Wyniki wyszukiwania - BazTech

1

Dynamic performance evaluation of ultra-fast SiC MOSFET power module – a comprehensive approach

Zięba Dawid, Rąbkowski Jacek

Przegląd Elektrotechniczny

|

2023

|

R. 99, nr 5

190--195

EN

The article describes a comprehensive approach to dynamic performance determination tests of SiC MOSFET power modules. Experimental verification was performed using ultra-fast switching (1,2 kV, 495 A) module from Microsemi. The obtained results are compared to results acquired by measurements performed with compliance to a commonly-used standard that does not consider phenomena that significantly impact switching processes of fast-switching SiC MOSFET power modules.

PL

W artykule przedstawiono metodykę badań parametrów dynamicznych modułów tranzystorowych nowej generacji bazujących na tranzystorach MOSFET z węglika krzemu (SiC). Przeprowadzono badania eksperymentalne dla bardzo szybko przełączającego modułu tranzystorowego firmy Microsemi (1,2 kV, 495 A). Otrzymane wyniki porównano z wynikami uzyskanymi na podstawie powszechnie wykorzystywanego standardu wyznaczania parametrów dynamicznych tranzystorów MOSFET, który nie uwzględnia szeregu zjawisk znacząco wpływających na procesy łączeniowe szybko przełączających tranzystorów SiC MOSFET.

2

Podstawowe parametry ochronne i użytkowe uprzęży stosowanych w zestawach zabezpieczających przed upadkiem z wysokości - metody badań

Baszczyński Krzysztof

Bezpieczeństwo Pracy : nauka i praktyka

|

2023

|

nr 5

19-23

PL

Jednym z głównych składników indywidualnych zestawów chroniących przed upadkiem z wysokości są uprzęże, które zakłada na siebie człowiek. W zależności od ich przeznaczenia mogą to być szelki bezpieczeństwa, uprzęże biodrowe, pasy do ustalania pozycji podczas pracy na wysokości, uprzęże alpinistyczne, szelki ratownicze i inne. Uprzęże pełnią ważną i odpowiedzialną rolę, decydując niejednokrotnie o życiu ich użytkownika. W związku z tym przed dopuszczeniem na rynek, a następnie do stosowania, konieczna jest kontrola ich parametrów. W artykule przedstawiono najważniejsze parametry uprzęży, takie jak: odporność na obciążenie statyczne i dynamiczne, zachowanie w warunkach dynamicznych, działanie na ciało użytkownika w stanie jego zawieszenia oraz naciski wywierane na powierzchnię manekina antropomorficznego. Scharakteryzowano stosowane obecnie metody badań tych parametrów oraz aparaturę badawczą. Wśród zaprezentowanych metod znalazły się zarówno metody znormalizowane, jak i własne - opracowane w Centralnym Instytucie Ochrony Pracy - Państwowym Instytucie Badawczym. Przedstawiono znaczenie poszczególnych parametrów z punktu widzenia bezpieczeństwa użytkowników uprzęży.

EN

The presence of harnesses that a person puts on is a characteristic feature of individual fall protection systems. Depending on the purpose of the system, these may be, for example, full body safety harnesses, sit harnesses, work positioning belts, mountaineering harnesses, rescue harnesses and others. The role of such harnesses is an important and responsible one, because their performance often decides about their user's life. Therefore, before they are launched on the market and approved for use, it is necessary to control their parameters. The paper presents the most important protective parameters, such as: resistance to static and dynamic loads, behavior in dynamic conditions, the effect of the harness on the user's body in the suspended state and the pressure of the harness on the surface of the anthropomorphic dummy. The currently used methods of testing these parameters and the research equipment have been characterized. The presented methods include both standardized and own methods developed at Central Institute for Labour Protection - National Research Institute. The importance of the individual parameters from the point of view of the harness user safety is discussed.

3

Dynamic performance of bridge piers impacted by heavy trucks

Huang Yao

Archives of Civil Engineering

|

2023

|

Vol. 69, nr 3

173--185

EN

Vehicle-bridge collision accidents often result in significant economic losses and negative social effects, with heavy trucks being the most destructive to bridge structures. Therefore, this study uses a high-precision finite element method to investigate the impact resistance of concrete bridge piers when subjected to heavy truck impact. The main conclusions of this paper are as follows: (1) When heavy trucks collide with bridge piers, two peak impact forces are generated due to engine and cargo collisions. The peak collision force generated by engine impact is 17.7% greater than that generated by cargo impact. (2) The damage to the bridge, when impacted by heavy trucks, is mainly concentrated on the affected pier. The primary damage characteristics of the bridge piers include punching shear damage at the impact point, tensile damage at the backside, and shear damage at the pier top. (3) The peak values of shear force and bending moment both appear at the bottom of the pier, and the combination of the two causes serious flexural-shear failure damage at the bottom of the pier. (4) The axial force is fluted along the pier height, and the axial force at the top and bottom of the pier is the largest, while the axial force at the middle section is relatively small. The instantaneous axial force of bridge pier will reach more than 2 times the axial force during operational period, seriously threatening the safety of bridge. Overall, this study provides valuable insights into the impact resistance of concrete bridge piers when subjected to heavy truck impact, which can help engineers and policymakers in designing more robust and safer bridges.

4

Dynamic performance and stability analysis of an active inerter-based suspension with time-delayed acceleration feedback control

Wang Yong, Jin Xian-Yu, Zhang Yun-Shun, Ding Hu, Chen Li-Qun

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2022

|

Vol. 70, nr 2

art. no. e140687

EN

An active inerter-based suspension with acceleration feedback control is proposed in this paper, the time delay generated in the controllers and actuators is considered, which constitutes the time-delayed active inerter-based (TDA-IB) suspension. The dynamic equation of the TDA-IB suspension is established and is a neutral type of delay differential equation (NDDE) in which the time delay exists in the highestorder derivative. The stability analysis is conducted by calculating the number of unstable characteristic roots based on the definite integral stability method, the stable and unstable regions are determined. The effect of time delay and feedback gain on the dynamic performance of the TDA-IB suspension under harmonic, random, and shock excitations is studied in detail and compared with the parallel-connected inerterbased (PC-IB) and traditional suspensions. The results show that the TDA-IB suspension is asymptotically stable for smaller feedback gain and time delay, through increasing the feedback gain, the stable regions shrink, and a smaller time delay could cause the system to become unstable. Furthermore, the time delay could regulate the resonance peak around the unsprung mass natural frequency and generate multiple high-frequency resonance peaks. If the time delay is chosen appropriately and falls into the stable range, the TDA-IB suspension could improve the dynamic performance for the suspension stroke and dynamic tire load while having a deterioration for the vehicle body acceleration compared with the PC-IB and traditional suspensions.

5

Analysis of the conditions for the exhaustion of the stability margin in the rail track of freight cars with three-piece bogies

Domin Yurii V., Domin Rostysla Yu., Cherniak Ganna Yu., Nozhenko Volodymyr S.

Archives of Transport

|

2021

|

Vol. 57, iss. 1

119--129

EN

The research on improvement of methodical approaches to definition of the probable reasons of infringement of conditions of stability of freight cars from derailment is carried out. Using a basic computer model of the dynamics of a freight car, the influence of the characteristics of the technical condition of their running gear and track on the indicators of empty cars stability from derailment was studied through the computational experiment. The article presents the main statements of the research methodology, which provides the analysis of probable causes of derailment of freight cars by conducting a series of numerical experiments with logging the progress of calculations and saving the results. Factor analysis was used to interpret the calculated data with an assessment of each of the factors influence or their combination on the probability of derailment. The developed procedure of the simulation experiment provides a step-by-step study of the freight cars derailment conditions, including factors structuring and ranking, development of experimental plan, calculating coefficients of wheel pairs resistance to derailment from rails, provided that the wheel flange rolls onto the rail head, and determining the degree of influence of relevant factors on the dynamic stability of cars from derailment. A comparative analysis of the stability of cars in rail tracks was performed using the introduced concept of the combined coefficient of stability of wheel pairs against derailment. Determining the probable causes of car derailment is based on scanning the parameter field. The results of the parametric study revealed the degree of influence on the freight cars stability of running gear technical condition characteristics. In particular, it is determined that the most dangerous in terms of stability loss of empty cars in the track is the exceeding of the wedges of the vibration dampers.

6

Multi-mode switching control of hybrid electromagnetic suspension based on road conditions adaptation

Meng Xiangpeng, Ding Renkai, Sun Zeyu, Wang Ruochen, Chen Long

Journal of Theoretical and Applied Mechanics

|

2020

|

Vol. 58 nr 3

697--710

EN

In this research, a hybrid electromagnetic actuator is proposed to coordinate the contradictions between dynamic performance and energy consumption of an electromagnetic suspension. The hybrid electromagnetic suspension (HEMS) is configured to operate in the passive energy regeneration mode, active control ride comfort mode or active control driving safety mode depending on the road excitation frequency. Then, the HEMS system is modeled. The simulation results show that the HEMS can automatically switch between different modes, and realize an effective coordination between dynamic performance and energy saving. Finally, a quarter car test is conducted, which verifies the effectiveness of the multi-mode switching control.

7

Comparative study of fault-tolerant performance of a segmented rotor SRM and a conventional SRM

Sun X., Xue Z., Han S., Chen L., Xu X., Yang Z.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2017

|

Vol. 65, nr 3

375--381

EN

Due to the separation of magnetic field, electrical isolation and thermal isolation, motor drives possess a high fault-tolerance characteristic. In this paper, comparative study of mutual inductance between the proposed segmented rotor switched reluctance motor (SSRM) and the conventional switched reluctance motor (SRM) is carried out first, illustrating that the proposed SSRM has less mutual inductance between phases than the conventional SRM. In addition, if winding faults or power converter faults lead to phase failure, a comparative analysis on fault-tolerant performance under phase failure condition between the proposed SSRM and the conventional SRM is simulated in detail using the finite element method (FEM). Simulation results reveal that dynamic performance of the proposed SSRM, including output torque and phase current, is better than that of the conventional SRM. That is, the capacity of operating with the fault under phase failure condition in the proposed SSRM is superior to that in the conventional SRM.

8

Diagnostics of bucket wheel excavator discharge boom dynamic performance and its reconstruction

Brkić A. D., Maneski T, Ignjatović D., Jovančić P. D., Spasojević Brkić V. K.

Eksploatacja i Niezawodność

|

2014

|

Vol. 16, no. 2

188--197

PL

W artykule badano możliwe przyczyny złych własności dynamicznych wysięgnika zrzutowego koparki kołowej C7OOS (BWE) pracującej w kopalni odkrywkowej Kolubara w Serbii. Do stworzenia modelu konstrukcji nośnej wysięgnika zrzutowego oraz przeprowadzenia obliczeń statycznych i dynamicznych wykorzystano metodę elementów skończonych (MES). Model został następnie zweryfikowany przy użyciu metody eksperymentalnej – analizy drgań. Wyznaczone cele osiągnięto poprzez analizę wyników MES, które zostały następnie zweryfikowane w badaniach doświadczalnych. Ustalono przyczyny słabego działania wysięgnika. Głównymi problemami eksploatacyjnymi okazały się być nieodpowiednia konstrukcja cięgien wysięgnika oraz montaż kabiny kierowcy. Aby poprawić charakterystyki pracy wysięgnika, rozważono możliwe opcje jego przebudowy. Wybór metody przebudowy ograniczały zasoby techniczne i finansowe użytkownika maszyny. Przebudowa dała poprawę charakterystyk pracy wysięgnika, co wykazano w praktyce.

EN

The paper focuses on an investigation into the possible causes of the bad dynamic performance of bucket wheel excavator C7OOS (BWE) discharge boom in the Kolubara opencast mine, Serbia. A discharge boom load carrying structure model was produced and its static and dynamic calculations were made by the finite element method (FEM). The model was then validated by the experimental method – vibration analysis. The set goals were achieved by the FEM result analysis, which were further confirmed in the experiment. The causes for discharge boom weak performance were established. The main operation problems were found in the inadequate design of the discharge boom tie(s) and the subsequent installation of a steering cabin. Possible discharge boom reconstructions were considered with a view to improving its operation performance. The selection of the reconstruction approach was limited by the technical and financial resources available to the machine users. After the completed reconstruction, the discharge boom improved operation performance was demonstrated in practice.

9

Improvement of microgrid dynamic performance under fault circumstances using ANFIS for fast varying solar radiation and fuzzy logic controller for wind system

Izadbakhsh M., Rezvani A., Gandomkar M.

Archives of Electrical Engineering

|

2014

|

Vol. 63, nr 4

551--578

EN

The microgrid (MG) technology integrates distributed generations, energy storage elements and loads. In this paper, dynamic performance enhancement of an MG consisting of wind turbine was investigated using permanent magnet synchronous generation (PMSG), photovoltaic (PV), microturbine generation (MTG) systems and flywheel under different circumstances. In order to maximize the output of solar arrays, maximum power point tracking (MPPT) technique was used by an adaptive neuro-fuzzy inference system (ANFIS); also, control of turbine output power in high speed winds was achieved using pitch angle control technic by fuzzy logic. For tracking the maximum point, the proposed ANFIS was trained by the optimum values. The simulation results showed that the ANFIS controller of grid-connected mode could easily meet the load demand with less fluctuation around the maximum power point. Moreover, pitch angle controller, which was based on fuzzy logic with wind speed and active power as the inputs, could have faster responses, thereby leading to flatter power curves, enhancement of the dynamic performance of wind turbine and prevention of both frazzle and mechanical damages to PMSG. The thorough wind power generation system, PV system, MTG, flywheel and power electronic converter interface were proposed by Rusing Mat-lab/Simulink.

10

Analyses of the Additional Stiffness Function of the Traction Bar on the Vertical Dynamics Performance of Subway Vehicle

Ma W., Song R.

Przegląd Elektrotechniczny

|

2012

|

R. 88, nr 1b

39-43

EN

This paper analyses the influence of the additional stiffness function of the traction bar on the vehicle vertical dynamic performance. Based on the subway vehicle dynamics model, the influences of the additional stiffness function of the traction bar on vehicle’s response to vertical impact, carbody vertical ride index and relevant phenomena of wheelset longitudinal vibration resonance were analyzed. Results indicate that the additional stiffness function of the traction bar will increase the stiffness of the secondary suspension system. It not only increase the response of the vehicle to vertical impact and reduces the ride comfort of vehicle, but also increase the vertical and longitudinal vibration acceleration, and the vertical dynamic load of the first and secondary suspension increased too. Put forward that the vertical dynamic performance of the vehicle can be improved through decrease the connection stiffness of the traction bar to 25% of the present value.

PL

W pracy nalizowano wpływ dodatkowej funkcji sztywności trakcyjnej belki na poziome dynamiczne właściwości pojazdu podziemnego. Rezultaty analizy pokazały że sztywność belki trakcyjnej zwiększa sztywność systemu zawieszenia. Może to zwiększać wibracje poziome pojazdu.

11

Transient stability analysis and control of power systems with considering flux decay by energy function approach

Lu D., Zhang X.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2012

|

Vol. 60, nr 1

3-8

EN

In this paper, transient stability of power systems with structure preserving models is considered. A Hamiltonian function which can be regarded as a Lyapunov function for the system is proposed. Based on this, the influence of flux decay dynamics, especially during a fault, on transient stability is analyzed. With the increase of load power, the variation of stability boundary in the rotor angle/Eq plane is shown. The Energy-based excitation control, aiming at injecting additional damping into the post-fault system may reduce the critical clearing time (CCT). This can be demonstrated by the comparison of different flux decay dynamics in the fault-on condition, and the reason is illustrated by the relationship between rotor angle/Eq and the stability boundary. An improved control strategy is proposed and applied to increase the CCT. Simulation results verify that improvement is obtained both in transient stability and dynamic performance.

12

Właściwości dynamiczne komputerowego systemu odtwarzania napięć i prądów

Dąbrowski R.

Pomiary Automatyka Kontrola

|

2006

|

R. 52, nr 6 bis

115-117

PL

Artykuł przedstawia zagadnienia budowy komputerowego systemu odtwarzania wzorcowych wartości napięć i prądów opartego o ekonomiczny kalibrator średnich klas dokładności i miernik kontrolny wysokich klas dokładności. Głównym tematem jest analiza parametrów dynamicznych systemu. Autor podejmuje próbę określenia optymalnych wartości parametrów pracy programu sterującego działaniem systemu. Przedstawia metodologię badań symulacyjnych czasu odpowiedzi i przeregulowania na wyjściu systemu w odpowiedzi na wymuszenie w postaci skoku jednostkowego. Na podstawie wyników tych badań przedstawia receptę w postaci wzoru na uzyskanie przez system optymalnych dynamicznie warunków pracy.

EN

Article presents some problems of computer controlled calibration system for generating voltage and current The low cost close loop system includes medium accuracy calibrator and high accuracy control meter. Main topic of this article is consideration of dynamics optimization possibilities, especially how dynamic performance of mentioned system can be improved by applying optimal parameters of control algorithm. Article describes simulation experiments which provides to formalized conclusion how to match parameters to get optimal system performance.

13

Dynamic Performance of Horizontal Flexible Anchor Lines During Fall Arrest - A Numerical Method of Simulation

Baszczyński K., Zrobek Z

International Journal of Occupational Safety and Ergonomics

|

2000

|

Vol. 6, No. 4

521--534

EN

Designing fall arrest systems, which contain horizontal flexible anchor lines is an important technical problem related to the safety of people who work at a height and need horizontal freedom of movement. The article presents a numerical simulation of the dynamic performance of horizontal flexible anchor lines during fall arrest. The model of a 2-component system – a horizontal flexible anchor line and a falling rigid mass, described with a second order non-linear differential equation - is the main element of this method. This method of simulation is realised by a computer program, which allows obtaining the most important data characterising a fall arrest. The article shows laboratory tests used for the verification of this method, which turned out to be a valuable source of information and which can be used for designing fall arrest systems.