Overload and overvoltage in low-voltage and medium-voltage networks due to renewable energy — Some illustrative case studies

2011 ◽  
Author(s):  
M.H.J. Bollen ◽  
N. Etherden
Keyword(s):  
Renewable Energy ◽  
Case Studies ◽  
Low Voltage ◽  
Illustrative Case ◽  
Medium Voltage

Application of Clean Development Mechanism (CDM) in Renewable Energy Generation from Micro-Hydel Projects of Himachal Pradesh

2014 ◽  
Vol 3 (4) ◽  
pp. 72-97
Author(s):  
A. N. Sarkar
Keyword(s):  
Renewable Energy ◽  
Case Studies ◽  
Clean Development Mechanism ◽  
Developed Countries ◽  
Himachal Pradesh ◽  
The State ◽  
Current Status ◽  
Illustrative Case ◽  
Hydro Power ◽  
Development Mechanism

Clean Development Mechanism (CDM) is defined as one of the “flexibility” mechanisms that allows entities based in Developed Countries (Annex I Parties) to develop emission-reducing projects in Developing Countries (non-Annex I Parties), and generate tradable carbon credits corresponding to the volume of carbon emission reductions achieved by those projects. CDM projects have been developed in several parts of the world across the sectoral economies, including renewable energy, with reportedly varying degrees of success and failures. In the renewable energy segment, CDM has been successfully deployed in Micro-Hydel power projects to mitigate and offset green-house gas emissions into the environment. The experiences of different implementing states are vastly different in past decade. CDM applications in Micro-Hydel projects have been quite notable to generate hydro-power and mitigate emissions in the state. This paper takes a holistic review about the current status in the performance of CDM projects in India, with special reference to Himachal Pradesh, particularly in the context of Small (Micro)-Hydel projects with a very high renewable energy potential. The achievements as well as strategy of implementation of Small-Hydel projects in Himachal Pradesh is discussed in the light of selected case studies of CDM projects that are at various stages of formulation, designing and implementation. Guidelines for CDM project designing and the potential for carbon markets for the hydro-power in the context of Himachal Pradesh is discussed. Some of the shortcomings in implementation of Micro-Hydel CDM project in the State are also discussed and highlighted in the paper. The paper has also examined the status of implementation and the quality of projects in the form of illustrative case studies in terms of their ability for energy extraction, creating energy trading opportunities, and stakeholder participation in sharing the project benefits during the lifetime as well as the beyond the life-time of the projects.

scholarly journals Multiobjective Approach for Medium- and Low-Voltage Planning of Power Distribution Systems Considering Renewable Energy and Robustness

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2517
Author(s):  
Diogo Rupolo ◽  
Benvindo Pereira Junior ◽  
Javier Contreras ◽  
José Mantovani
Keyword(s):  
Renewable Energy ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Optimization Techniques ◽  
Neighborhood Search ◽  
Medium Voltage ◽  
Multiobjective Approach

In this paper, a multiobjective approach to carry out the planning of medium-voltage (MV) and low-voltage (LV) distribution systems, considering renewable energy sources (RES) and robustness, is proposed. Due to the uncertainties associated with RES and demand, the proposed planning methodology takes into account a robust planning index (RPI). This RPI allows us to evaluate the robustness estimation associated with each planning solution. The objective function in the mathematical model considers the costs of investment and operation and the robustness of the planning proposals. Due to the computational complexity of this problem, which is difficult to solve by means of classical optimization techniques, MV/LV planning is solved by a decomposition search and a general variable neighborhood search (GVNS) algorithm. To demonstrate the efficiency and robustness of this methodology, tests are performed in an integrated distribution system with 50 MV nodes and 410 LV nodes. Our numerical results show that the proposed methodology makes it possible to minimize costs and improve robustness levels in distribution system planning.

scholarly journals STUDI PENGARUH TIDAK BEROPERASINYA PLTSa SUWUNG TERHADAP PROFIL TEGANGAN PADA PENYULANG SERANGAN

2018 ◽  
Vol 5 (2) ◽  
pp. 299
Author(s):  
Gede Endrawadi ◽  
I Wayan Sukerayasa ◽  
Wayan Gede Ariastina
Keyword(s):  
Renewable Energy ◽  
Power Plant ◽  
Distributed Generation ◽  
Power Supply ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Electrical Power ◽  
Energy Sources ◽  
Voltage Profile ◽  
Medium Voltage

The power plant with renewable energy sources is needed to reduce the pollution. One of this kind is in Bali, that is PLTSa (Garbage Power Plant) Suwung. However, PLTSa Suwung is no longer operating for now. PLTSa Suwung is connected with Serangan feeder, this connection named Distributed Generation. When PLTSa Suwung doesn’t operate, it will affect the Serangan feeder’s voltage profile. The change of voltage profile will be analyzed with EDSA Technical 2000 Service Pack 3.5 software. The research will give five scenarios with different electrical power supply from each scenario. The gap of the voltage profile between scenario 1 (100% power supply from PLTSa) and scenario 5 (0% power suplly from PLTSa) is 0,0079% for medium voltage bus and 0,0062% for low voltage bus. This small gap shows that the connected PLTSa Suwung doesn’t give effect to voltage profile of Serangan feeder.

Reduction of the Low Voltage Substation Constraints by Inserting Photovoltaic Systems in Underserved Areas

2019 ◽  
Vol 12 (2) ◽  
pp. 105-112
Author(s):  
Benbouza Naima ◽  
Benfarhi Louiza ◽  
Azoui Boubekeur
Keyword(s):  
Low Voltage ◽  
Voltage Drop ◽  
Electrical Energy ◽  
Utilization Rate ◽  
Photovoltaic Systems ◽  
Voltage Distribution ◽  
Medium Voltage ◽  
Pv Systems ◽  
Transformer Substation ◽  
Load Pattern

Background: The improvement of the voltage in power lines and the respect of the low voltage distribution transformer substations constraints (Transformer utilization rate and Voltage drop) are possible by several means: reinforcement of conductor sections, installation of new MV / LV substations (Medium Voltage (MV), Low Voltage (LV)), etc. Methods: Connection of mini-photovoltaic systems (PV) to the network, or to consumers in underserved areas, is a well-adopted solution to solve the problem of voltage drop and lighten the substation transformer, and at the same time provide clean electrical energy. PV systems can therefore contribute to this solution since they produce energy at the deficit site. Results: This paper presents the improvement of transformer substation constraints, supplying an end of low voltage electrical line, by inserting photovoltaic systems at underserved subscribers. Conclusion: This study is applied to a typical load pattern, specified to the consumers region.

scholarly journals Holistic simulation of wind turbines with fully aero-elastic and electrical model

2021 ◽  
Author(s):  
Marcus Wiens ◽  
Sebastian Frahm ◽  
Philipp Thomas ◽  
Shoaib Kahn
Keyword(s):  
Renewable Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Elastic Model ◽  
Electrical Model ◽  
Holistic Model ◽  
Electric System ◽  
Electrical Components

AbstractRequirements for the design of wind turbines advance facing the challenges of a high content of renewable energy sources in the public grid. A high percentage of renewable energy weaken the grid and grid faults become more likely, which add additional loads on the wind turbine. Load calculations with aero-elastic models are standard for the design of wind turbines. Components of the electric system are usually roughly modeled in aero-elastic models and therefore the effect of detailed electrical models on the load calculations is unclear. A holistic wind turbine model is obtained, by combining an aero-elastic model and detailed electrical model into one co-simulation. The holistic model, representing a DFIG turbine is compared to a standard aero-elastic model for load calculations. It is shown that a detailed modelling of the electrical components e.g., generator, converter, and grid, have an influence on the results of load calculations. An analysis of low-voltage-ride-trough events during turbulent wind shows massive increase of loads on the drive train and effects the tower loads. Furthermore, the presented holistic model could be used to investigate different control approaches on the wind turbine dynamics and loads. This approach is applicable to the modelling of a holistic wind park to investigate interaction on the electrical level and simultaneously evaluate the loads on the wind turbine.

Software-driven Security Attacks: From Vulnerability Sources to Durable Hardware Defenses

2021 ◽  
Vol 17 (3) ◽  
pp. 1-38
Author(s):  
Lauren Biernacki ◽  
Mark Gallagher ◽  
Zhixing Xu ◽  
Misiker Tadesse Aga ◽  
Austin Harris ◽  
...  
Keyword(s):  
Life Cycle ◽  
Case Studies ◽  
Gain Control ◽  
Illustrative Case ◽  
Security Attacks ◽  
Specific Point ◽  
Security Vulnerabilities ◽  
Significant Challenge ◽  
Hardware Realization ◽  
Over Time

There is an increasing body of work in the area of hardware defenses for software-driven security attacks. A significant challenge in developing these defenses is that the space of security vulnerabilities and exploits is large and not fully understood. This results in specific point defenses that aim to patch particular vulnerabilities. While these defenses are valuable, they are often blindsided by fresh attacks that exploit new vulnerabilities. This article aims to address this issue by suggesting ways to make future defenses more durable based on an organization of security vulnerabilities as they arise throughout the program life cycle. We classify these vulnerability sources through programming, compilation, and hardware realization, and we show how each source introduces unintended states and transitions into the implementation. Further, we show how security exploits gain control by moving the implementation to an unintended state using knowledge of these sources and how defenses work to prevent these transitions. This framework of analyzing vulnerability sources, exploits, and defenses provides insights into developing durable defenses that could defend against broader categories of exploits. We present illustrative case studies of four important attack genealogies—showing how they fit into the presented framework and how the sophistication of the exploits and defenses have evolved over time, providing us insights for the future.

scholarly journals Machine Learning and GIS Approach for Electrical Load Assessment to Increase Distribution Networks Resilience

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4133
Author(s):  
Alessandro Bosisio ◽  
Matteo Moncecchi ◽  
Andrea Morotti ◽  
Marco Merlo
Keyword(s):  
Machine Learning ◽  
Distribution System ◽  
Low Voltage ◽  
Regression Tree ◽  
Distribution Networks ◽  
Machine Learning Algorithms ◽  
Extreme Weather Events ◽  
Medium Voltage ◽  
Weather Events ◽  
Building Area

Currently, distribution system operators (DSOs) are asked to operate distribution grids, managing the rise of the distributed generators (DGs), the rise of the load correlated to heat pump and e-mobility, etc. Nevertheless, they are asked to minimize investments in new sensors and telecommunication links and, consequently, several nodes of the grid are still not monitored and tele-controlled. At the same time, DSOs are asked to improve the network’s resilience, looking for a reduction in the frequency and impact of power outages caused by extreme weather events. The paper presents a machine learning GIS-based approach to estimate a secondary substation’s load profiles, even in those cases where monitoring sensors are not deployed. For this purpose, a large amount of data from different sources has been collected and integrated to describe secondary substation load profiles adequately. Based on real measurements of some secondary substations (medium-voltage to low-voltage interface) given by Unareti, the DSO of Milan, and georeferenced data gathered from open-source databases, unknown secondary substations load profiles are estimated. Three types of machine learning algorithms, regression tree, boosting, and random forest, as well as geographic information system (GIS) information, such as secondary substation locations, building area, types of occupants, etc., are considered to find the most effective approach.

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