Métodos de cálculo da entrada de energia em para-raios – um estudo comparativo.

Abstract

In this work, the performance of zinc oxide (ZnO) surge arrester when submitted to several surge conditions and power frequency overvoltages was analyzed. Laboratory measurements of energy absorption in ZnO surge arresters were carried out at our High Voltage Laboratory. The absorbed energy was compared with two methods for energy calculation: proposed equations from international standards and papers, which is widely used for electric utilities, and digital simulations performed with the EMTP (Electromagnetic Transients Program). The comparison results shown that there was a good agreement between lab tests and EMTP simulations for energy produced by high current impulse. The energy analytical calculation presented better agreement for voltages near the power frequency.