Nikolay Hinov

Technical University of Sofia | TU · Department of Power Electronics

This paper presents a unified approach to the analysis of DC/AC converters based on an equivalent representation of their AC circuit as a series RLC circuit. The resonant DC/AC converter with reverse diodes was chosen as the basis of the examination, and the obtained ratios for this device were used to derive the main ratios describing the operatio...

This article presents an analysis and methodology for designing resonant inverters with energy dosing for induction heating applications. These power topologies are characterized by the fact that the power consumption of the DC power source does not depend on the magnitude and changes of the load but is a function of the operating frequency, the va...

This paper presents a model-based and neural network-based innovative design of single-ended transistor resonant DC/AC converters with zero voltage switching (ZVS). A characteristic of the proposed design method is that the determination of the circuit elements of the converter is performed with an automated procedure, as their values are determine...

In the present work, on the basis of current data on prices, manufacturers of photovoltaic systems and the electricity market, a technological and economic justification for the production of electricity through photovoltaic generators is presented. The main task is to assess the effectiveness and return on such an investment in the context of the...

In recent years, micro turbine technology has become a continuously reliable and viable distributed generation system. The application of distributed energy power generation sources, such as micro gas turbines (MGT), to charge electric vehicles offers numerous technical, economical benefits, and opportunities. MGT are considered as they are smaller...

In the present work, on the basis of current data on prices, manufacturers of photovoltaic systems and the electricity market, a technological and economic justification for the production of electricity through photovoltaic generators is presented. The main task is to assess the effectiveness and return on such an investment in the context of the...

In the present work several different types of cylindrical inductors are investigated. Comparison of the following parameters are made - temperature distribution in different loads, electrical losses in each turn of the inductors and current density distribution in the inductors. We look into the advantages and disadvantages in different applicatio...

Model-based optimization of transient response of parallel resonance inverters for electro-technological application is made. Optimization is implemented on the basis of an already developed general inverter model, operating as a current inverter and as a resonant inverter. A target function is selected to limit the start-up current and also guaran...

The manuscript presents the results of the modeling of a hybrid power supply for powering an autonomous load. The system consists of a fuel cell and a supercapacitor and the control of energy flows is realized with a DC-DC converter. The model is realized in MATLAB/Simulink environment. Simplified fuel cell and supercapacitor models have been used...

This paper presents a new metaheuristic approach based on a self-adaptive genetic algorithm (SAGA) for solving the short-term hydro-thermal-solar scheduling with combined-cycle (CCGT) units. First of all, the proposed approach is applied to a test system with different characteristics, considering the valve-point effect. The simulation results obta...

In current research a hybrid autonomous supplying system for electric vehicles applications is presented. The hybrid system is consisted of fuel cell, micro gas turbine and supercapacitor. There are realized with averaged models in MATLAB/Simulink environment. The supplying elements are connected to a DC bus for charging a different type of EVs. In...

The new economic order will be based on new logistics projects. In Caspian region, a new transport corridor is emerging, with Russia and India as the end points, offering good development prospects for countries across the region. A combination of political, technical and economic factors make the project viable, despite the fact that the backward...

This manuscript proposes a new unified approach for the analysis of voltage source inverters that summarizes and unifies the operating modes of a whole class of inverters powered by a voltage source: resonant, aperiodic and voltage source inverters. The study was performed on a full-bridge circuit of a series RLC inverter with reverse diodes, opera...

This article aims to present a comprehensive approach with corresponding software that uses index matrices. They have been developed by the authors for an automated model-based design. One of the main goals of this paper is to propose a simple model solving technique for powering electronic devices (particularly, for all subsystems: power supplies,...

This paper presents the analysis, modeling, simulation and practical studies of resonant inverters with a voltage limitation on the resonant capacitor. The power circuits obtained in this way are characterized by the fact that the power consumption does not depend on the load changes, but is a function of the operating frequency, the value of the r...

Energy integration is considered to play a key role in the successful development of the European Union. It is assumed that purely market-based mechanisms in this sector, according to the neo-liberal model, can secure a constant supply at low prices. This is the basis of the Union’s energy policy, launched by the European Commission (EC). The main...

The paper presents a new unified method for designing the two basic types of serial resonant DC-DC converters (series and with a parallel-loaded capacitor). The method is based on the use of a simplified generalized approach for the analysis of this type of power electronic devices. It is characterized by the fact that regardless of the specific op...

This paper presents a numerical study of the effect of the transmission configuration on the energy consumption of an electric vehicle. The first part of this study is related to a vehicle simulation model that takes into consideration vehicle resistances such as aerodynamic, rolling and inertial resistance as well as the traction force. The model...

The EU’s “Green Deal” plans a carbonfree energy mix, neglecting nuclear energy, despite high social costs. Photovoltaic and wind power plants lack proper solutions for storing the excessive electricity. Their EROI is still lower compared to that of conventional sources. A complementary pair of combined cycle gas turbines (CCGT) and photovoltaics is...

This paper considers the synthesis of control of an electro-technological system for induction brazing and its relationship with the guarantee of the parameters and the quality of this industrial process. Based on a created and verified 3D model of the electromagnetic system, the requirements to the system of power electronic converters for obtaini...

Smart integration of the upcoming proliferation of electric forms of transport in our energy system is the key in order to make it more robust and ready for a greener future. As such, technologies as Vehicle to Home are key in order to optimize the house consumption on an individual level. This paper develops the key blocks of a modified Vehicle to...

Forecasting is a special scientific study, the subject of which is the perspective for the development of the phenomenon. It is of great importance for many scientific and applied fields. This article presents a stochastic model for microgrid load forecasting. Statistical and stochastic methods are used for forecasting.

The paper represents practical method for calculation and simulation of loop control part of peak current mode buck converter. It's useful for initial design in very early stage of product development. The presented research is useful from the point of view of the synthesis of control of power electronic converters, where it is of special importanc...

This paper aims to present an approach which automates electronic circuit design. It is based on index matrices with real number elements and their software implementation. Both they are developed by the authors as an example of universal tool on a wide class of electrical devices, and this approach is performed for complex components which have mo...

The paper considers the possibility of improving the characteristics of power electronic converters by using model-based optimization. To show the validity of the approach, a specific example of a single-transistor resonant converter with direct mode detection is considered. This type of converter is characterized by the absence of a transient proc...

In this article, a stochastic model for prediction of microgrid photovoltaic power generation, using statistical and stochastic methods is presented. The study is performed in the following steps: Processing of a large database of historical data (Data Mining); Construction of a stochastic forecasting model; Reporting a symmetric mean absolute perc...

The paper discusses a methodology for model-based synthesis of power electron converter control using the MATLAB/ Simulink software environment. To illustrate the procedure, a specific example with synthesis of a Buck DC- DC converter controller is considered. The individual stages of the process and their respective implementation are indicated. A...

The paper presents a 2D model of a system for contactless inductive energy transmission. Graphical dependences for the inductance of the transmission coil on the frequency, on the magnetic permeability of the concentrators and on the distance between the coils are obtained. In addition, results for the power of the transmitting coil and the depende...

In the current research a model simulating a system consisting of DC-DC converter with fuel cell and supercapacitor is presented. The model is realized in MATLAB/Simulink environment. For energy storage device a supercapacitor is used. On the base of the developed model and the control system of the energy flows, a researches related with the neces...

In this article is proposed a method for forecasting vehicle traffic intensity in urban conditions and provides an estimate of the forecasting error. For input data in this study are used: the number of vehicles that have passed through a location of the road, based on data collected by observations; meteorological conditions; the day of the week;...

In the current research modeling and simulation of a hybrid electric vehicle (HEV) in PSIM environment is presented. A review of the frequently used structure of for realization of the HEVs are proposed. Consistently, the individual stages of modeling are presented including the choice of electric motor, power electronic converters and energy stora...

This report examines one of the many possible solutions of dynamic and static mode contactless power transfer, which determines the future of the automotive industry. Computer analysis of a contactless charging station for electric vehicles in certain frequency range and displacement between the transmitting and receiving coils are presented. Conce...

Piezoelectric energy harvesters have been extensively researched for use with wireless sensors or low power consumption electronic devices. Most of the piezoelectric energy harvesters cannot generate enough power for potential applications. In this study, we explore the parameters, including gap and proof mass, that can affect the damping of the ca...

The electromagnetic process happening between an induction brazing coil and the brazing assembly was studied and is described in the following pages. Using the tools of numerical analysis, we managed to achieve 3-D simulation of the process, which includes presentation of the magnetic field, thermal heat transfer, and time dependence. The results p...