Energy storage cabinet and micro-grid energy storage system

Abstract

The invention provides an energy storage cabinet and a micro-grid energy storage system, relates to the field of energy, and is used for simplifying the structure of the micro-grid energy storage system and reducing the maintenance difficulty. The energy storage cabinet comprises a battery unit, a converter, an auxiliary power supply unit, a heat dissipation system, a monitoring system and an external port. The direct current end of the battery unit is connected with the first end of the converter, the direct current end of the battery unit is further connected with the heat dissipation system and the monitoring system through the auxiliary power supply unit, and the second end of the converter is connected with the external port.

Description

Technical Field

[0001] This application relates to the field of energy technologies, and in particular, to an energy storage cabinet and a microgrid energy storage system. Background Art

[0002] A microgrid, also known as a micro power grid, is a small and independent power system. With the optimization of energy technologies and the demand for environmental protection, microgrids have gradually become an important means to solve energy supply and environmental protection problems. A general microgrid energy storage system includes an energy storage device, an uninterruptible power supply (UPS), and a grid-connected / off-grid switching switch cabinet. Among them, the energy storage device can also be referred to as an energy storage cabinet. To ensure the safe operation of the microgrid energy storage system, it is necessary to regularly inspect and maintain the UPS and the grid-connected / off-grid switching switch cabinet.

[0003] In the existing microgrid energy storage system, not only is it necessary to increase the laying of UPS cables during construction, but also a dedicated communication cable needs to be established between the energy storage device and the grid-connected / off-grid switching switch cabinet. Therefore, the cable wiring method of the microgrid energy storage system is relatively complex, and it will increase the maintenance difficulty of the microgrid energy storage system to a certain extent. Summary of the Invention

[0004] This application provides an energy storage cabinet and a microgrid energy storage system, which are used to simplify the structure of the microgrid energy storage system and reduce the maintenance difficulty.

[0005] To achieve the above object, the embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, an energy storage cabinet is provided. The energy storage cabinet includes a battery unit, an inverter, an auxiliary power supply unit, a heat dissipation system, a monitoring system, and an external interface. The DC terminal of the battery unit is connected to the first end of the inverter, and the DC terminal of the battery unit is also connected to the heat dissipation system and the monitoring system respectively through the auxiliary power supply unit. The second end of the inverter is connected to the external interface.

[0007] In the above technical solution, the DC terminal of the battery unit is connected to the monitoring system and the heat dissipation system respectively through the auxiliary power supply unit to supply power to the heat dissipation system and the monitoring system through the auxiliary power supply unit. Compared with the existing solution in which the heat dissipation system needs to be powered by a UPS outside the energy storage cabinet, the structure of the microgrid energy storage system is simplified, and the laying process of the cable between the monitoring system and the UPS is reduced. At the same time, since there is no need for UPS power supply, the monitoring system does not need to communicate between the UPS and the switch cabinet, that is, there is no need to lay a communication cable between the monitoring system and the switch cabinet outside the energy storage cabinet, further simplifying the wiring of the microgrid energy storage system and reducing the maintenance difficulty.

[0008] In combination with the first aspect, in one embodiment, the monitoring system is configured to: control the auxiliary power supply unit to regulate the heat dissipation system to be in a first mode or a second mode according to the state of charge (SOC) of the battery cell; wherein, the power consumption of the heat dissipation system in the first mode is greater than that in the second mode.

[0009] Based on the above solution, the monitoring system can control the heat dissipation system to be in different operating modes according to different state of charge of the battery cell. The higher the value indicated by the state of charge, the higher the remaining power of the battery cell. For example, when the value indicated by the state of charge of the battery cell is relatively high, the heat dissipation system is controlled to be in the first mode, and at this time the power consumption of the heat dissipation system is also relatively high; when the value indicated by the state of charge of the battery cell is relatively low, the heat dissipation system is controlled to be in the second mode, and at this time the power consumption of the heat dissipation system is also relatively low. In this way, by controlling the heat dissipation system to be in different operating modes, the heat dissipation system is prevented from always being in a high-power consumption state, reducing the power consumption of the heat dissipation system, thereby solving the problem that supplying power to the heat dissipation system will consume a large amount of power of the battery cell. Through the above regulation method, the battery cell can directly supply power to the heat dissipation system without the problem of rapid power consumption, which is beneficial to simplifying the wiring of the microgrid energy storage system and reducing the maintenance difficulty.

[0010] In combination with the first aspect, in one embodiment, the monitoring system is further configured to: control the auxiliary power supply unit to regulate the heat dissipation system to be in the second mode when the state of charge of the battery cell is less than a first threshold.

[0011] Based on the above solution, the monitoring system can set thresholds for different stages according to the state of charge of the battery cell, so as to adjust the power consumption of the heat dissipation system by controlling the heat dissipation system to be in different operating modes. For example, when the value indicated by the state of charge of the battery cell is lower than the first threshold, the heat dissipation system is controlled to enter the second mode, thereby reducing the power consumption of the heat dissipation system to a certain extent.

[0012] In combination with the first aspect, in one embodiment, the monitoring system is further configured to: control the auxiliary power supply unit to regulate the heat dissipation system to exit the second mode when the state of charge of the battery cell is greater than a second threshold, wherein the second threshold is greater than the first threshold.

[0013] Based on the above solution, the second threshold is the threshold for exiting the second mode. Setting the second threshold to be greater than the first threshold, that is, the threshold for exiting the second mode is greater than the threshold for entering the second mode, can avoid the situation that the heat dissipation system repeatedly enters and exits the second mode when the state of charge of the battery cell is near the first threshold, and can improve the stability of the heat dissipation system.

[0014] In combination with the first aspect, in one embodiment, the monitoring system is further configured to control the auxiliary power supply unit to regulate the heat dissipation system to turn off at a predetermined time.

[0015] Based on the above solution, the monitoring system in the embodiment of the present application can control the heat dissipation system to turn off during the time when heat dissipation is not required, achieving the purpose of optimizing the power consumption of the heat dissipation system and improving the power utilization rate of the battery unit.

[0016] In combination with the first aspect, in one embodiment, the monitoring system is further connected to the converter.

[0017] Based on the above solution, the monitoring system in the embodiment of the present application can also obtain power from the port of the converter. For example, during the process of the converter transmitting direct current to the battery unit, the monitoring system can be powered by the electric energy transmitted by the converter, thereby further reducing the power consumption of the battery unit.

[0018] In combination with the first aspect, in one embodiment, the converter includes an energy storage converter, the DC side of the energy storage converter is connected to the DC side of the battery unit, and the AC side of the energy storage converter is connected to the external port.

[0019] Based on the above solution, the energy storage converter is configured to convert the direct current output by the battery unit into alternating current and then output it, or the energy storage converter is configured to convert the received alternating current into direct current and then input it to the battery unit to charge the battery unit.

[0020] In combination with the first aspect, in one embodiment, the converter further includes a DC-DC converter, the first DC side of the DC-DC converter is connected to the DC side of the battery unit, and the second DC side of the DC-DC converter is connected to the DC side of the energy storage converter.

[0021] Based on the above solution, the DC-DC converter is configured to perform power conversion on the direct current output by the battery unit and transmit the converted direct current to the energy storage converter, and the energy storage converter converts the received direct current into alternating current and then outputs it. Or, the energy storage converter converts the received alternating current into direct current, and the DC-DC converter performs power conversion on the received direct current and then transmits it to the battery unit to charge the battery unit. The DC-DC converter can perform power conversion on the direct current transmitted between the DC side of the battery unit and the energy storage converter to further improve the power utilization rate while ensuring the normal operation of the energy storage converter.

[0022] In combination with the first aspect, in one embodiment, the converter includes a DC-DC converter, the first DC side of the DC-DC converter is connected to the DC side of the battery unit, and the second DC side of the DC-DC converter is connected to the external port.

[0023] Based on the above solution, the energy storage cabinet provided in the embodiments of the present application can also set different inverters according to different application scenarios. For example, when applied to a scenario powered by a DC power grid, the inverter in the energy storage cabinet can be a DC-DC converter, without the need for an energy storage inverter to perform AC-DC conversion, which can simplify the structure and wiring of the microgrid energy storage system and reduce the maintenance difficulty of the microgrid energy storage system.

[0024] In combination with the first aspect, in an implementation manner, the energy storage cabinet further includes a cluster control box. The DC end of the battery unit is connected to the first end of the cluster control box, and the second end of the cluster control box is connected to the first end of the inverter.

[0025] Based on the above solution, the cluster control box can include components such as a battery cluster unit (BCU) module, a cluster power control board, a fuse, a contactor, and a disconnect switch, and is used to control the power supply process of the battery unit or control the charging process of the battery unit.

[0026] In a second aspect, a microgrid energy storage system is provided. The microgrid energy storage system includes a switch cabinet and the energy storage cabinet provided in the first aspect or any one of the implementation manners in the first aspect. The external connection port of the energy storage cabinet is connected to the switch cabinet.

[0027] In combination with the second aspect, in an implementation manner, the microgrid energy storage system further includes a transformer, and the transformer is connected between the energy storage cabinet and the switch cabinet.

[0028] For the description of the second aspect in the present application, reference can be made to the detailed description of the first aspect; and for the beneficial effects of the second aspect, reference can be made to the analysis of the beneficial effects of the first aspect, which will not be elaborated here. Description of the Drawings

[0029] Figure 1 It is a schematic structural diagram of a microgrid energy storage system;

[0030] Figure 2 It is a schematic structural diagram of another microgrid energy storage system;

[0031] Figure 3 It is a schematic structural diagram of an energy storage cabinet provided by an embodiment of the present application;

[0032] Figure 4 It is a schematic structural diagram of another energy storage cabinet provided by an embodiment of the present application;

[0033] Figure 5 It is a schematic structural diagram of yet another energy storage cabinet provided by an embodiment of the present application;

[0034] Figure 6Schematic diagram of another energy storage cabinet provided by the embodiment of the present application;

[0035] Figure 7 Schematic diagram of a process for controlling a heat dissipation system provided by the embodiment of the present application;

[0036] Figure 8 Schematic diagram of another structure of a microgrid energy storage system provided by the embodiment of the present application;

[0037] Figure 9 Schematic diagram of yet another structure of a microgrid energy storage system provided by the embodiment of the present application. Detailed implementation manners

[0038] The fabrication and use of each embodiment will be discussed in detail below. However, it should be understood that many applicable inventive concepts provided by the present application can be implemented in a variety of specific environments. The specific embodiments discussed merely illustrate the specific ways of implementing and using the present application and the present technology, and do not limit the scope of the present application.

[0039] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those of ordinary skill in the art.

[0040] Each circuit or other component may be described or referred to as "configured to" perform one or more tasks. In this case, "configured to" is used to imply structure by indicating that the circuit / component includes a structure (such as circuitry) that performs one or more tasks during operation. Thus, even when the specified circuit / component is currently inoperable (e.g., not turned on), the circuit / component can still be referred to as configured to perform the task. A circuit / component used in conjunction with the phrase "configured to" includes hardware, such as circuitry that performs the operation. Additionally, in the embodiments of the present application, terms such as "first", "second", etc. do not limit the quantity and order.

[0041] In the present application, words such as "exemplary" or "for example" are used to indicate an example, illustration, or demonstration. Any embodiment or design described as "exemplary" or "for example" in the present application should not be construed as being more preferred or having more advantages than other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0042] Before introducing the embodiments of the present application, the background technology related to the present application will be introduced first.

[0043] Figure 1The figure shows a schematic structural diagram of a microgrid energy storage system 100. The microgrid energy storage system 100 is a distributed microgrid energy storage system, mainly including two distributed power sources, and an AC bus and a DC bus respectively connected to the two distributed power sources. For the specific structure of the distributed microgrid energy storage system, please refer to Figure 1 , which will not be elaborated here.

[0044] In the case of a complete power outage, the microgrid energy storage system 100 can achieve black start through power supply from the distributed power source or through power supply from the battery. The host of the black start control system realizes communication control with the energy converter (such as a DC converter), the controller, and the distributed power source in the microgrid energy storage system 100 through a communication cable. Among them, black start means that after the microgrid energy storage system 100 shuts down and enters a complete black state due to external or internal faults, without relying on the help of the power grid or other microgrid systems, only by starting the micro power sources with black start capabilities inside the microgrid energy storage system 100, and then driving the micro power sources without black start capabilities in the microgrid energy storage system 100, gradually expanding the recovery range of the microgrid energy storage system 100, and finally realizing the restart of the entire microgrid energy storage system 100.

[0045] Figure 1 The wiring of the microgrid energy storage system 100 shown is complex, and multiple communication cables need to be laid, which will cause a lot of inconvenience to the maintenance of the microgrid energy storage system 100.

[0046] Figure 2 The figure shows the structure of another microgrid energy storage system 200. The microgrid energy storage system 200 includes an energy storage cabinet 210, a transformer 220, a switch cabinet 230, and a UPS 240. The first interface of the energy storage cabinet 210 is connected to the low-voltage side of the transformer 220, the high-voltage side of the transformer 220 is connected to the first end of the switch cabinet 230, and the second end of the switch cabinet 230 is used to connect to the power grid 300 and the load 400. The low-voltage side of the transformer 220 is also connected to the input end of the UPS 240, and the output end of the UPS 240 is connected to the second interface of the energy storage cabinet 210.

[0047] Exemplarily, both the first interface and the second interface can be AC interfaces. The first interface is used to transmit the alternating current output by the energy storage cabinet 210 to the transformer 220, or to input the alternating current transmitted by the transformer 220 into the energy storage cabinet 210. The second interface is used to transmit the alternating current output by the UPS 240 to the internal devices of the energy storage cabinet 210 to supply power to the internal devices of the energy storage cabinet 210.

[0048] The above switchgear 230 can also be referred to as a grid-connected and islanding switching switchgear. When the switchgear 230 conducts the connection between the microgrid energy storage system 200 and the power grid 300, the microgrid energy storage system 200 is in the grid-connected operation mode, and can supply power to the power grid 300 and the load 400, or receive power supply from the power grid 300; when a fault occurs in the power grid 300, the switchgear 230 can quickly cut off the connection with the power grid 300, and switch the microgrid energy storage system 200 to the islanding operation mode (or called the island operation mode) to supply power to the load 400 (such as the servers in the data center).

[0049] The above transformer 220 is connected between the energy storage cabinet 210 and the switchgear 230, and is used for step-down processing of the high-voltage alternating current output by the power grid 300. For example, the 10 kV alternating current output by the power grid 300 is stepped down to 220 V alternating current; the transformer 220 is also used for step-up processing of the low-voltage alternating current output by the energy storage cabinet 210 to output high-voltage alternating current to the power grid 300.

[0050] In one embodiment, the above energy storage cabinet 210 includes a battery unit 211, an inverter 212, a heat dissipation system 213, an auxiliary power supply unit 214, and a monitoring system 215. The battery unit 211 is connected to the low-voltage side of the transformer 220 through the inverter 212. The heat dissipation system 213 is connected to the output end of the UPS 240 through the auxiliary power supply unit 214, and the monitoring system 215 is connected to the output end of the UPS 240. The monitoring system 215 is also connected to the switchgear 230 through a communication cable.

[0051] Among them, the inverter 212 is used to convert the direct current output by the battery unit 211 into alternating current and then output it to the transformer 220. The inverter 212 is also used to convert the alternating current stepped down by the transformer 220 into direct current and then charge the battery unit 211. After the UPS 240 performs power conversion on the alternating current on the low-voltage side of the transformer 220, it supplies power to the heat dissipation system 213 through the auxiliary power supply unit 214.

[0052] Exemplarily, the above auxiliary power supply unit 214 includes a plurality of power conversion devices and a plurality of auxiliary power supply circuits. The plurality of auxiliary power supply circuits are correspondingly connected to the plurality of power conversion devices, and are used for performing power conversion on the alternating current output by the UPS 240 and supplying power to the heat dissipation system 213 according to different types or different magnitudes of voltages required by different devices in the heat dissipation system 213. For example, the auxiliary power supply unit 214 includes a plurality of AC-DC power conversion devices, and the plurality of AC-DC power conversion devices can convert the alternating current output by the UPS 240 into direct current with different voltage amplitudes and supply power to various devices in the heat dissipation system 213 according to the rated voltages of different devices.

[0053] So that the heat dissipation system 213 can dissipate heat from the energy storage cabinet 210 in a timely manner, preventing the heat generated during the operation of the devices in the energy storage cabinet 210 from affecting the performance of the energy storage cabinet 210. The monitoring system 215 is not only used to monitor and control the working state of the energy storage cabinet 210, but also used to realize information interaction between the switch cabinet 230 and the UPS 240.

[0054] Figure 2 In the microgrid energy storage system 200 shown, not only is it necessary to increase the laying of the UPS 240 cable during construction, but also a dedicated communication cable needs to be established between the energy storage cabinet 210 and the switch cabinet 230. Therefore, the cable routing method of the microgrid energy storage system 200 is relatively complex and will increase the maintenance difficulty of the microgrid energy storage system 200 to a certain extent.

[0055] In view of this, the embodiment of the present application provides an energy storage cabinet. By deploying the control strategy of the heat dissipation system in the monitoring system, the heat dissipation system can be directly powered by the battery unit in the energy storage cabinet without using the UPS for power supply, which can simplify the structure and wiring of the microgrid energy storage system to a certain extent and reduce the maintenance difficulty.

[0056] The following combines Figures 3 to 6 to describe the structure of the energy storage cabinet provided by the embodiment of the present application.

[0057] As Figure 3 shown, the energy storage cabinet 510 provided by the embodiment of the present application includes a battery unit 511, an inverter 512, a heat dissipation system 513, an auxiliary power supply unit 514, a monitoring system 515, and an external connection port 516. The DC terminal of the battery unit 511 is connected to the first end of the inverter 512. The DC terminal of the battery unit 511 is also connected to the heat dissipation system 513 and the monitoring system 515 through the auxiliary power supply unit 514 respectively, for supplying power to the heat dissipation system 513 and the monitoring system 515 respectively through the auxiliary power supply unit 514. The second end of the inverter 512 is connected to the external connection port 516. The inverter 512 is used to output the electric energy provided by the battery unit 511 through the external connection port 516, or receive the electric energy input to the battery unit 511 through the external connection port 516.

[0058] In one embodiment, the auxiliary power supply unit 514 includes a plurality of DC-DC power conversion devices and an auxiliary power supply circuit connected to each DC-DC power conversion device. The auxiliary power supply unit 514 can convert the DC voltage output by the battery unit 511 and then output direct currents with multiple different voltage amplitudes to supply power to the devices inside the heat dissipation system 513 and the monitoring system 515 according to the rated voltages of different devices.

[0059] In the above technical solution, the DC terminal of the battery unit 511 is respectively connected to the monitoring system 515 and the heat dissipation system 513 through the auxiliary power supply unit 514, so as to supply power to the heat dissipation system 513 and the monitoring system 515 through the auxiliary power supply unit 514. Compared with the prior art solution where the heat dissipation system 513 needs to be powered by a UPS outside the energy storage cabinet 510, the structure of the microgrid energy storage system is simplified, and the laying process of the cable between the monitoring system 515 and the UPS is reduced. At the same time, since there is no need for UPS power supply, the monitoring system 515 does not need to communicate between the UPS and the switch cabinet, that is, there is no need to lay a communication cable between the monitoring system 515 and the switch cabinet outside the energy storage cabinet 510, further simplifying the wiring of the microgrid energy storage system and reducing the maintenance difficulty.

[0060] The above battery unit 511 can be a box-level battery, a cluster-level battery or a single battery. The box-level battery includes multiple cluster-level batteries, and the box-level battery can also be called an energy storage box. The cluster-level battery includes multiple single batteries, and the cluster-level battery can also be called a battery cluster. By way of example and not limitation, the embodiments of the present application are described by taking the battery unit 511 as a battery cluster as an example.

[0061] In one embodiment, as Figure 4 shown, the energy storage cabinet 510 further includes a cluster control box 517. The DC terminal of the battery unit 511 is connected to the first end of the cluster control box 517, and the second end of the cluster control box 517 is connected to the first end of the inverter 512. Exemplarily, the cluster control box 517 may include components such as a battery cluster unit (BCU) module, a cluster power control board, a fuse, a contactor, a disconnect switch, etc., for controlling the power supply process of the battery cluster to the power grid 300 and the load 400, or controlling the charging process of the battery cluster.

[0062] In one embodiment, as Figure 4 shown, the heat dissipation system 513 includes a power supply unit 5131, and a compressor control unit 5132, a fan control unit 5133 and a water pump control unit 5134 connected to the power supply unit 5131. The power supply unit 5131 is used to receive the electric energy output by the auxiliary power supply unit 514 and supply power to the compressor control unit 5132, the fan control unit 5133 and the water pump control unit 5134 respectively.

[0063] In one embodiment, continue to refer to Figure 4 , the monitoring system 515 is also connected to the inverter 512. In this way, during the process of the inverter 512 transmitting direct current to the battery unit 511, the monitoring system 515 can be powered by the electric energy transmitted by the inverter 512, thereby further reducing the power consumption of the battery unit 511.

[0064] In one embodiment, asFigure 4 As shown in the figure, the converter 512 includes a power conversion system (PCS). The DC side of the PCS is connected to the DC side of the battery unit 511, and the AC side of the PCS is connected to the external port 516. Among them, the PCS is used to convert the direct current output by the battery unit 511 into alternating current and then output it, or the PCS is used to convert the received alternating current into direct current and then input it to the battery unit 511 to charge the battery unit 511.

[0065] In another embodiment, as Figure 5 shown in the figure, the converter 512 may further include a DC-DC converter. The first DC side of the DC-DC converter is connected to the DC side of the battery unit 511, and the second DC side of the DC-DC converter is connected to the DC side of the PCS. The DC-DC converter is used to perform power conversion on the direct current output by the battery unit 511 and transmit the converted direct current to the PCS, and the PCS converts the received direct current into alternating current and then outputs it. Or, the PCS converts the received alternating current into direct current, and the DC-DC converter performs power conversion on the received direct current and then transmits it to the battery unit 511 to charge the battery unit 511. The DC-DC converter can perform power conversion on the direct current transmitted between the DC sides of the battery unit 511 and the converter 512 to further improve the power utilization rate while ensuring the normal operation of the converter 512.

[0066] In yet another embodiment, as Figure 6 shown in the figure, the converter 512 may only include a DC-DC converter. The first DC side of the DC-DC converter is connected to the DC side of the battery unit 511, and the second DC side of the DC-DC converter is connected to the external port 516.

[0067] Exemplarily, the DC-DC converter can perform power conversion on the direct current output by the battery unit 511 and then output direct current, or perform power conversion on the received direct current and then transmit it to the battery unit 511 to charge the battery unit 511.

[0068] Based on the above solutions, the energy storage cabinet provided by the embodiments of the present application can also set different converters according to different application scenarios. For example, when applied to a scenario powered by a DC power grid, the converter 512 in the energy storage cabinet 510 can be a DC-DC converter, and there is no need for the PCS to perform AC-DC conversion; when applied to a scenario powered by an AC power grid, the converter 512 in the energy storage cabinet 510 can be a PCS, or include a PCS and a DC-DC converter.

[0069] The specific structure of the energy storage cabinet 510 has been introduced in detail above in conjunction with the accompanying drawings. The following takes the Figure 4 structure shown as an example to illustrate how the energy storage cabinet 510 provided in the embodiments of the present application realizes the power supply of the battery unit 511 to the heat dissipation system without using a battery with a larger capacity.

[0070] In one embodiment, the monitoring system 515 is used to control the auxiliary power supply unit 514 to regulate the heat dissipation system 513 to be in the first mode or the second mode according to the state of charge of the battery unit 511; wherein, the power consumption of the heat dissipation system 513 in the first mode is greater than that in the second mode.

[0071] In one example, the above-mentioned first mode may be the normal mode, and the second mode may be the sleep mode. Among them, the normal mode of the heat dissipation system 513 means that the compressor control unit 5132 in the heat dissipation system 513 controls all compressors to work normally, the fan control unit 5133 controls all fans to work normally, and the water pump control unit 5134 controls all water pumps to work normally. At this time, the power consumption of the heat dissipation system 513 is relatively large. The sleep mode of the heat dissipation system 513 means that the compressor control unit 5132 in the heat dissipation system 513 controls multiple compressors among all compressors to work normally or derate, or the fan control unit 5133 controls multiple fans among all fans to work normally, or the water pump control unit 5134 controls multiple water pumps among all water pumps to work normally. At this time, the power consumption of the heat dissipation system 513 is lower than that in the normal mode.

[0072] In another example, the above-mentioned heat dissipation system 513 may also be in a third mode, and the third mode may be the standby mode. Among them, the standby mode of the heat dissipation system 513 means that the compressor control unit 5132 in the heat dissipation system 513 controls a small number of compressors among all compressors to work normally or derate, or all compressors stop working, or the fan control unit 5133 controls a small number of fans among all fans to work normally or controls all fans to stop working, or the water pump control unit 5134 controls a small number of water pumps among all water pumps to work normally or all water pumps stop working. At this time, the power consumption of the heat dissipation system 513 is even lower.

[0073] Further, the above-mentioned sleep mode can also be divided into multiple levels of sleep modes, such as a first-level sleep mode and a second-level sleep mode. Compared with the first-level sleep mode, the number of heat dissipation devices (such as compressors, water pumps, and fans) operating in the second-level sleep mode is less, and the power consumption is lower. Similarly, the above-mentioned standby mode can also be divided into multiple levels of standby modes, such as a first-level standby mode and a second-level standby mode. Compared with the first-level standby mode, the number of heat dissipation devices (such as compressors, water pumps, and fans) operating in the second-level standby mode is less, and the power consumption is lower. The embodiments of the present application do not make specific limitations on the division of the working modes of the above-mentioned heat dissipation system 513.

[0074] In the embodiments of the present application, the monitoring system 515 is respectively connected to the battery unit 511 and the heat dissipation system 513 through the auxiliary power supply unit 514, and can control the heat dissipation system 513 to be in different working modes according to different state of charge of the battery unit 511. The higher the value indicated by the state of charge, the higher the remaining power of the battery unit 511. For example, when the value indicated by the state of charge of the battery unit 511 is relatively high, the heat dissipation system 513 is controlled to be in the normal mode, and at this time, the power consumption of the heat dissipation system 513 is also relatively high; when the value indicated by the state of charge of the battery unit 511 is relatively low, the heat dissipation system 513 is controlled to be in the sleep mode, and at this time, the power consumption of the heat dissipation system 513 is lower than that in the normal mode; when the value indicated by the state of charge of the battery unit 511 is even lower, the heat dissipation system 513 is controlled to be in the standby mode, and at this time, the power consumption of the heat dissipation system 513 is lower than that in the sleep mode. In this way, by controlling the heat dissipation system 513 to be in different working modes, the heat dissipation system 513 will not always be in the normal mode, reducing the power consumption of the heat dissipation system 513, thereby solving the problem that supplying power to the heat dissipation system 513 will consume a large amount of power of the battery unit 511. Based on this, in the embodiments of the present application, the battery unit 511 can directly supply power to the heat dissipation system 513 through the auxiliary power supply unit 514, and there will be no problem of rapid power consumption.

[0075] In one embodiment, the monitoring system 515 is further configured to control the auxiliary power supply unit 514 to adjust the heat dissipation system 513 to be in the second mode when the state of charge of the battery unit 511 is less than the first threshold.

[0076] In one embodiment, the monitoring system 515 is further configured to control the auxiliary power supply unit 514 to adjust the heat dissipation system 513 to exit the second mode when the state of charge of the battery unit 511 is greater than the second threshold, where the second threshold is greater than the first threshold.

[0077] The following takes Figure 7Taking the processes shown in (a) and (b) as examples, the process of the monitoring system regulating the heat dissipation system to be in different working modes according to thresholds will be described in detail. As an example rather than a limitation, the working modes of the heat dissipation system in the embodiments of the present application are divided into a normal mode, a sleep mode, and a standby mode for illustration.

[0078] In one embodiment, as Figure 7 shown in (a) of, if the heat dissipation system 513 is in the normal mode, when the state of charge SOC of the battery unit 511 is less than the first threshold, the monitoring system 515 is used to control the heat dissipation system 513 to be in the sleep mode through the auxiliary power supply unit 514. Otherwise, when the state of charge SOC of the battery unit 511 is greater than the first threshold, the heat dissipation system 513 is in the normal mode; when the state of charge SOC of the battery unit 511 is less than the third threshold, the monitoring system 515 is used to control the heat dissipation system 513 to be in the standby mode through the auxiliary power supply unit 514. Otherwise, when the state of charge SOC of the battery unit 511 is greater than the third threshold and less than the first threshold, the heat dissipation system 513 is in the sleep mode; wherein, the first threshold is greater than the third threshold. The first threshold is the threshold for entering the sleep mode, and the third threshold is the threshold for entering the standby mode.

[0079] Exemplarily, the value range of the state of charge SOC of the battery unit 511 includes 0% to 100%. When SOC = 0%, it means that the battery unit 511 is fully discharged. When SOC = 100%, it means that the battery unit 511 is fully charged. For example, the first threshold can be set to 70%, and the third threshold can be set to 50%. Then when the monitoring system 515 learns that the state of charge SOC of the battery unit 511 = 70%, the monitoring system 515 can control the heat dissipation system 513 to enter the sleep mode through the auxiliary power supply unit 514 to reduce the power consumption of the heat dissipation system 513; when the state of charge SOC of the battery unit 511 continuously drops to 50%, the monitoring system 515 can control the heat dissipation system 513 to enter the standby mode through the auxiliary power supply unit 514 to further reduce the power consumption of the heat dissipation system 513.

[0080] In one example, the monitoring system 515 can output a control signal to the power supply unit 5131 in the heat dissipation system 513 through the auxiliary power supply unit 514. This control signal is used to control the heat dissipation system 513 to be in the sleep mode. After receiving this control signal, the power supply unit 5131 in the heat dissipation system 513 controls some heat dissipation devices to stop working or operate at a reduced power through the compressor control unit 5132, the water pump control unit 5134, and the fan control unit 5133 to reduce the power consumption of the heat dissipation system 513.

[0081] In another example, the monitoring system 515 can also output the state of charge (SOC) of the battery unit 511 to the power supply unit 5131 in the heat dissipation system 513 through the auxiliary power supply unit 514. For example, it outputs SOC = 70% to the power supply unit 5131. After receiving this state of charge SOC, the power supply unit 5131 controls some heat dissipation devices to stop working or operate at a reduced load according to a pre-set control strategy through the compressor control unit 5132, the water pump control unit 5134, and the fan control unit 5133, so as to reduce the power consumption of the heat dissipation system 513.

[0082] In one embodiment, as Figure 7 shown in (b) of, if the heat dissipation system 513 is in the standby mode, when the state of charge SOC of the battery unit 511 is greater than the fourth threshold, the monitoring system 515 is also used to control the heat dissipation system 513 to exit the standby mode and enter the sleep mode through the auxiliary power supply unit 514. Otherwise, when the state of charge SOC of the battery unit 511 is less than the fourth threshold, the heat dissipation system 513 is in the standby mode. That is, the fourth threshold is the threshold for exiting the standby mode, where the fourth threshold is less than the first threshold and greater than the third threshold. When the state of charge SOC of the battery unit 511 is greater than the second threshold, the monitoring system 515 is also used to control the heat dissipation system 513 to exit the sleep mode and enter the normal mode through the auxiliary power supply unit 514. Otherwise, when the state of charge SOC of the battery unit 511 is greater than the fourth threshold and less than the second threshold, the heat dissipation system 513 is in the sleep mode. That is, the second threshold is the threshold for exiting the sleep mode, where the second threshold is greater than the first threshold.

[0083] Exemplarily, still taking the foregoing first threshold of 70% and the third threshold of 50% as an example, the fourth threshold can be set to 60%, and the second threshold is set to 80%. Suppose at the first moment, the state of charge SOC of the battery unit 511 = 55%, although it is greater than the third threshold of 50%, it is still less than the fourth threshold of 60%. The value indicated by the state of charge SOC of the battery unit 511 does not reach the threshold for exiting the standby mode (i.e., the fourth threshold of 60%), and the heat dissipation system 513 is still in the standby mode; between the first moment and the second moment, the battery unit 511 is in the charging state, that is, the power grid 300 transmits electric energy to the battery unit 511 until at the second moment, the state of charge SOC of the battery unit 511 = 60%. At this time, the value indicated by the state of charge SOC of the battery unit 511 reaches the threshold for exiting the standby mode (i.e., the fourth threshold of 60%), and the monitoring system 515 can control the heat dissipation system 513 to exit the standby mode through the auxiliary power supply unit 514.

[0084] Similarly, if at the third moment, the state of charge (SOC) of the battery cell 511 is 75%, although it is greater than the first threshold of 70%, it is still less than the second threshold of 80%. The value indicated by the SOC of the battery cell 511 does not reach the threshold for exiting the sleep mode (i.e., the second threshold of 80%), and the heat dissipation system 513 remains in the sleep mode. Between the third moment and the fourth moment, the battery cell 511 remains in the charging state until at the fourth moment, the SOC of the battery cell 511 is 80%. At this time, the value indicated by the SOC of the battery cell 511 reaches the threshold for exiting the sleep mode (i.e., the second threshold of 80%), and the monitoring system 515 can control the heat dissipation system 513 to exit the sleep mode through the auxiliary power supply unit 514.

[0085] Based on the above solution, the fourth threshold is the threshold for exiting the standby mode. It is set that the fourth threshold is greater than the third threshold, that is, the threshold for exiting the standby mode is greater than the threshold for entering the standby mode, which can avoid the situation that the heat dissipation system 513 repeatedly enters and exits the standby mode when the SOC of the battery cell 511 is near the third threshold, and can improve the stability of the heat dissipation system 513. Similarly, the second threshold is the threshold for exiting the sleep mode. It is set that the second threshold is greater than the first threshold, that is, the threshold for exiting the sleep mode is greater than the threshold for entering the sleep mode, which can avoid the situation that the heat dissipation system 513 repeatedly enters and exits the sleep mode when the SOC of the battery cell 511 is near the first threshold, and can improve the stability of the heat dissipation system 513.

[0086] In an embodiment, the first threshold, the second threshold, the third threshold, and the fourth threshold are all inversely proportional to the charging rate of the battery cell 511; the first threshold, the second threshold, the third threshold, and the fourth threshold are all directly proportional to the discharging rate of the battery cell 511.

[0087] Exemplarily, assume that the charging rate is 1C, which means the current intensity at which the battery cell 511 can be fully charged to its rated capacity in 1 hour, and the charging rate is 0.2C, which means the current intensity at which the battery cell 511 can be fully charged to its rated capacity in 5 hours. Then, the first threshold, the second threshold, the third threshold, and the fourth threshold corresponding to the charging rate of 1C are all less than the first threshold, the second threshold, the third threshold, and the fourth threshold corresponding to the charging rate of 0.2C.

[0088] Similarly, assume that the discharging rate is 1C, which means the current intensity at which the battery cell 511 can discharge its rated capacity in 1 hour, and the discharging rate is 0.2C, which means the current intensity at which the battery cell 511 can discharge its rated capacity in 5 hours. Then, the first threshold, the second threshold, the third threshold, and the fourth threshold corresponding to the discharging rate of 1C are all greater than the first threshold, the second threshold, the third threshold, and the fourth threshold corresponding to the charging rate of 0.2C.

[0089] In the embodiment of the present application, the higher the charging rate of the battery unit 511, the greater the current intensity required for the battery unit 511 to be charged to its rated capacity within a specified time, that is, the battery unit 511 is more likely to reach a fully charged state. Setting a lower threshold can, to a certain extent, reduce the duration of the heat dissipation system 513 in the sleep mode and the standby mode, enabling the heat dissipation system 513 to timely dissipate the heat generated during the operation of the energy storage cabinet 510. The higher the discharge rate of the battery unit 511, the greater the current intensity for the battery unit 511 to discharge its rated capacity within a specified time, that is, the power of the battery unit 511 will decrease faster. Setting a higher threshold can, to a certain extent, make it easier for the heat dissipation system 513 to enter the sleep mode and the standby mode, reducing the power consumption of the heat dissipation system 513, so that more power of the battery unit 511 can be transmitted to the load 400 and the power grid 300 rather than the heat dissipation system 513.

[0090] In one embodiment, the monitoring system 515 is further configured to control the auxiliary power supply unit 514 to regulate the heat dissipation system 513 to be turned off at a predetermined time.

[0091] Exemplarily, the monitoring system 515 can predict the heat dissipation demand of the energy storage cabinet 510 according to the state of charge (SOC), charging rate, and discharge rate of the battery unit 511. For example, when the battery unit 511 is in a charging state and the charging rate is high, the heat dissipation system 513 is turned on to dissipate heat from the energy storage cabinet 510. When the charging rate of the battery unit 511 is low or the battery unit 511 is neither in a charging state nor in a discharging state, the heat dissipation system 513 is turned off.

[0092] In one example, the monitoring system 515 can control the auxiliary power supply unit 514 to stop supplying power to the power supply unit 5131 in the heat dissipation system 513 to turn off the heat dissipation system 513. In another example, the monitoring system 515 can send a control signal to turn off the heat dissipation system 513 to the power supply unit 5131 in the heat dissipation system 513 through the auxiliary power supply unit 514. After receiving the control signal, the power supply unit 5131 stops supplying power to all the water pumps, all the fans, and all the compressors in the heat dissipation system 513, so that the heat dissipation system 513 stops working.

[0093] In this way, controlling the heat dissipation system 513 to be turned on when heat dissipation is required and turned off when heat dissipation is not required according to the heat dissipation demand of the energy storage cabinet 510, so that the turning on and off of the heat dissipation system 513 depend on the state of the battery unit 511, can achieve the purpose of optimizing the power consumption of the heat dissipation system 513, thereby improving the power utilization rate of the battery unit 511.

[0094] The embodiment of the present application provides a microgrid energy storage system 500, as Figure 8As shown, this microgrid energy storage system 500 is applied to the scenario of a DC power grid 600. The microgrid energy storage system 500 includes an energy storage cabinet 510 and a switch cabinet 530. The external port 516 of the energy storage cabinet 510 is connected to the first end of the switch cabinet 530, and the second end of the switch cabinet 530 is used to connect to the DC power grid 600 and the load 400. Among them, the description of the switch cabinet 530 can refer to the relevant part in the previous text and will not be elaborated here. The energy storage cabinet 510 is used to supply power to the DC power grid 600 and the load 400 through the switch cabinet 530, or the DC power grid 600 is used to charge the energy storage cabinet 510 through the switch cabinet 530.

[0095] Exemplarily, the converter 512 in the energy storage cabinet 510 is a DC-DC converter.

[0096] In one embodiment, the microgrid energy storage system 500 may include one energy storage cabinet 510 or multiple energy storage cabinets 510, and the multiple energy storage cabinets 510 can be connected in series, in parallel, or in a hybrid connection. Among them, a hybrid connection refers to a connection method that includes both series connection and parallel connection. By way of example and not limitation, the embodiment of the present application will be described by taking the microgrid energy storage system 500 including one energy storage cabinet 510 as an example.

[0097] The embodiment of the present application also provides a microgrid energy storage system 500, as Figure 9 shown, this microgrid energy storage system 500 is applied to the scenario of an AC power grid. The microgrid energy storage system 500 further includes a transformer 520, and the transformer 520 is connected between the energy storage cabinet 510 and the switch cabinet 530. The transformer 520 is used to convert the voltage of the electric energy output by the energy storage cabinet 510, or to convert the voltage of the electric energy output from the AC power grid 300 to the energy storage cabinet 510. Among them, the description of the transformer 520 can refer to the relevant part in the previous text and will not be elaborated here.

[0098] Exemplarily, as Figure 9 shown, the converter 512 in the energy storage cabinet 510 includes a DC-DC converter and a power conversion system (PCS) for energy storage. Or, the converter 512 in the energy storage cabinet 510 includes a power conversion system (PCS) for energy storage.

[0099] The above analysis of the beneficial effects of the microgrid energy storage system 500 can all be correspondingly cited in the energy storage cabinet 510, and the embodiment of the present application will not elaborate here.

[0100] Finally, it should be noted that: the above are only the specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An energy storage cabinet, characterized in that: The energy storage cabinet includes a battery unit, a converter, an auxiliary power supply unit, a heat dissipation system, a monitoring system and an external port; The DC end of the battery unit is connected to the first end of the converter; the DC end of the battery unit is also connected to the heat dissipation system and the monitoring system respectively through the auxiliary power supply unit; the second end of the converter is connected to the external port.

2. The energy storage cabinet according to claim 1, characterized in that: The monitoring system is used to control the auxiliary power supply unit to regulate the heat dissipation system to be in a first mode or a second mode according to the charge state of the battery unit; wherein the power consumption of the heat dissipation system in the first mode is greater than the power consumption in the second mode.

3. The energy storage cabinet according to claim 2, characterized in that: The monitoring system is further configured to control the auxiliary power supply unit to regulate the heat dissipation system to be in the second mode when the state of charge of the battery unit is less than a first threshold.

4. The energy storage cabinet according to claim 3, characterized in that: The monitoring system is further used to control the auxiliary power supply unit to regulate the heat dissipation system to exit the second mode when the state of charge of the battery unit is greater than a second threshold, wherein the second threshold is greater than the first threshold.

5. The energy storage cabinet according to any one of claims 1 to 4, characterized in that: The monitoring system is also used to control the auxiliary power supply unit to regulate the cooling system to shut down at a predetermined time.

6. The energy storage cabinet according to any one of claims 1 to 5, characterized in that: The monitoring system is also connected to the converter.

7. The energy storage cabinet according to any one of claims 1 to 6, characterized in that: The converter comprises an energy storage converter, a DC end of the energy storage converter is connected to a DC end of the battery unit, and an AC end of the energy storage converter is connected to the external port.

8. The energy storage cabinet according to claim 7, characterized in that: The converter also includes a DC-DC converter, a first DC end of the DC-DC converter is connected to the DC end of the battery unit, and a second DC end of the DC-DC converter is connected to the DC end of the energy storage converter.

9. The energy storage cabinet according to any one of claims 1 to 8, characterized in that: The converter comprises a DC-DC converter, a first DC end of the DC-DC converter is connected to a DC end of the battery unit, and a second DC end of the DC-DC converter is connected to the external port.

10. The energy storage cabinet according to any one of claims 1 to 9, characterized in that: The energy storage cabinet further includes a cluster control box, the DC end of the battery unit is connected to a first end of the cluster control box, and the second end of the cluster control box is connected to a first end of the converter.

11. A microgrid energy storage system, characterized in that: The microgrid energy storage system includes a switch cabinet and an energy storage cabinet according to any one of claims 1 to 10, wherein an external port of the energy storage cabinet is connected to the switch cabinet.

12. The microgrid energy storage system according to claim 11, characterized in that: The microgrid energy storage system also includes a transformer, which is connected between the energy storage cabinet and the switch cabinet.

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