Cobalt

Q4

On the Development of Long-Range Water Quality Monitoring System for Outdoor Aquaculture Objects

Pikulins D., Gotlaufs R., Solovjova T., Aboltins A., Grizāns J., Migla S.

Q4

Electrical, Control and Communication Engineering, 2022, цитирований: 3,

open access

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doi.org, Abstract

Abstract The paper is dedicated to the development of hardware and software components for the autonomous water quality monitoring system (WQMS) for fishing farms. The system can measure main water quality parameters, storing and processing data on the remote server. The LoRaWAN technological solutions and infrastructure are utilized, providing the optimal tradeoff between data transmission range and adaptive power consumption. The main implementation and exploitation issues are described, and the proposed solutions are provided.

Q4

Device and Algorithm for Vehicle Detection and Traffic Intensity Analysis

Gorobetz M., Potapov A., Korneyev A., Alps I.

Q4

Electrical, Control and Communication Engineering, 2021, цитирований: 2,

open access

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doi.org, Abstract

Abstract To effectively manage the traffic flow in order to reduce traffic congestion, it is necessary to know the volumes and quantitative indicators of this flow. Various detection methods are known for detecting a vehicle in a lane, which, in turn, have their own advantages and disadvantages. To detect vehicles and analyse traffic intensity, the authors use a pulse coherent radar (PCR) sensor module. Testing of various modes of operation of the radar sensor was carried out to select the optimal mode for detecting vehicles. The paper describes a method for fixing vehicles of different sizes, filtering and separating the vehicle from the traffic flow. The developed vehicle detection device works in conjunction with signal traffic lights, through which traffic control takes place. The signal traffic lights, which have their own sensors and control units, communicate with each other via a radio channel; there is no need for cable laying. The system is designed to work on road maintenance sites. The paper describes the experimental data when testing on a separate section of the road. The experiment showed the advantage of traffic lights (cars passed the regulated traffic light faster) from the point of view of calculating the traffic flow over the normal traffic light operation. Reducing downtime in traffic jams, in turn, has a beneficial effect on the environmental situation, since at the moment internal combustion engines prevail in vehicles.

Q4

Algorithms for Railway Embedded Control Devices for Safety Manoeuvres

Beinaroviča A., Gorobetz M., Alps I.

Q4

Electrical, Control and Communication Engineering, 2020, цитирований: 0,

open access

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doi.org, Abstract

Abstract This study is dedicated to solve manoeuvres making task while working on the station with no marshalling hump. It is part of the project aimed at the development of intelligent safety and optimal control systems of autonomous electric vehicles and transport in general. The main manoeuvres safety depends on the lack of items and other objects on the rails as well as on the position of turnouts. In most cases rails, occupied with other wagons, as well as the wrong position of turnouts are marked with prohibiting red or blue signals of the traffic light. The authors propose an algorithm for the traffic light recognition by using a convolutional neural network (CNN) and traffic light indicator recognition. However, the situation when the locomotive needs to drive on the rails occupied with other wagons, for example, during the manoeuvres on the railway station can also appear. For this purpose, the authors have developed a CNN algorithm for the wagon recognition on the rails.

Q4

Design of Acoustic Signals for a Seal Deterrent Device

Aboltins A., Grizans J., Pikulins D., Terauds M., Zeltins M.

Q4

Electrical, Control and Communication Engineering, 2020, цитирований: 0,

open access

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doi.org, Abstract

Abstract During the past decade, attacks by grey seals on fishing nets in the Baltic Sea have caused considerable loss of fish catch and damage to fishing gears. One of the approaches to reduce the number of seal attacks on fishing nets is to use acoustic deterrent devices (ADDs). Unfortunately, most of the commercially available ADDs are not well suited to the deployment in the sea and require considerable additional investments. The objective of the present research is to develop a compact and cost-efficient ADD for deployment in the sea environment. This paper is devoted to the design of acoustic signals for a prototype ADD. Signals from other experimental and commercially available ADDs are studied and compared. Moreover, limitations imposed by the underwater environment, transducers, battery power, and fish hearing are analysed and considered during the development of signal patterns. The results of tests conducted in an artificial reservoir and in the sea are presented.

Q4

Experimental Evaluation of the Shadowing of a Planar Antenna Caused by a Quadcopter Frame

Heydarov I., Brodnevs D.

Q4

Electrical, Control and Communication Engineering, 2020, цитирований: 0,

open access

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doi.org, Abstract

Abstract The use of mobile data transfer can significantly increase the range of the remote-controlled operation of multirotor aerial vehicles. The planar antennas of ready-to-use 3G/LTE cellular communication dongles provide a low-cost and lightweight communication solution. In this paper, antenna shadowing caused by a quadcopter frame is experimentally investigated. The communication module is a 3G/LTE “Huawei 3372h” dongle with two planar built-in antennas and a receiver diversity function. The quadcopter frame is a widely used “F450” with Nylon arms and a PCB centre. It has been found that in order to minimize the antenna shadowing effect, planar antennas should be installed at the bottom of the frame, in parallel with the frame, with an air gap not less than the distance to the outer boundary of the reactive Near Field (NF).

Q4

Testing of Technical Indicators of Accumulators by Means of Complex Computer Model of EV

Fedotovs J., Bunina I., Zhiravetska A., Andrianova S.

Q4

Electrical, Control and Communication Engineering, 2020, цитирований: 3,

open access

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doi.org, Abstract

Abstract The accumulators utilized in electric transport differ from those of other applications. Their main features are high capacity, minimum size and weight, and reasonable price. There is extensive research worldwide to improve the battery technology. The aim of the research is to create a mathematical model of an electric vehicle that can capture the vehicle speed curve as a data input to generate the consumed and recovered battery current, which can allow the battery parameters to be analysed and conclude whether the vehicle can perform the trip around the city route with the selected battery parameters. This model serves as a tool to simplify and speed up the necessary calculations and to examine individual sections of the route and their impact on the battery. To complete this task, a simplified electric transport mathematical model gives an opportunity to check if the selected battery can be used in the electrical public transport of the city. The input parameters of the model are the parameters of electrical transport. Simulation of the most popular types of batteries has been performed for two routes of buses in Jelgava in order to determine whether the chosen batteries can provide the necessary bus movement. The mathematical model has been developed in the MATLAB/Simulink software. A GPS mobile application SpeedTracker has been used for data logging.

Q4

Wireless Sensor Networks: Towards Resilience Against Weather-Based Disruptions

Skirelis J., Patlins A., Kunicina N., Romanovs A., Zabasta A.

Q4

Electrical, Control and Communication Engineering, 2019, цитирований: 3,

open access

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doi.org, Abstract

Abstract The article discusses vulnerability of wireless sensors networks to weather-based disruptions considering the opinions of different experts published in a range of scientific materials. The introduction provides a brief overview of wireless signals in real world conditions focusing on how weather affects signals (rain, fog and clouds, snow, hail, lightning, wind, bodies of water, trees and physical obstruction). Information about the effects of weather on wireless sensor networks using Free Space Optical / Radio Frequency (FSO/RF) communication is then provided. Finally, the impact of weather conditions on MANET routing protocols is considered theoretically, and experimental simulations are performed by comparing the sustainability of different protocols to different weather conditions. After analysis of experiment results, ideas on how to decrease vulnerability of wireless networks to weather-based disruptions are discussed.

Q4

Waveform Impact on Wireless Power Transfer Efficiency using Low-Power Harvesting Devices

Eidaks J., Litvinenko A., Aboltins A., Pikulins D.

Q4

Electrical, Control and Communication Engineering, 2019, цитирований: 1,

open access

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doi.org, Abstract

Abstract The paper addresses the impact of peak-to-average power ratio (PAPR) and spectrum of the waveform, as well as load resistance on the performance of low-power harvesting device in a real-life wireless power transfer (WPT) scenario. In the current study, a combination of the classic voltage doubler circuit for RFDC conversion and premanufactured device for DC-DC conversion is used. For the investigation of conversion efficiency and harvesting device performance, three types of waveforms are used: single tone, multicarrier signals with low PAPR and multicarrier signal with high PAPR. In order to generate high-PAPR signal, subcarriers with the same amplitude and phase are summed, whereas for generation of low PAPR signal the phases of the subcarriers are chosen pseudo-randomly. Over-the-air transmission in 865 MHz ISM band is made using directional antennas and all multicarrier waveforms have equal 5 MHz bandwidth. To evaluate the performance of harvesting device and conversion efficiency, the average voltages at the input and output of the RF-DC converter as well as at the output of the DC-DC converter with corresponding input and load impedance are measured. The experiments have shown that the employed multicarrier signals can greatly improve the performance of harvesting device during WPT under certain conditions, which are discussed in the paper.

Q4

Adaptive Traction Drive Control Algorithm for Electrical Energy Consumption Minimisation of Autonomous Unmanned Aerial Vehicle

Korneyev A., Gorobetz M., Alps I., Ribickis L.

Q4

Electrical, Control and Communication Engineering, 2019, цитирований: 3,

open access

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doi.org, Abstract

Abstract The paper aims at researching and developing an adaptive control system algorithm and its implementation and integration in the control system of the existing unmanned aerial vehicle (UAV). The authors describe the mathematical model of UAV and target function for energy consumption minimisation and possible searching algorithms for UAV optimal control from an energy efficiency perspective. There are two main goals: to minimise energy consumption and to develop and investigate an adaptive control algorithm for UAV traction drive in order to increase energy efficiency. The optimal control algorithm is based on two target function values, when comparing and generating corresponding control signals. The main advantage of the proposed algorithm is its unification and usability in any electrical UAV with a different number of traction drives, different or variable mass and other configuration differences without any initial manual setup. Any electric UAV is able to move with maximal energy efficiency using the proposed algorithm.

Q4

Study of Load Characteristics of Various Types of Silicon PV Panels for Sustainable Energy Efficient Road Pavement

Patlins A., Hnatov A., Arhun S., Hnatova H., Migal V.

Q4

Electrical, Control and Communication Engineering, 2019, цитирований: 4,

open access

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doi.org, Abstract

Abstract This paper presents a new approach to the creation of innovative roads having sustainable energy efficient road pavement as their basis. It is a new type of intelligent roads that is able to service itself and provide power, i.e. it is also a renewable source of electricity. It is planned to use the studies on the PV panels in sustainable energy efficient road pavement to determine their load parameters. The work used the methods of mathematical analysis and theoretical electrophysics to carry out the studies on load characteristics of various types of silicon PV panels in order to define the most effective panels from the point of view of generated electrical energy load resistance values. The analysis of the obtained results of the experimental research has shown that in order to make the operation of PV panels of series FS-100M and FS-110P most efficient, their load must be maintained within 3–3.5 Ω range. If load resistance exceeds the specified limits, the work of PV panels of this series will be ineffective. The road having a sustainable energy efficient road pavement is able to track road conditions, traffic, weather conditions and react quickly to their changes. It is shown how road markings can change dependance on road conditions.

Q4

Deterioration Causes Evaluation of Third Generation Cellular LTE Services for Moving Unmanned Terrestrial and Aerial Systems

Brodņevs D., Kutins A.

Q4

Electrical, Control and Communication Engineering, 2018, цитирований: 5,

open access

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doi.org, Abstract

Abstract Well-deployed cellular networks offer a cheap wireless solution for the control channel deployment of Remote-Control Vehicles (RCV) and Unmanned Aerial Vehicles (UAV). However, a cellular data transfer service performance is affected by a different kind of User Equipment (UE) mobility. Operating conditions of UAV imply working at different altitudes, variable velocities with accelerations/decelerations and rapidly changed antennas angular position, which lead the wireless signal to be prone to negative effects. Available field measurement studies are not sufficient to provide excessive information on degradation problem causes for UEs moving along a complex trajectory. This paper presents an evaluation of the service quality of live operational 3G and LTE networks for both ground moving and flying UE. It has been found that antennas angular position variations in 3D (for example, during UAV manoeuvers) increase data transfer latency and jitter. Moreover, this effect in conjunction with higher interference at high altitudes may partially or fully block the data transfer service. This paper has been prepared to draw attention to the problem that makes the cellular data transfer service unusable for highly-manoeuvrable UAVs.

Q4

Considerations regarding the concept of cost-effective power-assist wheelchair subsystems

Galkin I., Podgornovs A., Blinov A., Vitols K., Vorobyov M., Kosenko R.

Q4

Electrical, Control and Communication Engineering, 2018, цитирований: 15,

open access

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doi.org, Abstract

Abstract The present paper deals with the concept of a cost-effective power-assistant wheelchair. An analysis of the market situation and recent technical achievements is done at the beginning. On its basis, a set of solutions suitable for the development of such wheelchairs has been composed. It is shown that the key features of the considered concept are: segmented electrical motor and drive, sectioned battery pack, modular charger and an ANN matrix that provides easy and intuitive interfacing of sensor networks, pseudo-bionic feedbacks and the decision-making unit. Within the scope of the paper, a 3D model has been developed and 3D modelling has been conducted. As a result, certain drawbacks in the design and placement of elements have been found and a modification of the concept has been proposed

Q4

Computationally Efficient Chaotic Spreading Sequence Selection for Asynchronous DS-CDMA

Litviņenko A., Āboltiņš A.

Q4

Electrical, Control and Communication Engineering, 2017, цитирований: 3,

open access

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doi.org, Abstract

Abstract The choice of the spreading sequence for asynchronous direct-sequence code-division multiple-access (DS-CDMA) systems plays a crucial role for the mitigation of multiple-access interference. Considering the rich dynamics of chaotic sequences, their use for spreading allows overcoming the limitations of the classical spreading sequences. However, to ensure low cross-correlation between the sequences, careful selection must be performed. This paper presents a novel exhaustive search algorithm, which allows finding sets of chaotic spreading sequences of required length with a particularly low mutual cross-correlation. The efficiency of the search is verified by simulations, which show a significant advantage compared to non-selected chaotic sequences. Moreover, the impact of sequence length on the efficiency of the selection is studied.

Q4

An Experimental Study of Ground-Based Equipment Real Time Data Transfer Possibility by Using Cellular Networks

Brodņevs D., Kutins A.

Q4

Electrical, Control and Communication Engineering, 2017, цитирований: 5,

open access

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doi.org, Abstract

Abstract An expanding mobile cellular network data transfer service offers cheaper wireless solutions for various data transfer needs. This paper presents an experimental testing of data transfer performance in 3G and 4G modes. The purpose of testing was to check the possibility of real-time and critical data transfer over the mobile cellular networks. The testing was performed in Riga in July and August 2016 using the most popular mobile service operators in Latvia: Tele2-LV, BITE-LV and LMT. The testing confirmed that the overload of Riga’s 4G networks causes serious service deterioration or even interruption. Riga’s 3G networks are more stable. However, 3G network service quality depends on a cell load. Lightly loaded 3G network meets real-time data transfer requirements of 100 ms one-way delay of the small packet traffic.

Q4

Organization and Implementation of Online Cytology Quality Assurance Program – Georgian Experience

Kldiashvili E., Romānovs A., Shakulashvili N., Burduli A., Ghortlishvili G., Agladze D.

Q4

Electrical, Control and Communication Engineering, 2017, цитирований: 0,

open access

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doi.org, Abstract

Abstract Medical information system (MIS) is at the heart of information technology (IT) implementation policies in healthcare systems around the world. Different architecture and application models of MIS are developed. Despite of obvious advantages and benefits, application of MIS in everyday practice is slow. On the background of analysis of the existing models of MIS in Georgia has been created a multi-user web-based approach. This article will present the architecture of the system and its application for cytology quality assurance programs. Five hundred Georgian language electronic medical records from the cervical screening activity illustrated by images were selected for quality assurance program. The primary goal of the MIS is patient management. However, the system can be used for quality assurance programs. The ideal of healthcare in the information age must be to create a situation where healthcare professionals spend more time creating knowledge from medical information and less time managing medical information. The application of easily available and adaptable technology and improvement of the infrastructure conditions is the basis for eHealth applications. The MIS is perspective and actual technology solution. It can be used for cytology quality assurance programs.

Q4

Alternative Energetics DC Microgrid With Hydrogen Energy Storage System

Zaļeskis G., Steiks I.

Q4

Electrical, Control and Communication Engineering, 2016, цитирований: 2,

open access

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doi.org, Abstract

Abstract This paper is related to an alternative energetics microgrid with a wind generator and a hydrogen energy storage system. The main aim of this research is the development of solutions for effective use of the wind generators in alternative energetics devices, at the same time providing uninterrupted power supply of the critical loads. In this research, it was accepted that the alternative energetics microgrid operates in an autonomous mode and the connection to the conventional power grid is not used. In the case when wind speed is low, the necessary power is provided by the energy storage system, which includes a fuel cell and a tank with stored hydrogen. The theoretical analysis of the storage system operation is made. The possible usage time of the stored hydrogen depends on the available amount of hydrogen and the consumption of the hydrogen by the fuel cell. The consumption, in turn, depends on used fuel cell power. The experimental results suggest that if the wind generator can provide only a part of the needed power, the abiding power can be provided by the fuel cell. In this case, a load filter is necessary to decrease the fuel cell current pulsations.

Q4

Algorithm of Energy Efficiency Improvement for Intelligent Devices in Railway Transport

Beinaroviča A., Gorobecs M., Ļevčenkovs A.

Q4

Electrical, Control and Communication Engineering, 2016, цитирований: 0,

open access

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doi.org, Abstract

Abstract The present paper deals with the use of systems and devices with artificial intelligence in the motor vehicle driving. The main objective of transport operations is a transportation planning with minimum energy consumption. There are various methods for energy saving, and the paper discusses one of them – proper planning of transport operations. To gain proper planning it is necessary to involve the system and devices with artificial intelligence. They will display possible developments in the choice of one or another transport plan. Consequently, it can be supposed how much the plan is effective against the spent energy. The intelligent device considered in this paper consists of an algorithm, a database, and the internet for the connection to other intelligent devices. The main task of the target function is to minimize the total downtime at intermediate stations. A specific unique PHP-based computer model was created. It uses the MySQL database for simulation data storage and processing. Conclusions based on the experiments were made. The experiments showed that after optimization, a train can pass intermediate stations without making multiple stops breaking and accelerating, which leads to decreased energy consumption.

Q4

Power Measurement and Data Logger with High-Resolution for Industrial DC-Grid Application

Apse-Apsitis P., Senfelds A., Avotins A., Paugurs A., Prieditis M.

Q4

Electrical, Control and Communication Engineering, 2015, цитирований: 5,

open access

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doi.org, Abstract

Abstract Power and energy measurement and monitoring is a key factor for many industries in terms of energy and cost efficiency evaluation. Due to trends of Smart Grid concept application in industrial environment, including decentralized DC-Grid implementation, for precise evaluation – faster and low-cost measurement equipment is needed. Manufacturing industry widely uses industrial robots that have dynamic load characteristics for which faster measurement equipment is needed. This paper gives a brief description of the developed power measurement equipment, its structure and interconnection with industrial Profinet network. Further as a testing method steady state and dynamic loads are selected and analyzed. For testing, specially created industrial DC-Grid testing environment and equipment was used. Testing results show that the selected method and idea is working and is able to measure dynamic loads with high resolution. For other industrial load types there is a discussion going on about the issue of how detailed the resolution is needed in industrial SmartGrids, as energy forecast is a new trend in robotic industry and manufacturing planning.

Q4

The Use of Kramers-Kronig Relations for Verification of Quality of Ferrite Magnetic Spectra

Ponomarenko N., Solovjova T., Grizans J.

Q4

Electrical, Control and Communication Engineering, 2015, цитирований: 6,

open access

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doi.org, Abstract

Abstract The complex initial permeability (CIP) as a function of frequency is one of the main properties of ferrites. This characteristic (CIP) is measured experimentally, therefore there can be found noisy, doubtful or incomplete parts of the spectrum. Thus there is a need for a method of evaluation of quality of CIP. In this article for evaluation of the quality of experimental CIP spectra of polycrystalline ferrite materials the KKR (Kramers-Kronig relations) are used. In order to apply KKR to experimentally measured data (i.e. data with finite limits) the method of transforming these integral relations into summation relations with finite limits is developed and described. This method can be used only for CIP given over the wide frequency rage, so that the imaginary part of CIP is fully presented. Using KKR with the help of CIP spectra model (based on the effects coming from polycrystal grain sizes and defects distribution) partly removes aforementioned limit. Thus with the help of the model we can also make CIP spectra reconstruction (in cases when CIP is noisy or incomplete) and CIP spectra decomposition.

Q4

Simulation of Induction Traction Drive with Supercapacitor Energy Storage System Test Bench

Stana G., Brazis V., Apse-Apsitis P.

Q4

Electrical, Control and Communication Engineering, 2015, цитирований: 2,

open access

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doi.org, Abstract

Abstract The paper describes the application of supercapacitor energy storage system for induction traction drive test bench that replaces a real electric public transport for performing testing and researches. The suitability and usage of such bench for research purposes is explained and the importance of the development of software mathematical model for performing simulations to be done before physical implementation measures is reasoned. The working principle of the bench and applied components are described. A virtual model of the bench was built and simulations were performed using Matlab/Simulink software. The basic topology of the virtual bench model is described as well. The calculations of this work show the scaling of supercapacitor energy storage system by setting different limits of working voltage range in order to adjust them to test bench parameters, whereas the modelling compares two simulation cases – the application of less supercapacitors and the application of more supercapacitors with the same common rated voltage. The autonomous mode simulations were also performed. Simulation results are analyzed and recommendations for the application of the supercapacitor energy storage system, with respect to initial supercapacitor circuit voltage, are given.

Q4

Research in Adaptronic Automatic Control System and Biosensor System Modelling

Skopis V., Uteshevs I.

Q4

Electrical, Control and Communication Engineering, 2015, цитирований: 3,

open access

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doi.org, Abstract

Abstract This paper describes the research on adaptronic systems made by the author and offers to use biosensors that can be later inserted into the adaptronic systems. Adaptronic systems are based, on the one hand, on the adaptronic approach when the system is designed not to always meet the worst condition, but to change the structure of the system according to the external conditions. On the other hand, it is an extension of common automatic control ad adaptive systems. So, in the introduction firstly the adaptronic approach and biosensor as a term is explained. Adaptive systems, upon which adaptronic ones are based, are also mentioned. Then the construction of biosensor is described, as well as some information is given about the classification of biosensors and their main groups. Also it is suggested to use lichen indicators in industry to control concentration of chemical substances in the air. After that mathematical models and computer experiments for adaptronic system and biosensor analysis are given.

Q4

Voltage Spectral Structure as a Parameter of System Technical Diagnostics of Ship Diesel Engine-Synchronous Generators

Gasparjans A., Terebkovs A., Zhiravetska A.

Q4

Electrical, Control and Communication Engineering, 2015, цитирований: 2,

open access

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doi.org, Abstract

Abstract A method of technical diagnostics of ship diesel engine – generator installation – is proposed. Spectral-power diagnostic parameters of the synchronous generator voltage and currents are used. The electric machine in this case is the multipurpose sensor of diagnostic parameters. A judgment on the quality of the operational processes in diesel engine cylinders and its technical condition is possible on the basis of these parameters. This method is applicable to piston compressor installations with electric drive. On the basis of such parameters as rotating torque, angular speed and angular acceleration it is possible to estimate the quality of the operating process in the cylinders of a diesel engine, the condition of its cylinder-piston group and the crank gear mechanism. The investigation was realized on the basis of a diesel-generator with linear load. The generator operation was considered for the case of constant RL load. Together with the above mentioned, the condition of bearings of synchronous machines, uniformity of the air gap, windings of the electric machine were estimated during the experiments as well. The frequency spectrum of the stator current of the generator was researched and analyzed. In this case the synchronous machine is becoming a rather exact multipurpose diagnostic sensor. The signal of non-uniformity in the operation process of diesel engine cylinders and its technical condition is the increasing of the amplitudes of typical frequencies.

Q4

Electromechanical Battery EMB Mass Minimization taking into Account its Electrical Machines Rotor Energy

Podgornovs A., Sipovichs A.

Q4

Electrical, Control and Communication Engineering, 2014, цитирований: 0,

open access

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doi.org, Abstract

Abstract In this paper the electromechanical battery (EMB) with synchronous machine is described. Theoretically, if electrical machines rotor stored energy is known, it is possible to reduce the flywheel mass of electromechanical battery. For example, the efficiency of energy recovery (kilowatt-hours out versus kilowatthours in) in nowadays appliances exceeds 95 % which is considerably better than of any electrochemical battery, such as lead-acid battery. For the rotor stored energy amount calculation, it is necessary to find all geometrical dimensions of the electrical machine. To achieve this goal the iterative calculation method was used. Electromechanical battery mass was analyzed as a discharge process rotation speed function. Taking into account the rotor stored energy, we can increase the minimum rotation speed thus reducing the electrical machine mass and increasing the flywheel mass, which provides EMB cost reduction. Additionally, the possibilities of using numerical approximation calculations of magnetization curves are discussed. Each iteration of numerical application necessary for the method for rapid calculation is essential when calculating the field problems. Nowadays there are a lot of computer added design programs for electromagnetic field calculation in different types of applications, electrical machines and apparatus. For the electromagnetic field calculation process some more commonly used magnetization curve approximation methods are described, and the machine calculation time is tested for different numbers of calculations.

Q4

Traffic Route Modelling and Assignment with Intelligent Transport System

Kunicina N., Galkina A., Zabasta A., Patlins A., Kondratjevs K.

Q4

Electrical, Control and Communication Engineering, 2014, цитирований: 1,

open access

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doi.org, Abstract

Abstract The development of signal transmitting environment for multimodal traffic control will enhance the integration of emergency and specialized transport routing tools in usual traffic control paradigms - it is one of the opportunities offered by modern intelligent traffic control systems. The improvement of effective electric power use in public transport system is an advantage of Intelligent Transport System (ITS). The research is connected with the improvement of on-line traffic control and adaptation of special traffic lighting alternatives by ITS. The assignment of the nearest appropriate transport will be done by passenger request, but unlike information system, the transport planning is done on demand. The task can be solved with the help of modern technical methods and equipment, as well as by applying control paradigms of the distributed systems. The problem is solved with the help of calculations hyper-graph and scheduling theory. The goal of the research is to develop methods, which support scheduling of the emergency transport, using high performance computing.

Q4

Current Sensorless Control Algorithm for Single-Phase Three-Level NPC Inverter

Suzdalenko A., Zakis J., Steiks I.

Q4

Electrical, Control and Communication Engineering, 2014, цитирований: 5,

open access

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doi.org, Abstract

Abstract The current measurement is becoming a challenging task in power converters operating at high switching frequencies, moreover traditional control system requires two control loops - first (slow) regulates DC-link voltage, second (fast) controls the shape of current, that all together results in complicated transfer function and long transition periods. The current sensorless control (CSC) allows neglecting the mentioned problems. This research for the first time presents the solution of CSC implementation in single-phase three-level neutral point clamped inverter. Mathematical equations were defined for inductor current peaks and transistor conduction time during discontinuous and continuous conduction modes, as well as major problem of current fitting between different voltage levels (consequently with different current peak-to-peak values) was solved, providing two solutions - pre-fitting and post-fitting trajectories. The verification of our theoretical assumptions and analytical equations was confirmed by the simulation analysis. Challenges of real experiments are discussed in the conclusion.