The principle, characteristics and main application of battery energy storage technology

On June 21, 110 kv Jianshan Energy Storage Power Station located in Zhenjiang Danyang officially put into operation. The substation is one of the important projects of Zhenjiang Energy Storage Power Station.

To alleviate Jianbi power plant coal-fired units retired electricity during peak in the summer of 2018 in the eastern region of Zhenjiang, Jiangsu company combined with electrochemical energy storage power station stationing the characteristics of flexible, short construction period, in Zhenjiang eastern region (Zhenjiang) in the new city, Danyang, Yang building the world's largest energy storage projects, including construction in Danyang area Danyang energy storage power station, building energy storage, development of new energy storage power station dam in the young, long prosperous energy storage power station, three jump energy storage power station, the construction of new district in Zhenjiang Dagang energy storage power station, this text energy storage power station, Beishan energy storage power station.

The project total power grid side of 101 mw, the total capacity of 202 megawatts (mw), is the largest worldwide battery energy storage power station project, the exploration practice in the field of distributed energy storage have demonstration effect, energy storage industry is expected to be in the whole country. After the completion of the project, provide for the operation of the load, FM, backup and black start, demand response and other services, give full play to the role of the power grid peak shaving to promote peak in Zhenjiang grid is cut, effectively alleviate the pressure of the eastern Zhenjiang grid power supply this summer.

It is understood that the rotor is built of mountain energy storage power station is the power of 5 mw, battery capacity of 10 mw energy storage power station demonstration project. Project covers an area of 1.8 mu, a total prefabricated tank type is decorated, through 10 kv cable line access built mountain become 10 kv bus bar side of the grid.

In addition, as the Jiangsu power grid "source network load" accurate load control system an important part of Yang in the areas of energy storage project is equipped with intelligent network interactive terminal, prevent the equipment such as island process control system, can achieve for scheduling the millisecond response, realizing fast removal of fault.

Battery energy storage technology is introduced

1. The principle of battery energy storage technology

Energy storage technology is realized through physical or chemical methods such as electrical energy storage, and as needed to release a series of related technology. In general, according to different way of storing energy can be classified as mechanical energy storage, electromagnetic energy storage and electrochemical energy storage. Mechanical energy storage and can be divided into pumping energy storage, compressed air energy storage, flywheel energy storage. Electromagnetic energy storage including superconducting magnetic energy storage and super capacitor energy storage. Electrochemical energy storage way is to electrical energy in the form of chemical energy storage and release. Electrochemical energy storage mainly includes the current device to achieve energy storage batteries and electrochemical capacitors, commonly used lead-acid battery lead batteries, carbon batteries, sodium sulfur batteries, flow batteries, lithium ion batteries and so on. Electrochemical energy storage technology with high efficiency and flexibility, the advantages of fast response gradually occupies more and more important status in the electric power energy storage market.

Different battery performance comparison in table 1

2. The characters and main use of battery energy storage technology

In order to promote the upgrading of the energy industry and realize clean, low carbon development in recent years, our country to develop clean energy, wind power, photovoltaic great-leap-forward development, new energy capacity proportion is increasing day by day. In clean energy development at the same time, however, volatility, intermittent new energy interconnection to the grid from the control run, adversely affect many aspects, such as security control, greatly limits the effective utilization of clean energy. Battery energy storage power station is associated with distribution/centralized new energy power generation applications, is one of the effective ways to solve the problem of new energy grid-connected, will with the scale increasing of new energy power generation and development of battery energy storage technology, become the supporting major key technology of clean energy development strategy in our country.

Battery energy storage as an important way, electrical energy storage has the power and energy according to different application requirements flexible configuration, fast response speed, not limited by geographical resources such as external conditions, suitable for large scale application and advantages of the mass production, makes the battery energy storage in cooperate with centralized/distributed new energy grid, power grid operation auxiliary has an irreplaceable position.

Figure 1Energy storage battery in the distributed power supply and application in the field of micro power grid

Large-scale battery energy storage power station in the power generation side, can be used as independent power plant in power grid frequency control/regulating, provide standby, peak peel and at the same time also can cooperate with renewable energy power generation increase renewable energy electricity online; Investment in transmission side can be used as the grid upgrade alternative, delay power grid upgrading, and provide secondary frequency modulation for grid services; In power distribution side can delay the upgrading of the distribution network, improve the security and economy of power distribution network operation and improve the ability of distributed power supply accepted in the user side through the peak valley price arbitrage, participate in demand side response to earn profits.

3. The application status of the battery energy storage technology at home and abroad

At present, countries around the world have invested a lot of manpower and material resources on a large scale of battery energy storage technology research. Built at home and abroad in recent years, the continuous large scale battery energy storage power station. The western countries represented by America's devotion to large-scale battery energy storage power station construction in recent years, such as the United States in California, Pennsylvania state established a large number of different energy storage form of energy storage power station, its applications include power generation, ancillary services, transmission and distribution, client, distributed generation and microelectronics industry network, large-scale grid in areas such as renewable energy, and the function and role of different energy storage power station has carried on the classification and definition, pointed out the direction for the development of large-scale energy storage power stations all over the world.

Table 2 foreign large-scale battery energy storage project

Based on large-scale domestic battery energy storage technology is also carried out a lot of research work, in the large-scale renewable energy power generation base, transmission and distribution, and the user side and distributed generation and micro power grid, and other fields, has built a number of demonstration projects, and carry out the energy storage system capacity configuration, control strategy and so on a number of research work, has made many research results.

National scenery storage lose demonstration project is "grid friendly new energy power generation" as the goal, is currently the largest in the world, and wind power, photovoltaic power generation, energy storage and transmission engineering four one of the renewable energy comprehensive demonstration project. Among them, the first phase of construction of 98.5 MW wind, 40 MW photovoltaic power generation and energy storage device 20 MW (including 14 MW / 63 MWH of lithium ion battery and 2 MW / 8 MWH all vanadium flow batteries), and supporting the construction of 220 kv smart substation. Through large-scale energy storage power station monitoring system has realized the coordinated control and energy management of a variety of energy storage devices, have smooth renewable power output fluctuation, auxiliary renewable power curve output as planned and various functions such as peak shaving in valley.

Figure 2 national scenery storage demonstration project panorama

Demonstration projects of energy storage power station (phase I) design a total installed capacity of 20 mw, the total storage capacity 95 MWH, at present already installed storage device 14 mw lithium iron phosphate (a total of 63 MWH) and 2 mw flow energy storage device (8 MWH).Through large-scale battery energy storage power station monitoring system has realized the dozens of megawatt multi-type battery energy storage power station system integration, unified scheduling and the engineering application, solved the battery energy storage power station coordinated control and energy management of the key problems, to achieve the smooth wind-light power output and tracking plan, participate in the system of FM, peak cutting and other advanced application function, improve the wind/photovoltaic power station power generation of predictability and controllability and schedulable.

Figure 3 national scenery storage demonstration projects of battery energy storage system

The upper energy management strategy based on energy storage power station can realize complementary scenery storage power, so as to achieve the scenery the joint output volatility meet less than 7% of the storage system design goals, tracking power plan meet the error is less than 3% of the system design goal.

Figure 4 national scenery storage demonstration project monitoring interface

4. The future application prospect of battery energy storage power station

The future development and application of large-scale battery energy storage system needs some work carried out from the following several aspects:

(1) from the large-scale energy storage battery design, integration, installation, operation, monitoring and other production process, pay attention to the safety of the battery problem, put forward the security boundary of different types of energy storage system, the possible battery overheat, deformation, burning, electrolyte leakage and other safety design has sufficient reliability of safety measures, to avoid safety accidents.

(2) full consideration of mass/large number of very large scale battery energy storage system energy storage unit and the complexity of network topology, the subsystem partition ZiZhiXiang station domain centralized management of the large-scale/vlsi battery energy storage power station optimization control architecture, fundamentally solve the energy storage unit contradiction between diversity and application target of unity, the all-round ability of promoting the comprehensive control of battery energy storage system.

(3) the effective use of big data, cloud computing, Internet of things, such as artificial intelligence method, both historical and real-time operational data, realizing the real-time operation state of battery energy storage system diagnosis and analysis, performance attenuation and safety warning, etc., to ensure that the large-scale centralized/distributed battery energy storage power station safe, stable and reliable operation.

(4) in view of the large-scale centralized/distributed battery energy storage power station and the centralized/distributed new energy power generation joint application scenario, consider intelligent operation scheduling, security and stability control, the whole life cycle management, multi-objective control management and operation benefit is the most superior, the various requirements put forward under different integration architecture of battery energy storage power station multi-objective collaborative optimization control method of crack is different form the battery energy storage system power management and scientific control problem.

(5) consider the large-scale centralized/distributed battery energy storage system may be made of different kinds and different stages of life of battery energy storage unit/arrangement in use power battery energy storage unit, such as hybrid integrated, research and reveal the multi-type battery energy storage power station in different types of energy storage unit health status, performance attenuation, the differences between the charge and discharge rate characteristics, analysis the battery charge and discharge characteristics of unit after the dynamic connection, proposed in view of the different types of battery energy storage system dynamic, intelligent, differentiation of charging and discharging control method, solve the battery management problem.

(6) from the battery energy storage module level, device level and system level, such as different level, the charge and discharge characteristics of different types of large capacity battery energy storage technology, working condition of applicability, safety and economic evaluation methods, to master advanced technology of large capacity storage efficiency of quantitative analysis and comprehensive evaluation method, support the battery energy storage technology research and engineering application.

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