Papers by Atanas Chervenkov
The article examines the work of a converter that synthesizes sinusoidal voltage supply to the ac... more The article examines the work of a converter that synthesizes sinusoidal voltage supply to the active-inductive load through method of controlled high-frequency pulses with sinusoidal pulse-width modulation. High frequency semiconductor key elements of the converter switched at zero current, i.e. with reduced switching losses, each high-frequency pulse transmitted to the load range specified quantity / dose / energy. The linear dependence on active power in load to the first harmonic amplitude of load voltage and regulation angle respectively is achieved. Simulations on the operation of the converter to achieve a sinusoidal voltage in the converter output are carried out. Simulink model of the investigated converter is composed.
2023 International Scientific Conference on Computer Science (COMSCI)
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Summary form only given. A method for determination of the optimum shape of the sidebar moving in... more Summary form only given. A method for determination of the optimum shape of the sidebar moving in the magnetic field with periodic non-sine structure is presented. The optimization criterion is the maximum of the induced electromotive force (e.m.f.). The equivalent shape of the sidebar is computed by means of frequentative solution of a variational problem with constant circumference of the
2021 17th Conference on Electrical Machines, Drives and Power Systems (ELMA), Jul 1, 2021
The magnetic and electric fields created of overhead line located in a densely populated area, ne... more The magnetic and electric fields created of overhead line located in a densely populated area, near a residential building are investigated. The goal of this study is to model the fields created of 110 kV distribution line, located in highly urbanized environment and to evaluate the field impact on the residential building, situated very close after new construction. The electromagnetic compatibility of high-voltage line is considered. To find the electromagnetic field components, a method using numerical solution of Maxwell's equations by finite-element method FEM is used. The magnetic field model is based on Poisson’s equation and on using of magnetic vector-potential. A modeling and simulation makes it possible to analyze real configuration and evaluate magnetic field levels and to establish electromagnetic compatibility. The electric and magnetic field levels in areas of the building are evaluate to verify the requirements of necessary exposure. The electromagnetic field has been investigated, taking into account the closer vicinity, where located a building recently built near the power line and it is possible to obtain high levels of the field. A magnetic flux density has relatively large values in a several areas of the building. The obtained electrical intensity levels are low, relative to the permissible norms for public exposure and ensure necessary safety requirements. The study allows the influence determination of the magnetic field and electric field of humans and can be evaluated risks of human health.
2019 16th Conference on Electrical Machines, Drives and Power Systems (ELMA), Jun 1, 2019
A grid-connected 30 kW small PV system, located in Southeast Bulgaria has been studied. Performan... more A grid-connected 30 kW small PV system, located in Southeast Bulgaria has been studied. Performance analysis of the PV system is done. The PV system is balanced according reactive power. The total harmonic distortion THD of the object is very low and satisfies the requirements of the standards. A model of PV system is created in MATLAB. Simulations of the operation in different modes have been carried out. The electromagnetic compatibility of analyzed small PV power system is satisfied.
The paper represents web-based educational platform, which delivers resources and theoretical ele... more The paper represents web-based educational platform, which delivers resources and theoretical electrical engineering related topics. The platform allows easily access by everyone because of its web-based nature. The system is based on top of the free open source software which makes its development efficient and time reduced significantly. The purpose of this interactive educational web-based platform is to provide a variety of significant, quality, and understandable content. Architecture of the platform is scalable and extendable. The article describes theoretical underpinnings, features, architecture, implementation of particular platform, and the application results.
The electromagnetic interference generated by multi-line power system for high voltage is conside... more The electromagnetic interference generated by multi-line power system for high voltage is considered. Capacitive penetration of electromagnetic disturbance in neighbouring electrical facilities, pipe system and vehicle located near overhead high-voltage lines are analyzed. A method for evaluation of the capacitive interference is proposed. The mutual capacitances and the interference voltage of low voltage line, arising from the disturbance by capacitive coupling are determined. The distribution of this voltage in the vicinity of high-voltage multi-conductor lines is obtained. The results, presented in this paper, illustrate the mechanism of capacitive interface between overhead multi-line power system and neighbouring electrical facilities.
An electromagnetic field EMF generated by high voltage overhead transmission line in an urban env... more An electromagnetic field EMF generated by high voltage overhead transmission line in an urban environment is presented. The electromagnetic interference generated by overhead high-voltage HV line is considered. The levels of the electric field and magnetic field around HV urban lines are investigated. They are calculated analytically and simulated numerically for various realistic cases like normal mode and short circuit mode. The magnetic field of a high-voltage power line under lightning strike is also simulated. An impact of electromagnetic field in electrical devices in adjacent building and people, which is located nearby urban HV line, is being studied. Model validation of numerical simulation with measuring results of electric field of an existing transmission line 110 kV is done. Results of the electric and magnetic field analysis of the overhead urban line were assessed to check the compliance exposure limits with the existing requirements. The presented method for the electromagnetic field modeling could be used for the evaluation of the impact on the human body by simulations of different, unusual situations like lightning strike.
Materials Science Forum, May 1, 2016
The magnetic and electrical field in the vicinity of overhead power line for high voltage - 220 k... more The magnetic and electrical field in the vicinity of overhead power line for high voltage - 220 kV is investigated. FEM model is created. Simulations of normal and emergency mode of the power line are made. The electrical intensity at idle mode in some areas, close to overhead power line, creates a high voltage level for humans. It can create also disturbances in the electrical equipment and the vehicles. These surges violate electromagnetic compatibility. The magnetic induction at emergency mode – short circuit and lightning strike in the areas around the towers could give a disturbing reaction of humans, animals and sensitive electronic devices. One solution for decreasing of the magnetic flux density to acceptable values is offered.
The possible application of a small wind power system, that can be deployed in many places in Bul... more The possible application of a small wind power system, that can be deployed in many places in Bulgaria at low wind speeds, is considered. An analysis of small wind power system is done. A model of small wind power system is created in MATLAB. A dynamic time conditions of the wind power system operation have been carried out. The studied system is balanced to generating power from wind generator and variable load by means of battery. The total harmonic distortion THD of the system is very low. The electromagnetic compatibility of the wind system is observed. The requirements of the standards are satisfied.
Proceedings of 11th Summer School Advanced Aspects of Theoretical Electrical Engineering -Sofia, 2016
The article examines the work of a converter that synthesizes sinusoidal voltage supply to the ac... more The article examines the work of a converter that synthesizes sinusoidal voltage supply to the active-inductive load through method of controlled high-frequency pulses with sinusoidal pulse-width modulation. High frequency semiconductor key elements of the converter switched at zero current, i.e. with reduced switching losses, each high-frequency pulse transmitted to the load range specified quantity / dose / energy. The linear dependence on active power in load to the first harmonic amplitude of load voltage and regulation angle respectively is achieved. Simulations on the operation of the converter to achieve a sinusoidal voltage in the converter output are carried out. Simulink model of the investigated converter is composed.
The non-linear circuit, which generates solitons, is obtained. The specific circuit scheme with e... more The non-linear circuit, which generates solitons, is obtained. The specific circuit scheme with electronic devicevariable capacitance diode, which helps generate solitons, has been chosen. The distribution of solitons along the linear surfaces is investigated. The model of investigation surface, where the solitons are propagated, is represented. It is considered as a linear circuit with distributed parameters with active losses. Surfaces with different area size are investigated. The greatest reduction is in the first cells of the surface area. The reduction of the soliton amplitudes along y-axis remain of less in the direction of x-axis. The surface area affects of the generation of solitons in the non-linear circuit. Index Terms Soliton, generation, propagation, non-linear circuit, distribution parameters, variable capacitance diode.
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Papers by Atanas Chervenkov