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

The results of a study using an artificial thunderstorm cell of the possible influence of incomplete ascending discharges from concentrated model elements of overhead line monitoring systems on their functioning in the electric field of a thundercloud and/or lightning are presented. It is shown that ascending incomplete discharges (streamers and/or leaders) are formed from the model elements of the overhead line monitoring system (sensors, receiving and transmitting devices of a concentrated type), which can affect the functioning of such devices, including due to the fact that frequencies close to the operating frequencies of the elements of the overhead line monitoring system are present in the spectrum of their currents. It is established that the spectral characteristics of incomplete streamer and leader discharges formed from model elements of sensors and of receiving and transmitting devices of the monitoring system under the influence of an artificial lightning cell include frequency ranges close to the frequency ranges of analog-to-digital converters of sensors and data transmission devices over a high-frequency channel of concentrated monitoring systems. The essential role of the streamer corona on the formation of the ultrahigh-frequency component of the current pulse of incomplete discharges is revealed. The obtained results can help to ensure lightning protection of monitoring systems in a real thunderstorm situation.

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Application of Artificial Thunderstorm Cell for Investigation of Effect of Incomplete Upward Discharges on Functioning of Concentrated Model Elements of Overhead Transmission Line Monitoring Systems

The article represents results of a physical simulation of incomplete upward leader discharges induced on air transmission lines’ elements, using charged artificial thunderstorm cells of negative polarity. The influence of such discharges on closely located model sensors (both of rod and elongated types) of digital monitoring systems, as well as on the models of receiver-transmission systems of local data collection (antennas), was determined. Effect of heterogeneity of electromagnetic field caused by incomplete upward discharges on frequency specter of signals generated on sensors and antennas was estimated. Wavelet analysis was carried out to determine the basic frequency diapasons of such signals. Based on experimental data obtained, suppositions about the extent of influence of nearby incomplete leader discharges on the functioning of currently used systems of transmission lines’ monitoring were made.

Artificial Negative Polarity Thunderstorm Cell Modeling of Nearby Incomplete Upward Discharges’ Influence on Elements of Monitoring Systems for Air Transmission Lines

A computer-aided design system (CAD) for the protection from lightning of the unit substations and overhead power lines was developed. A software package containing a calculation model of areas protected from direct lightning strikes, backflashover of the primary and secondary insulation, induced pulse voltage in the secondary circuits, protection from lightning of the power lines, and protection of power substations against the lightning overvoltage along with the overhead power lines was developed. A database of the generic solutions for protection from lightning was developed, it being a structured collection of files containing the layout of buildings and equipment at the substation and the arresters’ layout plan with taking into account the electromagnetic compatibility. A database for earthing arrangement of arresters is the structured set of the typical arresters earthing. In order to find the required generic solution, the user selects the desired file by parameters using the standard tools for working with Windows files. On the basis of the regulatory documents on system and software engineering, the procedure for verification of the computer programs, to be applied as a part of the CAD for the protection from lightning of substations and overhead power lines, was developed. The verification procedure is based on testing of computer programs, as part of the developed system, using test sets containing the test cases. Test cases and test sets for testing the computer programs were developed. The computer-aided design system (CAD) allows significantly reducing the cost for designing of the protection from lightning and improving the quality of the projects.

B. K. Maksimov

Papers

A Computer-Aided Design System for Protecting Substations and Overhead Power Lines from Lightning