Transient pressure variations in SF₆puffer circuit breakers

Abstract

The operation of the SF6 puffer circuit breaker relies on he pressurisation of gas by a combination of piston compression, nozzle blocking and gas heating. Theoretical modelling of the physical processes occurring during high-current interruption is important for mechanical design and for prediction of electrical performance. A high-current arc model has been developed, which takes account of observed gas behaviour throughout the arcing period and beyond current zero. The predicted pressurisation is compared with experimental work, and shows good agreement over a wide range of operating conditions. The theoretical model pays particular attention to the mechanisms of heat transfer within the upstream region of the interrupter, and incorporates a new description of the arc thermal boundary.

Experimental and theoretical investigation of an enclosed free burning arc in SF6

“…Piezoelectric pressure transducers have been used to measure pressure transients in high voltage circuit breakers [2]. The time constant for the charge amplifiers, which characterizes the time scale of the pressure transient to be measured, is set according to the typical rise time of the pressure variation.…”

Arc temperature profile measurement and characteristic analysis on an SF 6 high‐voltage CB

“…The arc, the gas flow, and their interaction in extinguish chamber is the key focus on the research on the breaking capacity [1][2][3][4][5]. Although models are becoming complex and accurate, there are still improvements needed to be made before the models can be used as a substitution for experiments, due to the complicated arc theory in CBs.…”

Composition of a Thermal Plasma Formed From Ptfe With Copper in Non-Oxidant Atmosphere, Part I: Definition of a Test Case With the Sf6

“…The arc surrounding material is made of polymer or contains it. In the working conditions the pressures can be vary from 1 bar to 30 bars [12,13]. That is why we choose to study the polyphasic compounds of plasma mixtures of (PTFE, SF 6 , Cu).…”