Developing and standard testing of a 245 kV / 300 kV eco-efficient High-Voltage Circuit Breaker and Switchgear

This paper presents the development and testing of a 245 / 300 kV, 63 kA circuit breaker and switchgear designed to operate at both 50 and 60 Hz, utilising the standard eco-friendly gas mixture (CO2/O2/C4-FN) as an alternative to SF6 (the most potent greenhouse gas currently known). Motivated by the growing demand for sustainable solutions in high-voltage switchgear, the project aims to address environmental concerns while maintaining performance standards expected by the industry. The paper details the development process, gives an overview of the executed tests, and demonstrates how combining voltage ratings can streamline product qualification and accelerate market readiness. The circuit breaker’s performance under various test scenarios—representative of real-world operational…