Papers by Nikolay Komitov
E3S Web of Conferences
The current century is characterized by an increasing use of renewable energy - wind farms, solar... more The current century is characterized by an increasing use of renewable energy - wind farms, solar parks, bio fuels, etc. Climate change and rising prices of fossil fuels lead to increased investment in renewable energy. This raises the need to examine the impact of various factors on the efficiency of energy production from renewable energy sources. This is related to the development of adequate models and the implementation of appropriate computer systems to manage and control these processes. The present work presents the main aspects of the modelling of a building heating installation using renewable energy sources - a solar photovoltaic panel and a HHO gas generator. The additional energy needed to heat the building is provided by a pellet boiler. An energy balance of the studied building is made taking into account the external and internal temperatures and energy loss. The computer model was developed in order to build a system for process control in the building’s heating sys...
A hot water system and heating of a building was studied. The system contains a bio-fuel tank, bo... more A hot water system and heating of a building was studied. The system contains a bio-fuel tank, boiler and radiators. The electro-thermal analogy was used in the modelling of the system and an electrical equivalent scheme was obtained based on the generalized heat model and the identification of the thermal parameters. An automatic water temperature control system with PI controller has been developed. A methodology is proposed for calculating the parameters of the controller under optimum control law and different values of the damping factor. A heat and power consumption in different modes of operation is calculated. Simulation results for the water temperature and the thermal capacity in the leakage of water from the boiler was obtained. The receive results were confirmed experimentally.
Upgrading of insulation and heating systems of existing residential and public buildings aims at ... more Upgrading of insulation and heating systems of existing residential and public buildings aims at reducing energy consumption and improving energy efficiency. The report spreadsheet is used as a medium to calculate the energy savings associated with refurbishment. Въведение Обновяването на изолацията и отоплителната инсталация на съществуващи жилищни и обществени сгради има за цел намаляване потреблението на енергия и повишаване на енергийната ефективност. Методиките, които са разработени обхващат подмяна на оборудване с енергийно ефективно, осъвременяване на оборудване или сграда, придобиване на енергийно ефективно оборудване или сграда. Разработена е методика, свързана с осъвременяване на оборудване или сграда и с нейна помощ се изчисляват енергийните спестявания при обновяване на изолацията и отоплителната инсталация на съществуващи жилищни и обществени сгради [2]. Спестената енергия представлява разликата между ползваната енергия преди и след въвеждането на мярката или програмата...
A soft-switched inverter is derived from the passively clamped quasi-resonant link circuit with t... more A soft-switched inverter is derived from the passively clamped quasi-resonant link circuit with three different clamps: coupled inductor, diode clamp and coupled inductor and capacitor. The proposed soft-switching inverter is formed from the traditional pulse-width modulated (PWM) inverter by simply augmenting with auxiliary resonant circuits, and the soft switching is achieved through applying PWM switching control signals with suitable delays for the switches. Only one auxiliary switch is used to generate zerovoltage instants for the inverter switching devices. The designed soft-switching inverter is used for powering an induction motor drive to test its effectiveness. The proposed drive system is modeled and its performance is simulated in PSpice. Several results are presented to illustrate the performance of the proposed inverter topology with three different clamps.
A parallel quasi resonant DC link converter for induction motor drive application is analyzed and... more A parallel quasi resonant DC link converter for induction motor drive application is analyzed and designed. The proposed soft-switching inverter is formed from the traditional pulse-width modulated (PWM) inverter by simply augmenting with auxiliary resonant circuits, and the soft switching is achieved through applying PWM switching control signals with suitable delays for the switches. The designed soft-switching inverter is used for powering an induction motor drive which is connected to drive the constant nominal load. The converter is designed to achieve the maximum voltage gradient and simultaneously to have low peak current and voltage stresses on the devices and thereby to reduce the losses.
Design of induction motor drive with parallel quasi-resonant converter
2017 XXVI International Scientific Conference Electronics (ET), 2017
A parallel quasi resonant DC link converter for induction motor drive application is analyzed and... more A parallel quasi resonant DC link converter for induction motor drive application is analyzed and designed. The proposed soft-switching inverter is formed from the traditional pulse-width modulated (PWM) inverter by simply augmenting with auxiliary resonant circuits, and the soft switching is achieved through applying PWM switching control signals with suitable delays for the switches. The designed soft-switching inverter is used for powering an induction motor drive which is connected to drive the constant nominal load. The converter is designed to achieve the maximum voltage gradient and simultaneously to have low peak current and voltage stresses on the devices and thereby to reduce the losses.
DSP based induction motor drive with parallel quasi-resonant converter
2016 XXV International Scientific Conference Electronics (ET), 2016
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Papers by Nikolay Komitov