A few days ago, the State Administration of market supervision and administration (the State Standardization Administration Committee) issued a batch of publicity of proposed project standards. Three of these standards are related to energy storage. Electrochemical energy storage technical specifications for grid-type converter, guidelines for safety evaluation of electrochemical energy storage power stations, and Flywheel energy storage converter for electric energy storage.

Technical Specification for electrochemical energy storage network converter

the main drafting units are China Electric Power Research Institute Co., Ltd., Sunshine Power Supply Co., Ltd. and Huawei Digital Energy Technology Co., Ltd.

The standard specifies the classification and coding, basic requirements, functional requirements, performance requirements, auxiliary systems and other requirements of electrochemical energy storage network converter, describes the corresponding test methods, stipulates the inspection rules, marks, packaging, transportation and storage, etc. It is applicable to the design, manufacture, test, detection, operation, maintenance and overhaul of network converter with ac port voltage of 35kV and below.

Objective significance: the characteristics of "double height", "Double Peak" and "double random" in the current power system are increasingly prominent, which puts forward higher requirements for the regulation and control of the power grid. Energy storage, as a high-quality flexible adjustment of resources and potential active support means, is an important equipment Foundation and key technology for building a new energy system and promoting the green and low-carbon transformation of energy,It is an important support to help achieve the goal of "carbon peak carbon neutralization" and can play a significant role in the challenge of "ensuring supply, ensuring safety and promoting consumption" in the new power system, and has realized engineering and commercial application.

With the increasing proportion of new energy, the local high proportion of new energy connected to the power grid lacks synchronous support power supply, and the level of short-circuit current decreases continuously, showing the characteristics of weak AC power grid, broadband oscillation, transient overvoltage, the problems of grid-connected stability of new energy sources such as phase-locked out-of-step are relatively frequent, and the problems of power system security and stability are becoming more and more prominent.

Compared with the traditional energy storage technology which adopts the grid-type phase-locked loop control technology, the grid-type energy storage technology can simulate the excitation and power angle characteristics of the generator, and has the active voltage support, automatic inertia support and frequency modulation response capability, it can improve the damping characteristics of the power grid to suppress broadband oscillation and improve the short circuit capability of the weak current network, which is an effective means to solve the stable operation of the new power system and the high proportion of new energy consumption.

The notice of the National Energy Administration on organizing the pilot demonstration of Renewable Energy Development (No. 66 [2023] of China Energy Development) clearly points out that it mainly supports grid-type wind power, grid-type photovoltaic power generation, technology research and development and engineering demonstration such as grid-type energy storage and low-frequency network delivery of new energy significantly improve the stable support capability of new energy connected to weak current network, such as voltage and frequency, greatly improve the safe and stable power transmission capacity of the transmission channel of the wind power photovoltaic large base project.

Xinjiang, Tibet, Jiangsu and other provinces and cities have successively proposed to install grid-type energy storage devices and build grid-type energy storage power stations to deal with the risks of new power systems and improve the immunity, active support, the improvement of network-related capabilities such as perception promotes the transformation of new energy from grid connection to networking.

However, at present, there is no clear relevant standard for grid-based energy storage converter in China. Therefore, in the process of designing, constructing and grid-connected grid-based energy storage power stations, it is impossible to carry out reliable and safe boundary design for grid-type converter, to carry out product type test, and to ensure the safe and reliable operation of grid-type energy storage power station. Therefore, in order to meet the actual needs of engineering and the needs of future technological development, it is necessary to put forward technical requirements for network-type converter, clarify test methods, clarify capability boundaries, point out the direction for the development of the industry, and improve the level of energy storage equipment, help energy storage equipment go as soon as possibleGet out and seize the tech heights.

Guidelines for safety evaluation of electrochemical energy storage power stations

the main drafting unit is China Electric Power Research Institute Co., Ltd.

The standard is applicable to the safety evaluation of electrochemical energy storage power stations such as lithium ion batteries, sodium ion batteries, lead-acid (carbon) batteries with installed capacity of 500kW/500kWh and above. The evaluation contents and methods of safety production rules and regulations evaluation, equipment and facilities evaluation, operation and maintenance evaluation, overhaul evaluation and comprehensive evaluation of electrochemical energy storage power station are stipulated.

Purpose significance: (1) necessity and feasibility of formulating and revising recommended national standards (1) necessity of project establishment: as a key technology supporting smart grid and energy transformation and development, energy storage has received extensive attention, among them, battery energy storage represented by lithium ion batteries has become one of the preferred storage carriers for large-scale energy storage.

In recent years, lithium-ion battery energy storage technology has been continuously improved in key technical fields such as Ontology Research and Development, large-scale integration, safety protection, function realization and engineering verification, and has passed the function verification of large-scale application, the technical standard system and application management system for power system application are becoming more and more perfect, and the problems in controllable and safe application are also gradually improving.

However, with the gradual increase of the application scale of battery energy storage, many problems and risks in the quality and safety of the energy storage system are exposed, which are embodied in two aspects: one is that the safety problems are prominent, in recent years, there have been many safety accidents of energy storage power stations at home and abroad, which are caused by the defects of the core components of energy storage, external excitation sources, operating environment and management defects, etc. The second is the lack of reliability, most of the energy storage power stations that have been put into operation have problems such as insufficient capacity, low efficiency, too fast life decay, frequent faults and so on, which seriously affect the normal operation of the power stations and bring certain hidden dangers to safe and economic dispatching operation.

The root cause of the above problems lies in the lack of strict implementation of technical standards and systematic closed-loop technical supervision requirements in the construction of energy storage projects, which cannot be effective for energy storage power stations.Safety supervision assessment.

Therefore, it is urgent to focus on the current situation of the lack of safety assessment specifications for electrochemical energy storage power stations, starting from four aspects: safety production rules and regulations evaluation, equipment and facilities evaluation, operation and maintenance evaluation and maintenance evaluation, to analyze the energy storage planning and design, the whole process of equipment selection, supervision, arrival sampling inspection, installation, commissioning, commissioning, grid connection acceptance, overhaul and so on should be evaluated and supervised to improve the quality and safety level of energy storage equipment, reduce the accident probability of energy storage power station in order to give full play to the comprehensive efficiency of electrochemical energy storage to support efficient and economical operation of power grid.

(2) project feasibility: 1) policy requirements.

After the "fire and explosion accident of 4.16 energy storage power stations" in Beijing, the security committee office of the State Council, the National Energy Administration and the National Development and Reform Commission all issued relevant policies and norms to clearly strengthen the quality and safety management of energy storage.

The formulation of safety assessment specifications for energy storage power stations echoes the above policy requirements.

2) industrial development and technological maturity.

With a large number of electrochemical energy storage power stations put into operation, the existing energy storage power stations have long-term major potential safety hazards. The newly-built energy storage power stations have the risk of "connecting to the grid with diseases". It is necessary to establish safety evaluation regulations for energy storage power stations, cooperate with on-site inspection to assess the safety risks of stock and new energy storage power stations, and propose corrective measures to provide safety basis for the activation and stable operation of energy storage power stations.

3) have rich experience in standard compilation.

The Chinese Academy of electric Sciences led the preparation of dozens of national standards, industry standards, enterprise standards and group standards in the field of electric energy storage, including GB/T 42288 "safety regulations for electrochemical energy storage power stations, for many years, we have developed research directions related to electric energy storage, and have the experience and ability to formulate and compile standards.

The application team has undertaken a number of scientific research projects related to the field of energy storage safety, and has carried out safety assessment work of many energy storage power stations in Jiangsu, Shanghai and other places. It has rich theoretical and practical research foundation, it can provide strong support for the compilation of this standard.

Flywheel energy storage converter for electric energy storage

the main drafting units are zhuzhou converter technology national engineering research center co., ltd., china electric power research institute co., ltd. and wahchi kinetic energy (beijing) technology co., ltd. The standard is applicable to the design, manufacture, test, detection, operation, maintenance and overhaul of flywheel energy storage converter with flywheel as energy storage carrier in power system.

The standard specifies functional requirements such as braking, on-line input, power control, alarm and protection, communication, operation information monitoring, electrical performance and safety performance of flywheel energy storage converter, the corresponding test methods are described, and the classification and coding, normal working conditions, grid-connected operation electrical conditions, cabinet requirements and protection levels, inspection rules, signs, packaging, transportation and storage, etc.

Objective significance: the current trend of carbon neutralization is accelerating, and the installed capacity and power generation of new energy are developing rapidly. However, when a large amount of new energy is incorporated into the power grid, the fluctuation of the power grid will be increased, and the safety of the power grid may be impacted. Therefore, the rigid demand of power grid frequency modulation is highlighted.

Flywheel energy storage uses the kinetic energy of the rotating body to realize energy storage at high speed, and realizes the conversion of electric energy and kinetic energy by controlling the flywheel. It has high power density, is not limited by the number of charge and discharge times, fast charge and discharge, and is green and pollution-free, with long service life and other characteristics, it has unique advantages in fast load regulation of power system. It is especially suitable for the application scenario of primary frequency modulation of power grid. The number of charge and discharge can reach hundreds or thousands of times per day. With the large-scale grid connection of new energy, the frequency fluctuation of power grid is increasing, so flywheel energy storage, a short-time and high-frequency energy storage technology support, is urgently needed.

In the power grid frequency modulation application, flywheel system accepts the dispatching instruction of the power grid, controls flywheel energy storage converter power, realizes fast energy response, flywheel energy storage converter not only needs to meet the technical requirements of grid connection, at the same time, it also needs to meet the requirements of high dynamic response of flywheel motor.

At present, the application of flywheel energy storage converter in the field of electric energy storage lacks standard specifications and guidance, so it is urgent to formulate relevant national standards.

Necessity (1): the development of power-grade flywheel energy storage bidirectional converter technology needs standards to guide the current technical scheme and technical indicators of flywheel energy storage converter are not unified and standardized, as a result, converter schemes are diversified in practical project applications, which cannot fully meet the key technical indexes such as fast charging and discharging response, adjustment, switching and so on of flywheel in electric energy storage, as well as the requirements of safety and reliability.

Therefore, it is necessary to formulate national standards based on the actual application requirements of electric energy storage, guide the technical development direction of flywheel energy storage converter for energy storage, and improve its comprehensive application performance.

Necessity (II): the need to standardize the high-quality development of the industry since 2022, flywheel energy storage for electric energy storage has entered the stage of large-scale application, and MW flywheel energy storage power station has been continuously put into construction, facing the increasing application scale, the application of flywheel energy storage converter in the field of electric energy storage lacks standard specifications and guidance, and needs to be guided by the practical application requirements of electric energy storage, according to the characteristics of flywheel energy storage, the national standard is formulated, the technical requirements for flywheel energy storage converter are clarified, the test method matching the actual operating conditions and requirements of flywheel energy storage system is proposed, and the development of flywheel energy storage converter industry is standardized.

Necessity (III): improve the national standard system of electric energy storage to fill the gap of flywheel energy storage converter national standard in the standard system of electric energy storage.

(2) project feasibility: 1) industrial development and technological maturity.

With the gradual expansion of new energy grid-connected scale, the application of flywheel energy storage to solve the problem of grid frequency modulation has become the preferred solution.

However, at present, there is no national standard for flywheel energy storage converter for electric energy storage at home and abroad, especially for single-machine high-power MW flywheel energy storage, there is no reference standard for the two-way flywheel energy storage converter, which cannot guarantee the safety and quality of stable operation of flywheel energy storage system from the root, the formulation of this standard can provide effective guarantee for the safety and quality of flywheel energy storage power station.

2) have rich experience in standard compilation.

The application team is the IEC/TC9 international standard, the National Bid Committee (SAC/TC278) and the industry traction electrical equipment standardization centralized unit, and has obtained the leading drafting right of five important international standards, organize the formulation of 139 national and industrial standards.

3) it has rich theoretical and practical support.

The application team is the only national engineering research center in the field of medium and high power converter technology in china, specializing in cutting-edge technology research, modular design and systematic application of core technology.

Relying on the core technology and platform of rail transit, a complete industrial chain from devices, devices to systems has been established. The overall technology is leading in China and has achieved the first set of performance breakthroughs in a series, achieve import substitution and fit the neck key technological breakthroughs in major technical equipment fields.

At the same time, the reporting team has rich experience in the development and application of flywheel energy storage converter products in the field of power frequency modulation.