J. Dirba, L. Lavrinovicha, N. Levin and V. Pugachev
Ovchinnikov, N. (2006). Electronically commutated motors and drives on their bases. St. Petersburg: KORONA-Vek (in Russian).
Dirba, J. (1997). Specific regimes of synchronous machines. Riga: RTU (in Latvian).
Dirba, J., Levin, N., Orlova, S., & Pugachov, V. (May 2011). Brushless synchronous motors for appliances and power tools. In: Intern. Conf. on Electrical and Control Technologies (ECT2011). Kaunas University of Tehnology (Lithuania), 222
High-Reliability Brushless Synchronous Motors for Hand Tools and Household Appliances / BEZKONTAKTU SINHRONIE DZINĒJI AR PAAUGSTINĀTU DROŠUMU IZMANTOŠANAI ELEKTROINSTRUMENTOS UN SADZĪVES TEHNIKĀ
N. Levin, V. Pugachev, J. Dirba and L. Lavrinovicha
The paper presents an overview of brushless electric motors used in hand electric tools and household appliances. Analysis of the motor types has shown that synchronous reluctance motors are the most reliable for lowpower drives of such tools and appliances due to their simple design, long service life and low cost of production. Solutions are proposed for significant decrease in the quadrature-axis magnetic flux of the synchronous reluctance motor. The motors are shown to develop the specific electromagnetic torque up to 0.35÷0.4 Nm/kg.
Suffian Mohamad Tajudin and Adila Hanim Aminordin Sabri
Radiation education is necessary for a wide variety of people, such as radiation workers particularly for students of secondary school and higher education institution who learn radiation sciences. The fact that we could not see or feel radiation makes it difficult to understand it. The use of radiation trajectories shown on a personal computer should be useful to overcome this difficulty. In order to understand radiation behaviour inside the material, we have developed a Simu-Rad (Copyright: LY2018002738) by using Monte Carlo simulation programme. One who has no programming knowledge is able to simulate photons in a material through the developed programme. The program could become a computer aided learning tool for radiation related courses. We aim to facilitate lecturer from ‘The Traditional Classroom’ to ‘The Flipped Classroom’ for radiation education concerning in the era of IR 4.0. To validate our radiation simulator, we calculate photon linear attenuation coefficient (µ) of an aluminium material which commonly used as a filter in diagnostic radiology. µ is one of the main characteristics to understand how the radiation attenuated inside the materials. We calculate at energy photon of 662 keV (Cs-137 radiation source) to compare our results of µ with the XCOM database. Consequently, the results from the developed simulator comparable with the database verified our programme to be used for radiation study.
The paper analyses the performance results of the recently developed short-term forecasting suit for the Latvian power system. The system load and wind power are forecasted using ANN and ARIMA models, respectively, and the forecasting accuracy is evaluated in terms of errors, mean absolute errors and mean absolute percentage errors. The investigation of influence of additional input variables on load forecasting errors is performed. The interplay of hourly loads and wind power forecasting errors is also evaluated for the Latvian power system with historical loads (the year 2011) and planned wind power capacities (the year 2023).
I. Grinevich, Vl. Nikishin, N. Mozga and M. Laitans
-Driven Systems. Cooperative Extension Energy Program Report. US: Washington State University.
4. von Jouanne, A., Wallace, A., Douglass, J., Wohlgemuth, C., & Wainwright, G. (1997). A laboratory assessment of in-service motor efficiency testing methods. In IEEE International Electric Machines and Drives Conference. Milwaukee, WI.
5. PCB Load & Torque Division. Fastener Testing. Retrieved 20 November 2016, from http://www.pcb.com/FasteningTechnology/FastenerTest
6. Robert Bosch GmbH. GDS 18 E Professional. Power Tools Division
The paper focuses on the application of synchrophasor measurements that present unprecedented benefits compared to SCADA systems in order to facilitate the successful transformation of the Nordic-Baltic-and-European electric power system to operate with large amounts of renewable energy sources and improve situational awareness of the power system. The article describes new functionalities of visualisation tools to estimate a grid inertia level in real time with monitoring results between Nordic and Baltic power systems.
I. Kurbatska, V. Bobrovs, S. Spolitis, P. Gavars, G. Ivanovs and R. Parts
Considering the growing demand for broadband of access networks, in the present paper we investigate various modulation formats as a way of increasing the performance of optical transmission systems. Non-return-to-zero (NRZ) on-off keying, return-to-zero (RZ) OOK, carrier suppressed RZ (CSRZ) OOK, duobinary (DB), NRZ differential phase shift keying (NRZDPSK), RZ-DPSK and CSRZ-DPSK formats are compared using the maximal achievable reach with bit error rate less than 10−9 as a criterion. Simulations are performed by using OptSim software tool. It is shown that using the transmission system without dispersion compensation the best results are shown by duobinary and CSRZ-OOK modulation formats, but with the system using dispersion compensating fiber (DCF) the longest transmission distance is achieved by RZ-DPSK modulation format. By investigating the influence of channel spacing for best-performed modulation formats, network reach decrease for transmission systems with DCF fiber has been observed due to channel crosstalk.
Marat L. Rudakov, Elena B. Gridina and Vyacheslav S. Ershov
The article describes the main performances of the global coal industry, as well as key occupational safety and health indicators (OSH indicators) of the coal mining industry of the Russian Federation. The main goal of the article is to present the results of research of potential utilisation of the Elmeri observation method in order to evaluate safety levels at underground coal mines. The investigation performed taking into consideration two root causes of the occupational traumatism (methane and/or dust explosions, as well as rock falls) has demonstrated good correlation between the calculated values of the safety index and results of the risk assessments at the same underground coal mine under consideration. In addition, the article includes a brief discussion of advantages and restrictions in respect of utilisation of the safety index as the OSH monitoring tool at coal mines.
Collaboration between heterogeneous systems and architectures is not an easy problem in the automation domain. By now, utilities and suppliers encounter real problems due to underestimated costs of technical solutions, frustration in selecting technical solutions relevant for local needs, and incompatibilities between a plenty of protocols and appropriate solutions. The paper presents research on creation of architecture of smart municipal systems in a local cloud of services that apply SOA and IoT approaches. The authors of the paper have developed a broker that applies orchestration services and resides on a gateway, which provides adapter and protocol translation functions, as well as applies a tool for wiring together hardware devices, APIs and online services.
To ensure that end-users and consumers have access to comprehensive, comparable and user-friendly information regarding the Internet access service quality, it is necessary to implement and regularly renew a set of legislative regulatory acts and to provide monitoring of the quality of Internet access services regarding the current European Regulatory Framework. The actual situation regarding the quality of service monitoring solutions in different European countries depends on national regulatory initiatives and public awareness. The service monitoring solutions are implemented using different measurement methodologies and tools. The paper investigates the practical implementations for developing a harmonising approach to quality monitoring in order to obtain objective information on the quality of Internet access services on mobile networks.