The need for a fire-induced flashover probability index (FIFPI) for Eskom’s transmission lines (South Africa) became evident soon after the installation the Advanced Fire Information System (AFIS) in 2004. Thousands of wildfires were detected by satellites close to transmission lines, but only a small percentage (4%) of these fires caused a flashover. Historical flashover data was compared to s...

Importance of thermal radiation for transition to flashover in a compartment fire will be demonstrated. A one zone model is developed with the objective of capturing the key mechanisms responsible for the initiation of flashover, i.e. physics of flashover. Thermal radiation is shown to be a key point and the inclusion of a three-dimensional radiation model is essential in the development of an ...

Flashover of polluted insulators is still a serious threat to the safe operation of a power transmission system. Despite the extensive investigations carried out on the pollution performance of the insulators, the flashover characteristics are not well understood. Recent theoretical and experimental research on polluted insulators is yet to yield a perfect generalized mathematical model which c...

Comparison of available correlations and predictive models used to predict the minimum heat release rate (HRR) necessary to cause flashover show consistent trends for a range of empirical data. Nonetheless, available experimental data for HRR at flashover in compartments of similar geometry and venting show substantial scatter. Both the experimental data and theoretical predictions based on com...

Equations for studying flashover fire were studied experimentally in this paper. Experiments were carried out in a chamber inside a full-scale burning test hall of the joint project between The Hong Kong Polytechnic University and the University of Science and Technology of China. Three correlation equations on estimating the critical heat release rates for flashover were considered. The two-la...

A flashover occurs when a fire spreads very rapidly through crevices due to intense heat. Flashovers present one of the most frightening and challenging fire phenomena to those who regularly encounter them: firefighters. Firefighters’ safety and lives often depend on their ability to predict flashovers before they occur. Typical pre-flashover fire characteristics include dark smoke, high heat, ...

Insulation co-ordination and the risk of failure for insulation can be predicted if critical flashover (CFO) and insulation withstand voltages are known. The paper aims at using the statistical method of evaluating the critical flashover and the withstand voltage for an airgap distance of 10cm. The work was carried out with a point-plane electrode (needle point) arrangement using air as the die...

In this work an attempt has been made to estimate the pollution flashover voltage under various meteorological factors using radial basis function (RBF) neural networks. Orthogonal least squares (OLS) learning method is used in order to improve the lines performance against the pollution flashover of the post insulators. The technique of RBF neural network is employed to model the relationship ...

Ice flashover threatens the security and reliability of power transmission. However, the ice flashover mechanism of insulators remains poorly understood. This study analyses water droplet freezing and ion distribution in ice layer under alternating electric field. It also investigates ion migration during icing process of insulator string under alternating electric field and its effects on insu...

Flashover is a phenomenon describing a room fire changed from the growth stage to the development stage. There is a rapid increase in size and intensity. The radiant heat flux back to the fuel surface and the floor of the room is known to be one of the key parameters leading to flashover. Indeed, a heat flux (largely due to radiation) of 20 kW/m to the room floor is often taken to be the condit...