CN117578539A - Energy storage system - Google Patents

Abstract

The present application provides an energy storage system, the energy storage system comprising: a confluence module; each energy module comprises a transduction unit, an energy switch unit and a battery unit which are sequentially connected, and the transduction unit is connected with the confluence module; the control module comprises a plurality of main control units, and each main control unit is connected with a corresponding energy switch unit to control the on or off of the energy switch unit. Through the system, the multistage independent control of the energy modules can be realized, so that the circulation problem and the safety problem caused by energy collection are avoided.

Description

an energy storage system

Technical field

This application mainly relates to the field of battery energy storage technology, and in particular to an energy storage system.

Background technique

With the global energy supply problem and the increasing depletion of non-renewable energy sources such as global fossil energy, and the accompanying impacts on the environment, climate, etc., the use of renewable energy sources such as electricity is becoming more and more important and widespread, and storage The energy system is an important part of the "production-generation-transmission-distribution-use-storage" in power production. The centralized energy storage system uses MW-level high-power DC/AC, and the batteries are independently designed using battery cabinets or battery racks and placed in Integration is carried out in containers. However, the centralized arrangement of batteries can easily expand the fire when a fire occurs. On the other hand, due to temperature imbalance, some batteries cannot operate at ideal temperatures, which further leads to the battery state of charge (State of Charge, SOC) differences.

At present, in large-scale energy storage systems, large-scale battery packs are usually used to convert power using centralized energy storage inverters in a series-parallel manner. This system architecture has higher requirements for battery consistency. The structure of the battery can easily lead to the barrel effect, that is, the system performance is determined by the worst battery. If multiple battery packs are connected in parallel, it is easy to cause energy accumulation, lead to local overheating, and induce safety issues, and the connections between multiple battery packs are also unstable. This will lead to circulation problems caused by mutual charging and discharging in multiple battery packs, which is not conducive to the storage or release of electrical energy.

Contents of the invention

The main purpose of this application is to propose an energy storage system to solve the circulation problems existing in the current energy storage system and the safety problems caused by the energy collection generated during the converging process.

In order to solve the above problems, this application provides an energy storage system. The energy storage system includes: a confluence module; a plurality of energy modules. Each energy module includes a transducer unit, an energy switch unit and a battery unit connected in sequence. The transducer unit Connect the bus module; the control module. The control module includes multiple main control units. Each main control unit is connected to a corresponding energy switch unit to control the on or off of the energy switch unit.

In one embodiment, the energy switch unit includes a main positive switch and a main negative switch. The main positive switch is arranged between the positive electrode of the energy conversion unit and the positive electrode of the battery unit. The main negative switch is arranged between the negative electrode of the energy conversion unit and the battery unit. between the negative poles.

In one embodiment, the battery unit includes multiple battery packs; the control module also includes multiple slave control units, and each slave control unit is connected to a corresponding battery pack to obtain battery information of the corresponding battery pack.

In one embodiment, the bus module includes a plurality of AC switch units, the first end of each AC switch unit is connected to the bus terminal, and the second end of each AC switch unit is connected to the transducing unit of part of the energy module.

In one embodiment, the control module further includes a master control unit connected to the transducer unit, the master control unit, the slave control unit and the AC switch unit.

In order to solve the above problems, this application also provides an energy storage system control process to control the above-mentioned energy storage system to perform power-on and power-off process operations.

In one embodiment, the general control unit is configured to: detect the status of the AC switch unit; when the AC switch unit is closed, send a first power-on command to the transducer unit to power on the transducer unit; When the power-on is completed, a second power-on command is sent to the main control unit, so that the main control unit controls the power-on of the energy module.

In one embodiment, the general control unit is configured to perform a self-check before detecting the status of the AC switch unit.

In one embodiment, the main control unit is configured to: when receiving the second power-on command, close the main negative switch; when the main negative switch completes closing, close the main positive switch; when the main positive switch completes closing, feedback Power-on completion information.

In one embodiment, the overall control unit is configured to: when receiving a power-off signal, send a shutdown command to the transducer unit to shut down the transducer unit; when the transducer unit completes the shutdown, send a power-off command to the main unit. control unit, so that the main control unit controls the energy module to power off; when the energy module completes powering off, it controls the AC switch unit to turn off.

In one embodiment, the main control unit is configured to: when receiving a power-off command, detect the current current value; if the current value is less than the set value, turn off the main positive switch; if the current value is greater than the set value, then The main positive switch is delayed to be disconnected; the main negative switch is delayed to be disconnected; after at least one of the main positive switch and the main negative switch is completely disconnected, the power-off completion information is fed back.

This application provides an energy storage system, which includes: a bus module; a plurality of energy modules, each energy module includes a transducer unit, an energy switch unit and a battery unit connected in sequence, and the transducer unit is connected to the bus module; The control module includes a plurality of main control units, and each main control unit is connected to a corresponding energy switch unit to control the on or off of the energy switch unit.

Through the above system structure, a modular structure is adopted to realize multi-level independent storage control of energy in the form of multiple branches to solve the circulation problem caused by mutual charging and discharging between multi-level energy parallel connections, and to reduce the convergence caused by multi-level energy collection. Energy flow may cause safety problems caused by local overheating and fire. The multi-modular structure allows the energy storage system to be freely designed and combined according to needs to meet multiple use needs. It can be applied to a wider range and adopts multiple branches. The parallel connection method can reduce the energy flow of the bus, reduce the specifications of the bus bar and thereby reduce the cost.

Description of the drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts. in:

Figure 1 is a schematic structural diagram of an embodiment of the energy storage system provided by this application;

Figure 2 is a schematic structural diagram of an energy module of an embodiment of the energy storage system provided by this application;

Figure 3 is a schematic structural diagram of the second embodiment of the energy storage system provided by this application;

Figure 4 is a schematic structural diagram of the third embodiment of the energy storage system provided by this application;

Figure 5 is a schematic diagram of the overall system power-on flow of an embodiment of the energy storage system provided by this application;

Figures 6a and 6b are schematic sub-flow diagrams of the power-on control of the transducer unit and the main control unit in Figure 5;

Figure 7 is a schematic diagram of the power-on flow of the energy module of an embodiment of the energy storage system provided by this application;

Figure 8 is a schematic diagram of the power-on flow of the energy module of the second embodiment of the energy storage system provided by this application;

Figure 9 is a schematic diagram of the system power-down process of an embodiment of the energy storage system provided by this application;

Figures 10a and 10b are schematic diagrams of the sub-processes of controlling the shutdown of the transducer unit and powering off the energy module in Figure 9;

Figure 11 is a schematic diagram of the power-down process of an energy module according to an embodiment of the energy storage system provided by this application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It can be understood that the specific embodiments described here are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for convenience of description, only some but not all structures related to the present application are shown in the drawings. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

The terms "first", "second", etc. in this application are used to distinguish different objects, rather than describing a specific sequence. Furthermore, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes Other steps or units inherent to such processes, methods, products or devices.

Reference herein to "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.

With the widespread application of renewable energy such as electricity, in daily life and power supply to large equipment, such as electric vehicles and other mobile equipment, in order to meet the needs of equipment energy storage and energy supply, this application provides an energy storage system , to solve problems such as the energy flow convergence caused by the series and parallel connection of battery packs in current large-scale energy storage systems and the circulation currents caused by mutual charging and discharging between multiple battery packs.

Referring to Figures 1 and 2, Figure 1 is a schematic structural diagram of an embodiment of the energy storage system provided by this application; Figure 2 is a schematic structural diagram of an energy module of an embodiment of the energy storage system provided by this application. Specifically, the energy storage system structure includes: a bus module 10, an energy module 20 and a control module 30; wherein each of the plurality of energy modules 20 includes a transducer unit 21, an energy switch unit 22 and a battery connected in sequence. Unit 23, the transducing unit 21 is connected to the bus module 10; the control module 30 includes a plurality of main control units 32, and each main control unit 32 is connected to a corresponding energy switch unit 22 to control the on or off of the energy switch unit 22. ; To realize multi-level independent control of the energy module 20 and improve the safety performance of the energy storage system.

Optionally, in an embodiment, the energy conversion unit 21 may use an energy storage converter. Specifically, a energy storage converter (PCS, Power Conversion System), also known as a bidirectional energy storage inverter, is connected to The device that realizes the two-way conversion of electric energy between the battery system and the power grid (and/or load) is the core component that realizes the two-way flow of electric energy between the energy storage system and the power grid. It is used to control the charging and discharging process of the battery and perform AC and DC conversion. ; Its working principle is that it is a four-quadrant operating converter device with controllable AC and DC sides, realizing bidirectional conversion of AC and DC power. The principle is to perform constant power or constant current control through microgrid monitoring instructions to charge or discharge the battery, while smoothing the output of wind power, solar power and other fluctuating power sources; the main functions of PCS include over-under voltage, overload, over-current, short circuit, Over-temperature protection, island detection capability for mode switching, communication functions with upper-level control systems and energy switches, grid-to-off-grid smooth switching control, etc. Among them, the energy conversion unit 21 can also use other bidirectional inverters In order to realize its function, the conversion device only needs to meet the usage requirements and conditions of the embodiments of this application, and is not specifically limited here.

Optionally, in one embodiment, the energy switch unit 22 includes a main positive switch 221 and a main negative switch 222. The main positive switch 221 is provided between the positive electrode of the transducing unit 21 and the positive electrode of the battery unit 23, and the main negative switch 222 It is disposed between the negative electrode of the transducer unit 21 and the negative electrode of the battery unit 23 . Specifically, in one embodiment, the main positive switch 221 and the main negative switch 222 are both provided in the high-voltage box included in the energy module 20 to control the on-off power on and off of the energy module 20 .

Optionally, in one embodiment, the command signal from the main control unit 32 is used to control the closing or disconnecting of the main positive switch 221 and the main negative switch 222, so that the corresponding energy module 20 completes a separate power-on and power-off process. Implement independent control of the energy module 20.

Optionally, in one embodiment, the energy switch unit 22 is also provided with a fuse 223, where the fuse 223 is used to fuse the line when the current in the line is too large. After the current exceeds a specified value for a period of time, the fuse 223 is used to fuse the line. The heat generated by itself melts the melt, thereby disconnecting the circuit and protecting the circuit; in some embodiments, the fuse 223 may use other types of overcurrent protectors, including but not limited to, to realize the current flow in the system. The circuit protection function when the predetermined maximum value is exceeded is not specifically limited here.

Optionally, in one embodiment, the battery unit 23 includes multiple battery packs 231; the control module 30 also includes multiple slave control units 33, and each slave control unit 33 is connected to a corresponding battery pack 231 to obtain the corresponding Battery information of battery pack 231. In some embodiments of the battery pack 231, the batteries in the battery pack 231 may include but are not limited to lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and lithium-ion batteries, which are not specifically limited here.

Optionally, in one embodiment, the bus module 10 includes a plurality of AC switch units 11 , the first end of each AC switch unit 11 is connected to the bus terminal, and the second end of each AC switch unit 11 is connected to some energy modules 20 transducer unit 21.

Optionally, in one embodiment, the control module 30 also includes a master control unit 31 , which is connected to the transducer unit 21 , the master control unit 32 , the slave control unit 33 and the AC switch unit 11 . The overall control unit 31 is used to control the connection and conduction relationship of the entire power on and off of the system, so as to realize the control function of the overall power on and off of the energy storage system 100 .

Optionally, in one embodiment, the overall control unit 31 may adopt a BMS control system. Specifically, BMS stands for Battery Management System (Battery Management System), which manages the charge and discharge of the battery so that the battery is at an optimal state. In the best condition, because the battery cell is an electrochemical process, multiple cells form a battery. Due to the characteristics of each cell, no matter how precise the manufacturing is, there will be errors and inconsistencies in each cell depending on the use time and environment. Therefore, the battery management system uses limited parameters to evaluate the current battery status. BMS has many uses. For large-scale battery systems, there are roughly two categories, one is for automobiles and the other is for energy storage. The three-layer architecture of the BMS system is the single battery management layer BMU and the battery pack. Management layer BCMU, battery pack (multiple groups) management layer BAMS; the battery pack 231 management layer is also called a PCS battery unit management layer; the master control unit 31 can also use other control systems to meet the use of the embodiments of this application. The requirements and conditions are enough, and there are no specific restrictions here.

Optionally, in one embodiment, as shown in Figure 3, which is a schematic structural diagram of a second embodiment of the energy storage system provided by this application; specifically, the bus module 10 includes two roads and two branches. The road corresponds to two AC switch units 11. Each AC switch unit 11 can be connected to multiple energy modules 20. The number of energy modules 20 can be freely selected and determined according to actual usage requirements or design plans, and will not be specified here. limited.

Optionally, in one embodiment, as shown in Figure 4, Figure 4 is a schematic structural diagram of a third embodiment of the energy storage system provided by the present application; it can be understood that the energy storage system 100 can also be configured with multiple The branches correspond to multiple AC switch units 11 and each AC switch unit 11 can be connected to multiple energy modules 20 . The number of AC switch units 11 can be freely selected according to actual usage requirements or design plans. Here No specific limit is made; the number of energy modules 20 can be freely selected and determined according to actual usage requirements or design plans, and is not specifically limited here; the method is adopted with different numbers of AC switch units 11 on the branches and different numbers of energy modules 20 By combining different solutions, the energy storage system 100 that meets different needs can be freely combined in a modular manner.

Optionally, in one embodiment, a high-precision electric meter is provided in the converging cabinet and is placed at the grid connection point of the converging cabinet, which can accurately detect the power of the grid; in other embodiments, the master control unit 31 is also provided in the converging cabinet. in the converging cabinet.

It can be understood that the above-mentioned energy storage system 100 can adopt a modular structure to realize multi-level independent storage control of energy in the form of multiple branches, so as to solve the circulation problem caused by mutual charging and discharging between multiple levels of energy in parallel, and reduce the energy consumption. The converging energy flow formed by multi-level energy collection may cause safety problems caused by local overheating and fire. Moreover, the multi-modular structure allows the energy storage system to be freely designed and combined according to the needs to meet multiple use requirements and has a wider scope of application. Wide, and the use of multi-branch parallel connection can reduce the energy flow of the bus, reduce the specifications of the bus bar and thereby reduce the cost.

Refer to Figure 5. Figure 5 is a schematic diagram of the overall system power-on process of an embodiment of the energy storage system provided by this application. Corresponding to the energy storage system described above, a corresponding set of energy storage systems is also designed. The control flow, in which the control operations are implemented by the control module 30.

Optionally, in one embodiment, the general control unit 31 is configured to: detect the status of the AC switch unit 11; when the AC switch unit 11 is closed, send a first power-on command to the transducer unit 21 to enable the transducer The unit 21 is powered on; when the transducing unit 21 completes powering on, a second power-on command is sent to the main control unit 32 so that the main control unit 32 controls the energy module 20 to be powered on.

Optionally, in one embodiment, the general control unit 31 is configured to perform a self-check before detecting the status of the AC switch unit 11 . Specifically, the content of the self-check includes: self-detection of no fault conditions after the low voltage is powered on and no other fault information received.

Refer to Figure 5, Figure 6a and Figure 6b, wherein Figure 6a and Figure 6b are schematic sub-flow diagrams of controlling the power-on of the transducing unit and the main control unit in Figure 5.

It can be understood that the specific system power-on process is: after the power-on operation, the system main control unit 31 receives low-voltage power. After receiving power, the main control unit 31 starts to perform self-test. When the self-test passes, it detects the AC module. The pull-in state of multiple AC switch units 11. If it is detected that the status of the AC switch unit 11 is off, it is determined that the power-on failure has occurred. If it is detected that the status of the AC switch unit 11 is pull-in, the transducer unit 21 is sent to power on. command to control the transducing unit 21 to perform a power-on operation; after the transducing unit 21 performs a power-on operation, the power-on status of the transducing unit 21 is fed back to the main control unit 31. If it is detected that the transducing unit 21 is still on standby. status, it is determined that power-on has failed. If it is detected that the transducer unit 21 is in the power-on state, the secondary main control unit 32 is controlled to perform a power-on operation; a power-on command operation is sent to the secondary main control unit 32, and the main control unit 32 After receiving the power-on command from the main control, the main control performs a self-test. When the self-test passes, it controls the battery unit 23 to power on and feeds back the power-on status of the battery unit 23. If the battery unit 23 is received within the set time, If the power-on feedback of 23 is completed, power-on is completed. If no feedback is received, the power-on failure is determined. The setting time is set according to the actual needs or setting plan. For example, the feedback time is set to feedback within 30 seconds. , the specific time is set specifically, and there is no specific limit here.

Optionally, in an embodiment, after the master control self-test, the control of the subsequent AC switch unit 11 and the transducer unit 21 and the main control unit 32 in the energy module 20 can be performed by multiple energy modules 20 Simultaneous control operations, the operations of each energy module 20 are independent of each other and do not affect each other, and the power-on and power-off operations of each energy module 20 are determined in the same way.

Optionally, in one embodiment, as shown in Figures 7 and 8, Figure 7 is a schematic diagram of the power-on flow of the energy module of an embodiment of the energy storage system provided by this application; Figure 8 is a schematic diagram of the energy storage system provided by this application. Schematic diagram of the power-on flow of the energy module of the second embodiment of the system; wherein, as shown in Figure 7, the main control unit 32 is configured to: when receiving the second power-on command, close the main negative switch 222; when the main negative switch When 222 completes closing, the main positive switch 221 is closed; when the main positive switch 221 completes closing, the power-on completion information is fed back. Specifically, in another embodiment, as shown in Figure 8, after receiving the power-on command issued by the main control unit 31, the main control unit 32 is powered on at low voltage and performs a self-test operation. After receiving power, the main control self-test process will be carried out. Specifically, the content of the self-test includes: after the low voltage is powered on, it will detect that there is no fault and no other fault information is received; after the main control unit 32 system self-test is completed, the control corresponding The main negative switch 222 is closed. After the operation is completed, it is detected whether the switch status of the main negative switch 222 is closed. If it is detected that the status of the main negative switch 222 is open, it is determined as a power-on failure and the switching fault of the main negative switch 222 is fed back. To the main control unit 32, if it is detected that the state of the main negative switch 222 is closed, the operation of closing the main positive switch 221 is performed; after completing the operation, it is detected whether the switch state of the main positive switch 221 is closed. If it is detected that the main positive switch 221 If the status of the main positive switch 221 is open, it is determined that the power-on failed and the switching fault of the main positive switch 221 is fed back to the main control unit 32. If it is detected that the switching status of the main positive switch 221 is closed, it is determined that the high-voltage power-on is successful and the high-voltage power-on is feedbacked. state.

Refer to Figure 9, Figure 10a and Figure 10b. Figure 9 is a schematic diagram of the system power-down process of an embodiment of the energy storage system provided by the present application; Figure 10a and Figure 10b are diagrams of the shutdown and control of the energy storage unit in Figure 9. Schematic diagram of the sub-process of powering off the energy module.

Optionally, in one embodiment, the general control unit 31 is configured to: when receiving a power-off signal, send a shutdown command to the transducer unit 21 to shut down the transducer unit 21; after the transducer unit 21 completes the shutdown, When, a power-off command is sent to the main control unit 32, so that the main control unit 32 controls the energy module 20 to power off; when the energy module 20 completes the power-off, it controls the AC switch unit 11 to turn off.

Optionally, in one embodiment, the power-down process of the system is specifically: after detecting the power-down command signal sent, the transducing unit 21 is controlled to perform a shutdown operation. As shown in Figure 10a, the transducing unit 21 receives After receiving the shutdown command signal, the shutdown operation is performed and the shutdown status of the transducer unit 21 after the shutdown operation is fed back to the general control unit 31. After the master control unit 31 detects that the transducer unit 21 is stopped, it further controls the corresponding energy module 20. Perform a power-off operation, as shown in Figure 10b. After receiving the power-off signal of the energy module 20 to perform the power-off operation, the main control unit 32 controls the corresponding battery unit 23 to power off, and feedbacks after completing the power-off operation. The power-off state of the battery unit 23 is transmitted to the main control unit 31. After receiving the power-off signal of the energy module 20, the main control unit 31 turns off the corresponding AC switch unit 11. If it is detected that the status of the AC switch unit 11 is closed , then it is determined as a fault and the fault problem is uploaded. If it is detected that the status of the AC switch unit 11 is disconnected, it is determined that the power-off is completed.

Among them, the corresponding system power-off process may include multiple energy modules 20 performing simultaneous power-off operations. The operations of each energy module 20 are independent of each other and do not affect each other. The power-on and power-off operations of each energy module 20 are determined in the same way. When When all energy modules 20 in the corresponding system are powered off successfully and the status of all corresponding AC switch units 11 is off, the entire system is powered off successfully.

Refer to FIG. 11 , which is a schematic diagram of the power-down process of an energy module according to an embodiment of the energy storage system provided by this application.

Optionally, in one embodiment, the main control unit 32 is configured to: when receiving a power-off command, detect the current current value; if the current value is less than the set value, turn off the main positive switch 221; if the current value Greater than the set value, the main positive switch 221 is delayed to be turned off; the main negative switch 222 is delayed to be turned off; after at least one of the main positive switch 221 and the main negative switch 222 is turned off, the power-off completion information is fed back.

Optionally, in an embodiment, it can be understood that the power-down process of the energy module 20 is specifically:

After receiving the power-off command from the main control, the current current is detected to check whether the current value is less than the set value. When the detected current value is greater than the set value, the delayed disconnection of the main positive switch 221 is enabled. When the detected current value is less than the set value, the main positive switch 221 is directly turned off; after the operation of turning off the main positive switch 221 is completed, the state of the main positive switch 221 is detected. If the detected state of the main positive switch 221 is When closed, the disconnection fault of the main positive switch 221 is fed back and there may be adhesion, and the main negative switch 222 is forced to be disconnected at the same time. If the status of the main positive switch 221 is detected to be disconnected, a delayed operation of disconnecting the main negative switch 222 is taken. ; After performing the operation on the main negative switch 222, detect the switching status of the main negative switch 222. If it is detected that the status of the main negative switch 222 is closed, the disconnection fault of the main negative switch 222 may be fed back and adhesion may exist. If it is detected When the state of the main negative switch 222 is off, the main positive switch 221 and the main negative switch 222 are detected simultaneously. If at least one of the switches is detected to be in the off state, it is determined that the high voltage power-off is successful and the high voltage status is fed back in real time. , if it is detected that the main positive switch 221 and the main negative switch 222 are both closed, it is determined that the power-off has failed, and the high-voltage status is fed back in real time.

Through the above-mentioned energy storage system devices and corresponding operating methods, it is possible to adopt a modular structure and realize multi-level independent storage control of energy in the form of multiple branches to solve the circulation problem caused by mutual charging and discharging between multi-level energy in parallel. , and reduce the safety problems caused by local overheating and fire caused by the converging energy flow formed by multi-level energy collection, and the multi-modular structure can realize the free design and combination of energy storage systems according to needs to meet multiple use needs. It has a wider scope of application, and the use of multiple branches in parallel can reduce the energy flow of the bus, reduce the specifications of the busbar and thereby reduce costs.

The embodiments of the present application have been introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and the core idea of the present application; at the same time, for Those skilled in the art may make changes in the specific implementation and application scope based on the ideas of the present application. In summary, the contents of this description should not be understood as limiting the present application.

Claims (10)

1. An energy storage system, the energy storage system comprising:

a confluence module;

each energy module comprises a transduction unit, an energy switch unit and a battery unit which are sequentially connected, and the transduction unit is connected with the confluence module;

the control module comprises a plurality of main control units, and each main control unit is connected with a corresponding energy switch unit to control the on or off of the energy switch unit.

2. The energy storage system of claim 1, wherein the energy switch unit comprises a main positive switch disposed between a positive electrode of the transduction unit and a positive electrode of the battery unit and a main negative switch disposed between a negative electrode of the transduction unit and a negative electrode of the battery unit.

3. The energy storage system of claim 2, wherein the battery cell comprises a plurality of battery packs;

the control module further comprises a plurality of slave control units, and each slave control unit is connected with a corresponding battery pack to acquire battery information of the corresponding battery pack.

4. The energy storage system of claim 3, wherein the bus module comprises a plurality of ac switching units, a first end of each of the ac switching units being connected to a bus terminal, a second end of each of the ac switching units being connected to a portion of the energy conversion unit of the energy module.

5. The energy storage system of claim 4, wherein the control module further comprises a master control unit, the master control unit connecting the transduction unit, the master control unit, the slave control unit, and the ac switching unit.

6. The energy storage system of claim 5, wherein the master control unit is configured to:

detecting the state of the alternating current switch unit;

when the alternating current switch unit is closed, a first power-on instruction is sent to the transduction unit so as to enable the transduction unit to be electrified;

and when the energy conversion unit finishes powering up, a second power-up instruction is sent to the main control unit, so that the main control unit controls the energy module to be powered up.

7. The energy storage system of claim 6, wherein the master control unit is configured to perform a self-test prior to detecting the state of the ac switching unit.

8. The energy storage system of claim 6, wherein the master control unit is configured to:

closing the main negative switch when the second power-on instruction is received;

closing the main positive switch when the main negative switch is closed;

and feeding back power-on completion information when the main positive switch is closed.

9. The energy storage system of claim 5, wherein the master control unit is configured to:

when receiving a power-down signal, sending a shutdown instruction to the transduction unit so as to shutdown the transduction unit;

when the energy conversion unit finishes stopping, a power-down instruction is sent to the main control unit, so that the main control unit controls the energy module to power down;

and when the energy module finishes power-down, controlling the alternating current switch unit to be disconnected.

10. The energy storage system of claim 9, wherein the master control unit is configured to:

detecting a current value when the power-down instruction is received;

if the current value is smaller than a set value, the main positive switch is disconnected, and if the current value is larger than the set value, the main positive switch is disconnected in a delay mode;

delay-turning off the main negative switch;

and feeding back power-down completion information after at least one of the main positive switch and the main negative switch is completely disconnected.