<abstract xmlns="http://www.w3.org/1999/xhtml">The paper considers the possibility of steam production and supply process improvement by perfection of the steam boiler control system, applying invariance principle that makes possible preemptive compensation of the influence of steam expenditure as a disturbance on the control process quality and efficiency. For the development of invariant control system, the mathematical modeling and simulation in MATLAB - SIMULINK environment is made. The control unit is low pressure steam boiler with one input impact to control - the heat flow of burning gas mixture fuel, one measured output parameter of the process - the steam pressure, and the main disturbance as a load impact - the steam expenditure. The mathematical and virtual models and block-diagrams for transient process simulation is compiled, allowing to start practical design and investigation of steam boiler invariant control system with high operation stability under essentially fluctuating load. The simulation results prove that the optimal solution for the transient process improvement in steam boiler, taking in account fluctuating load, is invariant PID-DPC two loop control system with disturbance impact on steam pressure preemptive compensation. Under invariant control the steam pressure overshoots decreases substantially in comparison with the traditional PID-feedback control method.</abstract>

Invariant Method of Load Independent Pressure Control in Steam Boiler

<abstract xmlns="http://www.w3.org/1999/xhtml">In this paper several modulation techniques for a three-level neutral-point-clamped quasi impedance source inverter are proposed and discussed. Mathematical descriptions with simulation results are presented for each modulation technique. Their advantages and disadvantages are shown and guidelines for further improvement are provided.</abstract>

Chernihiv State Technological University, Tallinn University of Technology

Simulation Study of Different Modulation Techniques for Three-Level Quasi-Z-Source Inverter

<abstract xmlns="http://www.w3.org/1999/xhtml">Focus is on implementation possibilities of surfacemount device (SMD) to be used in high power applications. SMD capacitors reduce the size and dimensions of a power circuit and increase the flexibility of placement of other components. Ceramic and electrolytic capacitors are compared by means of voltage ripple, volume, labour-intensity and impedance. A 1 kW experimental setup of a quasi-Z-Source inverter (qZSI) based converter was built to compare SMD capacitor performance in the quasi-Z-source (qZS) network.</abstract>

Implementation Possibilities of SMD Capacitors for High Power Applications

<abstract xmlns="http://www.w3.org/1999/xhtml">This paper presents findings of a R&amp;D project targeted to the development of a galvanically isolated step-down DC/DC converter for electrolyzer integration with renewable energy systems. The presented converter with an improved control algorithm for the full-bridge active rectifier features reduced energy circulation and switching losses. The performance can be improved under wide input voltage and load variations. The advantages of the converter were verified with a 1 kW converter prototype and the test results were in full agreement with the expected waveforms. The presented steadystate operation principle and mathematical analysis of the converter based on the simulation and experimental results can be used as design guidelines for component and parameter estimation in practical applications.</abstract>

New DC/DC Converter for Electrolyser Interfacing with Stand-Alone Renewable Energy System

<abstract xmlns="http://www.w3.org/1999/xhtml">Usually wireless devices require autonomous power supply. They are equipped with radio frequency transceiver modules with relatively high energy consumption especially in data transmission mode. This also means that autonomous power supply of wireless device requires relatively large energy storage. Rechargeable battery in this case is a good solution, but the charging process of a battery takes a long time. In this paper the use of supercapacitor as energy storage for autonomous power supply of wireless node is further elaborated on the example of light sensor for illumination measurement test bench.</abstract>

Autonomous Power Supply System for Light Sensor of Illumination Measurement Test Bench

<abstract xmlns="http://www.w3.org/1999/xhtml">Features of combined mechatronic systems creation with a rigid mechanics are observed in details. The usage of astatic regulators for the basic positioning loop is offered. Efficiency of regulators and observers adjustment on Bessel polynomial is shown for mechatronic positioning systems. Outcomes of synthesis of the load observer taking into account the drive dynamics and different forms of load in the system are resulted.</abstract>

Load Compensation in Mechatronic System with Observer

<abstract xmlns="http://www.w3.org/1999/xhtml">The paper presents configuration of the traction drive test bench with energy storage system, calculation of the scale factors, estimation of the energy storage system size and Matlab simulation results of the bench operation in a braking mode at different levels of the supercapacitor initial voltage.</abstract>

Estimation of Traction Drive Test Bench with Energy Storage System Operation in Regenerative Braking Mode

AHEAD OF PRINT

Volume 19 (2023): Issue 1 (June 2023)

Volume 18 (2022): Issue 1 (June 2022)

Volume 17 (2021): Issue 1 (June 2021)

Volume 16 (2020): Issue 2 (December 2020)

Volume 16 (2020): Issue 1 (January 2020)

Volume 15 (2019): Issue 2 (December 2019)

Volume 15 (2019): Issue 1 (September 2019)

Volume 14 (2018): Issue 2 (December 2018)

Volume 14 (2018): Issue 1 (July 2018)

Volume 13 (2017): Issue 1 (December 2017)

Volume 12 (2017): Issue 1 (July 2017)

Volume 11 (2016): Issue 1 (December 2016)

Volume 10 (2016): Issue 1 (July 2016)

Volume 9 (2015): Issue 1 (December 2015)

Volume 8 (2015): Issue 1 (July 2015)

Volume 7 (2014): Issue 1 (December 2014)

Volume 6 (2014): Issue 1 (October 2014)

Volume 5 (2014): Issue 1 (May 2014)

Volume 4 (2013): Issue 1 (December 2013)

Volume 3 (2013): Issue 1 (August 2013)

Volume 2 (2013): Issue 1 (April 2013)

Volume 1 (2012): Issue 1 (December 2012)

Electrical, Control and Communication Engineering

The aim of the Journal of Electrical, Control and Communication Engineering of Riga Technical University (RTU-ECCE Journal) is to provide an on-line forum for scientific discussions and feedbacks from the scientific society to particular scientists from all over the world on their later scientific achievements in the below mentioned fields.　The journal considers publication of all authors, but gives preference to the post-conference papers after one of the following events (International Scientific Conferences on Power and Electrical Engineering of Riga Technical University - RTUCON, Workshops on Advances in Information, Electronic and Electrical Engineering – AIEEE, International Doctoral School of Electrical Energy Conversion and Saving Technologies of Riga Technical University, Doctoral School of Energy and Geotechnology of TalTech), as well as the papers recommended by section editors of the journal. The submissions are reviewed, edited and published in the mentioned priority order.  The scope of RTU-ECCE journal includes (but not limited to) the following areas:    Electrical Engineering and Power Electronics:     Electrical machines, Apparatus, Drives, Motion Control and Robotics;    Components, Design and Application of Power Electronic Converters;    Electromagnetic Compatibility and Interference of Electrical Equipment;    Electrical Materials, Reliability and Diagnostics;    Medical and other Bio-contact Electrical Equipment.    Power and Energy Systems:     Power System Control, Automation, Stability and Protection;    Power Quality and Reliability;    Power Plants, Renewable and Distributed Energy Systems;    Power System Planning, Management, Economic Evaluation and Risk Assessment;    Electricity Market;    Smart Grids &amp; Microgrids.    Information Processing in the context of Electrical and Power Engineering     Electronic Circuits and Systems for Control Applications;    Control Theory, Analysis, Simulation and Implementation Software;    Principles of Physical Transmission and Processing of Information, New Interfaces and Protocols.    Microwave Technique and Antennas     Theory, Analysis and Simulation of Microwave Technique;    Software and Experimental Methods Dedicated for Microwave Equipment;    Antennas, Radar Systems and other Microwave Applications.  The editorial board of RTU-ECCE Journal is always open for discussion on the journal topics.   In 2012 the journal Electrical, Control and Communication Engineering separated from the RTU journal series Power and Electrical Engineering. Why subscribe and read  Electrical, Control and Communication Engineering is a peer-reviewed journal providing the latest information in the field of electrical engineering and information technologies. The journal focuses on recent research in electrical and control engineering paying special attention to the reports which have the most significant practical importance.The journal includes a wide range of publications on electrical and electronic equipment, as well as on other means for energy conversion, information processing and transmission purposes.  Why submit  The journal provides highly qualified feedback on the research, as well as international publicity. The editorial board will continuously care about the citation level of the journal.  Rejection Rate   30%   Archiving  Sciendo archives the contents of this journal in Portico - digital long-term preservation service of scholarly books, journals and collections.  Plagiarism Policy  The editorial board is participating in a growing community of Similarity Check System's users in order to ensure that the content published is original and trustworthy. Similarity Check is a medium that allows for comprehensive manuscripts screening, aimed to eliminate plagiarism and provide a high standard and quality peer-review process. 