scholarly journals Transient overvoltage characteristics in submarine cables of multi-terminal flexible HVDC transmission system

2021 ◽  
Vol 2108 (1) ◽  
pp. 012046
Author(s):  
Man Feng ◽  
Tao Li ◽  
Jinjuan Liu
Keyword(s):  
Power Transmission ◽  
Simulation Models ◽  
Submarine Cable ◽  
Hvdc Transmission ◽  
Transmission Equipment ◽  
Simulation Results ◽  
Design Selection ◽  
Grid Side ◽  
Submarine Cables ◽  
Transient Overvoltage

Abstract The overvoltage transient characteristics of submarine cables are one of the key technologies for submarine power transmission. This article takes the submarine cable of Zhoushan Multi-terminal Flexible HVDC Transmission Project as the research object. The MMC-HVDC simulation models at both ends of converter stations are built in PSCAD. The parameters and equivalent models of the flexible HVDC cables are determined, and the submarine DC cable operating overvoltage is calculated by using statistical methods. The simulation results show that the maximum overvoltage of the submarine cable, that is, the maximum overvoltage of the conductor to sheath, the sheath to the armour, and the armour to the ground are 400 kV, 7.27 kV and 0.45kV respectively. The maximum overvoltage when it occurs faults on grid-side or valve-side appears in the middle of the submarine cable. Maximum overvoltage of HVDC single pole grounding fault appears at the connection point of land cable and submarine cable. The simulation results and the discovery of features in this article provide reference in the design, selection, and testing of submarine power transmission equipment.

Modeling & Simulating of Hami-Zhengzhou UHVDC Transmission Project and Security & Stability Analysis of Send-Side Power System

2014 ◽  
Vol 1070-1072 ◽  
pp. 790-796
Author(s):  
Tian Xia ◽  
Xiao Xiao Qi ◽  
Li Jun Deng ◽  
Yi Xian Sun
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
High Voltage ◽  
Power Transmission ◽  
Control Strategies ◽  
Operation Condition ◽  
Hvdc Transmission ◽  
Failure Treatment ◽  
Commutation Failure ◽  
Simulation Results

Hami-Zhengzhou ±800kV DC project is the first ultra high-voltage project for Xinjiang power transmission, it is also the first DC transmission project binding thermal and wind power, with bipolar low-end operation in 2013 and bipolar operation in the middle of 2014. The rated power is 8,000MW. This article focused on Hami-Zhengzhou HVDC transmission system, established the electromechanical model, which improved commutation failure treatment in the traditional DC control system and made the simulation results more close to the real operation condition. Based on this model, security and stability analysis of power grid was carried out and the corresponding control strategies/schemes were brought up.

scholarly journals Global experience of HVDC composite insulators in outdoor and indoor environment

2020 ◽  
Vol 59 (1) ◽  
pp. 606-618
Author(s):  
Mohammad Akbar ◽  
Basharat Mehmood
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Transmission Lines ◽  
Power Transmission ◽  
Green Energy ◽  
Attractive Alternative ◽  
Hvdc Transmission ◽  
Ceramic Insulators ◽  
High Power Transmission ◽  
Aging Performance

AbstractHigh-voltage direct current (HVDC) transmission is known as green-energy transfer technology and has recently become an attractive alternative of high-voltage alternating current (HVAC) due to its high-power transmission capability and lower power loss. Use of composite insulators on direct current (DC) transmission lines experienced rapid growth in recent years due to their high hydrophobicity and better performance in contaminated environment than conventional ceramic insulators. During their service operation on DC lines, insulators are prone to more accumulation of contaminants due to unidirectional electric field. The contaminants under wet conditions allow leakage current to flow on the insulator surface. Being organic in nature, polymeric insulators have a tendency to age under the combined effects of electrical and environmental stresses. To fully understand the long-term aging performance of DC composite insulators, a detailed survey was considered necessary. Towards that end, this paper critically summarizes worldwide experience of aging performance of composite insulators in the field as well as in laboratory conditions.

Hybrid Fluid Flow Simulation Combining Full Physics Simulation and Artificial Intelligence

2021 ◽  
Author(s):  
Mokhles Mezghani ◽  
Mustafa AlIbrahim ◽  
Majdi Baddourah
Keyword(s):  
Artificial Intelligence ◽  
Reservoir Simulation ◽  
History Matching ◽  
Hybrid Approach ◽  
Flow Simulation ◽  
Latin Hypercube Sampling ◽  
Simulation Models ◽  
Fine Scale ◽  
Simulation Results ◽  
Optimization Loop

Abstract Reservoir simulation is a key tool for predicting the dynamic behavior of the reservoir and optimizing its development. Fine scale CPU demanding simulation grids are necessary to improve the accuracy of the simulation results. We propose a hybrid modeling approach to minimize the weight of the full physics model by dynamically building and updating an artificial intelligence (AI) based model. The AI model can be used to quickly mimic the full physics (FP) model. The methodology that we propose consists of starting with running the FP model, an associated AI model is systematically updated using the newly performed FP runs. Once the mismatch between the two models is below a predefined cutoff the FP model is switch off and only the AI model is used. The FP model is switched on at the end of the exercise either to confirm the AI model decision and stop the study or to reject this decision (high mismatch between FP and AI model) and upgrade the AI model. The proposed workflow was applied to a synthetic reservoir model, where the objective is to match the average reservoir pressure. For this study, to better account for reservoir heterogeneity, fine scale simulation grid (approximately 50 million cells) is necessary to improve the accuracy of the reservoir simulation results. Reservoir simulation using FP model and 1024 CPUs requires approximately 14 hours. During this history matching exercise, six parameters have been selected to be part of the optimization loop. Therefore, a Latin Hypercube Sampling (LHS) using seven FP runs is used to initiate the hybrid approach and build the first AI model. During history matching, only the AI model is used. At the convergence of the optimization loop, a final FP model run is performed either to confirm the convergence for the FP model or to re iterate the same approach starting from the LHS around the converged solution. The following AI model will be updated using all the FP simulations done in the study. This approach allows the achievement of the history matching with very acceptable quality match, however with much less computational resources and CPU time. CPU intensive, multimillion-cell simulation models are commonly utilized in reservoir development. Completing a reservoir study in acceptable timeframe is a real challenge for such a situation. The development of new concepts/techniques is a real need to successfully complete a reservoir study. The hybrid approach that we are proposing is showing very promising results to handle such a challenge.

Towards multi-method geophysical sensing on submarine cables 

2021 ◽  
Author(s):  
Zhongwen Zhan ◽  
Mattia Cantono ◽  
Jorge Castellanos ◽  
Miguel González Herráez ◽  
Zhensheng Jia ◽  
...  
Keyword(s):  
Laser Interferometry ◽  
Distributed Sensing ◽  
Ocean Dynamics ◽  
Submarine Cable ◽  
Geophysical Research ◽  
Acoustic Sensing ◽  
Rayleigh Backscattering ◽  
Submarine Earthquakes ◽  
Distributed Acoustic Sensing ◽  
Submarine Cables

<p>The oceans present a major gap in geophysical instrumentation, hindering fundamental research on submarine earthquakes and the Earth’s interior structure, as well as effective earthquake and tsunami warning for offshore events. Emerging fiber-optic sensing technologies that can leverage submarine telecommunication cables present an new opportunity in filling the data gap. Marra et al. (2018) turned a 96 km long submarine cable into a sensitive seismic sensor using ultra-stable laser interferometry of a round-tripped signal. Another technology, Distributed Acoustic Sensing (DAS), interrogates intrinsic Rayleigh backscattering and converts tens of kilometers of dedicated fiber into thousands of seismic strainmeters on the seafloor (e.g., Lindsey et al., 2019; Sladen et al., 2019; Williams et al., 2019; Spica et al., 2020). Zhan et al. (2021) successfully sensed seismic and water waves over a 10,000 km long submarine cable connecting Los Angeles and Valparaiso, by monitoring the polarization of regular optical telecommunication channels. However, these new technologies have substantially different levels of sensitivity, coverage, spatial resolution, and scalability. In this talk, we advocate that strategic combinations of the different sensing techniques (including conventional geophysical networks) are necessary to provide the broadest coverage of the seafloor while making high-fidelity, physically interpretable measurements. Strategic collaborations between the geophysics community and telecommunication community without burdening the telecomm operation (e.g., by multiplexing or using regular telecom signals) will be critical to the long term success.</p><p> </p><p>Marra, G., C. Clivati, R. Luckett, A. Tampellini, J. Kronjäger, L. Wright, A. Mura, F. Levi, S. Robinson, A. Xuereb, B. Baptie, D. Calonico, 2018. Ultrastable laser interferometry for earthquake detection with terrestrial and submarine cables. Science, eaat4458.</p><p>Lindsey, N.J., T. C. Dawe, J. B. Ajo-Franklin, 2019. Illuminating seafloor faults and ocean dynamics with dark fiber distributed acoustic sensing. Science. <strong>366</strong>, 1103–1107.</p><p>Sladen, A., D. Rivet, J. P. Ampuero, L. De Barros, Y. Hello, G. Calbris, P. Lamare, 2019. Distributed sensing of earthquakes and ocean-solid Earth interactions on seafloor telecom cables. Nat Commun. <strong>10</strong>, 5777.</p><p>Spica, Z.J., Nishida, K., Akuhara, T., Pétrélis, F., Shinohara, M. and Yamada, T., 2020. Marine Sediment Characterized by Ocean‐Bottom Fiber‐Optic Seismology. Geophysical Research Letters, 47(16), p.e2020GL088360.</p><p>Williams, E.F., M. R. Fernández-Ruiz, R. Magalhaes, R. Vanthillo, Z. Zhan, M. González-Herráez, H. F. Martins, 2019. Distributed sensing of microseisms and teleseisms with submarine dark fibers. Nat Commun. <strong>10</strong>, 5778.</p><p>Zhan, Z., M. Cantono, V. Kamalov, A. Mecozzi, R. Muller, S. Yin, J.C. Castellanos, 2021. Optical polarization-based seismic and water wave sensing on transoceanic cables. Science, in press.</p>

Research of UHV DC Transmission Based on the Current Control

2011 ◽  
Vol 143-144 ◽  
pp. 19-23
Author(s):  
Hai Long Zhao ◽  
Zhong Ying Lin
Keyword(s):  
Transmission System ◽  
Current Control ◽  
Good Effect ◽  
Submarine Cable ◽  
Long Distance ◽  
Harmonic Control ◽  
Dc Power ◽  
Current Transmission ◽  
Simulation Results ◽  
Time Type

Compared with AC (alternating current) transmission, DC(direct current) transmission has obvious superiority at high power, long distance, submarine cable transmission and asynchronous interconnected between exchange systems etc.. This paper constructed a kind of 12 pulse bridge UHV DC transmission system that includes control protection function through MATLAB/Simulink tool. By setting the breaker parameters, this paper studied the 12 pulse bridge UHV DC transmission system AC/DC side in case of setting down time, type and cleared. The simulation results demonstrate that this system has a good effect in harmonic control and it has no power compensations in realizing HV DC process, and it can completely work as an important reference in constructing HV DC power grid.

Effect of Strain Rate on the Simulation of MEMS Safety and Arming Device

2014 ◽  
Vol 609-610 ◽  
pp. 849-855
Author(s):  
Wen Rui Ma ◽  
Guang He
Keyword(s):  
Finite Element Analysis ◽  
Strain Rate ◽  
Impact Load ◽  
Simulation Models ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Experimental Results ◽  
Analysis Software ◽  
Element Analysis ◽  
Simulation Results

Under launch impact load, LIGA nickel that manufacturing MEMS fuze safety and arming (S&A) device will have obvious strain rate effect. By using finite element analysis software ANSYS/LS-DYNA, simulation models of a small-caliber ammunition MEMS fuze setback S&A device with strain rate effect and without strain rate effect were respectively established. The results of the two simulation modules were quite different. Comparisons between experimental results and simulation results show that simulation results considering strain rate effect agree well with experimental results, which proves strain rate effect should not be ignored in the simulation of MEMS S&A device.

Fuzzy Logic Controller for Force Feedback Control of Quadcopter via Tether

2020 ◽  
Author(s):  
Bennett Breese ◽  
Drew Scott ◽  
Shraddha Barawkar ◽  
Manish Kumar
Keyword(s):  
Fuzzy Logic ◽  
Control Strategy ◽  
Fuzzy Logic Controller ◽  
Force Feedback ◽  
Power Transmission ◽  
Extensive Simulation ◽  
Control Scheme ◽  
Area Surveillance ◽  
Simulation Results ◽  
Long Endurance

Abstract Tethered drone systems can be used to perform long-endurance tasks such as area surveillance and relay stations for wireless communication. However, all the existing systems use tethers only for data and power transmission from a stationary point on the ground. This work presents a control strategy that enables a quadcopter to follow a moving tether anchor. A force feedback controller is implemented using Fuzzy Logic. Using force-based strategy provides effective compliance between the tether’s anchor and the drone. The drone can thus be controlled by mere physical movement/manipulation of tether. This enhances the safety of current tethered drone systems and simplifies the flying of drones. Fuzzy Logic provides an intuitive edge to the control of such systems and allows handling noise in force sensors. Extensive simulation results are presented in this paper showing the effectiveness of the proposed control scheme.

Design and Robustness of Quilt Packaging Superconnect

2012 ◽  
Vol 2012 (1) ◽  
pp. 000524-000530
Author(s):  
M. Ashraf Khan ◽  
Jason M. Kulick ◽  
Alfred M. Kriman ◽  
Gary H. Bernstein
Keyword(s):  
Thermal Cycling ◽  
High Speed ◽  
Low Cycle Fatigue ◽  
Simulation Models ◽  
Electrical Performance ◽  
Cycle Fatigue ◽  
Signal Delay ◽  
Thermal Reliability ◽  
Simulation Results ◽  
Quilt Packaging

Quilt Packaging (QP) is a novel high-speed superconnect (i.e. direct interchip interconnect), developed to improve electrical performance — signal delay, power loss, etc. Ultrahigh bandwidth has already been demonstrated for QP, but its unique structure requires thermal reliability issues to be studied. To this end, simulation models were developed to study the robustness of QP. QP structures were fabricated, and thermal cycling tests were performed focusing on the reliability for various shapes of nodules, the basic physical interconnect unit of QP. Simulations were performed to determine stress over a range of temperatures and estimate low cycle fatigue lifetimes. Simulations considered two types of solder and several adhesives. Thermal cycling experiments indicate that QP provides a robust structure, in agreement with the simulation results.

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