive electrode and the negative electrode of the single cell core 1, and the bidirectional power switch 3 is connected in parallel with the solid-state thermal transistor 2.

[0039] For example, the positive electrode of the single cell 1 is connected to the upper electrode plate 7 through the first connecting wire 8, the negative electrode of the single cell 1 is connected to the lower electrode through the second connecting wire 9, one end of the bidirectional power switch 3 is connected to the first connecting wire 8, and the other end is connected to the second connecting wire 9.

[0040] The external voltage source of the solid-state thermal transistor 2 of the present invention is provided by each single cell 1. In order to ensure that the redox reaction of the solid-state thermal transistor 2 can occur in real time and dynamically, the present invention connects the solid-state thermal transistor 2 in parallel with the bidirectional power switch 3. Among them, the bidirectional power switch 3 is a high-frequency power electronic switch, which can switch the voltage direction for the solid-state thermal transistor 2 in real time, so that the semiconductor heat conduction layer 6 undergoes a redox reaction.

[0041] Such as Figure 3 As shown, for example, the battery energy storage system includes a plurality of series-connected battery packs, each battery pack includes a plurality of parallel-connected cell strings, each cell string includes a plurality of series-connected single cells, and solid-state thermal transistors 2 are arranged on multiple sides of the single cell 1 of each single cell.

[0042] For example, one solid-state thermal transistor 2 is arranged on the left side, upper side and lower side of the single cell 1 of each single cell, or one solid-state thermal transistor 2 can also be arranged on the left side, upper side, lower side, front side and rear side of the single cell 1 of each single cell. The right side of the single cell 1 of each single cell is the positive and negative electrodes, and no solid-state thermal transistor 2 is arranged, which is convenient for installation.

[0043] By arranging the solid-state thermal transistors 2 on multiple sides of the single cell 1, the heat dissipation and heat preservation performance of the single cell 1 are adjusted through the multiple solid-state thermal transistors 2, so as to improve the temperature adjustment effect.

[0044] For example, each cell string includes 10 series-connected single cells, and the positive and negative electrodes of the single cell 1 of two adjacent single cells are connected through a wire 10.

[0045] For example, in order to realize the dynamic real-time adjustment of the surface temperature of each single cell 1, each single cell includes a temperature sensor, and each temperature sensor is communicatively connected to the battery management system. The temperature sensor is used to send the collected temperature parameters of the single cell 1 to the battery management system (BMS).

[0046] The bidirectional power switch 3 of each single cell is connected to the battery management system (BMS). The battery management system automatically issues a control command to adjust the direction of the bidirectional power switch 3 in real time, so as to adjust the external voltage direction of the solid-state thermal transistor 2 in real time and adjust the thermal conductivity of the solid-state thermal transistor 2 to achieve the purpose of thermal management of the single cell 1. Through such precise thermal management measures for the single cell 1, the temperature of the battery energy storage system after series and parallel connection can reach the temperature range corresponding to the best operating efficiency.

[0047] The battery energy storage system of the present invention has the following effects compared with the traditional heat management measures relying on HVAC power: low heat management energy consumption, small floor space occupied by the battery energy storage system equipment, low overall investment cost of the equipment, and the battery can operate at high and low temperatures.

[0048] As Figure 4 shown, the present invention also provides a temperature regulation method for the above battery energy storage system, including the following steps:

[0049] S1. The battery management system obtains the temperature of each single cell 1 of each single battery through the temperature sensor of each single cell.

[0050] S2. The battery management system adjusts the surface temperature of each single cell 1 in real time through the solid-state thermal transistor 2 according to the temperature of each single cell 1, so that the temperature of the battery energy storage system is within the set temperature. Specifically: the battery management system controls the direction of the voltage applied to the solid-state thermal transistor 2 through the bidirectional power switch 3, changes the thermal conductivity coefficient of the solid-state thermal transistor 2 to make the single cell 1 release heat or store heat, thereby dynamically adjusting the surface temperature of each single cell 1 in real time, and further ensuring that the temperature of the battery energy storage system after the series-parallel connection of the single cells 1 reaches a temperature range corresponding to the best operating efficiency.

[0051] The present invention applies a voltage across the solid-state thermal transistor 2 to change the internal structure of the semiconductor thermal conduction layer 6 (SCO material), thereby changing the thermal conductivity coefficient of the solid-state thermal transistor 2 to achieve the purpose of adjusting the surface temperature of the single cell 1.

[0052] As Figure 5 shown, for example, the battery management system adjusts the surface temperature of each single cell 1 in real time according to the temperature of each single cell 1, so that the temperature of the battery energy storage system is within the set temperature, including the following steps:

[0053] S21. If the real-time temperature T of the single cell 1 电芯 is greater than the temperature T corresponding to the best operating efficiency of the single cell 1 最佳 , and the temperature change rate of the single cell 1 is greater than 0, control the bidirectional power switch 3 to be forward-biased, the solid-state thermal transistor 2 undergoes an oxidation reaction, the thermal conductivity coefficient of the semiconductor thermal conduction layer 6 (SCO material) of the solid-state thermal transistor 2 increases, improving the heat dissipation effect of the single cell 1 to achieve the purpose of cooling; if the temperature change rate of the single cell 1 is not greater than 0, the bidirectional power switch 3 is in the off state.

[0054] S22. If the real-time temperature T of the single cell 1 电芯 is less than or equal to the temperature T corresponding to the best operating efficiency of the single cell 1 最佳, and the temperature change rate of the single cell 1 is less than or equal to 0, the bidirectional power switch 3 is controlled to be negatively biased, and the solid-state thermal transistor 2 undergoes a reduction reaction, and the thermal conductivity of the semiconductor thermal conduction layer 6 (SCO material) of the solid-state thermal transistor 2 decreases, reducing the heat dissipation effect of the single cell 1 to achieve the purpose of heat preservation; if the temperature change rate of the single cell 1 is greater than 0, the bidirectional power switch 3 is in a closed state.

[0055] The present invention combines the solid-state thermal transistor 2 with the battery energy storage system, and controls the closing state of the bidirectional power switch 3 to achieve the heat dissipation and heat storage effects of the battery system, and achieve the purpose of thermal management.

[0056] The present invention organically combines the thermal management measures with the battery management system, and through the automatic feedback control of the battery management system, the purpose of self-adaptive temperature regulation and balance of the battery energy storage system is realized, and the battery energy storage system is maintained in the temperature range corresponding to the best operating efficiency.

[0057] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery energy storage system, characterized in that, it includes a plurality of single cells, and each of the single cells includes a single cell core, a solid-state thermal transistor, and a bidirectional power switch; wherein, the solid-state thermal transistor is arranged on the single cell core, both ends of the solid-state thermal transistor are respectively connected to the positive electrode and the negative electrode of the single cell core, and the bidirectional power switch is connected in parallel with the solid-state thermal transistor.

2. The battery energy storage system according to claim 1, characterized in that, the solid-state thermal transistor includes a lower electrode plate, a solid electrolyte layer, a semiconductor heat conduction layer, and an upper electrode plate which are stacked in sequence from bottom to top.

3. The battery energy storage system according to claim 2, characterized in that, the lower electrode plate of each solid-state thermal transistor is in contact with the surface of the single cell core.

4. The battery energy storage system according to claim 2, characterized in that, the positive electrode of the single cell core is connected to the upper electrode plate through a first connection wire, the negative electrode of the single cell core is connected to the lower electrode through a second connection wire, one end of the bidirectional power switch is connected to the first connection wire, and the other end is connected to the second connection wire.

5. The battery energy storage system according to any one of claims 2-4, characterized in that, the material of the semiconductor heat conduction layer is strontium cobaltate.

6. The battery energy storage system according to claim 1, characterized in that, the battery energy storage system includes a plurality of battery packs connected in series, each battery pack includes a plurality of cell strings connected in parallel, each cell string includes a plurality of the single cells connected in series, and the solid-state thermal transistors are arranged on multiple sides of the single cell core of each single cell.

7. The battery energy storage system according to claim 1, characterized in that, each single cell further includes a temperature sensor, each temperature sensor is communicatively connected to a battery management system, and the temperature sensor is used to send the temperature of the single cell core collected to the battery management system.

8. The battery energy storage system according to claim 7, characterized in that, the bidirectional power switch of each single cell is connected to the battery management system, and the battery management system is used to adjust the surface temperature of each single cell core in real time through the solid-state thermal transistor according to the temperature of each single cell core, so that the temperature of the battery energy storage system is within a set temperature.

9. A temperature adjustment method for the battery energy storage system according to any one of claims 1-8, characterized in that, it includes the following steps: acquiring the temperature of the single cell core of each single cell; adjusting the surface temperature of each single cell core in real time through the solid-state thermal transistor according to the temperature of each single cell core, so that the temperature of the battery energy storage system is within a set temperature.

10. The temperature adjustment method for the battery energy storage system according to claim 9, characterized in that, adjusting the surface temperature of each single cell core in real time through the solid-state thermal transistor according to the temperature of each single cell core includes the following steps: controlling the direction of the voltage applied to the solid-state thermal transistor through the bidirectional power switch, changing the heat conduction coefficient of the solid-state thermal transistor to make the single cell core release heat or store heat, and dynamically adjusting the surface temperature of each single cell core in real time.

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