Experimental Research on Break Dynamic Insulation Characteristics of C4F7N/CO2Mixed Gas

The insulation strength of high-voltage switchgear opening and closing break is the basis to ensure its safe operation, and it is also one of the important factors affecting its successful closing and breaking. In order to study the break insulation characteristics of the mixed gas of perfluoroisobutyronitrile (C4F7N) and carbon dioxide (CO2), Build a test and research platform for dynamic insulation characteristics of C4F7N/CO2 mixed gas break of the prototype circuit breaker closing-opening process under no-load high DC voltage, Measure the base pressure of 0.7MPa arc extinguishing chamber, the dynamic breakdown voltage of pure SF6, 5%C4F7N/95%CO2, 9%C4F7N/91%CO2 and 13%C4F7N/ 87%CO2 mixed gas, study mixed gas break insulation strength changes. The results show that, compared with pure SF6, C4F7N/CO2 mixed gas break dynamic breakdown voltage dispersion is greater, the expected penetration time is longer than SF6; increase the content of C4F7N in the mixed gas, The rate of change of the dielectric strength of the mixed gas break is improved.