Effect of Ice Shedding on Discharge Characteristics of an Ice-Covered Insulator String during AC Flashover

Considering the ice shedding phenomena on ice-covered outdoor insulators, this paper conducted the artificial experiments by using a five-unit suspension ceramic insulator string covered with wet-grown ice to investigate the effects of ice shedding on the icing discharge characteristics. According to IEEE Standard 1783/2009, the minimum flashover voltage (VMF), propagation of discharges to flashover and related leakage current (LC) were measured. It was found that VMF after ice shedding can be increased by about 17% as compared with that before ice shedding. The initiation and formation of discharge arcs across ice-free regions caused by ice shedding become difficult, showing an unstable propagating path, indeterminate arc shape and longer arc column. Although VMF under ice shedding conditions is higher than that without ice shedding, the fundamental component, and harmonics show lower amplitudes for the latter case. The ratios of harmonics to the fundamental are well in accordance with discharge characteristics during the flashover for which the ratios show a relatively stable varying tendency in the absence of ice shedding, but show changeable and indeterminate variation under ice shedding conditions. The obtained results are helpful to understand the icing state and its influence on surface discharges for preventing the icing flashovers.

[1]  M. Farzaneh,et al.  Using chaotic features of leakage current for monitoring dynamic behavior of surface discharges on an ice-covered insulator , 2017, IEEE Transactions on Dielectrics and Electrical Insulation.

[2]  Masoud Farzaneh,et al.  Nonlinear characteristics of leakage current for flashover monitoring of ice-covered suspension insulators , 2016, IEEE Transactions on Dielectrics and Electrical Insulation.

[3]  Wang Yaoxuan,et al.  Asynchronism of ice shedding from the de-iced conductor based on heat transfer , 2016 .

[4]  M. Farzaneh,et al.  Study of discharge in air from the tip of an icicle , 2008, IEEE Transactions on Dielectrics and Electrical Insulation.

[5]  M. Farzaneh,et al.  Three-dimensional modeling of potential and electric-field distributions along an EHV ceramic post insulator covered with ice-Part II: effect of air gaps and partial arcs , 2005, IEEE Transactions on Power Delivery.

[6]  M. Farzaneh,et al.  A Multi-Arc Model for Predicting AC Critical Flashover Voltage of Ice-covered Insulators , 2007, IEEE Transactions on Dielectrics and Electrical Insulation.

[7]  A. El-Hag,et al.  Fundamental and low frequency harmonic components of leakage current as a diagnostic tool to study aging of RTV and HTV silicone rubber in salt-fog , 2003 .

[8]  M. Hara,et al.  A study of the leakage current of H.V. insulators under glaze and rime , 1978, Canadian Electrical Engineering Journal.

[9]  Hao Jiang,et al.  Analysis of icicle growth process of composite insulator under energized condition and its impact factors , 2015, IEEE Transactions on Dielectrics and Electrical Insulation.

[10]  Bing Luo,et al.  Insulator Contamination Forecasting Based on Fractal Analysis of Leakage Current , 2012 .

[11]  T. Suda.  Frequency characteristics of leakage current waveforms of a string of suspension insulators , 2005, IEEE Transactions on Power Delivery.

[12]  Jianlin Hu,et al.  DC Flashover Performance of Ice-Covered Composite Insulators with Parallel Air Gaps , 2015 .

[13]  Masoud Farzaneh,et al.  Flashover performance of IEEE standard insulators under ice conditions , 1996, Proceedings of 1996 Transmission and Distribution Conference and Exposition.

[14]  Caixin Sun,et al.  Simulation and Experimental Investigation of DC Ice-Melting Process on an Iced Conductor , 2010, IEEE Transactions on Power Delivery.

[15]  M. Farzaneh,et al.  Experimental investigation of the process of Arc propagation over an ice surface , 2010, IEEE Transactions on Dielectrics and Electrical Insulation.

[16]  Xingliang Jiang,et al.  Effect of shed configuration on DC flashover performance of ice-covered 110 kV composite insulators , 2013, IEEE Transactions on Dielectrics and Electrical Insulation.

[17]  H. Kordkheili,et al.  Determining the probability of flashover occurrence in composite insulators by using leakage current harmonic components , 2010, IEEE Transactions on Dielectrics and Electrical Insulation.

[18]  Jiazheng Lu,et al.  Voltage Distribution and Flashover Performance of 220 kV Composite Insulators under Different Icing Conditions , 2018 .

[19]  J. Talaisys,et al.  Voltage harmonic content of long artificially generated electrical arc in out-door experiment at 500 kV towers , 2014, IEEE Transactions on Dielectrics and Electrical Insulation.

[20]  Yong Liu,et al.  Investigation on shed icicle characteristics and induced surface discharges along a suspension insulator string during ice accretion , 2017 .

[21]  F Meghnefi,et al.  Monitoring leakage current of ice-covered station post insulators using artificial neural networks , 2010, IEEE Transactions on Dielectrics and Electrical Insulation.

[22]  Caixin Sun,et al.  Evaluating the safety condition of porcelain insulators by the time and frequency characteristics of LC based on artificial pollution tests , 2010, IEEE Transactions on Dielectrics and Electrical Insulation.

[23]  Masoud Farzaneh,et al.  Flashover Characteristics of Silicone Rubber Sheets under Various Environmental Conditions , 2016 .

[24]  Qin Hu,et al.  Ion Migration in the Process of Water Freezing under Alternating Electric Field and Its Impact on Insulator Flashover , 2017 .

[25]  M. Farzaneh,et al.  Role of air gaps on AC withstand voltage of an ice-covered insulator string , 2006, IEEE Transactions on Dielectrics and Electrical Insulation.

[26]  M. Farzaneh,et al.  Three-dimensional modeling of potential and electric-field distributions along an EHV ceramic post insulator covered with ice - Part I: Simulations of a melting period , 2005, IEEE Transactions on Power Delivery.

[27]  H. Ahmad,et al.  Odd harmonics and third to fifth harmonic ratios of leakage currents as diagnostic tools to study the ageing of glass insulators , 2010, IEEE Transactions on Dielectrics and Electrical Insulation.

[28]  Brian G. Stewart,et al.  Arc Energy and Temperature During Its Propagation Over Ice-Covered Surfaces , 2014, IEEE Transactions on Plasma Science.

[29]  Lin Yang,et al.  Icing Condition Assessment of In-Service Glass Insulators Based on Graphical Shed Spacing and Graphical Shed Overhang , 2018 .

[30]  M. Farzaneh,et al.  Modeling of the AC ARC Discharge on Ice Surfaces , 1997, IEEE Power Engineering Review.

[31]  Qin Hu,et al.  Effect of grading ring on ice characteristics and flashover performance of 220 kVcomposite insulators with different shed configurations , 2015, IEEE Transactions on Dielectrics and Electrical Insulation.

[32]  Masoud Farzaneh,et al.  Self-Normalizing Multivariate Analysis of Polymer Insulator Leakage Current Under Severe Fog Conditions , 2017, IEEE Transactions on Power Delivery.

[33]  E. Pyrgioti,et al.  Investigation and classification of field leakage current waveforms , 2012, IEEE Transactions on Dielectrics and Electrical Insulation.