High-speed train is supplied by alternating current (AC) power and bases on single-phase four quadrant (4Q) converter as one necessary part of the AC-DC-AC transform process. This paper introduce hysteresis control system of 4Q-converter and it's regulating characteristics. Regulating characteristics are obtained on the basis of energy balance equation and describes dependence of output voltage and regulating coefficient of the hysteresis control system ξ in rectifier-mode and recuperation-mode. The nonlinear character of the control characteristic and

The dynamics of the development of alternative power sources over the past severaldecades are presented, which gives reason to talk about the trends in the further development of windenergy. An analysis of the structures and technical characteristics of wind generators classifiedaccording to the international standard IEC 61400 is given. According to the classification of theinternational standard IEC 61400, the structures of wind generators are presented, namely, types ofelectric motors, power circuits of semiconductor converters that provide the generation of electricalenergy to the general industrial electrical network. The use of power electronics in various types ofwind turbine generation systems and offshore wind farms provides improved wind turbineperformance. Semiconductor converters are used in frequency and voltage control to regulate activeand reactive powers. The issue of the possibility of operation of wind generators in wide wind ranges,the issue of emission of reactive power and higher harmonics of currents to the general industrialelectrical network, as well as the issue of efficiency of various structures of wind generators areconsidered. A wind turbine control system with an asynchronous generator is proposed. A study oftransient control processes and energy compatibility of a full energy conversion wind turbine with apower supply network by simulation computer modeling in the Matlab / Simulink softwareenvironment is given. The obtained result indicates the fundamental possibility of operation of anasynchronous generator with a short-circuited rotor as part of a wind turbine operating in conditionsof variable wind speed. The proposed layout of the wind turbine with full energy conversion allowspower to be delivered to the AC grid at a variable frequency of rotation of the wind motor shaft,which allows to increase the control range and maximize the generated power at low wind speeds.

The methodology for modeling static and dynamic power losses in power IGBT and MOSFET transistors in the Matlab and Multisim software environments is given. It is shown that when modeling switching processes in power transistors, Matlab / Simulink does not allow determining the dynamic components of power losses, namely, the energy of turning on the transistor, the energy of turning off the transistor, as well as the recovery energy of power diodes. At the same time, the simulation of static power losses of power diodes and transistors in Matlab/Simulink is carried out with a significant error due to incorrect representation of the current-voltage characteristics. It is shown that for a more correct and accurate simulation of the operation of power transistors, including power losses in power switches, it is more appropriate to conduct simulations in the Multisim software environment, which takes into account more than 47 parameters during simulation, including temperature characteristics, parasitic input and output capacitances and inductances, nonlinearities of current-voltage characteristics and others. In Multisim, a circuit of a half-bridge inverter with power MOSFETs controlled by the IR2104PBF driver has been developed. It is shown that the switching of power transistors is significantly influenced by the parameters of the driver microcircuit, namely the size of the storage capacitor of the driver, as well as the value of the active resistance of the gate resistor. It is shown that the simulation in Multisim correctly displays the transient processes of turning on and off power transistors and reverse recovery of diodes, which allows determining the dynamic losses of power transistors and power diodes.

У статті наведено дослідження перехідних процесів і результати розрахунків статичних і динамічних втрат потужності в силових IGBT- та MOSFET-транзисторах при моделюванні у програмних середовищах Matlab / Simulink і NI Multisim. Визначено, що моделювання в NI Multisim більш коректне і точно відображує перехідні процеси ввімкнення та вимкнення силових транзисторів і зворотного відновлення діодів, що дає змогу  визначати динамічні втрати силових транзисторів і силових діодів. Показано, що модель силових транзисторів у NI Multisim враховує більше сорока семи параметрів, включаючи температурні характеристики, паразитні вхідні та вихідні ємності і індуктивності, нелінійності вольт-амперних характеристик транзисторів тощо. У програмному середовищі NI Multisim розроблено схему транзисторного MOSFET-ключа IRFZ44n, керування здійснює драйвер IR2104PBF. Подано адекватність часів ввімкнення та вимкнення силового транзистора, характер перехідних процесів при резистивному та резистивно-індуктивному навантаженні, залежність сумарних втрат потужності від частоти комутації.

The growing implementation of distributed energy resources requires the development of the architecture of traditional electricity systems. With the growing deployment of distributed energy resources, especially for small combined heat and power plants and renewable energy sources based on distributed generation units, the architecture of the future power supply system must be transformed in order to carry out more complex operations. The article provides an overview of micronetwork configurations with greater flexibility and reliability, parameters, structures, and control methods for electronically connected distributed energy resource  installations. Of the configurations considered, DC micronetwork and high-frequency AC micronetwork have shown better performance for some special applications, such as low-voltage and geographically small networks. The corresponding parameters in the structures of the blocks of distribution energy resources and the topology of power electronics are considered. With the increase in the nominal capacity of distribution power resource units, multilevel converters provide effective ways to reduce cost and increase efficiency. Methods of controlling electronically connected aggregates of distribution energy resources under different operating modes are described. Under  the influence of load and line impedance characteristics, different strategies of load distribution among units of distribution energy resources, control of instantaneous active and reactive power are compared. A multi-level hierarchical control architecture, micronetwork power and energy management is described. A  comparison of control architectures based on centralized and distributed technology indicates that the modern micronetwork must become smart and flexible with the help of  telecommunication infrastructures and the next generation of information technology.