scholarly journals Increasing the Utilization of Existing Infrastructures by Using the Newly Introduced Boundary Voltage Limits

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5106
Author(s):  
Daniel-Leon Schultis ◽  
Albana Ilo
Keyword(s):  
Smart Grids ◽  
Low Voltage ◽  
Flow Analysis ◽  
Load Flow ◽  
Distribution Grid ◽  
Worst Case ◽  
Voltage Level ◽  
Safety Margins ◽  
Voltage Limit ◽  
Electricity Infrastructure

The increasing share of distributed generation aggravates voltage limit compliance at customers’ delivery points. Currently, grid operators validate compliance with the voltage limits specified in Grid Codes by conducting load flow simulations at the medium voltage level, considering the connected low voltage grids as ‘loads’ to reduce the modeling effort. This approach does not support the accurate validation of limit compliance, as the voltage drops at the low voltage level are unknown. Nevertheless, to guarantee acceptable voltages even under worst-case conditions, safety margins are involved that impair the utilization of the electricity infrastructure. This study conducts load flows simulations in a test distribution grid, revealing the variable character of the voltage limits at different system boundaries. The conventional load model is extended by new parameters—the boundary voltage limits—to enable the consideration of variable voltage limits in load flow analysis of LINK-based smart grids. The standardized structure of the LINK-architecture allows for the systematic and accurate validation of voltage limit compliance by reducing the required modeling data to the technically necessary minimum. Use cases are specified that allows smart grids to increase the utilization of the electricity infrastructure by day-ahead scheduling and short-term adaptation of boundary voltage limits.

scholarly journals Effect of Individual Volt/var Control Strategies in LINK-Based Smart Grids with a High Photovoltaic Share

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5641
Author(s):  
Daniel-Leon Schultis ◽  
Albana Ilo
Keyword(s):  
Local Control ◽  
Smart Grids ◽  
Reactive Power ◽  
Low Voltage ◽  
Control Strategies ◽  
Load Flow ◽  
Electric Power System ◽  
Mobility Control ◽  
Holistic View ◽  
Voltage Limit

The increasing share of distributed energy resources aggravates voltage limit compliance within the electric power system. Nowadays, various inverter-based Volt/var control strategies, such as cosφ(P) and Q(U), for low voltage feeder connected L(U) local control and on-load tap changers in distribution substations are investigated to mitigate the voltage limit violations caused by the extensive integration of rooftop photovoltaics. This study extends the L(U) control strategy to X(U) to also cover the case of a significant load increase, e.g., related to e-mobility. Control ensembles, including the reactive power autarky of customer plants, are also considered. All Volt/var control strategies are compared by conducting load flow calculations in a test distribution grid. For the first time, they are embedded into the LINK-based Volt/var chain scheme to provide a holistic view of their behavior and to facilitate systematic analysis. Their effect is assessed by calculating the voltage limit distortion and reactive power flows at different Link-Grid boundaries, the corresponding active power losses, and the distribution transformer loadings. The results show that the control ensemble X(U) local control combined with reactive power self-sufficient customer plants performs better than the cosφ(P) and Q(U) local control strategies and the on-load tap changers in distribution substations.

Measurement uncertainty impact on simplified load flow analysis in MV smart grids

2018 ◽  
Author(s):  
Antonio Cataliotti ◽  
Valentina Cosentino ◽  
Salvatore Guaiana ◽  
Salvatore Nuccio ◽  
Dario Di Cara ◽  
...  
Keyword(s):  
Measurement Uncertainty ◽  
Smart Grids ◽  
Flow Analysis ◽  
Load Flow ◽  
Load Flow Analysis

scholarly journals Analisis Pemasangan Filter Pasif Untuk Mengurangi Harmonisa Pada Transformator Rectifier Di PT. Indah Kiat Pulp And Paper Perawang

SainETIn ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 59-68
Author(s):  
Rido Rahmadani
Keyword(s):  
Power Factor ◽  
Low Voltage ◽  
Flow Analysis ◽  
Harmonic Distortion ◽  
Chloride Ion ◽  
Load Flow ◽  
Electrolysis Process ◽  
Pulp Industry ◽  
Load Flow Analysis ◽  
Power Load

The chlor-alkali process is an electrolysis process which plays an important role in the chemical industry such as the pulp industry. The process produces a product in the form of H2 gas, CL2 gas and NaOH (where the source of chloride ion used is NaCl). This electrolysis process requires a dirrect current with a large current  and a low voltage. In this electrolysis process a three phase controlled 12 pulse rectifiers are used which a connected with multi-winding transformers. In the rectifiers process there will be harmonic distortion on the source side of the transformer which can reduce the power quality of the system. To overcome the harmonic problems that occur in the system, an installation analysis of the equipment in the form of a passive single tuned  filter is aimed at reducing harmonic distortion of current and voltage and increasing the power factor (cos φ). From the result of harmonic analysis using ETAP software, after the installation of harmonic filters orde 11, 13 and 23, the harmonic current value (THDI) and harmonic voltage (THDV) has decreased, namely, before the filter installation, THDI value is 6,5% whereas after installation of filters, THDI value becomes 0,98%, thus there is a THDI decrease of 5,52%. Furthermore, for the voltage harmonic value (THDV) before filter installation is 1,48% while after filtering, THDV value becomes 0,26%, thus there is a THDV decrease of 1,22%. From the results of the simulation of the flow of power (load flow analysis), after installation of filters there is an increase in the value of the power factor (cos φ). Namely, before the filter installation, the value of power factor (cos φ) is 0,8 while after the filter installation the value of the power factor (cos φ) to 0,96, thus an increase in the power factor (cos φ) of 16%.   Keywords : harmonic filter, single tuned filter, power factor, transformer rectifier

scholarly journals Incremental Heuristic Approach for Meter Placement in Radial Distribution Systems

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3917 ◽  
Author(s):  
Giovanni Artale ◽  
Antonio Cataliotti ◽  
Valentina Cosentino ◽  
Dario Di Cara ◽  
Salvatore Guaiana ◽  
...  
Keyword(s):  
Radial Distribution ◽  
Power Distribution ◽  
Smart Grids ◽  
Distribution Systems ◽  
Low Voltage ◽  
Distribution Network ◽  
Load Flow ◽  
State Variables ◽  
Medium Voltage ◽  
Meter Placement

The evolution of modern power distribution systems into smart grids requires the development of dedicated state estimation (SE) algorithms for real-time identification of the overall system state variables. This paper proposes a strategy to evaluate the minimum number and best position of power injection meters in radial distribution systems for SE purposes. Measurement points are identified with the aim of reducing uncertainty in branch power flow estimations. An incremental heuristic meter placement (IHMP) approach is proposed to select the locations and total number of power measurements. The meter placement procedure was implemented for a backward/forward load flow algorithm proposed by the authors, which allows the evaluation of medium-voltage power flows starting from low-voltage load measurements. This allows the reduction of the overall costs of measurement equipment and setup. The IHMP method was tested in the real 25-bus medium-voltage (MV) radial distribution network of the Island of Ustica (Mediterranean Sea). The proposed method is useful both for finding the best measurement configuration in a new distribution network and also for implementing an incremental enhancement of an existing measurement configuration, reaching a good tradeoff between instrumentation costs and measurement uncertainty.

scholarly journals An Analysis of the Systematic Error of a Remote Method for a Wattmeter Adjustment Gain Estimation in Smart Grids

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 37 ◽  
Author(s):  
Robertas Lukočius ◽  
Žilvinas Nakutis ◽  
Vytautas Daunoras ◽  
Ramūnas Deltuva ◽  
Pranas Kuzas ◽  
...  
Keyword(s):  
Systematic Error ◽  
Power Factor ◽  
Smart Grids ◽  
Low Voltage ◽  
Voltage Drop ◽  
Estimation Method ◽  
Data Communication ◽  
Pattern Search ◽  
Error Monitoring ◽  
Worst Case

Smart energy meters supporting bidirectional data communication enable novel remote error monitoring applications. This research targets characterization of the systematic worst-case error of the previously published remote watthour meter’s gain estimation method based on the comparison of synchronous measurements by the reference and meter under test. To achieve the research aim a methodology based on global maximization of the systematic error objective function assuming the typical low voltage electrical distribution network operation parameters ranges as defined by the standard recommendations for network design. To cross verify the reliability of the assessed solutions the suggested error analysis methodology was implemented utilizing two stochastic global extremum search techniques (genetic algorithms, pattern search) and the third one utilizing nonlinear programming solver. It was determined that the wattmeter adjustment gain worst-case error does not exceed 0.5% if the remote wattmeter monitored load power factor is larger than 0.1 and a network is designed according to the recommendation of the acceptable voltage drop less than 5%. For a load exhibiting power factor larger than cos φ = 0.9 the worst-case error was found to be less than 0.1%. It is concluded therefore that considering the systematic worst-case error the previously suggested remote wattmeter adjustment gain estimation method is suitable for remote error monitoring of Class 2 and Class 1 wattmeters.

scholarly journals Review of Voltage and Reactive Power Control Algorithms in Electrical Distribution Networks

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 58 ◽  
Author(s):  
Daiva Stanelyte ◽  
Virginijus Radziukynas
Keyword(s):  
Smart Grids ◽  
Reactive Power ◽  
Low Voltage ◽  
Distribution Networks ◽  
Power Grids ◽  
Renewable Energy Resources ◽  
Distribution Grid ◽  
Harmonic Compensation ◽  
Distributed Power Generation ◽  
Control Devices

The traditional unidirectional, passive distribution power grids are rapidly developing into bidirectional, interactive, multi-coordinated smart grids that cover distributed power generation along with advanced information communications and electronic power technologies. To better integrate the use of renewable energy resources into the grid, to improve the voltage stability of distribution grids, to improve the grid protection and to reduce harmonics, one needs to select and control devices with adjustable reactive power (capacitor batteries, transformers, and reactors) and provide certain solutions so that the photovoltaic (PV) converters maintain due to voltage. Conventional compensation methods are no longer appropriate, thus developing measures are necessary that would ensure local reactive and harmonic compensation in case an energy quality problem happens in the low voltage distribution grid. Compared to the centralized methods, artificial intelligence (heuristic) methods are able to distribute computing and communication tasks among control devices.

scholarly journals Active Distribution Grid Power Flow Analysis using Asymmetrical Hybrid Technique

2017 ◽  
Vol 7 (4) ◽  
pp. 1738 ◽  
Author(s):  
Paramet Wirasanti ◽  
Egon Ortjohann
Keyword(s):  
Power Flow ◽  
Flow Analysis ◽  
Load Flow ◽  
Hybrid Technique ◽  
Distribution Grid ◽  
Performance Study ◽  
Power Flow Analysis ◽  
Flexible Mode ◽  
Decoupling Analysis ◽  
Grid Operation

A conventional distribution power flow analysis has to be improved regards the changes in distribution network. One of the changes is a grid operation because a new grid concept, e.g. micro-grid and aggregation, is aimed to be operated based on area itself. Consequently, each area can be actively operated in either grid connected mode or islanding mode. Hence, this paper proposes an asymmetrical power flow analysis using hybrid technique to support this flexible mode change. The hybrid technique offers an opportunity to analyze power flow in a decoupling way. This means that the power flow analysis can be performed separately in each grid area. Regards the distributed generation, this paper also introduces a model based on inverter-based operation, i.e. grid forming, grid supporting and grid parallel. The proposed asymmetrical hybrid load flow method is examined in three case studies, i.e. a verification study with the DIgSILENT PowerFactory, a demonstration of decoupling analysis approach and a performance study with the Newton-Raphson method.

scholarly journals Mosaik and PADE: Multiagents and Co-simulation for smart grids modeling

2020 ◽  
Vol 27 (2) ◽  
pp. 107-115
Author(s):  
Lucas Silveira Melo ◽  
Filipe Saraiva ◽  
Ruth Leão ◽  
Raimundo Furtado Sampaio ◽  
Giovanni Cordeiro Barroso
Keyword(s):  
Distributed Generation ◽  
Smart Grids ◽  
Low Voltage ◽  
Electricity Distribution ◽  
Multi Agent Systems ◽  
Distribution Grid ◽  
Distributed Generations ◽  
Agent Systems ◽  
Multi Agent ◽  
Study Case

This paper describes the integration process between two tools in order to perform co-simulation for representation and analysis of dynamic environments in the context of smart grids. The integrated tools are Mosaik, a software to co-simulation management, and PADE, a software to multi-agent systems development. As a study case for demonstrate the integration, a scenary was utilized composed of a low voltage electricity distribution grid with 37 load bus, 20 photo-voltaic distributed generations, randomly connected to load bus, as well as, 20 PADE agents associated to distributed generation, modeling the behavior of electricity storage systems. The simulation results show the integration happening and demonstrate how useful is to model the dynamics of distributed electric resources with multi-agent systems.

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