Modified empirical arc model for simulating HVdc open conductor faults

One fault that has hitherto not widely been investigated is the open circuiting of an HVdc conductor, as its occurrence is relatively rare. Using electromagnetic transient (EMT) simulation, this paper addresses the void in HVdc fault analysis by giving useful insight into the impact of HVdc open conductor faults on current and voltage transients. In order to simulate the resulting series arc between falling HVdc conductors, the Schavemaker model, a well-known empirical model, is adapted by introducing the dynamics of varying arc length. The modified Schavemaker arc model is implemented in PSCAD/ EMTDC. This study analyzes the impact of each parameter of the Schavemaker arc model on the arc conductance variation during an open conductor fault. This study shows that the arc time constant is the most influential parameter on the arc conductance variation while the time-varying reference arc voltage and arc cooling power introduces the effect of variable arc lengths to the Schawmaker model.