Internal fault diagnosis of SF6 high voltage circuit breaker based on gas composition analysis

摘要

SF₆ is a stable synthetic gas, it will break down into sulfur and fluorine atoms under the high temperature of breaking arc in the circuit breaker. SF₆ circuit breaker in breaking the arc and failure or internal discharge will produce low fluoride and metal fluoride decomposition products, including SOF₂, SO₂F₂, SOF₄, SO₂, H₂S, CF₄, HF, CS₂, CO, CO₂ and ALF₃, etc., through the detection and analysis of these decomposition products, cooperate with electrical test, you can analyze and judge the equipment fault focus. The saturating adsorbent adsorbed in the circuit breaker gas chamber may also release a small amount of decomposition such as SO₂, CS₂, H₂S to the outside through the release equilibrium reaction, therefore, the value of internal insulation could not be judged by the value of attention alone. The equipment should be diagnosed by combining the changes of humidity and other characteristic components, the electrical characteristics of equipment, and the operating conditions. In this paper, several different types of SF₆ circuit breaker internal decomposition abnormal situation are introduced. And the comprehensive diagnosis of the equipment is carried out by combining the electrical characteristics and operating conditions of the equipment. The judgment basis has been revised into China southern power grid enterprise standard <;power equipment maintenance test procedures>.