Validação experimental de modelos elétricos de circuitos de ensaio de tensão residual em para-raios

Abstract

This dissertation proposes the adoption of an electric model for residual voltage tests in zinc oxide (ZnO) arresters for standardized and non-standardized waveforms, using models of lightning already consolidated in the literature. The proposed model was validated from tests performed at the UFPA High and Extra High Voltage Laboratory (LEAT), obtaining results of residual voltage and discharge current measurements. In the tests, a 30kVrms nominal voltage arrester was used, subjected to a discharge current of 10kA with waveforms ranging from 8μs to 5μs of wavefront time. In order to vary the front and tail values of the impulsive waveforms, It was used the available inductors in the LEAT to change the values of the front and the tail of the impulsive waveforms. Additionally, simulations were performed in the ATP Draw software to evaluate the accuracy of the model for other waveform types, which initially could not be performed in the LEAT. The model result was compared to the measurement results. The model proved to be satisfactory for all impulsive waveforms. The parameters of the model are easy to determine, and all necessary information for the lightning arrester and pulse generator is contained in manufacturers' manuals and catalogs.