scholarly journals Reconfiguring Distribution Grids

Optimizing the grid structure becomes necessary in case of post-emergency power restoration or when overloaded. In normal operation, distribution grid parameters are adjusted to reduce the overload and the electricity losses; reconfiguration is not considered. The grid topology is reconfigurable by solving the optimization problem by the branch-and-bound algorithm subject to keeping the parameters within their acceptable limits in the context of line resistance, electricity losses, and power flows for all possible grid layouts. Simulation of a 10-kV distribution grid with four power centers shows that reconfiguring reduces power consumption by 2.9% and the inline active power losses by 256 kW. In this case study, reconfiguring has helped keep the voltage within the acceptable range while not overloading the lines. This study shows the proposed approach is suitable for dynamic grid reconfiguration as a way to reduce the overload and the electricity losses; at the same time, the approach does not require calculating nonlinear steady-state equations for each possible grid topology.

2014 ◽  
Vol 15 (6) ◽  
pp. 607-619 ◽  
Author(s):  
Balakrishna Pamulaparthy ◽  
Swarup KS ◽  
Rajagopal Kommu

Abstract Distribution automation (DA) applications are limited to feeder level today and have zero visibility outside of the substation feeder and reaching down to the low-voltage distribution network level. This has become a major obstacle in realizing many automated functions and enhancing existing DA capabilities. Advanced metering infrastructure (AMI) systems are being widely deployed by utilities across the world creating system-wide communications access to every monitoring and service point, which collects data from smart meters and sensors in short time intervals, in response to utility needs. DA and AMI systems convergence provides unique opportunities and capabilities for distribution grid modernization with the DA system acting as a controller and AMI system acting as feedback to DA system, for which DA applications have to understand and use the AMI data selectively and effectively. In this paper, we propose a load segmentation method that helps the DA system to accurately understand and use the AMI data for various automation applications with a suitable case study on power restoration.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1967
Author(s):  
Gaurav Kumar Roy ◽  
Marco Pau ◽  
Ferdinanda Ponci ◽  
Antonello Monti

Direct Current (DC) grids are considered an attractive option for integrating high shares of renewable energy sources in the electrical distribution grid. Hence, in the future, Alternating Current (AC) and DC systems could be interconnected to form hybrid AC-DC distribution grids. This paper presents a two-step state estimation formulation for the monitoring of hybrid AC-DC grids. In the first step, state estimation is executed independently for the AC and DC areas of the distribution system. The second step refines the estimation results by exchanging boundary quantities at the AC-DC converters. To this purpose, the modulation index and phase angle control of the AC-DC converters are integrated into the second step of the proposed state estimation formulation. This allows providing additional inputs to the state estimation algorithm, which eventually leads to improve the accuracy of the state estimation results. Simulations on a sample AC-DC distribution grid are performed to highlight the benefits resulting from the integration of these converter control parameters for the estimation of both the AC and DC grid quantities.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 830
Author(s):  
Filipe F. C. Silva ◽  
Pedro M. S. Carvalho ◽  
Luís A. F. M. Ferreira

The dissemination of low-carbon technologies, such as urban photovoltaic distributed generation, imposes new challenges to the operation of distribution grids. Distributed generation may introduce significant net-load asymmetries between feeders in the course of the day, resulting in higher losses. The dynamic reconfiguration of the grid could mitigate daily losses and be used to minimize or defer the need for network reinforcement. Yet, dynamic reconfiguration has to be carried out in near real-time in order to make use of the most updated load and generation forecast, this way maximizing operational benefits. Given the need to quickly find and update reconfiguration decisions, the computational complexity of the underlying optimal scheduling problem is studied in this paper. The problem is formulated and the impact of sub-optimal solutions is illustrated using a real medium-voltage distribution grid operated under a heavy generation scenario. The complexity of the scheduling problem is discussed to conclude that its optimal solution is infeasible in practical terms if relying upon classical computing. Quantum computing is finally proposed as a way to handle this kind of problem in the future.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4270
Author(s):  
Gianpiero Colangelo ◽  
Gianluigi Spirto ◽  
Marco Milanese ◽  
Arturo de Risi

In the last years, a change in the power generation paradigm has been promoted by the increasing use of renewable energy sources combined with the need to reduce CO2 emissions. Small and distributed power generators are preferred to the classical centralized and sizeable ones. Accordingly, this fact led to a new way to think and design distributions grids. One of the challenges is to handle bidirectional power flow at the distribution substations transformer from and to the national transportation grid. The aim of this paper is to review and analyze the different mathematical methods to design the architecture of a distribution grid and the state of the art of the technologies used to produce and eventually store or convert, in different energy carriers, electricity produced by renewable energy sources, coping with the aleatory of these sources.


Author(s):  
Colin Stagner ◽  
Sarah Seguin ◽  
Steve Grant ◽  
Daryl Beetner

The accurate and timely discovery of radio receivers can assist in the detection of radio-controlled explosives. By detecting radio receivers, it is possible to indirectly infer the presence of an explosive device. Radio receivers unintentionally emit low-power radio signals during normal operation. By using a weak stimulation signal, it is possible to inject a known signal into these unintended emissions. This process is known as stimulated emissions. Unlike chemical traces, these stimulated emissions can propagate through walls and air-tight containers. The following case study discusses methods for detecting and locating two different types of radio receivers. Functional stimulated emissions detectors are constructed, and their performance is analyzed. Stimulated emissions are capable of detecting super-regenerative receivers at distances of at least one hundred meters and accurately locating superheterodyne receivers at distances of at least fifty meters. These results demonstrate a novel technique for detecting potential explosive threats at stand-off detection distances.


2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Joannes I. Laveyne ◽  
Dimitar Bozalakov ◽  
Greet Van Eetvelde ◽  
Lieven Vandevelde

In Belgium, and many other countries, rooftop solar panels are becoming a ubiquitous form of decentralised energy production. The increasing share of these distributed installations however imposes many challenges on the operators of the low-voltage distribution grid. They must keep the voltage levels and voltage balance on their grids in check and are often regulatory required to provide sufficient reception capacity for new power producing installations. By placing solar panels in different inclinations and azimuth angles, power production profiles can possibly be shifted to align more with residential power consumption profiles. In this article, it is investigated if the orientation of solar panels can have a mitigating impact on the integration problems on residential low voltage distribution grids. An improved simulation model of a solar panel installation is constructed, which is used to simulate the impact on a residential distribution grid. To stay as close to real-life conditions as possible, real irradiation data and a model of an existing grid are used. Both the developed model as the results on grid impact are evaluated.


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