The research and development of relay protection and monitoring technology for 1,000 kV ultra-high voltage transmission in foreign countries is introduced, and the relevant technical problems that need to be studied in this area in China are put forward. A substation relay protection and monitoring system platform constructed on the basis of IEC 61850 standard is given, which can be adapted to the characteristics of ultra-high voltage transmission, with strong real-time, and is a kind of information platform integrating relay protection, emergency control and system stabilization.

Keywords: extra-high voltage transmission; relay protection; monitoring system; power system

At present, China has formed a large regional power grid with the interconnection of Northeast, Northwest, North China, East China, Central China and South China power grids. With the construction of large hydropower bases, thermal power bases and nuclear power bases, there is bound to be a demand for long-distance, large-capacity ultra-high voltage or ultra-high voltage transmission. In China's existing power grid, the highest voltage level of DC ± 500 kV, the highest voltage level of AC is also 500 kV. the next few years, the upcoming AC 750 kV, and even AC 1,000 kV and above voltage level. Therefore, the ultra-high voltage power transmission technology, especially some key technical issues for in-depth study is very necessary.

1 Domestic and foreign ultra-high voltage transmission technology status and development trend

　　From the foreign situation, the United States, Canada, Brazil, Venezuela and South Africa and other countries have AC 750 kV voltage level transmission lines in operation; Kazakhstan Ekibastuz

Kokchetav transmission line voltage level of 1,200 kV, the line was put into operation in 1985, only a single return line, 900 km long, using 8-split conductor A1/ST330/43. .

A 1 000 kV experimental single-circuit line has been built near Pisa by the Italian power company Enel. However, this voltage level has not been used for transmission on the Italian grid to date. between 1975 and 1979, the US BPA Power Company commissioned an experimental line in Oregon with a maximum voltage of 1 200 kV, with the aim of investigating the environmental impacts at this voltage level. However, this voltage level has not been used in the BPA grid to date. The Tokyo Electric Power Company in Japan is now constructing the world's first AC double circuit overhead line with a voltage rating of 1,000 kV and a length of 287 km. The transmission line maximum working voltage of 1 100 kV, the maximum continuous current of 8 000 A, the natural capacity of each line back to about 5 000 MW, double back line capacity of about 13 000 MVA, corridor width is still limited to 100 m, tower height of about 110 m, the average stall distance of 549 m, the conductor phase spacing of 9 m. The use of 8 splitting conductor, 8 steel-core aluminum stranded wires, each cross-section 610 mm2 or 810 mm2, with the use of 8 split conductor, 8 steel-core aluminum stranded wires, each section 610 mm2 or 810 mm2, with the use of this voltage level. mm2 or 810 mm2, arranged in an octagonal shape, its effective diameter of about 1 m, this split wire electric field uniformity, corona noise is very small. Two overhead ground wires are used for lightning protection, each of which contains 5 groups of 6 optical fibers. Each insulator assembly consists of two or four insulator strings with 40 insulators per string, and the length of the insulator strings is about 9 m.

China has previously conducted some basic preliminary research on power transmission and transformation technology and equipment for voltage levels above 500 kV AC. In order to cooperate with the bidding of 750 kV system relay protection for Northwest Grid and to provide necessary technical data for the design, operation and scientific research of 750 kV system relay protection, Northwest Grid commissioned the Dynamic Modeling Laboratory of the System Institute of China Electric Power Academy of Sciences to carry out the dynamic modeling test of the 750 kV system relay protection device. The laboratory is China's first can simulate the 750 kV system of dynamic mode laboratory, it is Nanrui relay protection, four sides of the relay protection, Guodian Nanshi, Xu Jigong, ABB, GE, ALSTOM and TMT & D The eight famous relay protection manufacturers of a total of 37 sets of relay protection products line protection, reactor protection, transformer protection and busbar protection and other aspects of the dynamic mode of the test, the test is the first of its kind in the country, the test is the first time the large scale of the test. The scale of the test was the first time in China, and received wide attention at home and abroad.

2 foreign ultra-high voltage transmission relay protection and monitoring technology research and development situation

　　(1) AREVA. Shanghai AREVA Power Automation Co., Ltd. was established in September 2001 as a joint venture between AREVA Group (holding 59%) and Shanghai Power Transmission and Distribution Company Limited (holding 41%), and has acquired the power transmission and distribution department of French Alstom Company as a whole. This is AREVA Power Automation's first research center in China. The main task of this research center is to carry out research on the principles of relay protection for UHV transmission lines and technology development, and to develop relay protection devices and other safety automation devices suitable for UHV power systems.

　　(2) Siemens. Siemens provides the SIPROTEC series of microcomputer relay protection products suitable for ultra-high-voltage power systems and generators, which are not only capable of controlling ultra-high-voltage primary equipment, but also capable of real-time display of measured values and realizing control by intervals. With a complete interval database and communication interfaces for various protocols, the protection data can be analyzed and managed by the user. the most striking feature of the SIPROTEC series of microcomputer relays is that all functions related to the secondary equipment can be integrated into a single device for each interval using artificial intelligence. the SIPROTEC series of microcomputer relays can also be be used as an integral part of the SICAM substation automation system for optimal configuration.

　　(3) GE. Although GE entered China's market relatively early, its relay protection and monitoring system products entered relatively late, so the product has less performance in China's power users.GE's UHV substation relay protection products based on ALPS technology are more adaptive, with series compensation, single-phase tripping, three-phase tripping and reclosing of the line can be selected, and it is a multi-functional digital protection device.

　　(4) TMT&D Corporation. Unlike the other companies, TMT&D's primary equipment and relay protection products do not have operational performance at voltage levels of 1,000 kV and above, and certainly do not have experience in the research and development, testing, construction and operation of products at voltage levels of 1,000 kV and above. Although their protection types are complete, the configuration mode and human-machine interface are quite different from our country.

3 Substation Relay Protection and Monitoring System Platform Based on IEC 61850 Standard

　　China Electric Power Research Institute (CEPRI) has completed the preliminary experimental research on realizing substation automation based on IEC 61850 standard, and has successfully developed a substation relay protection and monitoring system platform based on IEC 61850 standard.