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Tytuł:
Comparative bench testing of steel arch support systems with and without rock bolt reinforcements
Stanowiskowe badania porównawcze obudowy podporowej i podporowo-kotwiowej
Autorzy:
Pytlik, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/220232.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
podatna obudowa podporowa
obudowa kotwiowa
obudowa podporowo-kotwiowa
wartość pracy obudowy
nośność obudowy
yielding steel arch support
rockbolting support system
mixed support
support work value
support load capacity
Opis:
The mining of hard coal deposits at increasingly greater depth leads to an increase in hazards related to the loss of stability of steel arch supports as a result of excessive static and dynamic loads. Camber beam reinforcement via rockbolting is often utilised in order to improve the stability of the yielding steel arch support.This article presents the results of comparative bench tests of the ŁP10/V36-type steel arch support, tested with and without reinforcement by means of self-drilling bolts with drunken R25 threads, using short joists formed from V32 and V25 sections. It also presents the results of comparative tests of the ŁPP10/4/V29/I-type steel arch support, tested with and without reinforcement by means of rock bolts with trapezoidal Tr22/13 threads, using short joists formed from V25 sections. The obtained test results, in the form of load courses and work values of the steel arch and mixed (arches and rock bolts) support systems, demonstrate that the utilisation of mixed support may significantly improve the stability of workings, particularly immediately after they are driven. A mixed support system quickly achieves its maximum load capacity together with a significant increase in its work value. It may thus prevent the stratification of the rocks surrounding the working, and therefore better utilise the self-supporting capacity of the rock mass. As evidenced by the test results, the mixed support work may be as much as 3.5 times as great compared to the steel arch support at the beginning of the height reduction process initiated by loading – i.e. until its reduction by a presupposed value of 100 mm.
Eksploatacja pokładów węgla kamiennego na coraz większych głębokościach powoduje wzrost zagrożeń związanych z utratą stateczności podporowej obudowy górniczej w wyniku nadmiernych obciążeń statycznych i dynamicznych. W celu poprawy stateczności podatnych odrzwi obudowy podporowej często stosuje wzmocnienie odrzwi poprzez przykotwienie łuku stropnicowego. W artykule przedstawiono wyniki stanowiskowych badań porównawczych odrzwiowej obudowy podporowej typu ŁP10/V36, badanej bez wzmocnienia oraz ze wzmocnieniem za pomocą kotwi samo- wiercących z gwintem falistym R25, przy użyciu krótkich podciągów wykonanych z kształtownika V32 oraz V25. Przedstawiono również wyniki badań porównawczych odrzwiowej obudowy podporowej typu ŁPP10/4/V29/I, badanej bez wzmocnienia oraz ze wzmocnieniem za pomocą kotwi z gwintem trapezowym Tr22/13, przy użyciu krótkich podciągów wykonanych z kształtownika V25.Uzyskane wyniki badań w postaci przebiegów obciążania oraz wartości pracy obudowy podporowej i podporowo-kotwiowej wykazują, że stosowanie obudowy podporowo-kotwiowej może znacząco poprawić stateczność wyrobiska górniczego szczególnie zaraz po jego wydrążeniu. Dzięki temu, że obudowa podporowo-kotwiowa szybko uzyskuje swoją maksymalną nośność przy znaczącym wzroście wartości pracy może zapobiegać rozwarstwianiu skał wokół wyrobiska, a przez to lepiej wykorzystać samonośność górotworu. Jak wykazują wyniki badań, praca W obudowy podporowo-kotwiowej może być nawet ponad 3.5-krotnie większa od obudowy podporowej na początku procesu jej obniżania pod wpływem obciążenia – to znaczy do czasu jej obniżenia o umowną wartość 100 mm.
Źródło:
Archives of Mining Sciences; 2019, 64, 4; 747-764
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Models of maritime safety for development of navigation support systems
Autorzy:
Gucma, M.
Powiązania:
https://bibliotekanauki.pl/articles/223567.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
navigation support system
pilot navigation
sea transport support
system wspomagania nawigacji
nawigacja pilot
transport morski
Opis:
Navigation support systems are part of modern maritime transportation chain where larger and larger vessels are handled in ports. Support systems for sea navigation must meet certain criteria for access, integrity, accuracy and other factors. Modelling of safety criteria for technical creation of support systems like PNS (Pilot Navigation System) or LDS (Laser Docking System) consists of several stages both conceptual, and real time experimental. Even basic systems must be designed and developed in manner where assumed safety factors are met.
Źródło:
Archives of Transport; 2016, 37, 1; 31-41
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Faults Classification Of Power Electronic Circuits Based On A Support Vector Data Description Method
Autorzy:
Cui, J.
Powiązania:
https://bibliotekanauki.pl/articles/220938.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power electronic circuits
fault classification
support vector data description
support vector machine (SVM)
Opis:
Power electronic circuits (PECs) are prone to various failures, whose classification is of paramount importance. This paper presents a data-driven based fault diagnosis technique, which employs a support vector data description (SVDD) method to perform fault classification of PECs. In the presented method, fault signals (e.g. currents, voltages, etc.) are collected from accessible nodes of circuits, and then signal processing techniques (e.g. Fourier analysis, wavelet transform, etc.) are adopted to extract feature samples, which are subsequently used to perform offline machine learning. Finally, the SVDD classifier is used to implement fault classification task. However, in some cases, the conventional SVDD cannot achieve good classification performance, because this classifier may generate some so-called refusal areas (RAs), and in our design these RAs are resolved with the one-against-one support vector machine (SVM) classifier. The obtained experiment results from simulated and actual circuits demonstrate that the improved SVDD has a classification performance close to the conventional one-against-one SVM, and can be applied to fault classification of PECs in practice.
Źródło:
Metrology and Measurement Systems; 2015, 22, 2; 205-220
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Social support as a mediator for musical achievement
Autorzy:
Nogaj, Anna Antonina
Ossowski, Roman
Powiązania:
https://bibliotekanauki.pl/articles/430446.pdf
Data publikacji:
2015-06-01
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
social support
musical achievements
Opis:
This article focuses on the issue of social support received by students of music schools in the context of their musical achievements. The theoretical part of this article contains the characteristics of factors related to the musical achievements of students; the support they receive from their environment is essential for their success in the process of musical education and their subsequent artistic career, in addition to their musical abilities and traits of personality. The research part is devoted to detailed analysis of the support level received by music school students and its correlation to their level of musical achievement. Social support is analysed with a view to its structure, distinguishing the following kinds of support: emotional, evaluative, informative and instrumental received from people who are significant to the music school student and indicates the essential presence of support in the process of musical achievement. Moreover, as part of the presentation of the study, the authors introduce their original tool for measuring social support tailored to the realities of music schools - the Scale of Social Support of the Students of Music Schools (Gluska, 2011). This tool may be applied in the work of educational psychologists and teachers in music schools.
Źródło:
Polish Psychological Bulletin; 2015, 46, 2; 300-308
0079-2993
Pojawia się w:
Polish Psychological Bulletin
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Perceived social support and life-satisfaction
Autorzy:
Kasprzak, Elżbieta
Powiązania:
https://bibliotekanauki.pl/articles/430255.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
life-satisfaction
perceived social support
extent of relationships
closeness of relationships
Opis:
The article concerns the relationship between life-satisfaction and the features of interpersonal relationships and social support. The research presented in this paper concerned the satisfaction with the relationships with family members, friends, colleagues and acquaintances, the extent of the relationships among these groups, and the perceived social support. The aim of the presented research is to assess the impact of these characteristics on life-satisfaction. In addition, the changes that occurred after the social skills training in the level of life-satisfaction and its determinants were examined. The study group consisted of 60 participants. The results show that the strongest determinants of life-satisfaction are practical support and the satisfaction with the relationships with friends. After the social training the structure of the determinants changed. The factors which were relevant before the training appear to be insignificant now; however, the emotional support, satisfaction with family relationships and the number of friends gain in importance. The social skills training was also effective and increased the level of life-satisfaction.
Źródło:
Polish Psychological Bulletin; 2010, 41, 4; 144-154
0079-2993
Pojawia się w:
Polish Psychological Bulletin
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The conditions for proper operation of the arch-rectangular support
Warunki poprawnej pracy odrzwiowej obudowy łukowo-prostokątnej
Autorzy:
Rotkegel, Marek
Powiązania:
https://bibliotekanauki.pl/articles/219613.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
obudowa odrzwiowa
obudowa łukowo-prostokątna
analiza wytrzymałościowa
frame support
arch-rectangular support
strength analysis
Opis:
Steel arch-rectangular support has a wide range of applications in Polish coal mines due to its asym-metrical shape. The frame has an arched outline on one side of the side wall, while on the opposite side it is rectangular. As a result, the support is ideal for securing set up room and recovery room. It can also be successfully used to secure three-way intersections of underground workings. To a large extent, however, the importance of these advantages is diminished by relatively low load-bearing parameters, resulting from a partially straight canopy, as well as the asymmetrical distribution of the load acting on the support in underground conditions. In order to ensure the proper and optimal operation of such frames, in addition to the standard requirements for roof supports, additional conditions must be met. The basic requirement is to support the end of the canopy on the corner of the excavation. This article presents examples of arch-rectangular supports, their applications as well as laboratory tests and strength analysis of the frames and its elements. These tests allowed the requirements regarding the construction of the frame, the selection of the support and the conditions of building in the excavation to be specified.
Stalowa odrzwiowa obudowa łukowo-prostokątna znajduje w polskich kopalniach węgla kamiennego i ma szereg zastosowań, wynikających przede wszystkim z jej niesymetrycznego kształtu. Odrzwia po stronie jednego ociosu mają zarys łukowy, natomiast po stronie przeciwległego ociosu – prostokątny. Z tego względu idealnie nadają się do zabezpieczania rozcinek rozruchowych i kanałów likwidacyjnych ścian. Odrzwia powodzeniem mogą być także stosowane do zabezpieczania trójstronnych skrzyżowańwyrobisk korytarzowych. Jednak z znacznym stopniu wagę tych zalet pomniejszają niezbyt wysokie parametry podpornościowe, wynikające z częściowo prostoliniowej stropnicy, oraz niesymetryczny rozkład obciążenia działającego na odrzwia w warunkach dołowych. Dla zapewnienia właściwej i optymalnej pracy takich odrzwi oprócz standardowych wymagań dotyczących wykonywania obudo-wy konieczne jest spełnienie dodatkowych warunków. Podstawowym jest zapewnienie oparcia końca stropnicy o naroże wyrobiska. W artykule przedstawiono przykłady obudów łukowo-prostokątnych, ich zastosowania, a także badania stanowiskowe i analizę wytrzymałościową odrzwi i ich elementów. Badania te pozwoliły sprecyzowaćwymagania dotyczące konstrukcji odrzwi, doboru obudowy oraz zabudowy w wyrobisku.
Źródło:
Archives of Mining Sciences; 2019, 64, 1; 213-222
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of selected methods of the yielding of a circular arch support made of V profiles
Autorzy:
Rotkegel, Marek
Szot, Łukasz
Fabich, Sławomir
Powiązania:
https://bibliotekanauki.pl/articles/1853839.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wał
podpora stalowa
metoda elementów skończonych
shaft
circular support
arch support
Opis:
Steel yielding arch support constructed of V profiles is commonly used to protect galleries and, in some cases, to reinforce or secure a shaft support. For this purpose, a closed, circular-shaped arch support is used, with arches overlapped by clamps that are typical for this type of construction. The support has high resistance to the impact of even (distributed over the entire surface of the support) load, however, as a result of significant deformation associated with a change in the radius of the curvatures, the support shows limited yielding capacity. This is due to the increase in resistance to slide on the locks, resulting from changes in the geometry of the ring caused by the rock mass. This article presents the results of research and analysis concerning the elements of the arch support with notches in arches. The research team tested the effect of the depth and location of the notches of the section’s flanges on the load impacting on the clamp’s bolts and the strength of the roof support. Moreover, the tests covered the influence of the number and location of clamps in a frictional joint on the change in the nature of work and yielding capacity. Finally, the research included both strength tests of the support’s elements, as well as strength analyses based on the finite element method.
Źródło:
Archives of Mining Sciences; 2020, 65, 3; 531-550
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental studies of static and dynamic steel arch support load capacity and sliding joint temperature parameters during yielding
Autorzy:
Pytlik, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1853806.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nośność statyczna
wyrobisko
podpora stalowa
yielding steel arch support
support shackle torque
static and dynamic load capacity
support work
arch acceleration in sliding joints
joint sparking and heating temperature during yielding
Opis:
Difficult geological and mining conditions as well as great stresses in the rock mass result in significant deformations of the rocks that surround the workings and also lead to the occurrence of tremors and rock bursts. Yielding steel arch support has been utilised in the face of hard coal extraction under difficult conditions for many years, both in Poland and abroad. A significant improvement in maintaining gallery working stability is achieved by increasing the yielding support load capacity and work through bolting; however, the use of rock bolts is often limited due to factors such as weak roof rock, significant rock mass fracturing, water accumulation, etc. This is why research and design efforts continue in order to increase yielding steel arch support resistance to both static and dynamic loads. Currently, the most commonly employed type of yielding steel arch support is a support system with frames constructed from overlapping steel arches coupled by shackles. The yield of the steel frame is accomplished by means of sliding joints constructed from sections of various profiles (e.g. V, TH or U-type), which slip after the friction force is exceeded; this force is primarily dependent on the type of shackles and the torque of the shackle screw nuts. This article presents the static bench testing results of ŁP10/V36/4/A, ŁP10/V32/4/A and ŁP10/V29/4/A yielding steel arch support systems formed from S480W and S560W steel with increased mechanical properties. The tests were conducted using 2 and 3 shackles in the joint, which made it possible to compare the load capacities, work values and characteristics of various types of support. The following shackle screw torques were used for the tests: Md = 500 Nm – for shackles utilised in the support constructed from V32 and V36 sections. Md = 400 Nm – for shackles utilised in the support constructed from V29 sections. The shackle screw torques used during the tests were greater compared to the currently utilised standard shackle screw torques within the range of Md = 350-450 Nm. Dynamic testing of the sliding joints constructed from V32 section with 2 and 3 shackles was also performed. The SD32/36W shackles utilised during the tests were produced in the reinforced versions and manufactured using S480W steel. Since comparative testing of a rock bolt-reinforced steel arch support system revealed that the bolts would undergo failure at the point of the support yield, a decision was made to investigate the character of the dynamics of this phenomenon. Consequently, this article also presents unique measurement results for top section acceleration values registered in the joints during the conduction of support tests at fullscale.Filming the yield in the joint using high-speed video and thermal cameras made it possible to register the dynamic characteristics of the joint heating process at the arch contact point as well as the mechanical sparks that accompanied it. Considering that these phenomena have thus far been poorly understood, recognising their significance is of great importance from the perspective of occupational safety under the conditions of an explosive atmosphere, especially in the light of the requirements of the new standard EN ISO 80079-36:2016, harmonised with the ATEX directive.
Źródło:
Archives of Mining Sciences; 2020, 65, 3; 469-491
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Support for families in protecting the mental health of children
Autorzy:
Wójta-Kempa, Monika
Powiązania:
https://bibliotekanauki.pl/articles/1827589.pdf
Data publikacji:
2020-03-04
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
family
mental health
children’s mental health
support for families
Opis:
The family can be a background of health crises and – at the same time – the greatest source of support for a child. It plays a crucial role in reducing the risk of disorders and increasing the psychological immunity of teenagers. The article presents a number of threats to the mental health of young people, derived from different research. Its main goal is to present the importance of the support system for parents and families in protection of children's mental health. Against this background, some parental errors and deficiencies are analysed as the reasons for ignoring the first symptoms of a child’s crisis. Support for the youth and their families should be provided not only from parents but also from teachers, pedagogues and their wider social environment. Many institutions, including medical staff, schools, governmental and non-governmental organisations may effectively support parents and caregivers in prevention and intervention in a situation of mental crisis. The article discusses the determinants of effective help for families experiencing mental health crises of children.
Źródło:
Studia Demograficzne; 2020, 176, 2; 95-111
0039-3134
Pojawia się w:
Studia Demograficzne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Powered support in dynamic load conditions - numerical analysis
Autorzy:
Masny, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/1853835.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
węgiel kamienny
tąpanie
modelowanie numeryczne
hard coal
rock burst
dynamic
powered support
numerical modelling
Opis:
Tremors occur randomly in terms of time, energy as well as the location of their focus. The present state of knowledge and technology does not allow for the precise prediction of these values. Therefore, it is extremely important to correctly select a powered roof support for specific geological and mining conditions, especially in the case of areas where dynamic phenomena are often registered. This article presents information on rock burst hazard associated with the occurrence of rock mass tremors and their influence on a powered roof support. Furthermore, protection methods of a powered roof support against the negative effects of dynamic phenomena are discussed. As a result of an analysis the methodology, to determine the impact of dynamic phenomena on the powered roof support in given geological and mining conditions is presented.
Źródło:
Archives of Mining Sciences; 2020, 65, 3; 453-468
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A concept of Internet decision support system for integrated plant protection
Autorzy:
Zaliwski, A.S.
Wolny, S.
Powiązania:
https://bibliotekanauki.pl/articles/66731.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
plant protection
pest management
decision support system
Internet
Źródło:
Journal of Plant Protection Research; 2003, 43, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity analysis of sandwich beams and plates accounting for variable support conditions
Autorzy:
Studziński, R.
Pozorski, Z.
Garstecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/201924.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sandwich panels
sensitivity analysis
optimal design
support conditions
Opis:
The paper addresses the problems of the sensitivity analysis and optimal design of multi-span sandwich panels with a soft core and flat thin steel facings. The response functional is formulated in a general form allowing wide practical applications. Sensitivity gradients of this functional with respect to dimensional, material and support parameters are derived using adjoint variable method. These operators account for the jump of the slope of a Timoshenko beam or a Reissner plate at the position of concentrated active load or reaction, thus extending the sensitivity operators known in literature. The jump of slope is the effect of shear deformation of the core. Special attention is focussed on sensitivity and optimisation allowing for variable support position and stiffness, because local phenomena observed in supporting area of sandwich plates often initiate failure mechanisms. Introducing optimally located elastic supports allows to reduce the unfavourable influence of temperature on the state of stress. Several examples illustrate the application of derived sensitivity operators and demonstrate their exactness.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 1; 201-210
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Social support as a regulator of self-care attitude in persons with myocardial infarction
Autorzy:
Wilski, Maciej
Sienkiewicz Wilowska, Julia Anastazja
Powiązania:
https://bibliotekanauki.pl/articles/430603.pdf
Data publikacji:
2014-12-01
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
social support
self-care
myocardial infarction
Opis:
The article presents the results of research on the relationship between social support and self-care of people with myocardial infarction. 127 patients treated in a rehabilitation centre participated in the study. The Inventory of Socially Supportive Behaviours (ISSB) and the Self-care Questionnaire (KTS) developed by the author, were used. The findings suggest that persons receiving little support are characterised by lower level of self-care than people with medium and high level of support. No such difference was noted between people with medium and high support level. This suggests that social support is of considerable importance for the changes in the level of self-care only in the case of people previously receiving little support. The research also indicates that informational support is related to higher level of self-care whereas instrumental support is related to lower level of self-care. Emotional support was significant only for the care for social functioning.
Źródło:
Polish Psychological Bulletin; 2014, 45, 4; 521-532
0079-2993
Pojawia się w:
Polish Psychological Bulletin
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of laboratory tests of steel arch support
Symulacja laboratoryjnych badań stalowej obudowy łukowej
Autorzy:
Horyl, P.
Snuparek, R.
Marsalek, P.
Pacześniowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/219962.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nośność odrzwi
stalowa obudowa podatna łukowa
obudowa sztywna
metoda elementów skończonych
total load-bearing capacity
steel arch yielding support
rigid support
FEM
Opis:
The total load-bearing capacity of steel arch yielding roadways supports is among their most important characteristics. These values can be obtained in two ways: experimental measurements in a specialized laboratory or computer modelling by FEM. Experimental measurements are significantly more expensive and more time-consuming. However, for proper tuning, a computer model is very valuable and can provide the necessary verification by experiment. In the cooperating workplaces of GIG Katowice, VSB-Technical University of Ostrava and the Institute of Geonics ASCR this verification was successful. The present article discusses the conditions and results of this verification for static problems. The output is a tuned computer model, which may be used for other calculations to obtain the load-bearing capacity of other types of steel arch supports. Changes in other parameters such as the material properties of steel, size torques, friction coefficient values etc. can be determined relatively quickly by changing the properties of the investigated steel arch supports.
Najważniejszymi parametrami wytrzymałościowymi stalowych, podatnych odrzwi obudowy wyrobisk korytarzowych jest ich maksymalna i robocza nośność. Wartości tych nośności mogą być określane dwoma sposobami: doświadczalnie, w specjalistycznym laboratorium badawczym lub za pomocą modelowania komputerowego metodą elementów skończonych (MES). Badania laboratoryjne odrzwi są drogie i czasochłonne, jednak dla kalibracji i weryfikacji modelu numerycznego wyniki tych badań są niezbędne. Weryfikację tą, zakończoną sukcesem, przeprowadzono we współpracy Głównego Instytutu Górnictwa w Katowicach, Technicznego Uniwersytetu VSB w Ostrawie oraz Instytutu Geoniki ASCR w Ostrawie. Niniejszy artykuł przedstawia przebieg procesu kalibracji modelu numerycznego odrzwi w warunkach obciążeń statycznych. W efekcie tych działań uzyskano model komputerowy odrzwi odwzorowujący ich pracę w stanowisku badawczym. Opracowany model może być wykorzystywany do obliczania nośności innych typów odrzwi. Zmiany parametrów odrzwi wpływających na ich nośność, takich jak własności mechaniczne stali, wielkość momentu dokręcenia nakrętek śrub strzemion, współczynnik tarcia itp. Mogą być zmieniane w modelu stosunkowo szybko.
Źródło:
Archives of Mining Sciences; 2017, 62, 1; 163-176
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on regional emergency DC power support strategy of VSC-MTDC transmission system
Autorzy:
Li, Congshan
Sheng, Tingyu
Fang, Yan
Li, Yikai
Powiązania:
https://bibliotekanauki.pl/articles/1841327.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
coordinated control
dynamic active power support
emergency DC power support
VSC-MTDC
skoordynowana kontrola
dynamiczne wspomaganie mocy czynnej
awaryjne wsparcie zasilania prądem stałym
Opis:
In the asynchronous interconnected power grid that is composed of the multiterminal voltage-source converter high voltage direct current (VSC-MTDC) system, the control methods of each converter station and the frequency of the connected AC systemare not the same. When a fault occurs in any place of the asynchronous interconnected system, it will cause the system to have power shortage or surplus, affecting the safe and stable operation of the interconnected power grid. In order to solve the problem of insufficient regional active power reserve, based on the VSC-MTDC asynchronous regional interconnection system and the principle of regional sharing, the dynamic power controller under disturbance conditions is established, and the controller parameters are set to achieve the accuracy of unbalanced power in the disturbance area measuring. Then, according to the degree of the disturbance power, considering the factors that affect the support effect of the converter station, an emergency DC power support (EDCPS) scheme under different power disturbances is formulated to achieve power compensation for the disturbance area. Basedon PSCAD/EMTDC software, the proposed control strategy is simulated. The result showst hat the converter station closer to the disturbance area has a better support effect, and the dynamic active power controller can timely and accurately deliver to the disturbance area when the active power reserve is insufficient.
Źródło:
Archives of Electrical Engineering; 2021, 70, 1; 145-160
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 194

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