3D Modeling and Simulation on Capacitive Interruption in High-Voltage Circuit Breakers

In a general case, due to the axisymmetry of a HVCB (high-voltage circuit breaker), the models for fluid dynamics simulation and electrostatics simulation are created on two-dimensional planar. However, in some particular cases, for instance 8 evenly distributed through-holes machined on the auxiliary nozzle, precise three-dimensional modeling is obligatory for obtaining a reliable analysis result. In this contribution a three-dimensional simulation method is presented, which consists of two parts: a 3D fluid dynamics simulation implemented by Ansys CFX and a 3D electrostatic analysis implemented by COMSOL Electrostatics. The difference between using a precise three-dimensional model and compromised two-dimensional models is also investigated by a time-resolved comparison of analysis result. This provides an available reference for modeling simplification in a similar situation. Finally, the analysis result is utilized by a sophisticated equation to evaluate the transient breakdown voltage for the capacitive current switching test. The capacitive interruption performance in turn can be estimated by comparing the transient breakdown voltage to the transient recovery voltage.