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Severe lightning environment has been the major cause of overhead transmission line outages. In order to minimise the impact of lightning overvoltage, it is necessary to further evaluate lightning performance of any line before implementing specific protection methods. Therefore, in this work, a thorough study on back flashover tripping patterns of a 275/132 kV quadruple steel monopole towers in Malaysia is presented. Several design parameters such as lightning current magnitude, tower footing resistance and power frequency voltage were varied to investigate their influences on the line performance associated with lightning events. The results show that each parameter gives a significant effect on the flashover patterns. For each case, no flashover was recorded on the higher voltage circuits (275 kV), even though the line consists of tall structures, which might be more susceptible to lightning strikes at the upper part. Regardless of the effect of tower height, flashovers occur mainly on 132 kV circuits due to difference in the line insulation level. The results obtained were then used in designing appropriate protection scheme to further improve the transmission line lightning performance, mainly in terms of reducing the double circuit line outages. [ABSTRACT FROM AUTHOR]

Severe lightning environment has been the major cause of overhead transmission line outages. In order to minimise the impact of lightning overvoltage, it is necessary to further evaluate lightning performance of any line before implementing specific protection methods. Therefore, in this work, a thorough study on back flashover tripping patterns of a 275/132 kV quadruple steel monopole towers in Malaysia is presented. Several design parameters such as lightning current magnitude, tower footing resistance and power frequency voltage were varied to investigate their influences on the line performance associated with lightning events. The results show that each parameter gives a significant effect on the flashover patterns. For each case, no flashover was recorded on the higher voltage circuits (275 kV), even though the line consists of tall structures, which might be more susceptible to lightning strikes at the upper part. Regardless of the effect of tower height, flashovers occur mainly on 132 kV circuits due to difference in the line insulation level. The results obtained were then used in designing appropriate protection scheme to further improve the transmission line lightning performance, mainly in terms of reducing the double circuit line outages. [ABSTRACT FROM AUTHOR]

Surge arrester is widely used as a protective device to reduce possibility of flashover during transient overvoltage event. The device needs to withstand high energy discharged by the overvoltage which may increase the degradation rate of its characteristics. In this study, a set of transmission line surge arresters with different dimensions and ratings was simulated to investigate their discharge energy capabilities during fast‐front surge events using the finite element analysis method. To validate the accuracy of the method, the arrester models were also simulated by the use of PSCAD/EMTDC and EMTP‐RV software and compared with the specifications provided by the manufacturer. In spite of distinctive representations of the arrester models in COMSOL Multiphysics, EMTP‐RV and PSCAD, the comparison made between the simulation results indicates a satisfactory agreement. The manufacturers' data were used to validate that the proposed simulation model is acceptable. It was found that the simulation results were comparable with the manufacturer's test data of the discharge voltages and energy withstand capability, thus proving that all studied cases were adequately modelled. Parametric analyses were also conducted using finite element method to study the effects of varying the design geometry of the ZnO blocks and the arrester's housing on the energy absorption, which cannot be evaluated using PSCAD and EMTP‐RV software. [ABSTRACT FROM AUTHOR]

There are many factors, which influence the behaviours of partial discharge (PD) within a void located in a solid dielectric material. One of the important factors is the waveform of the applied voltage on the electrode of a system, such as its amplitude and frequency. In this study, a two‐dimensional axial‐symmetric model of a cylindrical void in polyethylene layers has been developed using finite element analysis software. The model was used to simulate PD activity in the void under square waveform applied voltage under different amplitudes of the voltage. The model has considered the effect of charge propagation along the void surface during a PD occurrence. The obtained simulation results were compared with the measurement results reported from previous literature to validate the PD model that has been developed in this work. It was found that the simulation and measurement results are within reasonable agreement with only slight disagreement. From the comparison, critical parameters from the model that affect PD behaviours under square waveform applied voltage were found to be the electron generation rate and the inception, extinction and critical charge propagation fields. These findings may increase an understanding of PD behaviours within a void in a dielectric material under square waveform applied voltage, which is important for insulation diagnosis. [ABSTRACT FROM AUTHOR]