The results of a physical simulation using negatively charged artificial thunderstorm cells to test the spectrum of possible electromagnetic effects of upward streamer discharges on the model elements of transmission line monitoring systems (sensor or antennas) are presented. Rod and elongated model elements with different electric field amplification coefficients are investigated. A generalization is made about the parameters of upward streamer current impulse and its electromagnetic effect on both kinds of model elements. A wavelet analysis of the upward streamer corona current impulse and of the signal simultaneously induced in the neighboring model element is conducted. A generalization of the spectral characteristics of the upward streamer current and of the signals induced by the electromagnetic radiation of the nearby impulse streamer corona on model elements is made. The reasons for super-high and ultra-high frequency ranges in the wavelet spectrum of the induced electromagnetic effect are discussed. The characteristic spectral ranges of the possible electromagnetic effect of upward streamer flash on the elements of transmission line monitoring systems are considered.

Physical Simulation of the Spectrum of Possible Electromagnetic Effects of Upward Streamer Discharges on Model Elements of Transmission Line Monitoring Systems Using Artificial Thunderstorm Cell

The impact of space point definition on dynamic electro-geometrical model of lightning strike probability

Overhead high-voltage lines are a common choice for power transmission, but their planning, installation and management are often challenging tasks because of the surrounding public interest and of their importance as critical infrastructures. This is particularly true in the case of industrial installations requiring a high continuity of service. The working group formed by the University of Brescia (UniBS), the University of Padova (UniPD), and Torino Transmission Operating Area (AOT) of Terna Rete Italia S.p.A. (Terna) has studied an innovative solution featuring a remotely-operated switchgear mounted directly on the trellis holding the conductors. This strategy reduces visual impact, land use and vulnerability of the system to weather adversity, but noise exposure of the population requires appropriate study. This work introduces a new technical solution, discusses its benefits, and assesses the audible noise impact of the improved transmission line, considering the combined effect of switchgear action and corona discharge around the conductors. The sound emission data are fed as input into a sound propagation software enabling evaluating the noise perceived by people living in the neighborhoods. A mitigation solution is proposed and analyzed.

Maintenance of a High-Voltage Overhead Transmission Line: Sustainability and Noise Impact Assessment

The design of new types of transformer equipment, in particular, station service voltage transformers (SSVTs), requires a detailed consideration of all technical aspects and conditions of their application and their design features. One problem is to provide their resistance to effects associated with their interaction with the grid. During transient events in the network caused by the operation of switching equipment or short circuits, the transformers are affected by the oscillating voltage, which, under certain conditions, can cause resonance overvoltages inside their windings. The design of SSVTs differs from that of common power transformers, mostly because different types of windings are used, which determines the essential difference in the natural oscillation frequencies and the theoretical possibility of the development of resonance overvoltages under changed combinations of network parameters and switching conditions. In this paper, the problems of estimating the natural and dominating oscillation frequencies in SSVT windings and the voltages on the longitudinal insulation of SSVT windings under the resonance conditions are considered. The proposed approach is applicable not only to SSVTs, but also to other types of transformer equipment.

Resonance Overvoltages in Primary Winding of a Station Service Voltage Transformer

Station Service Voltage Transformers (SSVT) combines the operating characteristics of power transformers and the design characteristics of measuring voltage transformers. Due to its lower initial cost and higher power supply reliability, its applications have been extended beyond that of auxiliary power. During transient events in the network caused by the operation of switching equipment or short circuits, the transformers are affected by the oscillating voltage, which, under certain conditions, can cause resonance overvoltage inside their windings. Based on the ATP-EMTP platform, the ferromagnetic resonance of SSVT is simulated and its simulation model, simulation algorithm, and waveform are analyzed. Based on the simulation analysis results, this paper puts forward the preventive measures of transformer ferromagnetic resonance from the perspective of voltage harmonics and insulation coordination.

Research On Ferromagnetic Resonance Overvoltage Based On Station Service Voltage Transformers

To the methodology of testing the fuel systems of aircraft under lightning strike

Test Procedure for Aircraft Fuel Systems in the Case of a Lightning Strike

Evaluation of moisture-discharge voltages of glass plate insulators under artificial pollution

The aim of this research work is to improve the reliability of high-voltage insulators in conditions of pollution and moisture during the operation of electrical installations in areas of Syria prone to industrial and natural pollution. In this work, it was considered two types of Russian production; PSV120B (dirt-resistant design) and PS160D (normal design). Moreover, the electrical strength characteristics of high-voltage glass plate insulators (GPI) of these two types, which operated on 66 kV and 230 kV overhead lines in the Sheikh-Najjar industrial area in Syria, were evaluated. The existing results are demonstrated the theoretical and experimental studies of the geometric parameters impact of the PSV120B and PS160D types of the insulators on their moisture-discharge voltages and intensities per unit construction height and along the creepage path from the average specific surface conductivity (in the range of (5–60 µs) with artificial pollution in accordance with modern regulatory documents.

Study the Impact of Geometric Parameters of Glass Plate Insulators on their Moisture-Discharge Voltages under Artificial Pollution

A method for improving the performance reliability of electrical installations under the conditions of polluting the insulation of the 66 and 230 kV overhead lines (OHL) and outdoor switchgears (OSG) in the Sheikh-Najar industrial region near Aleppo, the economic capital of Syria, is considered. According to the relevant regulatory documents, the most efficient approach to selecting the insulation levels is the one based on compiling regional and local insulation pollution maps (IPMs) in the territory where the grid facilities are located. An electronic local IPM in the Sheikh-Najar industrial region was compiled using the characteristics of industrial pollution sources. The article presents the climatic characteristics of the Aleppo city area, the electrical circuit diagram and insulation characteristics of the existing 66 and 230 kV OHLs and OSGs, the characteristics of industrial pollution sources (in terms of produced goods types and amounts), estimated pollution degrees (PD) at various distances from the enterprise boundaries with a circular wind rose, and those adjusted for the real wind rose in the city of Aleppo, and the local IPM of the Sheikh-Najar region drawn using the AutoCAD software. It has been established that there are zones with insulation pollution degrees 2, 3 and 4 in the Sheikh-Najar industrial region territory. Based on the study results, recommendations have been elaborated for increasing the specific effective creepage distance of the OHL and OSG insulation by adding linear insulators to the strings, for choosing the optimal types of substation electrical equipment, and for taking preventive measures. To refine the boundaries of local IPM zones, it is recommended to study the features characterizing the pollution of electrical installations insulation caused by both industrial and natural factors, as well as to generalize the experience gained from the operation of electrical installations in the Sheikh-Najar industrial region. 

S. I. Khrenov

Papers

To the methodology of testing the fuel systems of aircraft under lightning strike

Test Procedure for Aircraft Fuel Systems in the Case of a Lightning Strike

Evaluation of moisture-discharge voltages of glass plate insulators under artificial pollution

Study the Impact of Geometric Parameters of Glass Plate Insulators on their Moisture-Discharge Voltages under Artificial Pollution

Compilation of a Local Electrical Insulation Pollution Map in the Sheikh-Najar Industrial Region of Syria