Vacuum Circuit Breaker: Working Principle and Advantages Analysis
Vacuum circuit breaker is a widely used protective device in power systems, and its working principle and advantages are as follows:
1、 Working principle
The working principle of a vacuum circuit breaker is mainly based on the arc extinguishing process in vacuum. When the moving and stationary contacts are opened by the operating mechanism, an arc is generated between the contacts. Due to the special shape of the contact design, a magnetic field is generated when current passes through, and the arc moves rapidly along the tangent direction of the contact surface under the action of this magnetic field. At the same time, the surface of the contact emits steam at high temperatures, and some of the metal vapor condenses on the metal cylinder (shielding cover). When the arc naturally crosses zero, it extinguishes and the dielectric strength between the contacts quickly recovers.
2、 Advantage analysis
1. Efficient arc extinguishing capability: Vacuum circuit breakers extinguish arcs in a vacuum environment, allowing the arc to be quickly and effectively extinguished. Due to the absence of free electrons or gas particles in vacuum to maintain the arc between electrodes, the arc will immediately break when the contact opening space is small. This efficient arc extinguishing capability helps reduce damage to electrical equipment caused by overload currents and improve the stability of the power system.
2. Long service life: The arc extinguishing chamber of the vacuum circuit breaker is designed to be sturdy, and the vacuum environment makes the corrosion and wear of the contacts very small. Therefore, vacuum circuit breakers can be used for a long time without extensive maintenance, reducing operating costs.
3. Compact design: Vacuum circuit breakers have the characteristics of small size and light weight, which makes them very suitable for use in environments with limited space, such as commercial buildings and power plants.
4. Low maintenance requirements: Due to the fact that vacuum circuit breakers do not produce harmful gases during arc extinguishing and have minimal contact corrosion, maintenance requirements are relatively low. This helps reduce maintenance time and costs, and improve equipment reliability.
5. Environmental friendliness: Vacuum circuit breakers do not produce any harmful gases during arc extinguishing, which meets environmental requirements and has a positive impact on protecting the environment.
In summary, vacuum circuit breakers play an important role in power systems due to their efficient arc extinguishing capability, long service life, compact design, low maintenance requirements, and environmental friendliness, providing stable and reliable protection for circuit equipment.