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Tainá Fernanda Garbelim Pascoalato
Departamento de Engenharia Elétrica, UNESP, Ilha Solteira, SP
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Anderson Ricardo Justo de Araújo
Faculdade de Engenharia Elétrica e de Computação, UNICAMP, Campinas, SP
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Sérgio Kurokawa
Departamento de Engenharia Elétrica, UNESP, Ilha Solteira, SP
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José Pissolato Filho
Faculdade de Engenharia Elétrica e de Computação, UNICAMP, Campinas, SP
Keywords:
electromagnetic transient, switching maneuver, frequency-dependent soil, transmission line parameters, overhead ground wires
Abstract
This article investigates the influence of overhead ground wires (OGWs) on transient responses in power transmission lines (TLs). For this study, several simulations were performed considering two three-phase TLs, one of 138 kV and the other of 230 kV, both towers situated on the soil of 1000 Ω.m. The ground-return impedance and admittance are calculated by Nakagawa’s formulation and the frequency-dependent soil electrical parameters are represented by the Alípio and Visacro’s formulation. The line parameters (resistance, inductance, and capacitance) were calculated for a frequency range from 10 Hz to 10 MHz, for the TLs with and without OWGs. Then, the transient voltages developed for energizing (switching maneuver at one phase) the TLs for these same conditions were studied. The results showed that a significant variation is obtained for the self and mutual resistances and inductances when the effect of the OGWs is reflected on the impedance and admittance matrices of the line. However, this variation is negligible for the capacitance. As a consequence, the voltages generated in the open-receiving end of the TLs presented variations that are more expressive for the induced voltages on the non-energized phases.
