In 2013, State Grid Corporation invested in the Portuguese National Grid Corporation (REN), and the China Electric Power Research Institute and REN jointly established the R&D Netster. To further promote the exchange of intelligent substation technology between China and Europe, R&D Netster held a technical seminar on “Future Substation†in Lisbon in May 2014. European power grid companies, international power equipment manufacturers, European and American technical experts participated in the meeting. The State Grid Corporation also sent representatives to make a keynote report, jointly discussing and communicating the future development direction of the substation, and deeply understanding Europe and the United States. And other countries' development ideas for future substations. Based on the on-site discussion of this seminar, this paper analyzes the development of substations in China and Europe based on domestic and foreign research.
1 Intelligent substation connotation
In 2004, State Grid Corporation issued the “Technical Guidelines for Intelligent Substation Technical Guidelinesâ€. For the first time, the intelligent substation was defined and defined. As a top-level design of intelligent substation, this definition puts systematic requirements on the development ideas and construction concepts of intelligent substation. . In 2012, the standard was revised and updated to be a national standard and officially released, providing guidance for the development of China's intelligent substation.
There is no clear definition and unified understanding of smart substations in foreign countries, but substations adopting IEC61850 standard are generally referred to as “Next GeneraTIon SubstaTIon†in Europe. European and American countries also have different titles, Intelligent substaTIon, Smart SubstaTIon and Substation of the future are widely used, but in general, the concept of Smart substation is being gradually accepted. For the connotation of smart substation itself, because of the differences in national conditions and their own development priorities, more is Paying attention to local or self-focused areas, this means that the results of China's intelligent substation will be highly adaptable and compatible in the international promotion.
2 Development status
At this stage, the development of China's intelligent substation focuses on engineering construction (power demand continues to grow). After several batches of intelligent substation pilot projects, China's intelligent substation has entered a new stage, and no longer only emphasizes the application of new technologies. However, the problem of construction cost has been taken into consideration. Therefore, a new generation of intelligent substation with small land occupation, low cost and high efficiency has become the future development direction. The construction of distributed modular substation is a new attempt and exploration. The benefits of developing intelligent substations in China are firstly to provide support for the development and construction of smart grids, and to further ensure the safety and reliability of grid operation. Secondly, the innovation of technology can improve the overall technical level of substations, and finally economic and Convenience considerations.
Due to the relatively stable demand for electricity in European countries, the construction speed of power grids is slow, and the demand for renovation and upgrading of old stations is relatively strong. Actively adopting new technologies and new equipment to improve the utilization efficiency of substations and power grids has become the driving force for the development of intelligent substations. Since the grid companies in European countries are more commercialized, the most direct benefit of developing smart substations is the reduction of total cost driven by the cost-effective driving force (this cost includes both the previous design and Construction, including post-operation and maintenance), followed by integration of equipment functions (for ease of operation and maintenance) and improvement of service quality, and finally the reliability of the grid, convenient access to new energy and reduced land occupation area.
3 Technical focus
3.1 IEC61850
Since its release in 2004, the IEC61850 standard has been widely used in digital substations and intelligent substations. It has become the basis for the construction of intelligent substations and even a new generation of intelligent substations in China. Due to the demand, investment and other factors in European countries, the engineering application based on this standard is relatively small. Therefore, the application of this standard engineering is less vigorous, but it is composed of 41 transmission operators (TSO) in 34 countries in Europe. The European network of transmission system operator for electricity firmly believes that the IEC61850 standard is the basis for the future development of substations, and that the entire European country can obtain economic and technical benefits through the promotion and application of the standard. And called for a comprehensive application.
3.2 Electronic Transformer
China's electronic transformers are actually the general name of electronic voltage transformers, electronic current transformers and optical transformers. They have been applied together since the application of IEC61850 standard, and together with IEC61850 standards have become the two major digital substations. Core features. Although China's electronic transformers have exposed a series of problems such as unstable operation in actual engineering, it is undeniable that electronic transformers are still considered as the trend of future technological development. This has formed a consensus in the industry. .
In Europe, the electronic transformers are collectively referred to as "Non-Conventional Instrument Transformers" (NCIT), and their superior performance is considered to be the future development direction. The digital sampling technology of the merged unit and the network tripping technology based on the GOOSE message of the switch device are also considered as the future development trend. Process-layer bus technology based on electronic transformers and GOOSE applications will become the focus of future development in countries such as Europe and the United States.
3.3 Other technologies
European countries have also proposed the following technical development directions for intelligent substations: convenient interaction of internal data of substation (state monitoring, equipment self-test, remote debugging and remote tuning), new system functions (synchronization vector, automatic operation, distributed state estimation) , condition monitoring and evaluation, improved substation block lock function, system and protection plug and play, wide area protection and monitoring, constraint management, flexible applications and simple debugging processes, most of these new technologies or new functions They are all based on operation and maintenance.
Due to its systematic characteristics, China's intelligent substation has more intelligent functions in addition to all the above technologies and functions, because China's intelligent substation is intelligent primary equipment and networked. Based on the secondary equipment, through the standardized collection, transmission and access of standardized information, an integrated monitoring system is constructed to realize unified storage, unified management and unified analysis of the total station information, and thus more intelligent functions are realized. The basics.
4 problems
China's intelligent substation has been improved and improved many times, and the overall level has been effectively improved. However, combined with the current reality, the following problems still exist:
1) The level of equipment intelligence is not high.
2) The stability of the operation of the electronic transformer is poor, and the communication interface is not standardized.
3) The level of practical application and intelligence of advanced application functions of substation is not high.
4) The technical integration between the intelligent substations and the interdisciplinary has not been carried out in depth.
5) Intelligent substation operation and maintenance level and maintenance efficiency are low.
6) Insufficient ability of intelligent substation for automatic inspection and debugging.
For European countries, power companies (such as France, Spain, etc.) and equipment manufacturers that have had IEC61850 engineering construction have strong feelings about the development and construction of intelligent substations, mainly in the following points:
1) Lack of a unified IEC61850 configuration tool. Although IEC6850 has a unified information model and configuration process, there are no specific technical requirements for configuration tools, which also leads to lack of interoperability between configuration tools. This problem also exists in China, and the problem is more prominent, because the topology configuration of the primary wiring of the substation in China has not been carried out at present, and the fusion between the SSD file and the ICD file of the topology diagram and the device are not realized. Association.
2) There is a problem with interoperability. Due to differences in the understanding of the IEC61850 standard in European countries, there are a series of interoperability problems in the implementation of specific projects. Due to the unified guidance and coordination in China, especially the six interoperability tests conducted by the equipment manufacturers in the early days of the National Center, it laid the foundation for the interoperability between different manufacturers.
In addition, there are some non-technical factors hindering the development of smart substations in European countries. For example, European countries generally believe that employee boycotts, lack of new technologies (such as communication technology), and short life cycles of equipment and systems will be potential for the development of smart substations in the future. Problems and major resistance.
5 Development direction
The European countries have established a smart substation website for academic exchanges, and on November 26-28, 2013, a seminar on “Next-Generation Smart Substations†was held in Frankfurt, Germany, focusing on smart substation investments. Discussions in the areas of network security, IEC61850 standard application, grid communication, data management and analysis, and new energy integration were also held. At the end of the conference, a seminar on GOOSE and SV applications was held.
In 2014, European countries applied the IEC61850 standard to a seminar on the large-scale application of IEC61850 standard in transmission grids and distribution networks under the smart grid architecture in Prague, Czech Republic on October 15-16, 2014. The impact and application of the second edition of IEC61850, system architecture optimization based on the IEC61850 standard, advanced application functions, substation operation and maintenance, system tool development, and future smart grid applications are discussed. It can be seen that the current and future focus of European countries is still on the in-depth analysis and understanding of new technology applications and the discussion and exchange of related technologies. Later, it will be a large number of popularization and application of IEC61850 standard and electronic transformers.
For China, the future development focus of China's smart substation is to continuously improve and perfect the problems existing in the current intelligent substation, and at the same time further develop towards the high integration of equipment, deep integration of systems, more open structure and more intelligent functions. Guided by this, we will carry out the construction of a new generation of intelligent substation with high system integration, reasonable structural layout, advanced equipment and equipment, economical energy saving and environmental protection, and support and regulation.
6 Conclusion
Intelligent substations are the future substations. The engineering construction of intelligent substation in China is internationally leading. China's development model combining technology research and engineering construction is correct.
Of course, when summarizing the achievements in the development and construction of smart substations in China, we also found that the views of European power grid companies or power peers can supplement and improve the development of smart substations in China:
1) Focus on the research of the underlying technology. It is recommended to further deepen the basic technology research, further expand the research field, and provide support for the comprehensive development of intelligent substation.
2) Pay attention to the control of the life cycle cost of intelligent substation. It is suggested that the future development of smart substation should be considered from the whole life cycle to optimize the cost from design, construction, development, testing, commissioning and operation and maintenance.
3) Pay attention to the convenience of operation and maintenance of intelligent substation. It is suggested that the recommendations of operation and maintenance personnel should be fully considered from the whole station design, equipment development and testing and debugging, and relevant research on operation and maintenance technology should be actively carried out to promote the maintenance and management of intelligent substation more convenient and efficient, which can not only reduce the life cycle cost of the substation, At the same time, it can further improve the safety and reliability of substation operation.
4) Focus on and promote the transformation of the operation and management model brought about by new technologies. It is suggested to combine the actual situation and new features of the development and construction of intelligent substation in China, and comprehensively consider the application of professional management and new technology to realize the harmonious development of intelligent substation in management and technology.
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