Liubei station of ± 800kV flexible DC transmission project in Guangdong and Guangxi, which is a power transmission project of Wudongde Hydropower Station of China Southern Power Grid Corporation participated by CRRC Times Electric (TEC), has successfully boosted to 800kV, and successfully completed the DC short circuit fault self-clearing test. This means that Wudongde flexible DC transmission project has the full line operation conditions, which provides security for long-distance, high-voltage and large capacity power transmission.
The Guangdong Guangxi UHV power transmission project of Wudongde Hydropower Station of China Southern Power Grid Corporation is the first UHV Hybrid DC project in the world. It is a UHV multi terminal DC demonstration project and a key project of "west to East power transmission" with clear national 13th five-year plan for energy and power development.
CRRC TEC started the pre research and development of crimp IGBT devices in 2011, and successfully developed the first sample of devices in 2015. After continuous iterative improvement, optimization and upgrading, the device performance has reached the same level as the international mainstream products, and successfully completed various verification tests of the application of flexible DC transmission converter valve and circuit breaker, and successfully withstood the test. At present, it has been applied in a number of flexible HVDC projects in batches, which provides support for the improvement of the technical level and international competitiveness of China's HVDC equipment.
Wudongde project is loaded with the company's 4500V crimp IGBT, which is the most critical core device in the flexible DC converter valve. In response to the localization requirements of national major technical equipment, CRRC times Electric has developed a large size DMOS + IGBT chip, which has the characteristics of low on-off voltage drop, low switching loss and soft turn off characteristics. The product adopts silver sintering and flexible crimping technology, and has the characteristics of high voltage, large capacity, high reliability and high overload capacity. It can improve the safety, stability and economy of power grid operation and power transmission under the requirement of high voltage, large capacity and long distance flexible DC transmission project.