The breaking process of VTZ-12 vacuum circuit breaker under DC conditions can be divided into the following four key stages, combining arc characteristics and arc extinguishing mechanisms to achieve rapid current interruption:
Arc Ignition Stage (0-3mm):
An electric arc is generated the instant the contacts separate, and the current changes from a concentrated to a diffused pattern. During this stage, the arc must be quickly ignited to prevent contact overheating. The linkage structure needs to be optimized in the design to shorten the arc ignition distance.
Arc Extinguishing Stage (3-8mm):
When the contacts separate to 3-4mm, the arc enters a diffused pattern, at which point the insulation strength recovers most quickly. The arc axis is accelerated using a tripping spring and a magnetic field (longitudinal or transverse), causing it to move rapidly along the tangential direction of the contact surface and extinguish.
Arc Transmission Stage:
The arc is divided into multiple arc axes, moving outwards from the contacts under the control of a strong magnetic field. The magnetic field generated by the resistive current further suppresses arc diffusion, ultimately achieving current interruption.
Insulation Recovery Stage:
After the vacuum environment is disrupted, the arc energy is rapidly depleted, and the insulation strength between the contacts recovers quickly. The breaking process is typically completed within milliseconds to ensure system stability.
Key Technical Points:
Magnetic Field Control: Arc extinguishing efficiency is improved by accelerating the arc axis movement through contact design (e.g., spiral grooves) or an external magnetic field.
Vacuum Requirements:
High vacuum (absolute pressure below atmospheric pressure) ensures the arc is extinguished in a vacuum, preventing contact overheating.
Parameter Optimization:
Parameters such as opening distance and tripping speed need to be adjusted according to the current rating and commutation frequency to ensure reliable interruption.
Shaanxi West Power Tongzhong Electrical Co., Ltd.
Our address
Nanpo Village, Chencang Avenue Jintai District Baoji City, Shaanxi Province, China.
Phone Number
+86 18091767067(WhatsApp/Wechat/Telegram)
