On December 31, 2018, jointly developed by C-EPRI Electric Power Engineering/Science & Technology Co., Ltd. (hereinafter referred to as C-EPRI) and the DC Transmission Technology Institution of the Global Energy Interconnection Research Institute, the 500kV DC circuit breaker of the Zhangbei Renewable Energy VSC-HVDC Demonstration Project (hereinafter referred to as "Zhangbei Project") , passed all type tests on the first try. More than ten experts from the DC Department of State Grid Corporation of China witnessed the key tests such as the 25kA high-current breaking and reclosing, and highly praised the test results.

In order to ensure the quality of the project, the C-EPRI Project Team has developed strict test procedures for the components, the branches and the equipment, (a total of 83 tests). During the half-month, the R&D test team worked all days with shifts to carry out the preliminary tests for all 940 test items to ensure that the functions are verified in advance and the problems are discovered timely, providing guarantee for the success of the overall type test, the product quality and the project progress.

The 500kV DC circuit breaker developed by C-EPRI has been fully optimized in terms of electrical topology, core components and overall integration, realized the modular and standardized design, and improved the economic efficiency, reliability and maintainability. Its specifications of the 3kA rated current flow, 4.5kA overload current, and 25kA/2.5ms rated breaking current, surpass the operation requirements of Zhangbei Project.

For the next step, C-EPRI will make efforts to complete the production test of Zhangbei Project HVDC Circuit Breaker, providing support for the project’s quality and timely implementation.