The closed loop performance of every switched mode power supply depends on the optimal design of the compensation network. Choosing the right type of compensation determents, the dynamic performance of the converter and as such warrants a closer examination. This paper comperes the two main types of compensation – digital and analog. It first lays the theoretical background covering the possible ways to discretizes an analog compensator.
This paper shows a case study on the new e-mobility courses design, development, implementation and evaluation for undergraduate automotive engineering students at Riga Technical University. According to actual automotive market development and industry demands, the automotive engineering curricula has been supplemented with new Electrical Road Vehicle Technology and Innovative Automotive Technology courses. The case study shows the main challenges of interdisciplinary course content adaptation for automotive engineering students with mechanical engineering background. The created courses comply with gaining comprehensive knowledge of electrical engineering topics, like advanced electrical drives, electrical machines, energy storage technologies and power electronics. Both courses have been successfully implemented and evaluated, using analysis of assignment fulfillment and student survey result assessment that have shown obvious correlations. The student survey results reflect the lack of knowledge or competence in separate course topics and can be effectively used for further course development and content complexity adjustments.
The transition of courses based on the classic combination of lectures, calculation exercises and laboratory works to student-centred learning sessions and group assignments has been a typical transition for courses at Aalto University and elsewhere. The entirety of the course Electricity Distribution and Markets and its development over time is reviewed, covering the online content, lecture make-up, and the various parts of the assignment work, including the use of a multi-cultural group-forming algorithm, with reference to feedback from students. The methodology employed during the development of this course and in the assessments of group work and flipped classroom techniques made in this paper is trial and error, and the paper evaluates the efficacy of the various pedagogical methods that have been tried through the lens of student feedback.
this paper describes experience of changing microcontroller related course from face-to-face to remote format, which took place in Riga Technical University during the COVID-19 pandemic during years 2020 and 2021. The name of the subject is Laboratory exercises in electronics. The primary ideology of that course is to let students touch and feel electronics without using any virtual stuff like simulators. Therefore, replacing everything with simulation is not a solution to such kind of course. In this publication, we want to describe system that is mixture of real physical system installed in the laboratory and remote interface interacting with the physical system.
In the last decade, narrowly focused industries that are a hybrid of different fields have become more and more relevant. One of these innovative industries is electrical processes in biotechnology.Currently, the development of the program and the teaching of these techniques open up new horizons for higher scientific institutions to enter the scientific discourse and occupy the relevant niches.It is very important to take part and contribute to the development of the industry.Based on the basic laws of electrical circuits, the course focuses on electrical processes in biotechnology. Knowledge of the basic functions of electrical appliances characterizing modes, with particular attention to biotechnology for electrical appliances used in the laboratory and the latest semiconductor equipment, as well as electrical safety questions.The functions of automation are considered, the principles of system control are presented, methods of electrical measurements of bioelectrical parameters, selection and regulation of electrical devices, diagnostics, safety, as well as the use of sensors, control of biotechnological processes.The purpose of this publication is to develop abstracts for the curriculum in the specialty "Engineer-Microbiology".
Ongoing social changes require deepening the partnership of educational institutions. The EuroTeQ Engineering University project, initiated by six leading European universities of science and technology, became one of the first responses to this challenge. This paper is devoted to the organization of a cross- border competitive learning format that would equally suit both the host and the EuroTeQ participants. Here, successful and unsuccessful EuroTeQ students are compared to the host university students when they work together in a common educational environment. In this way, the strengths and weaknesses of the EuroTeQ platform are assessed. Additionally, several directions for its further development are outlined.
To meet the increasing demand for clean water as The scarcity of natural and clean water is a vital problem that facing many rich or rural regions of the world no difference between developing countries or Europe or the rich Arab Gulf countries where the clean water is rare and consumed many times higher than the available water. What most people do not know is the enormous cost of desalination and consumption of large amounts of petroleum fuels (such as oil and natural gas), the cost of which represents a large share of the total cost of desalination Therefore, when used to produce desalinated water (solar desalination), solar energy provides a renewable, clean, safe and free energy source that reduces dependence on oil fuels, reduces greenhouse gas emissions, and provides a sustainable source of desalinated water production. This paper presents the Reverse Osmosis process, its key elements, and the results that could be generated by its combination with solar photovoltaic technology.
This paper describes development of DC motor test bench that is based on thyristor power electronics converters and allows multiple type load tests for scientific and education purposes. The control of the test bench is automated thus allowing create multiple load profiles, automatic data acquisition that makes it more attractive for student’s laboratory practice. The digital twin of the test bench has been created into Matlab Simulink software. Using this model it is possible analyze stability of the speed regulator theoretically and design stable PID regulator and after that provide experimental result validation by using test bench. The paper will discuss control algorithms that are used in the motor control and motor parameter experimental detection. There is implemented also possibility virtually emulate different values of inertia thus showing influence of different inertias on speed regulation process.
Two-wheel single-axis mobile robots generally are pendulum and balancing (inverted pendulums). The ability to transform from a pendulum to a balance gives these robots additional benefits. The robot should perform the transformation quickly and move as little as possible out of place. The mathematical model of the planar mobile robot was created. It describes the statics and dynamics of pendulum and balance robots. The optimal regulator was used to control the position of the pendulum. In this case, the transformation takes place in a minimum of time.
in this paper different under-frequency load shedding (UFLS) systems are compared using the phase plane approach. Paper presents different UFLS systems of the Baltic states before and after synchronizing with continental Europe in 2025, and their response to the same emergency scenario. The main aim of the paper is to show the advantages of existing UFLS system with upgraded settings in relation to the proposed UFLS system without UFLS-2 system.
This paper presents the main experimental evaluation results of SiC MOSFET and GaN FET performance in a 3-phase 3-level neutral point diode clamped inverter prototype. The prototype is built with 650 V class commercially available SiC Schottky diodes and SiC MOSFETs that are replaced and compared with GaN FETs to assess semiconductor device performance in auxiliary converters for transportation application. Inverter variable frequency operation in wide switching frequency range is analyzed for both cases and the acquired results show low switching losses and high efficiency with different input and output parameters. Analysis results approve that despite higher purchase costs, the wide bandgap semiconductor devices can achieve excellent performance in transportation applications, compared to Si IGBTs. High initial price is compensated by reduced losses throughout converter life cycle and, hence, the use of wide bandgap devices is technically and economically effective. Utilization of GaN FETs, compared to SiC MOSFETs, have shown similar experimental results in terms of converter efficiency and loss distribution, but considerably higher initial purchase price and, hence, SiC MOSFETs are approved to be recommended for auxiliary converter design currently because of better price-performance balance.
Nowadays, the demand for monitoring in buildings is only growing. Understanding the current situation in buildings is the key to energy efficient building management system control. Unfortunately, at the moment, most buildings are equipped with an insufficient number of measuring points. Due to lack of data, it could be impossible to assess how the dynamics of a building might be improved, and what economic effect might be achieved by supplementing its BMS system, or by installing one. For the study of such objects, a system is necessary that can be quickly installed and adapted to the existing infrastructure. Similar systems are also crucial to understanding the behavior and testing new building materials in experimental buildings. To conduct such monitoring studies, many authors use various wireless monitoring systems. One of the essential criteria for the convenient use of such systems is the autonomous working time of a sensor node. The battery life of the sensors is affected by numerous parameters such as the communication protocol, its speed, current in different modes, operating voltage ranges etc. As a result, many combinations of MCUs and radio communication methods are unsuitable for this purpose due to height energy consumption. Popular solutions for such systems are boards based on Atmega and STM MCUs. However, due to political unrest and the disruption of supply chains for electronic components, most of these solutions in 2022 have become unavailable due to the lack of parts in stock for production. This motivates us to explore other possible solutions that are available. In this study, as a solution, the authors explore the ESP8266 microcontroller under different configurations to achieve longer autonomous time. Several authors have previously used this MCU for similar needs in combination with the MQTT protocol. However, is not clear whether such systems are suitable for longterm monitoring. In this paper, authors experimentally evaluated and optimized the energy efficiency of a sensor node based on ESP8266. During optimization, authors relied on detailed energy profile measurements across different variables such as various sleep mode configurations, as well as different approaches to communication. Measurements indicate that, with a certain configuration, ESP8266 can work autonomously for up to 10 years on an 18650 battery.
According to the COVID-19 pandemic, educational institutions around the world were forced to urgently switch to distance learning. A particularly difficult situation has arisen in higher educational institutions when teaching special technical disciplines, where practical and laboratory exercises, which were conducted in laboratories and special classes before the COVID-19 pandemic, play an important role. Therefore, the paper presents a method for conducting practical and laboratory classes during on-line training on the example of the Department of Automotive Electronics of the Kharkiv National Automobile and Highway University (Ukraine). It is shown that the use of information technologies makes it possible to largely compensate for the lack of full-time classes. For special (subject) disciplines, the perception of information is achieved by using films demonstrating methods for the implementation of subject tasks. The main task of the teacher when conducting practical exercises in the conditions of distance learning is the competent selection of the source video material and its optimal fragmentation. In this regard, a classification of educational video content is proposed, and examples of its use by teachers during online classes are considered. The results of this work are intended to help educators improve the level of engineering education during distance learning.
Industrial greenhouses have automated control systems for climate, lighting, irrigation, ventilation and heating regulation using feedback sensors. Nowadays it is a trend to increase the measurement data amount as various additional IoT sensors are installed, thus the regulation becomes more precise, and due to available data, enables also new analytical features to create new control rules or strategies. This article focuses on PAR sensor development for such IoT sensor system, that will be used as main feedback signal to create lighting control strategy, same time increasing energy efficiency and reducing also costs. As artificial lighting energy consumption costs create 20-40% of total greenhouse costs, it is worth to have a more precise lighting control system, monitoring the energy crop obtains during the day from the sun, and then the missing amount (also period) of light energy then is provided by artificial lighting. First tests are performed in laboratory and industrial greenhouse of SIA “Latgales darzenu logistika” focusing on IoT based Photosynthetically Active Radiation measurements.
In this paper a centroid-based object system has been developed and implemented in manufacturing process for the purpose of object fault recognition, tracking and counting manufactured products passing on conveyer belt. This kind of addition of a subsystem for the manufacturing operation gives a possibility to evaluate product quality, calculate efficiency of the process and time it has been done in.
Cybersecurity of power hardware is becoming increasingly critical with the emergence of smart and connected devices such as Grid-connected inverters, EVs and their chargers, microgrid controllers, energy storage / energy management controllers, and smart appliances. Cyber-attacks on power hardware have had far-reaching and widespread impacts. For such cyber-physical systems, security must be ensured at all levels in the design - hardware, firmware, software and interfaces. Although previous approaches to cybersecurity have focused mainly on vulnerabilities in the firmware middleware, or software, vulnerabilities in the hardware itself are hard to identify and harder to mitigate, especially when most hardware components are proprietary and not examinable. This paper presents one approach to mitigate this conundrum - a completely open-source implementation of a microcontroller core along with the associated peripherals based on the well-known RISC-V instruction set architecture (ISA). The proof-of-concept architecture presented here uses the “Shakti” E-Class microcontroller core integrated with a fully custom PWM controller implemented in Verilog, and validated on a Xilinx Artix FPGA. For critical applications such designs may be replicated as a custom ASIC thereby guaranteeing total security of the computing hardware.
This paper presents a comparison between grid-connected flyback-based microinverter with primary and secondary side fundamental power ripple decoupling. The flyback converter is proposed to work in continuous conduction mode due to high-power capability. The unfolding circuit and H-bridge inverter are used as a primary side and secondary side decoupling methods. Unfolding circuit operates at the grid frequency, unfolds/folds the rectified sinusoidal waveform, and provides a current pathway to the grid. The comparison is done in terms of energy accumulated in inductances and capacitors, conduction and switching losses, voltage stress across semiconductors. The grid current is controlled through the Proportional Resonant controller. Finally, the simulation using PowerSim software is verifying the theoretical evaluation The spider diagram is used to show the comparison of both solutions. The recommendations are given in conclusions.
The selection of components for an electric propulsion unit driven by a brushless DC motor (BLDC motor) is often carried out experimentally. As a result, if the initial choice of components was unsatisfactory, the consumer is forced to purchase other components with slightly different parameters, after which the compliance testing is repeated. In this article, we will consider an example of how the performance of a selected electric motor and controller can be predicted using the parameters provided by the motor’s manufacturer, and also touch upon the issue of the BLDC parameters experimental determination.
The aim of the work is to develop a method of load distribution between the elements of the energy system with low-power generation sources based on a modified resource allocation algorithm. Suggested effective accounting mechanism of multicriteria, insufficiency and initial information limitation, possibility of flexible task setting and objective priority functions change and restrictions, with use of linguistic characteristics. The approbation of the offered technique on statistical data of renewable energy sources which provide consumers with the electric power in a certain territory is carried out and their optimum mode of work is investigated.
The paper presents the process of introducing synchronous condensers in the Latvian and Baltic electricity transmission network, taking into account the technical and economic studies on various technical solutions and expected investment costs. Existing market monitoring has been evaluated and summarized, including the comparison of the technical parameters. The synchronisation prefeasibility studies have been performed and their impact on the implemented solutions are presented in chronological way. The necessary activities are described in order for the Latvia and Baltic States to prepare for the desynchronization of the Baltic power systems from the existing BRELL ring and synchronization with the continental Europe power system.
