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

Apiculture has become a profitable profession due to the high economic importance of honey and various beehive products. Honeybees are tiny social insects that perform a crucial function in the agricultural field and are necessary for good yields. Honeybees are the biological indicators of environmental health. Unforeseen rapid decrease in honeybee numbers characterized by the departure of honeybees from the colonies and accompanied by the total absence of any dead bees in the hive surrounding and inside it suggests a condition called Colony Collapse Disorder (CCD). Pesticides, pathogens, and other ecological stresses such as nutritional deficiency may add to bee extinction or CCD. Besides this, the exposure to low-level radiofrequency and microwave radiations from mobile phones also have profound undesirable effects on honeybees. Research has shown changes in biology and behaviour which includes some undesirable changes in the biomolecules concentration in honeybees because of radiation exposure. Extremely low-frequency electromagnetic field (ELF- EMF ) also affects honeybee`s immune system and navigation activities. The radiation induces emotional disturbance and genetic disorders in brood which attributes to a decline in the breeding efficiency of bees. The present review is an attempt to compile the causes of CCD and discuss the management practices to be followed by the beekeepers to avoid the devastating loss to them and the planet Earth.

Colony collapse disorder: A peril to apiculture

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

Special high-voltage busbar (current carrier) designs are widely used to connect various objects in stations and substations (generators, transformers, switchgear, etc.) and individual components of these systems (e.g., switchgear cells). Connecting various high-voltage objects at stations and substations with flexible wires is a thing of the past; this is now done with rigid non-corona busbars with air insulation, gas-filled current carriers, and current carriers with polymer insulation. In recent years, highly compact busbars have mainly involved the use of new insulating media (primarily gases and polymer dielectrics with high breakdown strengths), along with improvements in the technology for production and application of these materials. Various types of high-voltage busbars are currently in use: shielded air busbars, busbars with cast polymer insulation, sealed shielded busbars with primary insulation by high breakdown-strength gases. Losses in busbars are reduced by using technical solutions employing insulating media with low dielectric constants and the busbars are built to avoid corona at the rated working voltage. The solutions for busbar construction at present have various advantages and disadvantages, depending on the design of the busbar and the object on which it is used. Further improvements in high-voltage busbars will involve the creation of new polymer materials, technologies for their use, and the development and application of new gases with high breakdown strengths.

Technological Aspects of the Use of Cast Polymer Insulation for High-Voltage Switchgear and Busbars

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.

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

Operating-lock systems are intended to prevent emergencies and injury-causing hazards at power substations. To arrange operating locks in switch and control gear (SCG) cells, it is necessary to have technical tools of no-voltage and voltage detection on conductor buses. The use of no-contact capacitance voltage detectors is an efficient way to make the installation process less labor-intensive. A matter of substantial interest is the design of a no-contact device able to indicate the absence or supply of voltage in each separate conductor bus and initiate phase rotation. The designed voltage detector uses a system of three capacitance electric- field detectors installed in the SCG opposite to the respective lines. Each of the detectors is affected by the fields generated by all the lines when energized. Thus, the output signal of each detector is the sum of partial signals conditioned by the voltage of each separate phase. Each of the three partial components in such signals is detected by digital signal processing. The operation of the detectors under uncertainty was modeled by the Monte Carlo technique in the MATLAB environment. Each imitative test with a random set of parameters results in vector responses from the detectors. The test results help draw diagrams on a complex plane for full-phase and open-phase modes. It is shown that the pertinence of signal vectors to a specific region makes it possible to unambiguously identify the absence or supply of voltage for each separate conductor bus.

An Algorithm for a No-Contact Digital Three-Phase Voltage Detector

The article discusses the impact of ultra-high-frequency (microwave) radiation of a new generation of 5G networks on honey bees. It has been shown that alternating electromagnetic fields can have a harmful effect on bees. Exposure standards are considered, an analysis of the 5G electromagnetic radiation (EMR) effect on bees and methods of protection against exposure is carried out. The Specific Absorption Rate (SAR) value was calculated and it was concluded that the specific absorbed power is significantly less than the value causing the thermal effect on a honey bee. EMP protection can be provided by time, distance and shielding. An effective means of protection against the electromagnetic radiation effects is shielding of radiation sources using shields. When shielding high-frequency electromagnetic fields, the induced currents are concentrated near the screen surface; wherein at the penetration distance δ into the screen material the magnitude of components E and H decreases by 2.73 times. The results of calculating the efficiency of shielding bee hives from 5G EMR and energy flux density (EFD) inside bee hives showed the applicability of shields made of aluminum and steel to protect bees from 5G radiation.

S. S. Zhulikov

Papers

Technological Aspects of the Use of Cast Polymer Insulation for High-Voltage Switchgear and Busbars

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

An Algorithm for a No-Contact Digital Three-Phase Voltage Detector

Impact of next-generation 5G cellular communications on honey bees

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