Flexible DC transmission technology creates 12 world firsts
Zhangbei green power large-scale transmission to Beijing
Our reporter Song Meiqian correspondent Wang Ning
"Close, execute!" At 10 o'clock in the morning on June 29 this year, with the operator's order, the knife switch and 4 DC circuit breakers in the valve hall of Zhangbei Converter Station were successfully closed, and the main control room was on the monitoring screen. The photovoltaic power curve began to rise gradually. Today, the Zhangbei Renewable Energy Flexible DC Grid Demonstration Project has been officially put into operation for nearly two months. The green power from Zhangjiakou is continuously supplying new power to the Beijing Power Grid.
Tian Shenglin, director of the construction department of the State Grid Corporation of Jibei Electric Power Co., Ltd., said: “The Zhangbei flexible DC grid test and demonstration project has a total investment of 12.5 billion yuan. China's plan for large-scale energy development and utilization of world-class problems."
According to Tian Shenglin, flexible DC technology is a new type of DC transmission technology with a voltage source converter as the core. Its main function is to integrate and package various clean energy sources into DC power at the receiving end. Then the direct current is transformed into stable alternating current and sent to the user. This technology has the characteristics of fast response speed, good controllability, and flexible operation mode. It is suitable for grid connection of renewable energy, grid connection of distributed power generation, and island power supply. Our country names this technology as flexible DC technology.
"The reason why we built this innovative project in Zhangjiakou, Hebei Province, is because it is a region rich in renewable energy resources, with many typical elements such as wind, light, and energy storage. It can be called the hometown of wind and light. "Ocean", wind and solar energy can be developed up to 85 million kilowatts, with good conditions for multi-energy complementary construction. At the same time, Zhangjiakou area has small power demand and limited new energy acceptance capacity, but the adjacent Beijing-Tianjin-Hebei power load center needs to have a strong Energy support.” Tian Shenglin said that the Zhangbei Rouzhi Project has connected hundreds of wind farms and thousands of photovoltaic power plants in Zhangjiakou and Chengde, Hebei into an organic whole, building a full-element Internet of Things, full-space display, full-information monitoring, The "Seven All" management and control system of full-scenario simulation, full-think tank guidance, full-process analysis, and full-life management realizes a line of interconnection channels.
"Flexible DC transmission technology is the most advanced power transmission technology in the world. It is equivalent to inserting a fully controllable'water pump' into the power system. It makes up for the limitation that conventional DC transmission can only control the direction and can accept clean electricity on a large scale. "Central South Electric Power Design Institute Beijing converter station design chief engineer Yang Ming told reporters that wind energy and solar energy are gifts from nature. In order to balance this power output, we have established the world’s largest wind and solar storage in Zhangbei. Integrated transmission equipment, with an energy storage capacity of 50,000 kilowatts. The world’s largest pumped-storage power station has been built in Fengning, with a total installed capacity of 3.6 million kilowatts, which will act as a reservoir in the entire system. When the power is abundant Use them to store energy and allow them to replenish the grid in time when the power is short, which increases the flexibility of the grid and more effectively guarantees the stable output of electricity.
The research and development of the main equipment of the project has gathered first-class technological innovation and equipment manufacturing units at home and abroad. Among them, the National Grid Global Energy Internet Research Institute undertook the research and development of the flexible DC converter valve with the world's highest voltage level and the world's largest transmission capacity. After three years of repeated exploration, the entire team finally overcome the technical difficulties.
"As a key supporting project for the 24th Winter Olympics, the Zhangbei Flexible DC Project is a practice of the concept of "Green Olympics" and "Low-Carbon Olympics". After transportation, approximately 22.5 billion kWh of clean electricity can be delivered to Beijing each year, which will not only meet the needs of the Winter Olympics, but will also greatly increase the proportion of new energy power consumption in Beijing, equivalent to saving 7.8 million tons of standard coal each year and reducing carbon dioxide emissions by 2040. Million tons.
Song Meiqian
Song Meiqian