CN212085818U

CN212085818U - Power grid side energy storage device of modularization combination

Info

Publication number: CN212085818U
Application number: CN202021007563.0U
Authority: CN
Inventors: 高岩; 治万山; 史梓男; 贡晓旭; 袁国强; 杨金双
Original assignee: Beijing Xiqing Energy Technology Co ltd
Current assignee: Beijing Xiqing Energy Technology Co ltd
Priority date: 2020-06-04
Filing date: 2020-06-04
Publication date: 2020-12-04
Anticipated expiration: 2030-06-04

Abstract

A modularly combined grid-side energy storage apparatus comprising: the system comprises an energy storage battery module, an energy storage converter step-up transformer module, a static reactive generator module, a 10kV power distribution device module, an integrated power supply module and a master control module; the energy storage converter step-up transformer module, the static var generator module and the integrated power supply module are all electrically connected with the 10kV power distribution device module, the 10kV power distribution device module is electrically connected with the external power grid side, and the energy storage converter step-up transformer module is electrically connected with the energy storage battery module; and the master control module realizes the overall monitoring and control of the power grid side energy storage device combined in a modularized manner. By adopting the modular mode, the device has the advantages of multiple applicable scenes, convenient, simple and flexible combination among modules, complementary advantages, convenience for maintenance and overhaul of the whole device, convenience for replacement and maintenance of fault elements and great improvement on the safety and reliability of the energy storage device on the power grid side.

Description

Power grid side energy storage device of modularization combination

Technical Field

The utility model relates to an energy memory especially relates to an energy memory of electric wire netting side of modularization combination.

Background

With the rapid development and pilot demonstration application of the energy storage technology, the functional complexity is increased day by day, the regulatory requirements on safety, environmental protection and energy conservation are strict day by day, the requirements on comfort, flexibility and individuation are different, and the safe and stable operation of the power grid and the energy storage system can be ensured by the flexible implementation of the scheme of accessing the energy storage system into the system and the combination with the planning of the regional power grid. The energy storage system can be utilized to improve the consumption capacity of renewable energy sources, increase the generated energy of the renewable energy sources, reduce the emission of pollutants such as carbon dioxide, nitrogen oxides and the like caused by fossil fuels, greatly promote clean substitution and promote the energy production and consumption revolution; the energy storage system indirectly replaces a thermal power generating unit to complete partial peak regulation and frequency modulation tasks while developing auxiliary services such as peak regulation and frequency modulation, reduces and optimizes frequent increase and decrease of output of the thermal power generating unit, reduces consumption of resources such as coal and the like, and improves the overall energy efficiency level of the society; the energy storage system delays the construction of the power supply, avoids the construction of the power supply due to the over-fast increase of the load, reduces the consumption of power generation fuels such as coal, natural gas and the like, and obviously reduces the atmospheric pollution and the emission of greenhouse gases.

At present, the existing compressed air energy storage is a large-scale physical energy storage technology, and is suitable for peak shaving of a power grid and integration and synchronization of large-scale renewable energy sources. The traditional compressed air energy storage technology is mature, but is influenced by factors such as terrain, fossil fuel pollution and the like; the super capacitor energy storage has the advantages of high power density, high charging speed, long cycle life, good low-temperature performance, safety, reliability, environmental friendliness and the like, is mature and applied to storage equipment and standby power supplies in electronic products, has more applications in energy braking in the traffic field, and basically realizes large-scale production and clear profit mode. But supercapacitors have a short discharge time when used in energy-type applications.

The energy storage technology has wide application prospects in the aspects of reducing power failure loss, improving the quality of electric energy, effectively improving the utilization rate of the existing power transmission and distribution electric equipment and the like. With the progress of the application research of the energy storage technology, the energy storage technology is developing toward the high efficiency of energy conversion, the high density of energy, and the low cost of application. There is an urgent need in the art for a grid-side energy storage device that reduces peak-to-valley difference and power generation cost, meets the demand for system power generation capacity, reduces wind and light abandonment, can delay the capacity expansion demand of power transmission facilities, alleviates the congestion of power transmission lines, delays the capacity expansion demand of power distribution facilities, stabilizes voltage fluctuation caused by renewable energy, avoids reverse current on lines with large proportion of distributed energy, can improve the quality of electric energy, and simultaneously improves the reliability of power supply/reduces the power supply interruption time.

The existing power grid side energy storage devices adopt an integral construction mode, so that the application scene is single, the flexibility is poor, the arrangement is complex and difficult, the design and construction efficiency is low, the construction period is long, and the cost is high; the whole device is difficult to maintain and overhaul and is not convenient, if a component breaks down or fails, the influence on the whole system is large, the safety and reliability of the energy storage device on the power grid side are not high, and the maintenance, overhaul, debugging and replacement are inconvenient.

SUMMERY OF THE UTILITY MODEL

In order to solve the inconvenience that above-mentioned prior art brought, the utility model provides a modularization combination, energy conversion is high-efficient, energy densifier and low-cost electric wire netting side energy memory, this kind of modularization combination's electric wire netting side energy memory includes: the system comprises an energy storage battery module, an energy storage converter step-up transformer module, a static reactive generator module, a 10kV power distribution device module, an integrated power supply module and a master control module; the energy storage converter step-up transformer module, the static var generator module and the integrated power supply module are all electrically connected with the 10kV power distribution device module, the 10kV power distribution device module is electrically connected with the external power grid side, and the energy storage converter step-up transformer module is electrically connected with the energy storage battery module; the master control module is electrically connected with the energy storage battery module, the energy storage converter step-up transformer module, the static var generator module, the 10kV power distribution device module and the integrated power supply module, so that the monitoring and control of the whole modular combined power grid side energy storage device are realized; the integrated power module is electrically connected with the energy storage battery module, the energy storage converter step-up transformer module, the static var generator module, the 10kV power distribution device module and the master control module, and provides a low-voltage auxiliary control power supply for the energy storage battery module, the energy storage converter step-up transformer module, the static var generator module, the 10kV power distribution device module and the master control module.

Further, the energy storage battery module comprises a direct current positive electrode module and a direct current negative electrode module, the direct current positive electrode module and the direct current negative electrode module respectively comprise a plurality of groups of battery clusters and a confluence cabinet, and the plurality of groups of battery clusters are connected in series and then are connected to the confluence cabinet; and a battery cluster main positive contactor and a battery cluster main negative contactor are respectively arranged in each collecting cabinet.

Furthermore, each group of battery clusters is provided with a battery management system, and the battery management system can be communicated with the master control module.

Further, the energy storage converter step-up transformer module comprises a 10kV high-voltage switch cabinet, a step-up transformer and a plurality of groups of energy storage converters. The power supply control device is responsible for rectifying and reducing voltage of commercial power to charge the energy storage battery module under the normal condition state of the commercial power, or is used for boosting the power inversion of the energy storage battery module to provide power for emergency electric equipment under the condition of commercial power outage.

Further, the Static Var Generator (SVG) module comprises a control cabinet, an isolating switch, a power cabinet and a reactor; the reactive power compensation system is responsible for performing reactive power compensation on the whole equipment, improving the power factor and optimizing the quality of electric energy.

Further, the 10kV power distribution device module comprises a 10kV incoming line cabinet, a 10kV energy storage outgoing line cabinet, a station transformer outgoing line cabinet, a metering cabinet and a bus equipment cabinet, and is used for connecting the boost transformation module of the energy storage converter with the power grid side; the grid side and the station are connected by a transformer or the like.

Furthermore, the integrated power module comprises an alternating current incoming line cabinet, an alternating current feeder cabinet, a station transformer, a UPS power cabinet, a communication power cabinet, a direct current charging feeder cabinet and a battery cabinet, and is used for providing a low-voltage control power supply for each functional module.

Further, the master control module comprises a workbench, a comprehensive data network cabinet, a second plane scheduling data private network cabinet, a first plane scheduling data private network cabinet, a communication cabinet, a comprehensive distribution cabinet, a scheduling management information cabinet, an intelligent auxiliary monitoring cabinet, a synchronous device cabinet, a fault recording cabinet, a frequency-voltage abnormity and anti-islanding protection cabinet, an electric energy quality monitoring cabinet, a public monitoring cabinet, a communication telecontrol cabinet, a comprehensive application server cabinet and a monitoring host cabinet, and is used for collecting the receiving and sending command control signals of each module and transmitting the communication with the power grid.

The technical scheme of the utility model beneficial effect who brings does:

1. the utility model provides a power grid side energy memory of modularization combination through adopting the modular construction mode, and it is many to be suitable for the scene, and the associativity is convenient, simple, nimble between the module, and the advantage is complementary, through the reasonable equipment of modularization, realizes arranging in a flexible way, is showing and is improving power grid side energy memory design and efficiency of construction, shortens construction cycle and cost greatly.

2. The utility model discloses a modular combination mode, the whole device of being convenient for is maintained and is overhauld, simultaneously, mutual independence between each module, and partial equipment or component failure are less to overall system reliability influence, and the change and the maintenance of the fault element of also being convenient for have improved electric wire netting side energy memory's fail safe nature greatly.

Drawings

Fig. 1 is the whole composition structure schematic diagram of the modular combined power grid side energy storage device of the present invention.

Fig. 2 is a schematic diagram of the structure of the middle energy storage battery module of the present invention.

Fig. 3 is the structural schematic diagram of the boost converter module of the energy storage converter of the present invention.

Fig. 4 is a schematic diagram of a structure of a Static Var Generator (SVG) module.

Fig. 5 is a schematic diagram of the structure of the module of the 10kV distribution device of the present invention.

Fig. 6 is a schematic diagram of the structure of the integrated power module of the present invention.

Fig. 7 is a schematic diagram of the structure of the central control module of the present invention.

Wherein the drawings are described as follows:

10. an energy storage battery module; 20. the energy storage converter step-up conversion module; 30. a static var generator module; 40. a 10kV power distribution device module; 50. an integrated power module; 60. a master control module; 70. a grid side; 80. a load side;

100. a modularly combined energy storage device; 101. a battery cluster; 102. a combiner cabinet; 103. a battery cluster main positive contactor; 104. a battery cluster total negative contactor;

201. a 10kV high-voltage switch cabinet; 202. a step-up transformer; 203. an energy storage converter;

301. a control cabinet; 302. an isolating switch; 303. a power cabinet; 304. a reactor;

401. a 10kV inlet cabinet; 402. a metering cabinet; 403. a bus equipment cabinet; 404. an SVG outlet cabinet; 405. a transformer cabinet for a station; 406. a 10kV energy storage outgoing line cabinet;

501. an AC inlet cabinet; 502. an AC feeder cabinet; 503. a station transformer; 504. a UPS power cabinet; 505. a communication power supply cabinet; 506. a DC charging and feeding cabinet; 507. a battery cabinet;

601. a work table; 602. monitoring the main cabinet; 603. a comprehensive application server cabinet; 604. a comprehensive data network cabinet; 605. a second plane schedules a data private network cabinet; 606. a first plane scheduling data private network cabinet; 607. a communication cabinet; 608. a comprehensive distribution cabinet; 609. a scheduling management information cabinet; 610. an intelligent auxiliary monitoring cabinet; 611. a contemporaneous device cabinet; 612. a fault recording cabinet; 613. frequency and voltage abnormity and anti-islanding protection cabinet; 614. a power quality monitoring cabinet; 615. a public measurement and control cabinet; 616. communication telemechanical cabinet.

The above-mentioned drawings use and carry out supplementary explanation to the technical scheme of the utility model to help clearly understand the utility model. However, the drawings are not intended to limit the present invention. Furthermore, the contents of the drawings are not to scale and should not be interpreted as limiting the invention. The whole or the constituent parts of the contents shown in the drawings can be combined and changed based on the technology of the art.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined purpose, the following description of preferred embodiments is made with reference to the accompanying drawings, and the following detailed description is given for a specific implementation of a modular combined power grid-side energy storage device according to the present invention:

referring to fig. 1, the utility model provides a grid side energy storage device 100 of modularization combination specifically includes: 1 energy storage battery module 10 and corresponding 1 energy storage converter (PCS) step up and become module 20, 1 Static Var Generator (SVG) module 30, 1 10kV power distribution device module 40, 1 integrated power module 50 and 1 total control module 60.

The energy storage converter step-up transformer module 20, the Static Var Generator (SVG) module 30 and the integrated power module 50 are electrically connected with the 10kV power distribution device module 40, the 10kV power distribution device module 40 is electrically connected with the external power grid side 70, and the energy storage converter step-up transformer module 20 is electrically connected with the energy storage battery module 10; the master control module 60 is electrically connected with the energy storage battery module 10, the energy storage converter step-up transformer module 20, the static var generator module 30, the 10kV power distribution device module 40 and the integrated power supply module 50, so that the modular combined power grid side energy storage device 100 is integrally monitored and controlled;

the integrated power module 50 is electrically connected with the energy storage battery module 10, the energy storage converter step-up transformer module 20, the static reactive power generator module 30, the 10kV power distribution device module 40 and the master control module 60, and provides a low-voltage auxiliary control power supply for the energy storage battery module 10, the energy storage converter step-up transformer module 20, the static reactive power generator module 30, the 10kV power distribution device module 40 and the master control module 60; the external grid side 70 is electrically connected with the external load side 80;

the energy storage battery module 10 is used for storing electric energy when the power grid side is normal and releasing the stored electric energy when the power grid side 70 is abnormal, the energy storage converter step-up transformer module 20 is used for performing transformation and transformation conversion on the electric energy output by the 10kV power distribution device module 40 when the power grid side 70 is normal, transmitting the energy to the energy storage battery module 10 for storage, and performing transformation and transformation conversion on the electric energy output by the energy storage battery module 10 when the power grid side 70 is abnormal, and outputting the electric energy to the power grid side 70 through the 10kV power distribution device module 40 to be matched and connected with an emergency power supply;

the static var generator module 30 is used for generating reactive power to the 10kV distribution equipment module 40 to perform reactive power compensation and improve power factor; the 10kV distribution device module 40 is used for distributing power of the power grid side 70 to the energy storage converter step-up transformer module 20 and the integrated power module 50 respectively to embody the function of distributing power, and the connection with the static var generator module 30 is to supply reactive power to the power grid side 70 through the 10kV distribution device module 40.

The energy storage battery module 10 is electrically connected with the energy storage converter step-up transformer module 20 through a cable, and the energy storage converter step-up transformer module 20 is electrically connected with an energy storage outlet terminal of the 10kV power distribution device module 40 through a cable; the station transformer outlet end of the 10kV power distribution device module 40 is connected with the integrated power supply module 50 through a cable, and the SVG (static var compensation/generation) outlet end of the 10kV power distribution device module 40 is connected with the static var generator module 30 through a cable; the incoming line end of the 10kV switchgear module 40 is connected to the grid side 70 by a cable.

The integrated power module 50 is electrically connected with the energy storage battery module 10, the energy storage converter step-up transformer module 20, the static var generator module 30, the 10kV power distribution device module 40 and the master control module 60 through low-voltage auxiliary control cables, and the master control module 60 is electrically connected with the energy storage battery module 10, the energy storage converter step-up transformer module 20, the static var generator module 30, the 10kV power distribution device module 40 and the integrated power module 50 through communication cables and control cables.

The specific composition structure of each module in the modularly combined grid-side energy storage device 100 is as follows: referring to fig. 2, the energy storage battery module 10 in the energy storage device 100 on the grid side of the modular combination is composed of a plurality of sets of battery clusters 101, each set of battery clusters 101 is connected in series to a bus cabinet 102, and a battery cluster main positive contactor and a battery cluster main negative contactor are configured in the bus cabinet 102 and controlled by a main control module 60 through a communication line.

As shown in fig. 3, the energy storage converter step-up module 20 in the power grid-side energy storage device 100 of the modular combination includes an energy storage converter, a matched step-up transformer 202 and a matched 10kV high-voltage switch cabinet 201, which are devices for realizing bidirectional conversion connection of ac and dc electric energy. The protection function of the energy storage converter meets the basic requirement of 5.5 in the GB/T34120 standard: 1) the open-phase protection energy storage converter has an output open-phase protection function. 2) Internal short-circuit protection when the internal short circuit of the energy storage converter (such as IGBT direct connection, direct current bus short circuit and the like), an electronic circuit, a protection fuse and an alternating current contactor in the energy storage converter can quickly and reliably act. All the transformers are 10kV three-phase non-excitation voltage regulation local boosting transformer. The local boost transformer is called as a local boost transformer or a transformer for short, and all the local boost transformers are wiring modes of copper bar incoming wires and cable outgoing wires. The rated voltage of the local step-up transformer is as follows: 10.5kV, the rated voltage ratio of local boosting change is as follows: 10.5kV/0.38 kV. The 10kV high-voltage switch cabinet 201 can charge the battery module 10 with commercial power on the power grid side 70 through the connection of the cable, and can also supply the load on the power grid side with the electricity stored in the energy storage battery module 10.

As shown in fig. 4, a Static Var Generator (SVG) module 30 includes a power cabinet 303, a control cabinet 301, a reactor 304, and a disconnector 302. Corresponding filtering branches are arranged for harmonic waves generated by the power grid side 70 and the modularized combined power grid side energy storage device 100, an AVC (automatic voltage control) interface needs to be reserved and scheduled for reactive compensation equipment, a MODBUS (TCP/IP) or OPC 2.0 protocol is supported, and an interface with a transformer substation monitoring system is reserved. The response speed requirement of a Static Var Generator (SVG) module 30 is not more than 20ms, 10kV incoming line reactive power and bus voltage are used as control targets, the bus voltage is preferentially used as the control target in normal operation, the power quality change of a power grid is dynamically tracked, reactive output is dynamically adjusted according to the change condition, a reactive compensation device manufacturer determines hardware selection and program configuration after carefully analyzing the field environment, the phenomenon of harmonic amplification even causing power grid resonance is avoided, and the technical requirements of reactive power, voltage adjustment, power factor, harmonic management and the like are met. After the dynamic reactive power compensation device is arranged, the voltage deviation of a grid-connected point is within-7% to + 7%, and the voltage change of a bus where the dynamic reactive power compensation device is switched is not suitable to exceed 2.5% of a rated voltage value. The reactive power compensation device with the complete set design adopts a comprehensive coordination control strategy, so that the dynamic compensation response time of the complete set of device is not more than 20ms, and the capacitor branch and the static reactive power compensation branch of the reactive power compensation device in the field can be rapidly and correctly switched under the emergency condition, wherein the power factors are that the average power factor reaches 0.98, and the voltage source obtains: the Static Var Generator (SVG) module 30 can acquire the self-acquisition voltage by UAB/UBC/UCA, meets the requirement on precision, and has the communication function with NCS and AVC.

As shown in fig. 5, the 10kV distribution device module 40 includes a 10kV incoming line cabinet 401, a metering cabinet 402, a bus equipment cabinet 403, an SVG outgoing line cabinet 404, a substation outgoing line cabinet 405, and an energy storage outgoing line cabinet 406. The 10kV incoming cabinet 401 is connected with the power grid side 70 through a cable for the upper-level voltage access, the 10kV outgoing cabinet 402 is connected with the 10kV high-voltage switch cabinet 201 in the energy storage converter step-up transformer module 20 for the load carried under the current-level voltage, the station transformer cabinet 403 is connected with the alternating current incoming cabinet 501 of the integrated module 50 through a cable for the transformer carried by the current-level voltage, and all the devices are connected through a cabinet top horizontal bus copper plate. All the connection modes are well known by the person skilled in the art, and the innovation point of the novel method is not in all the connection modes. The connection mode between each device and each module is well known to those skilled in the art.

As shown in fig. 6, the integrated module 50 includes a station transformer 503, an ac inlet cabinet 501, an ac feeder cabinet 502, a UPS power cabinet 504, a communication power cabinet 505, a dc charging and feeding cabinet 506, and a battery cabinet 507. The integrated module 50 is responsible for providing necessary ac/dc loads for the constituent devices in the other constituent modules in the grid-side energy storage device 100, and providing a stable and reliable ac/dc working power supply, including: the power supply comprises an AC 380V/220V alternating current power supply, an AC220V inverter power supply, a DC 220V direct current power supply and a DC 48V communication direct current power supply. The power supply system is divided into an alternating current feeder screen, a direct current feeder screen, a UPS power supply screen and a storage battery screen, and each feeder cabinet is 9 lines in the number of loops of the alternating current feeder screen. The integrated module 50 adopts an IEC 61850 protocol for external communication.

As shown in fig. 7, the master control module 60 includes a workbench 601, a monitoring host cabinet 602, a comprehensive application server cabinet 603, a comprehensive data network cabinet 604, a second plane scheduling data private network cabinet 605, a first plane scheduling data private network cabinet 606, a communication cabinet 607, a comprehensive wiring cabinet 608, a scheduling management information cabinet 609, an intelligent auxiliary monitoring cabinet 610, a synchronous device cabinet 611, a fault recording cabinet 612, a frequency-voltage anomaly and anti-islanding protection cabinet 613, an electric energy quality monitoring cabinet 614, a public monitoring cabinet 615, and a communication telemechanical cabinet 616; the master control module 60 follows the integrated design concept, adopts a distributed system structure, can flexibly expand, integrate and integrate various application functions of the energy storage power station monitoring on the basis of a unified support platform, realizes and uses various application functions, has a unified database model and a man-machine interaction interface, and performs unified maintenance. All the connection modes are well known by the person skilled in the art, and the innovation point of the novel method is not in all the connection modes. The connection mode between each device and each module is well known to those skilled in the art.

The grid-side energy storage device 100 performs rectification and inversion through the energy storage converter step-up conversion module 20, thereby realizing charging and discharging of the energy storage battery module 10. Under the normal condition of the mains supply, the energy storage battery module 10 is in a standby working state (floating charge mode), and under the condition of abnormal power failure of the power grid side 70, the device automatically and seamlessly switches to the off-grid discharge mode through the information collected by the master control module 60, wherein the switching time is 0 ms.

The power grid side energy storage device 100 in the modularized combination can realize normal power backup in two application scenarios, normal power grid side and abnormal power grid side, under the control of the master control module 60, and has two basic operation modes, normal power grid side power supply and abnormal power grid side power supply:

1) power supply network side (power supply network side 70 normal)

The master control module 60 gives an instruction, and the energy storage converter step-up transformer module 20 adjusts the rectified voltage to be equivalent to the battery pack voltage (controls the charging and discharging current to approach 0). The energy storage battery module 10 is charged by the power distribution of the 10kV power distribution device module 40 and the rectification of the energy storage converter step-up transformer module 20 on the power grid side 70.

2) Grid side exception (grid side 70 power supply exception)

When the power supply of the power grid side 70 is abnormal, for example, the power grid side is powered off, or the power consumption peak of the power grid is heavily loaded, part of the load can be connected to the power grid side 70 through the energy storage battery module 10 after being inverted and boosted by the energy storage converter boosting transformation module 20 and through the 10kV power distribution device module 40, the energy storage device 100 can realize 0ms uninterrupted switching, so that the power supply reliability and the power consumption peak clipping of the power grid side 70 are realized, and the power supply of the power grid side 70 is not influenced.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. A modular combined grid-side energy storage device, characterized in that the modular combined grid-side energy storage device (100) comprises: the system comprises an energy storage battery module (10), an energy storage converter step-up transformer module (20), a static var generator module (30), a 10kV power distribution device module (40), an integrated power supply module (50) and a master control module (60); the energy storage converter step-up transformer module (20), the static var generator module (30) and the integrated power module (50) are electrically connected with the 10kV power distribution device module (40), the 10kV power distribution device module (40) is electrically connected with the external power grid side (70), and the energy storage converter step-up transformer module (20) is electrically connected with the energy storage battery module (10); the master control module (60) is electrically connected with the energy storage battery module (10), the energy storage converter step-up transformer module (20), the static reactive generator module (30), the 10kV power distribution device module (40) and the integrated power supply module (50), so that the overall monitoring and control of the modular combined power grid side energy storage device (100) are realized; the integrated power module (50) is electrically connected with the energy storage battery module (10), the energy storage converter step-up transformer module (20), the static reactive generator module (30), the 10kV power distribution device module (40) and the master control module (60) and provides a low-voltage auxiliary control power supply for the energy storage battery module (10), the energy storage converter step-up transformer module (20), the static reactive generator module (30), the 10kV power distribution device module (40) and the master control module (60).

2. The modularly combined grid-side energy storage device according to claim 1, wherein the energy storage battery modules (10) comprise a dc positive module and a dc negative module, each of which comprises a plurality of groups of battery clusters (101) and a combiner box (102), wherein the plurality of groups of battery clusters (101) are connected in series and then connected to the combiner box (102); a battery cluster main positive contactor (103) and a battery cluster main negative contactor (104) are respectively arranged in each collecting cabinet (102).

3. The modularly combined grid-side energy storage device according to claim 2, characterized in that each group of said battery clusters (101) is equipped with a battery management system, which communicates with said general control module (60).