Investigation on the Influence of Opening Velocity for Vacuum Arc Control under Different Axial Magnetic Field Contact

Abstract

The world campaign toward green energy in the electrical engineering field highlighted replacing traditional SF6 circuit breakers with environmentally friendly vacuum circuit breakers (VCBs) in transmission-level power systems as an effective method to reduce SF6 greenhouse gas emissions. However, the challenge of interrupting high currents and minimising arc re-ignition caused the anode phenomena effect, which significantly led to the focus on optimising the vacuum circuit beaker's contact opening velocity for a succession of arc control and improving interruption ability at high voltage levels shortly after arc initiation. Increased focus on the influence of opening velocity in vacuum interrupters for arc control, driven by the need to improve VCBs performance, safety, reliability, and energy efficiency in modern electrical systems, advances in arc physics, material science, and the integration of smart grid technologies. By optimising opening velocity in vacuum arcs under different axial magnetic field contact designs, this paper aims to enhance the operation of vacuum circuit breakers, ensuring their continued success in fault protection. The research was conducted by simulation using the finite element analysis (FEA) method using Ansys software. The experiment used three kinds of AMF contacts: 1/3, 2/3, and Cup type contacts, with 100mm diameter, subjected to a peak current of 9.8kA, 12.1kA, 14.7kA, and 17.3kA. The contact opening velocities applied were 1.8m/s, 2.4m/s, and 3.0m/s, representing low opening velocity (LOV), medium opening velocity (MOV), and high opening velocity (HOV), respectively. The results on axial magnetic field distribution, arc voltage, and arc morphology behaviour have been studied and analysed