How does SF6 circuit breaker work ?
SF6 circuit breaker is a new type of circuit breaker that uses sulfur hexafluoride gas as an insulating medium and arc extinguishing medium. Sulfur hexafluoride gas is a colorless, odorless, non-toxic, non-flammable inert gas with high electrical strength and good arc extinguishing performance. Its dielectric strength far exceeds that of traditional insulating gases. Therefore, its use in electrical equipment can reduce the size of equipment, eliminate fires, and improve the reliability and safety of power systems.
Working principle of SF6 circuit breaker:
SF6 circuit breaker uses sulfur hexafluoride density relay to monitor gas pressure changes. When the sulfur hexafluoride gas pressure drops to the first alarm value, the density relay operates and reports the signal of gas replenishment pressure. When the sulfur hexafluoride gas pressure drops to the second alarm value, the density relay operates and reports the signal of locking pressure, and at the same time disconnects the tripping circuit of the switch to achieve opening and closing locking.
Below 150℃, SF6 has good chemical inertness and does not chemically react with metals, plastics and other materials commonly used in circuit breakers. When decomposed into various components under high temperature caused by high power, they will re-synthesize in a very short time after the arc is extinguished. SF6 has good arc extinguishing performance. In a simple interrupted arc extinguishing chamber, its arc extinguishing ability is 100 times greater than that of air. In SF6, when the arc current is close to zero, there is a high temperature only on the arc column core with a small diameter. And it is surrounded by a non-conductive layer. In this way, after the current passes zero, the electric strength drop of the arc gap is quickly restored.
The advantages of SF6 circuit breakers include good corona resistance, high dielectric strength, and the ability to work stably in a high-voltage electric field environment. The arc extinguishing chamber structure of SF6 circuit breakers is simple, which enhances the reliability and mechanical life of the circuit breaker.
LW25-126 outdoor high voltage porcelain SF6 circuit breaker by Shaanxi West Power Tongzhong Electrical Co., Ltd.It has Superior Breaking Capability,When interrupting magnetizing current, the overvoltage is less than twice the operating voltage. Additionally, when interrupting charging current, there is no re-striking or re-ignition occurs,Reliable Insulation.The properties of SF6 gas remain stable over time, protecting the insulating and conductive components from oxidation and ensuring stable temperature operation.
