Modeling of current-limiting air-core series reactor for transient recovery voltage studies

This paper presents a methodology for obtaining the current-limiting air-core series reactor model suitable for the transient recovery voltage (TRV) studies, which is constructed from the reactor geometry, accounting for the winding design and disposition, as well as the insulating material properties. The model is based on the ladder connection of frequency-dependent lumped-parameter reactor winding elements (representing partial capacitances, resistances, inductances and conductances). A frequency-dependent equivalent admittance matrix is formed for the ladder network, which is further processed using the vector fit technique, resulting in a Foster-type network suitable for a direct incorporation within the EMTP-ATP environment. A parametric analysis is provided in the paper as well, featuring different impacts that the variation of reactor design properties produces on the inherent TRV response.