scholarly journals Issues and Challenges for HVDC Extruded Cable Systems

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4504
Author(s):  
Giovanni Mazzanti
Keyword(s):  
Renewable Energy Sources ◽  
Alphabetical Order ◽  
Underground Cables ◽  
Overhead Lines ◽  
Available Energy ◽  
Exponential Increase ◽  
Cable Systems ◽  
The Will ◽  
Cross Country ◽  
Transient Voltages

The improved features of AC/DC converters, the need to enhance cross-country interconnections, the will to make massive remote renewable energy sources available, and the fear of populations about overhead lines have fostered HVDC cable transmission all over the world, leading in the last two decades to an exponential increase of commissioned HVDC cable projects, particularly of the extruded insulation type. Comprehensive surveys of the issues to be faced by HVDC extruded cable systems appeared in the literature some years ago, but they are not so up-to-date, as HVDC extruded cable technology is developing fast. Therefore, the contribution this paper aims at giving is a systematic, comprehensive and updated summary of the main present and future issues and challenges that HVDC cable systems have to face to further improve their performance and competitiveness, so as to meet the growing quest for clean and available energy worldwide. The topics covered in this review–treated in alphabetical order for the reader’s convenience–are accessories, higher voltage and power, laying environment (submarine and underground cables), modeling, multiterminal HVDC, operation and diagnostics, recyclable insulation, space charge behavior, testing, thermal stability, transient voltages.

scholarly journals Accuracy and Reliability of Switching Transients Measurement with Open-Air Capacitive Sensors

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1405
Author(s):  
Barakou ◽  
Steennis ◽  
Wouters
Keyword(s):  
Electromagnetic Compatibility ◽  
Cross Coupling ◽  
Interference Rejection ◽  
Underground Cables ◽  
Overhead Lines ◽  
Capacitive Divider ◽  
Measurement Methodology ◽  
Extra High Voltage ◽  
Transient Voltages ◽  
Line Coupling

Contactless capacitive (open-air) sensors are applied to monitor overvoltages near overhead line terminations at a substation or at the transition from underground cables to overhead lines. It is shown that these sensors, applied in a differentiating/integrating measuring concept, can result in excellent characteristics in terms of electromagnetic compatibility. The inherent cross-coupling from open-air sensors to other phases is dealt with. The paper describes a method to calibrate the sensor to line coupling matrix based on assumed 50 Hz symmetric phase voltages and in particular focuses on uncertainty analysis of assumptions made. Network simulation shows that predicted maximum overvoltages agree within typically 7% compared to reconstructed values from measurement, also with significant cross-coupling. Transient voltages from energization of an (extra-)high voltage connection can cause large and steep rising ground currents near the line terminations. Comparison with results obtained by a capacitive divider confirms the intrinsic capability in interference rejection by the differentiating/integrating measurement methodology.

scholarly journals Photovoltaic Maximum Penetration Limits on Medium Voltage Overhead and Underground Cable Distribution Feeders: A Comparative Study

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3843
Author(s):  
Sultan Sh. Alanzi ◽  
Rashad M. Kamel
Keyword(s):  
Power System ◽  
Power Factor ◽  
Distribution System ◽  
Power Flow ◽  
Underground Cables ◽  
Overhead Lines ◽  
Medium Voltage ◽  
Load Power ◽  
Bus Voltage ◽  
Pv Penetration

This paper investigates the maximum photovoltaic (PV) penetration limits on both overhead lines and underground cables medium voltage radial distribution system. The maximum PV penetration limit is estimated considering both bus voltage limit (1.05 p.u.) and feeder current ampacity (1 p.u.). All factors affect the max PV penetration limit are investigated in detail. Substation voltage, load percentage, load power factor, and power system frequency (50 Hz or 60 Hz) are analyzed. The maximum PV penetration limit associated with overhead lines is usually higher than the value associated with the underground cables for high substation voltage (substation voltage = 1.05 and 1.04 p.u.). The maximum PV penetration limit decreases dramatically with low load percentage for both feeder types but still the overhead lines accept PV plant higher than the underground cables. Conversely, the maximum PV penetration increases with load power factor decreasing and the overhead lines capability for hosting PV plant remains higher than the capability of the underground cables. This paper proved that the capability of the 60-Hz power system for hosting the PV plant is higher than the capability of 50 Hz power system. MATLAB software has been employed to obtain all results in this paper. The Newton-Raphson iterative method was the used method to solve the power flow of the investigated systems.

scholarly journals An Effective Method to Calculate Frequency Response of Distribution Networks for PLC Applications

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 649 ◽  
Author(s):  
Hongshan Zhao ◽  
Weitao Zhang ◽  
Yan Wang
Keyword(s):  
Frequency Response ◽  
Distribution Networks ◽  
Dynamic Changes ◽  
Binary Function ◽  
Underground Cables ◽  
Overhead Lines ◽  
Medium Voltage ◽  
Response Characteristics ◽  
Network Topologies ◽  
Propagation Matrix

Modelling and estimating power-line communication (PLC) channels are complicated issues due to the complex network topologies, various junctions, and changeable loads. This paper focuses on the frequency response characteristics (FRCs) of medium-voltage (MV) PLC networks with special consideration of two scenarios that are often neglected but generally exist. In the first scenario, the MV distribution network is of the ring topology. In the second scenario, the MV overhead lines and underground cables join at junctions, and the shields of underground cables are grounded with nonzero grounding impedances at the junctions. These conditions lead to the failure of currently popular methods to different degrees. For this reason, we developed an effective method to calculate the FRCs of distribution networks for PLC applications. With this method, the frequency responses of nodes are simply expressed as the binary function of the overall tube propagation matrix and overall node scattering matrix, which is convenient for calculations and analyses. The proposed method was validated by the agreement between the calculated and measured FRCs. The results of two test examples showed that the proposed method performed better in comparison with the traditional approximate method when nonideal grounding conditions were taken into account. The proposed method is also independent of the network topology, so it can adapt to the dynamic changes of the network structure.

An Energy Ontology Focusing on Demand Side Management in Smart Homes

2016 ◽  
Vol 19 ◽  
pp. 124-131
Author(s):  
Beate Naser ◽  
Franziska Schäfer ◽  
Jörg Franke
Keyword(s):  
Energy Production ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Electric Energy ◽  
Smart Homes ◽  
Demand Side Management ◽  
Demand Side ◽  
Conceptual Foundation ◽  
Available Energy ◽  
Solar Power Plants

By increasing the share of renewable energy sources, the volatility of available energy is rising. More and more fluctuating power generation by solar power plants and wind turbines has to be integrated into the power grid. Demand side management (DSM) represents one possible solution to achieve this goal by including energy production and energy consumption simultaneously. In this paper, we especially focus on the field of electric energy in smart homes. Considering the implementation of different DSM devices, an ontology-based approach can serve as a conceptual foundation for a necessary knowledge base. We propose an advanced energy ontology for smart homes, integrating important aspects for a successful DSM. We describe how power producers, storages and consumers are represented in our ontology. Finally, we show the scenario-based utilization of our approach.

Energy

2012 ◽  
Author(s):  
José Goldemberg
Keyword(s):  
Renewable Energy ◽  
Smart Grids ◽  
Carbon Capture ◽  
New Technologies ◽  
Renewable Energy Sources ◽  
Carbon Capture And Storage ◽  
Energy System ◽  
Renewable Energy Resources ◽  
Available Energy ◽  
World Energy

Without a doubt, the topic of energy--from coal, oil, and nuclear to geothermal, solar and wind--is one of the most pressing across the globe. It is of paramount importance to policy makers, economists, environmentalists, and industry as they consider which technologies to invest in, how to promote use of renewable energy sources, and how to plan for dwindling reserves of non-renewable energy. In Energy: What Everyone Needs to Know, José Goldemberg, a nuclear physicist who has been hailed by Time magazine as one of the world's top "leaders and visionaries on the environment," takes readers through the basics of the world energy system, its problems, and the technical as well as non-technical solutions to the most pressing energy problems. Addressing the issues in a Q-and-A format, Goldemberg answers such questions as: What are wind, wave, and geothermal energy? What are the problems of nuclear waste disposal? What is acid rain? What is the greenhouse gas effect? What is Carbon Capture and Storage? What are smart grids? What is the Kyoto Protocol? What is "cap and trade"? The book sheds light on the role of population growth in energy consumption, renewable energy resources, the amount of available energy reserves (and when they will run out), geopolitical issues, environmental problems, the frequency of environmental disasters, energy efficiency, new technologies, and solutions to changing consumption patterns. It will be the first place to look for information on the vital topic of energy.

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