Dynamic modeling of de arc discharge on ice surfaces

Farzaneh, M.; Fofana, I.; Tavakoli, C.; Chen, X.

doi:10.1109/tdei.2003.1207474

Cited by 58 publications

(53 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Voltage source Transformer The AC and DC minimum flashover and maximum withstand voltages of the insulator were determined under the conditions given in Table 3 These results show that the effect of polarity on the insulator string is around 25%, which is in accordance with the results presented in [32]. Consequently, from the results obtained, it can be concluded that the minimum flashover voltage is lower under DC-and AC than under DC+.…”

Section: Evaluation Sequencesupporting

confidence: 81%

“…The flashover characteristics, as a function of surface conductivity, insulator length, and insulator diameter, determined by the dynamic model were quite satisfactory when compared to the experimental results of an insulating cylinder [32], [33], [125], [126], a short string of five IEEE standard insulators [32], [124], [125] and a post insulator [33], [125], [127] covered with artificial ice.…”

Section: Dynamic Modelsmentioning

confidence: 74%

“…Since the instantaneous behavior of arc parameters needs to be observed, a dynamic model must be developed based on equations and information related to the dynamic behavior of the arc [32], [33] as well as on the consideration of static multi-arc concepts [36] under DC and AC voltages. Therefore, to reach this goal, an AC and DC two-arc dynamic model was developed to analyze the flashover of icecovered insulators used under EHV network.…”

Section: Methodsmentioning

confidence: 99%

“…In order to study the mechanism of arc propagation over an ice surface [27], [28] and estimate the critical flashover voltage [18], [22], [29], [30], different static and dynamic models were originally established under AC and DC voltages [26], [31], [32], [33]. Contrary to static models which calculate the critical flashover voltage of ice-covered insulators, dynamic models can contribute to a better understanding of the discharge mechanisms involved in the time dependent evolution of the main parameters of the flashover.…”

Section: Equipment (Cigele) and Canada Research Chair On Engineering mentioning

confidence: 99%

“…In order to take into account the arc temperature as a function of the applied voltage level for DC+ and DC-, formulas were also derived based on a series of simulations and experiments related to short insulators [32].…”

Section: Dynamic Modelsmentioning

confidence: 99%

See 4 more Smart Citations

Two-arc dynamic modeling of AC and DC flashovers of EHV post station insulators covered with ice based on laboratory experiments /

Ledari¹

2014

View full text Add to dashboard Cite

Ice and snow accretion on insulators has been recognized as a significant risk factor in the reliability of overhead transmission lines and substations. Accumulated ice on insulators can initiate corona discharge along ice-free zones, often called air gaps. In the presence of a highly conductive water film on the surface of the ice, while applied voltage is sufficiently high, corona discharge activity may be initiated and developed into partial arcs. Under certain conditions, these partial arcs may result in complete flashover.The general objective of this research is to study the flashover phenomenon on icecovered extra-high-voltage (EHV) post insulators. Hence, a two-arc dynamic model based on the existing mathematical models was proposed to predict the parameters of AC and DC flashovers. The model considers the arc as time-dependent impedance constituted of a resistance in series with an inductance. The residual ice layer is defined in terms of an equivalent resistance, where the equivalent surface conductivity is calculated by taking into account the water film flowing along the ice surface. The present contribution proposes a novel approach to determine the equivalent surface conductivity, based on fluid mechanics and the Navier-Stokes equations, as well as on a series of experiments carried out to measure the water film flow rate and conductivity.Moreover, the mechanisms of discharge initiation and arc development on the surface of the ice accumulated on the insulators were studied. Special attention was paid to evaluate the effect of the volume conductivity of the ice surface on the arc propagation velocity for different freezing water conductivities, using high-speed video camera techniques.The proposed models were successfully validated in laboratory using station post insulators -typically used in Hydro-Quebec 735 kV substations -under AC and DC voltages. The maximum AC and DC withstand voltages were experimentally determined based on IEEE Std 1783. Furthermore, the influence of the number and position of air gaps on the flashover performance of ice-covered insulators was investigated experimentally. Experimental results revealed that the air gap configuration affects the maximum withstand voltage significantly. The main characteristics of flashover, including minimum flashover voltage and leakage current, derived from the proposed two-arc dynamic model, respond properly to the variation of major parameters, namely, insulator length and freezing water conductivity.Finally, in order to interpret the performance of insulators under different air gap positions, the voltage and electric field distributions along the ice-covered insulator were simulated numerically during the melting period, using the Finite Element Method (FEM). Simulations results confirm that increasing the number of air gaps improves the maximum withstand voltage and uniformity of voltage distribution of EHV post insulators. Based on the results, the use of booster sheds and grading rings to improve the insulating performance of...

show abstract

Section: Evaluation Sequencesupporting

confidence: 81%