The world's first UHV multi-terminal hybrid DC demonstration project started

On May 15th, the world's largest mixed-capacity DC transmission project with the largest transmission capacity and highest voltage level—Wudongde Power Station Power Transmission Guangdong Guangxi UHV multi-terminal DC demonstration project officially started. Liu Baohua, deputy director of the National Energy Administration, attended the construction mobilization meeting. And speak.

Liu Baohua emphasized that the construction and implementation of the Wudongde Power Station's power transmission to Guangdong's Guangxi UHV multi-terminal DC demonstration project is an important measure to implement the national hydropower development strategy and promote the optimal allocation of clean energy. It is clearly defined in the 13th Five-Year Plan for Power Development. The key construction projects have great significance for the demonstration of science and technology innovation in China's power grid planning, design and construction. Relying on this project can drive the independent research and development of key equipment of domestic large-capacity flexible DC power grid, further improve the technical level of China's power equipment manufacturing, and accumulate experience for large-scale promotion and application of flexible DC transmission technology. All relevant units should raise their ideological understanding, strengthen organizational leadership, overcome difficulties, scientific construction, adhere to safety first, quality first, and successfully complete construction tasks on schedule.

Wudongde Power Station Power Transmission Guangdong Guangxi UHV multi-terminal DC demonstration project adopts ±800 KV multi-terminal technology, and the project will build Yunnan Kunbei, Guangxi Liubei, Guangdong Longmen ±800 KV converter station, with a new commutation capacity of 16 million kilowatts. The construction of ±800 KV DC transmission line is 1489 km, with a total investment of about 24.25 billion yuan. It is expected to be put into operation at the end of 2020.

The responsible comrades of the Power Department of the National Energy Administration, the New Energy Department and the Southern Energy Regulatory Bureau participated in the above activities.

Extended reading

Wudongde Power Station Power Transmission Guangdong Guangxi UHV Multi-terminal DC Demonstration Project

Create multiple world firsts

RThe world's largest UHV multi-terminal DC transmission project!

RThe world's first UHV multi-terminal hybrid DC project!

RThe world's first UHV flexible DC converter station project!

RThe world's first flexible DC transmission project with DC fault self-cleaning capability for overhead lines!

Wudongde Power Station Power Transmission Guangdong Guangxi UHV multi-terminal DC demonstration project survey and design is divided into 12 sections, China Energy Construction Institute, Northeast Institute, Zhongnan Institute, Southwest Institute, North China Institute, Guangdong Institute, Yunnan Institute 7 The home unit undertook the survey and design work of 10 of the tenders.

Wudongde Power Station Power Transmission Guangdong Guangxi UHV multi-terminal DC demonstration project starts from Yunnan Kunbei Converter Station in the west, to Liubei Converter Station in Guangxi and Longmen Converter Station in Guangdong. It adopts ±800 kV three-terminal hybrid DC technology. The total length of the line is 1489 kilometers and the transmission capacity is 8 million kilowatts.

★Line length: 1489 km

★Delivery capacity: 8 million kilowatts

★Production time: 2020

★Completed and put into production: 2021

Technical characteristics

The project adopts a more economical and more flexible multi-terminal DC system. The Yunnan Kunbei converter station at the sending end adopts UHV conventional DC, and the Liubei converter station in Guangxi and the Longmen converter station in Guangdong adopt UHV flexible DC. The technical advantage of flexible DC is that it breaks through the bottleneck of conventional DC to the receiving power grid system, and represents the future development direction of DC transmission technology.

Engineering significance

The project is a key trans-provincial transmission project identified by the National 13th Five-Year Plan for Energy Development and the 13th Five-Year Plan for Power Development. It is a national demonstration project for UHV multi-terminal DC. After the completion of the project, the annual consumption of coal in Guangdong, Hong Kong and Macao Dawan District will be reduced by 9.2 million tons and carbon dioxide emissions will be 24.5 million tons.

From the winning bid in March 2017, to the start of the project, what are the 7 companies that China can build? Let's say one family.

First, the Electric Code General Hospital

The General Electric Power Institute undertakes the design lead work for feasibility study and subsequent stages. The engineering design organization management form adopts the working mode of lead organization, independent design and joint research, and implements unified organization, unified management and unified coordination of engineering design to realize the coordination and unification of design principles and content depth.

According to the owner's request, the General Electric Power Institute took the lead in organizing various design units to carry out the feasibility study of Wudongde DC project in September 2016. The feasibility study review meeting was organized from March 14 to 15, 2017, December 19, 2017. On the 20th to the 20th, the feasibility study and closing meeting was completed, 14 concentrated work, 2 rounds of on-site survey work, 10 rounds of research and technical discussion work, nearly 40 related meetings, and 14 evaluation opinions. On May 3, the General Electric Power Regulation Institute organized a preliminary design closing meeting for the DC line and grounding line project of the UHV multi-terminal DC demonstration project in Wudongde Power Station in Chengdu, Sichuan.

In the construction of Wudongde DC project, Luosida Company of Electric Power Regulation Institute uses aerial survey, halava, 3D GIS, BIM, virtual reality, Internet + and other technologies to provide 3D digital management from engineering path optimization to infrastructure construction, and then to engineering. After completion, digitally hand over the entire process of information services.

In the initial stage of engineering feasibility study, using the pre-image and special library, auxiliary site selection and line selection, the project aviation flight was used to optimize the selection of the halava, shortening the path length by 22.75km and reducing the house demolition by 72,200 square meters. At the same time, build a mobile collaborative office platform to provide technical support for the feasibility study and initial working group on online communication, work briefing, meeting notice, real-time work dynamics, design file management, route and site map, project address book, and schedule.

Second, the Northeast Institute

The Northeast Institute is responsible for the design of the 210-kilometer DC line in Guangxi, and has applied several design innovations in its work:

In the route selection, the HELVA technology and the latest high-definition satellite imagery, aerial film, geological remote sensing and GPS are used to optimize the selection of the best path solution.

The negative protection angle design reduces the lightning trip rate.

1. Apply advanced technologies such as aerial film, DEM digital ground model and transmission line optimization decision-making software, adopt dynamic programming principle, and carry out tower planning research in wind-divided area and ice area.

2. Adapt to complex terrain, the tower's all-round long and short legs are used in conjunction with high and low foundations.

3. Apply flexible graphite grounding device.

4. Wudongde project and the northwestern engineering interchange channel optimization design, avoiding multiple crossovers and reducing engineering operation and maintenance risks.

5. At present, the Northeast Institute has completed the preliminary design closing, and the construction drawing design is underway. The next step will be to deliver the drawings and carry out the design work service according to the schedule.

Third, Central South Hospital

The Central South Institute is responsible for the design of the Liubei Converter Station in Guangxi, applying a number of innovations.

1. In the world, the engineering upgrades the voltage level of flexible DC to UHV ±800kV for the first time. It innovatively proposes a full-bridge and half-bridge hybrid topology of the converter valve, which can realize self-clearing of overhead line faults and meet the high overhead of DC overhead transmission. Claim.

2. Flexible DC high and low end valve group online retreat, three-terminal DC operation mode, inter-station coordination control strategy are the first.

3. For the first time in China, the connection of ±800kV UHV DC line is realized in the station, and the high-speed DC parallel switch realizes the online retraction of the receiving end converter station, and the operation mode is flexible and reliable.

4. For the first time in China, the bridge arm reactor is placed on the DC side of the converter valve, which effectively reduces the influence of transient current.

5. Grid structure valve hall span further refreshes the domestic power industry new high

6. The design team brainstormed and boldly innovated, and completed the unique layout design of flexible DC and conventional DC for the special capacity of Liubei Converter Station.

Fourth, Southwest Hospital

The Southwest Institute is responsible for the inspection and design consultation of the ±800 KV  converter station in Kunming and the ±800KV DC line and grounding line in Yunnan. At present, the backbone of the business has been dispatched to actively carry out the construction drawing design, and the quality and quantity will be completed according to the business requirements.

It is expected that the construction part of the project will complete the construction drawing design at the end of June 2018, and the construction part design will be completed at the end of December 2019.

Fixth, North China Institute

The North China Institute has contracted the DC line design of the Tianzhu County-Jinchengjiang section of Guangxi in Guangxi. The line passes through the three administrative districts, Tianzhu County, Nandan County and Jinchengjiang District, from west to east. The terrain is 100% high mountain Daling, with a total length of 160.9 kilometers.

The North China Institute organizes its capable and dedicated efforts to overcome complex and severe external conditions, completes path review, detailed site survey and construction drawing design with high quality and efficiency. At present, it is undergoing intense construction drawing design, oriented by design optimization and innovation. Consolidate the foundation for the smooth construction of the project.

Sixth, Guangdong Institute

The Guangdong Institute is responsible for the consulting design of the Wudongde DC project in Guangdong receiving converter station, grounding pole and DC line in Guangdong Province.

Since the feasibility study of the project started on September 29, 2016, the Guangdong Academy quickly established a design team with strong technical skills, strong combat capability, tacit understanding and courage to serve; in just over 2 months, through the Yuexi Yuedong 5 In the 15 counties of the city, there are 40 site sites and 46 grounding sites, 3 DC route schemes, 100 agreements, and 4 unique routing reports. The proposed site and route recommendations are The feasibility review passed the expert review.

At present, the Guangdong Institute is intensively carrying out the preliminary design work of the converter station, the grounding pole and the DC line, as well as the work of the three-way and one-level commutation of the converter station.

Seven, Yunnan Institute

The Yunnan Branch is responsible for the total length of the section line of 134 kilometers. Among them, the 60-kilometer section of the Panzhou section of Liupanshui City is the most crowded, full-most complex meteorological condition and the largest change in geological conditions, which places extremely high demands on design work.

This section of the channel is tight, and many places are measured in the field. The preliminary design is three times more than the conventional project. Under the careful planning and organization of the Yunnan Institute, the preliminary design review, special review and closing work have been completed, and the construction unit has completed the environmental impact assessment. Review of water and soil protection, complete all electrical and structural drawing design work of the line segment, and the current drawings have publishing conditions.

By: JUCRO Electric (Focus on Vacuum Interrupter, Vacuum circuit breaker, Vacuum contactor and Switchgear)

October 2018