Switch Controller Implementation for Testing a Supercritical CO₂ Circuit Breaker Using Synthetic Test Circuit

This paper presents the design and implementation of a microcontroller-based switch controller for automated and precise operation of a synthetic test circuit used in high-voltage circuit breaker evaluation. The controller, built around the ELEGOO MEGA R3 Board (ATmega 2560), manages high-current and high-voltage operations, integrating quick exhaust solenoid valves, relay modules, fiber-optic communication, and a character display for user interaction. Key features include advanced timing mechanisms to initiate the spark gap immediately after current zero-crossing, essential for evaluating the dielectric recovery strength of supercritical <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{CO}_{2}\left(\text{scCO}_{2}\right)$</tex> as an eco-friendly alternative to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{S F}_{6}$</tex>. Safety measures, such as isolating personnel from high-voltage hazards by routing only air tubes and fiber-optic cables inside the test area, enhance operational security. A pressure and temperature transducer, integrated with a MATLAB-based data acquisition system, enables real-time monitoring of critical test parameters to ensure precise experimental conditions. The proposed system offers a robust, flexible, and scalable solution for advancing research in sustainable circuit breaker technologies.