The Numerical Study of Vacuum Arc Plasma Parameter Distribution for the Transmission Voltage Level Vacuum Interrupters

Vacuum circuit breakers are an environmentally friendly electrical equipment. At present, vacuum circuit breakers are widely used in 40.5 kV distribution power system with the excellent opening capacity and low maintenance loss. Decreasing the use of high greenhouse gas SF6 is an urgent task to build an environmentally friendly power system toward the dual carbon goal. Developing the vacuum circuit breakers to transmission level is one of the effective ways to replacing SF6. In the vacuum arc, the arc evolution process determines the performance of the circuit breaker. The arc plasma distribution in the inter-electrode region is an important characteristics of the vacuum arc evolution process. Because it is difficult to measure the arc parameters in the experiment, the present work establishes a magneto-hydrodynamic model to calculate the arc parameters. The current density distribution characteristics is also calculated in the model and it is found that the current constriction phenomenon mainly occurs near the anode. Moreover, the influence of opening velocities and magnetic fields on the arc plasma is investigated. The higher magnetic field and lower velocity could suppress the arc constriction. The results can provide a theoretical reference for the development of transmission level vacuum interrupters.