800-kV, 80-kA breaker begins operation in Shaanxi

The world's first 800-kilovolt, 80-kiloampere high-capacity circuit breaker has entered commercial operation at the Qindao 750-kV substation in Shaanxi province, marking a breakthrough in high-voltage power equipment.

The 800-kilovolt, 80-kiloampere high-capacity circuit breaker enters commercial operation in Shaanxi. [Photo provided to chinadaily.com.cn]

The circuit breaker was jointly developed by the State Grid Shaanxi Electric Power Research Institute, Xi'an Jiaotong University, the China Electric Power Research Institute and Pinggao Electric Co. It has fully independent intellectual property rights, with all core components manufactured domestically, making it the world's first engineering application of a circuit breaker at this voltage and current level.

The equipment addresses the challenge of excessive short-circuit currents in the Northwest China power grid, supporting the safe operation of ultra-high-voltage grids and the development of a new power system.

National Grid research programs supported the project, with the development team overcoming key technical challenges in high-current interruption by improving arc simulation, interrupter design, contact and nozzle materials, and high-power operating mechanisms.

The team completed a prototype in February 2025, passed all type tests in September, and received technical certification from the Chinese Society for Electrical Engineering in November.

The project is expected to enhance the safety and stability margin of the Northwest China power grid.