scholarly journals Cluster Analysis of Distribution Grids in Baden-Württemberg

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 4016 ◽  
Author(s):  
Tobias Rösch ◽  
Peter Treffinger
Keyword(s):  
Distribution System ◽  
Structural Characteristics ◽  
Peak Load ◽  
Distribution Grid ◽  
Development Data ◽  
Western Germany ◽  
Grid Construction ◽  
Cost Efficient ◽  
Regenerative Energy ◽  
Distribution Grids

With the growing share of renewable energies in the electricity supply, transmission and distribution grids have to be adapted. A profound understanding of the structural characteristics of distribution grids is essential to define suitable strategies for grid expansion. Many countries have a large number of distribution system operators (DSOs) whose standards vary widely, which contributes to coordination problems during peak load hours. This study contributes to targeted distribution grid development by classifying DSOs according to their remuneration requirement. To examine the amendment potential, structural and grid development data from 109 distribution grids in South-Western Germany, are collected, referring to publications of the respective DSOs. The resulting data base is assessed statistically to identify clusters of DSOs according to the fit of demographic requirements and grid-construction status and thus identify development needs to enable a broader use of regenerative energy resources. Three alternative algorithms are explored to manage this task. The study finds the novel Gauss-Newton algorithm optimal to analyse the fit of grid conditions to regional requirements and successfully identifies grids with remuneration needs. It is superior to the so far used K-Means algorithm. The method developed here is transferable to other areas for grid analysis and targeted, cost-efficient development.

scholarly journals A Two-Step State Estimation Algorithm for Hybrid AC-DC Distribution Grids

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1967
Author(s):  
Gaurav Kumar Roy ◽  
Marco Pau ◽  
Ferdinanda Ponci ◽  
Antonello Monti
Keyword(s):  
State Estimation ◽  
Distribution System ◽  
Renewable Energy Sources ◽  
Estimation Algorithm ◽  
The State ◽  
Second Step ◽  
Distribution Grid ◽  
Dc Distribution ◽  
Attractive Option ◽  
Distribution Grids

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.

scholarly journals Performance Analysis of Plug-in Electric Vehicle Supported DVR for Power-Quality Improvement and Energy Back-Up Strategy

2020 ◽  
Vol 8 (6) ◽  
pp. 945-952
Keyword(s):  
Electric Vehicle ◽  
Power Quality ◽  
Distribution System ◽  
Power Flow ◽  
Fossil Fuels ◽  
Electrical Power ◽  
Peak Load ◽  
Electrical Energy ◽  
Distribution Grid ◽  
Dynamic Voltage Restorer

Electric vehicle technology becomes increasingly important as it takes care of the environmental issues related to ICE vehicle and reduces the dependency on fossil fuels. Electric vehicle being greatly dependent on the limited electrical energy provided by a battery, the power flow efficiency is very important in this context. Electric vehicle integration to the distribution grid is increased at a faster rate because it can act as power backup to the grid/local loads reducing the peak load and filling the valley point. Most of software engineers own an Electric Vehicle based on eco-friendly principles. The Batteries in the car are connected to the charging point (or) grid monitoring of State of Charging (SOC) facilities in the parking area of company. When the Renewable power (solar energy) is available, the batteries will be charged to hundred percentage of SOC. Then excess power from PV will connect to load as well as grid. When the electrical power supply cutoff the car batteries will act as a battery bank of UPS and support to the critical load with condition based Allowable SOC. The total capacity of the batteries depends upon the no of cars available at a particular shift in a day. This work proposes the power backup of EV is utilized as an UPS to Software Company as well as used to support the Dynamic Voltage Restorer (DVR) to mitigate the fault occurring in the distribution system. Additionally, the EV supported DVR compensates voltage harmonics, voltage sag-swell, voltage interruptions coming from distribution to enhance power-quality of entire EV system without any additional compensation devices. The entire system is modeled using MATLAB/SIMULINK and the results confer the feasibility of the proposed objective.

scholarly journals Experimental Validation and Deployment of Observability Applications for Monitoring of Low-Voltage Distribution Grids

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5770 ◽  
Author(s):  
Karthikeyan Nainar ◽  
Catalin Iosif Ciontea ◽  
Kamal Shahid ◽  
Florin Iov ◽  
Rasmus Løvenstein Olsen ◽  
...  
Keyword(s):  
Real Time ◽  
Data Storage ◽  
Distribution System ◽  
Low Voltage ◽  
Experimental Studies ◽  
Distribution Grid ◽  
Grid Voltage ◽  
Laboratory Setup ◽  
Field Deployment ◽  
Distribution Grids

Future distribution grids will be subjected to fluctuations in voltages and power flows due to the presence of renewable sources with intermittent power generation. The advanced smart metering infrastructure (AMI) enables the distribution system operators (DSOs) to measure and analyze electrical quantities such as voltages, currents and power at each customer connection point. Various smart grid applications can make use of the AMI data either in offline or close to real-time mode to assess the grid voltage conditions and estimate losses in the lines/cables. The outputs of these applications can enable DSOs to take corrective action and make a proper plan for grid upgrades. In this paper, the process of development and deployment of applications for improving the observability of distributions grids is described, which consists of the novel deployment framework that encompasses the proposition of data collection, communication to the servers, data storage, and data visualization. This paper discussed the development of two observability applications for grid monitoring and loss calculation, their validation in a laboratory setup, and their field deployment. A representative distribution grid in Denmark is chosen for the study using an OPAL-RT real-time simulator. The results of the experimental studies show that the proposed applications have high accuracy in estimating grid voltage magnitudes and active energy losses. Further, the field deployment of the applications prove that DSOs can gain insightful information about their grids and use them for planning purposes.

scholarly journals Harmonic Effects Due to the High Penetration of Photovoltaic Generation into a Distribution System

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4021
Author(s):  
Jorge Luiz Moreira Pereira ◽  
Adonis Ferreira Raiol Leal ◽  
Gabriel Oliveira de Almeida ◽  
Maria Emília de Lima Tostes
Keyword(s):  
Distribution System ◽  
Harmonic Distortion ◽  
Distribution Grid ◽  
Pv System ◽  
Pv Systems ◽  
Harmonic Content ◽  
High Penetration ◽  
New Energy ◽  
The Individual ◽  
Distribution Grids

The growth in global electricity demand has expanded the search for new energy resources. Renewable sources such as photovoltaic (PV) systems have proven to be major alternatives. PV generators connected to distribution grids have exhibited significant growth in the last decade, so it is essential to analyse the impacts resulting from this increase. This work investigated the influence of high PV system penetration in distribution grids in terms of harmonic levels. In particular, this study addressed the distortions in voltage and current waveforms in the presence and absence of PV generators connected to a distribution grid. Additionally, the total harmonic content and the individual harmonic frequencies of voltage and current were analysed. This study was performed with an IEEE 37 bus distribution system and the Open Distribution System Simulator software (OpenDSS). The results show that the voltage limits of some phases far away from a substation can exceed the limits. Furthermore, the total harmonic distortion (THD) and individual harmonic distortion (IHD) levels for voltage and current were significantly high for harmonics of the 3rd, 5th, and 7th orders, where current levels violate the standard levels.

scholarly journals RES and ES Integration in Combination with Distribution Grid Development Using MILP

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 383
Author(s):  
Mateusz Andrychowicz
Keyword(s):  
Energy Storage ◽  
Distribution System ◽  
Renewable Energy Sources ◽  
Power Level ◽  
Peak Load ◽  
Operating Conditions ◽  
Mixed Integer ◽  
Distribution Grid ◽  
Specific Level ◽  
Load Curtailment

In the paper, a new method of long-term planning of operation and development of the distribution system, taking into account operational aspects such as power flows, power losses, voltage levels, and energy balances, is presented. The developed method allows for the allocation and selection of the power of Renewable Energy Sources (RES), control of energy storage (ES), curtailing of RES production (EC), and the development of the distribution grid (GD). Different types of RES and loads are considered, represented by generation/demand profiles reflecting their typical operating conditions. RES allocation indicates the node in the distribution system and the power level for each type of RES that may be built. Energy storage (ES) allows generation to be transferred from the demand valley to the peak load. Curtailment of RES generation indicates the moment and level of power by which generation will be reduced, while the grid development (GD) determines between which network nodes a new power line should be built. All these activities allow to minimize the costs of planning work and development of the distribution system at a specific level of energy consumption from RES in the analyzed distribution system using a Mixed Integer-Linear Programming (MILP).

scholarly journals Price-Based Demand Side Response Programs and Their Effectiveness on the Example of TOU Electricity Tariff for Residential Consumers

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 287
Author(s):  
Jerzy Andruszkiewicz ◽  
Józef Lorenc ◽  
Agnieszka Weychan
Keyword(s):  
Power Systems ◽  
Distribution System ◽  
Peak Load ◽  
Demand Side ◽  
Case Study Analysis ◽  
Efficiency Assessment ◽  
Electricity Use ◽  
Residential Electricity ◽  
Demand Side Response ◽  
Residential Consumers

Demand side response is becoming an increasingly significant issue for reliable power systems’ operation. Therefore, it is desirable to ensure high effectiveness of such programs, including electricity tariffs. The purpose of the study is developing a method for analysing electricity tariff’s effectiveness in terms of demand side response purposes based on statistical data concerning tariffs’ use by the consumers and price elasticity of their electricity demand. A case-study analysis is presented for residential electricity consumers, shifting the settlement and consequently the profile of electricity use from a flat to a time-of-use tariff, based on the comparison of the considered tariff groups. Additionally, a correlation analysis is suggested to verify tariffs’ influence of the power system’s peak load based on residential electricity tariffs in Poland. The presented analysis proves that large residential consumers aggregated by tariff incentives may have a significant impact on the power system’s load and this impact changes substantially for particular hours of a day or season. Such efficiency assessment may be used by both energy suppliers to optimize their market purchases and by distribution system operators in order to ensure adequate generation during peak load periods.

scholarly journals Analysis of Various Options for Balancing Power Systems’ Peak Load

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 513
Author(s):  
Henryk Majchrzak ◽  
Michał Kozioł
Keyword(s):  
Power Systems ◽  
Distribution System ◽  
Peak Load ◽  
Electric Energy ◽  
End Users ◽  
Energy Market ◽  
Market Participants ◽  
Continuous Energy ◽  
Storage Solutions ◽  
Transmission And Distribution

The balancing of the power of the Polish Power System (KSE) is a key element in ensuring the safety of electric energy supplies to end users. This article presents an analysis of the power demand in power systems (PS), with emphasis on the typical power variability both in subsequent hours of the day and on particular days and in particular months each year. The methodology for calculating the costs of electric energy undelivered to the end users and the amount of these costs for KSE is presented. Different possibilities have been analyzed for balancing power systems’ peak load and assumptions have been formulated for calculating the amount of the related costs. On this basis, a comparative analysis has been made of the possibility to balance peak load using operators’ system services, trans-border connections, and various energy storage solutions. On the basis of the obtained results, optimal tools have been proposed for market-based influence from transmission and distribution system operators on energy market participants’ behaviors in order to ensure the power systems’ operating safety and continuous energy deliveries to end users.

scholarly journals Improving PV Resilience by Dynamic Reconfiguration in Distribution Grids: Problem Complexity and Computation Requirements

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 830
Author(s):  
Filipe F. C. Silva ◽  
Pedro M. S. Carvalho ◽  
Luís A. F. M. Ferreira
Keyword(s):  
Distributed Generation ◽  
Optimal Solution ◽  
Dynamic Reconfiguration ◽  
Scheduling Problem ◽  
Low Carbon ◽  
Distribution Grid ◽  
Medium Voltage ◽  
Classical Computing ◽  
The Impact ◽  
Distribution Grids

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.

scholarly journals Progresses in Analytical Design of Distribution Grids and Energy Storage

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4270
Author(s):  
Gianpiero Colangelo ◽  
Gianluigi Spirto ◽  
Marco Milanese ◽  
Arturo de Risi
Keyword(s):  
Renewable Energy ◽  
Power Flow ◽  
State Of The Art ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Distribution Grid ◽  
Mathematical Methods ◽  
Power Generators ◽  
Bidirectional Power Flow ◽  
Distribution Grids

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.

Pipeline Instrumentation: The British Gas National Transmission System

1987 ◽  
Vol 20 (1) ◽  
pp. 18-25
Author(s):  
P Gilbert
Keyword(s):  
Distribution System ◽  
Transmission System ◽  
Process Conditions ◽  
Pipeline System ◽  
Operating Pressure ◽  
Distribution Grid ◽  
History Of Development ◽  
History Of ◽  
Instrument Engineer ◽  
Transmission And Distribution

The transmission and distribution system operated by British Gas plc is the largest integrated pipeline system in Europe. The whole system comprises a national transmission system which carries gas from five terminals to the twelve gas regions. Each region in turn carries the gas through a regional transmission system into a distribution grid and thence onto its customers. The national, regional and distribution system all present the instrument engineer with different technical challenges because of the way in which they have been built and are operated, however, it is simplest to characterise them by their process conditions. The operating pressure is highest in the national transmission system being up to 75 bar, in the regional transmission system the pressure is usually less than 37 bar, and in the distribution grid it is less than 7 bar. In general, the pipe diameters decrease from the national system downwards, and the measured flowrates are lowest in the distribution grids. This paper is concerned only with instrumentation on the national transmission system. The discussion will cover current technology which is typical of that being installed at present, and concentrates on the more commonly found instrumentation. The paper begins with a brief history of development of the national transmission system and a description of how it is operated. This is followed by a discussion on the application of computers to the control of unmanned installations. A section concerning the measurement of pressure and its application to the control of the system comes next. The main part of the paper contains an analysis of high accuracy flowmetering and the paper concludes with some comments on developments in instrumentation and their application to changing operation of the national transmission system.

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