Transient overvoltage analysis in the medium voltage substations based on full-wave modeling of two-layer grounding system

In this paper, a comprehensive investigation of substation grounding soil structure effects on switching/lightning transients is presented. The full-wave computational solution Method Moments (MoM) adopted to solve Maxwell’s equations. significant advantage technique its ability deal effectively with systems (SGSs) at high frequency. This evaluation carried out considering two structures: (1) uniform and (2) layered structure. impacts both structures the peak transient overvoltage values are compared. To begin with, harmonic impedance matrix (HIM) multi-terminal SGS computed. Then, vector fitting approach employed incorporate accurate behavior by relying obtained HIM into time domain simulations. Finally, overvoltages maximum ground potential rise (GPR) chief contribution paper assessment two-layer large taking account frequency dependence model electrical parameters soil, which not generally investigated instead, treated simplistically. According results study, lack an exact system models may lead underestimations/overestimations GPR values. demonstrate need for modeling be incorporated power analysis in wide range frequencies. • impact lightning/switching performance MV has been examined. have considered. Multilayer using thin wire approximation performed. Multi terminal grid modeled connected EMTP platform. dependent effect parameter Transient SGS, dependence.