On October 10, Sino-Russian energy and power cooperation projects - China-Russia DC back-to-back networking project entered the commissioning stage. This is currently planning and constructing China's power transmission and transformation project with the highest voltage rating and largest capacity purchased from abroad. It will set up a bridge for mutually beneficial energy cooperation between China and Russia.

Progress: New highlights of Sino-Russian energy cooperation Accelerate the opening of Sino-Russian power transmission channels China and Russia are neighboring countries, as well as a world leader in energy consumption and production. Therefore, energy cooperation plays a decisive role in bilateral relations. Sino-Russian energy cooperation is an important part of the strategic cooperative partnership between the two countries. Energy cooperation is more like a lever, and the new world of Sino-Russian cooperation is being picked up.

However, the construction of the Sino-Russian DC back-to-back networking project was not easy: the project was officially started on July 26, 2007, and in November 2008, China completed the 500-kV Heihe converter station and the 411-km 500-kV Xinghe transmission line. Construction tasks. In August 2008, due to the stagnation of the Russian side construction project, the DC portion of the Heihe Converter Station was temporarily suspended. After repeated coordination and communication between China and Russia, on May 20, 2011, the State Grid Corporation of China resumed the restart of the project. On January 16, 2009, the 500 kV Heihe Converter Station 220 kV AC system has been put into operation to provide power support for the Heihe region in Heilongjiang Province and Russia-China border trade. After the construction of the DC part was resumed, it was only possible to recover from the Chinese side's AC operating status to back-to-back DC operation.

In order to accelerate the import of Russian electricity into China, the State Grid Corporation of China has accelerated the opening of power transmission channels from Russia to China. On November 29, 2010, China and Russia completed the construction of a 500kV trans-national transmission line in Heilongjiang. In Heihe City, Russia's “Amur-Heihe” 500 kV power transmission line from China to China has reached the final stage of sprinting before construction and operation. Equipment installation and commissioning are currently underway.

According to the person in charge, on the basis of Sino-Russian cooperation in scheduling and speeding up negotiations on electricity prices, China-Russia DC back-to-back networking project is expected to start commissioning in early December 2011 and start commercial operation in early 2012. The annual power supply capacity will reach 43 Billion kWh.

"The cooperation between China and Russia in developing electricity, especially the construction of the Sino-Russian DC back-to-back networked transmission project, has enhanced the transmission capacity of the northeast China, especially the Heilongjiang region, and solved the problem of power transmission for China's large-scale electricity purchase from the Russian Far East." Heilongjiang Electric Power Zhang Manzhou, deputy general manager of the company, told reporters.

Outstanding technical advantages lay the foundation for the market Li Chengren, deputy director of the Institute of Accounting and Auditing at the State Grid Energy Research Institute, said that “back-to-back” is a special way of HVDC transmission that merges Rectifier and inverter stations for HVDC transmission. In a converter station, the commutation process of converting AC to DC and then DC to AC is completed in the same place. Its rectifying and inverting structure and AC side facilities are exactly the same as HVDC power transmission and have the most basic advantages of conventional HVDC power transmission. They can realize asynchronous networking and can better realize interconnection of different AC voltage grids.

“The technical characteristics of the Sino-Russian DC back-to-back networking project are conducive to the safe and stable operation of the power grid, because both China and Russia are AC grids. This project is equivalent to a DC wall. When China and Russia have different currents and frequencies, they can ensure stable grid operation. "Li Chengren concluded that.

Wei Changxin, construction project manager of the Heihe Converter Station project of the Northern Branch of the State Grid Corporation of China DC Branch, told reporters: “Compared with conventional DC transmission, the advantage of 'back-to-back' is even more prominent. The two AC synchronous grids are isolated and can effectively cut off. The influence of the interconnected AC synchronization networks limits the short-circuit current, and the tie-line power control is simple and the scheduling and management are convenient.

Another major highlight of the Sino-Russian DC back-to-back networking project is the localization of equipment. The reporter learned that the capacity of the 500 kV Sino-Russian DC Connected Black River Back-to-Back Converter Station is 750 MW, and 6+1 converter transformers are installed. In the converter station project, the domestic results of domestic HVDC transmission technology have been fully applied, and complete design, engineering design, equipment manufacturing and on-site construction and commissioning have all been implemented independently. “The localization rate of the main equipment is up to 100%. At the same time, China-Russia 500 kV AC lines all use domestic circuit protection products, which also lays the foundation for domestic equipment to enter the Russian market.” Liu Tieyan, Deputy Director of the National Development and Reform Commission and Director of the Energy Bureau This assessment was made when the construction of the 500 kV Heihe Converter Station was inspected.

The challenge: The converter station is subjected to extreme tests. The “heart” is strong and fearless. The earthquake struck the Amur region in the Far East of Russia at 14:10 on October 14th as an important component of the Sino-Russian DC back-to-back networking project, 500 thousand. Volvo China-Russia DC-connected Heihe Converter Station was separated from the Far East region of Russia by only one river, and it was clearly felt. According to Duan Hongshi, deputy squad leader of Class A of Heihe River Converting Station of Harbin UHP Co., the valve tower of the converter valve of the converter station has a slight angle swing when an earthquake occurs.

Duan Hongshi told reporters that as the "heart" of the DC project, the converter valve is not only expensive, but also the operating conditions are very demanding. When the earthquake occurred in Wenchuan in 2008, a converter station caused an excessive swinging angle of the valve tower due to the earthquake, resulting in a unipolar shutdown and direct loss of the power load of 360 megawatts. In view of this, the valve tower of the converter station of the Heihe Converter Station adopts the indoor suspension structure for the anti-vibration measures. The standard body porcelain insulator and the adjusting screw are used to suspend the valve body and the lightning arrester on the steel beam at the top of the valve hall. Duan Hongshi explained that the suspension design enables the valve to have a good bearing capacity for both dynamic and static conditions. The valve design also takes into account the special requirements of the earthquake and can withstand 0.9 g of acceleration swing.

At the same time of excellence in design, Heilongjiang Electric Power Co., Ltd. was also aware of the emergency plan for preventing natural disasters in the Far East after the earthquake warning in Russia’s Far East, and requested Harbin Ultra High Voltage Company’s operation teams at the Heihe Converter Station to stop working at heights. The personnel evacuated from the equipment site area and inspected the vulnerable parts such as the valve cooling pipe and the valve protection optical fiber, contacted the converter valve equipment manufacturer, construction unit, and maintenance team in advance and were ready for troubleshooting.

In the end, after 18 hours of close monitoring, no failure occurred in the valve tower of the Heihe Converter Station, and all stations were operating normally.

Keeping the ice and snow cold and ensuring safe operation The weather in the northern part of Heilongjiang Province is harsh, and strong winds and snowfalls frequently occur. The upcoming cold winter also presents a problem for the safe operation of the converter station. It is reported that in 2010, in the coldest December of Heihe, the temperature dropped to minus 40 degrees Celsius, the lowest temperature in the same period in history.

How to deal with the challenge of freezing and guarantee the safe operation of the Sino-Russian 500 kV Black River dc back-to-back converter station?

According to Sun Ligang, Secretary of the branch of the Heihe Converter Station of the Harbin Ultra-High Voltage Bureau, Heilongjiang Electric Power Co., Ltd. has started early warning and emergency plans for low-temperature cold waves, and the Heihe Electric Power Bureau has stepped up special visits to power transmission facilities under its jurisdiction. At present, the 500 kV Heihe Converter Station has researched and developed comprehensive measures for preventing cold and freezing, and organized all station personnel to conduct special night patrols and infrared temperature measurement, and locked key cold-proof and anti-freezing sites. It is accompanied by three voltage-rated SF6 tank circuit breakers. Key inspections are carried out on key links such as tropical operation, switch body ice coating, SF6 air chamber pressure, hydraulic spring mechanism oil level, and energy storage.

In addition, the staff also conducted special patrol inspections on all safety agency box heaters, tank switch body heating units, relay protection rooms, high-voltage room heating and thermal insulation facilities, and fire prevention facilities. At the same time, the cable trenches were also plugged and prevented. Installation of small animal facilities, optical fiber protection panels, valve body temperature, valve room interior temperature and humidity, water cooling systems, and water-cooled wall-penetration pipes have been inspected in a centralized manner to fully respond to the coming ultra low-temperature cold waves.

Significance: Safeguarding Energy Security and Promoting Economic Development Utilizing Russian Power Resources to Develop the Local Economy Heihe City, Heilongjiang Province and Russia's Amur State are separated by only one river. According to reports, Amur State has abundant power resources. At present, it has an annual surplus of 8 billion kwh. China-Russia cooperation in the development of DC back-to-back networking projects will promote the complementarity of China-Russia power resources and provide opportunities for the development of export-oriented economies in the Heihe region.

Heihe City is one of the first batch of open cities approved by the State Council. With the unique advantages of location, abundant resources, and ecological advantages, the border trade has developed from the initial barter to barter, spot foreign trade, private trade, and tourism. Trade, entrepot trade and other forms of international trade coexist.

The Sino-Russian power trade started in the form of border barter, and Russia’s surplus power entered China, providing clean energy support for the economic construction of Heihe City. According to statistics, in the first three quarters of this year, the power consumption of the Wuxishan Electric Power Processing Area of ​​Heihe Electric Power Co., Ltd., which is owned by Heilongjiang Electric Power Co., Ltd., reached 1.396 billion kWh. These power resources mainly come from Russia's Amur region.

The reporter learned from Heilongjiang Electric Power Co., Ltd. that from 1992 to the end of September 2011, China had purchased 4.6 billion kwh of Russia Telecom. At the end of January-September this year alone, Heilongjiang has purchased 925 million kWh of electricity from Russia, an increase of 30 million kWh from the contracted electricity, and 188 million kWh more than the same period of last year, a year-on-year increase of 25.5%. With the continuous deepening of Sino-Russian economic and trade cooperation, China will continue to increase the scale of electricity purchases against Russia in the future.

Enriching the content of cooperation to realize mutual benefit and win-win It is learned that Heilongjiang Electric Power Co., Ltd. will rely on the back-to-back conversion station project in the Heihe River, make full use of the energy resources of the Far East region of Russia, increase the power grid construction, and improve the northern grid of Heilongjiang Province that is still weak. The transformation of transmission lines and their corresponding substations to 220 kV, the construction of a new 220 kV Nenchang and Duobaoshan transformers, the construction of a 500 kV Heihe-Xingfu transmission line, and the construction of 500 kV EHV power transmission in the northern part of Heilongjiang Province The line is the backbone network grid power supply network, providing strong energy support for mineral development, industrial and agricultural development.

Experts said that the Sino-Russian DC Back-to-Back Networking Project will increase the energy efficiency of Russia’s Far East region, promote the establishment of Heilongjiang Province and strengthen the northeastern grid of “West Power Transmission to the East, North Power Transmission to the South” coordinated with the UHV, and expand China and Russia. The cooperation between countries on energy projects will enhance the complementarities between China and Russia and at the same time, it will also greatly promote China-Russia border trade and local economic development, and provide broad cooperation for promoting the rapid development of the energy industry and port cities in China and Russia. Space and strong energy security.

Li Chengren believes that the back-to-back project plays a significant role in promoting the economic development of China and Russia. It has enriched the content of China-Russia energy cooperation and has accumulated experience in cooperation. The scale of Russia’s power grid is the largest in Europe. Russia’s Far East region has rich coal and hydropower resources. This project plays an important role in the development of these resources, supporting the development of Russia’s energy economy, promoting employment, and increasing Russian energy efficiency in the Far East.

“In the long run, China-Russia electricity cooperation has achieved encouraging results and its potential has gradually emerged.” Ma Weiyun, professor of the Russian Academy of Heilongjiang University, said that nowadays, China’s energy sources mainly come from the Middle East, Africa, and Australia, geographically far away, and maritime shipping is extremely insecure. Important waterways have been dominated by the powers of big countries. Therefore, it is particularly urgent to ensure the multi-channel and diversification of energy import. Russia is currently China's fifth largest energy importer and has broad development prospects. China and Russia are geographically close to each other, with convenient pipeline transportation, low cost, and large volume of transportation. In the future, if the two countries can cooperate in depth, they will develop large economies for the two countries. There are benefits.