METHODOLOGY FOR THE DYNAMIC LINE RATING ANALYSIS AND OPTIMAL MANAGEMENT OF POWER NETWORKS

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Publications

Towards a high-resolution offshore wind Atlas : the Portuguese case

Publication . Couto, António; Silva, João M. Henriques da; Costa, Paula Silva; Santos, D.; Simões, Teresa; Estanqueiro, Ana

ABSTRACT: An accurate offshore wind resource assessment is a key tool for planning marine wind renewable exploitation. To achieve this goal, without resort to an extensive and costly network of anemometric stations or buoys, it becomes necessary to use the so-called atmospheric mesoscale models. This work presents a high spatial resolution (1x1 km) offshore wind resource Atlas for Portugal and the model calibration steps. During the calibration steps, the most adequate: i) atmospheric parameterizations - physics options, ii) initial and boundary conditions (IBC) meteorological datasets, and iii) data assimilation scheme were achieved through sensitivity tests using the common statistical metrics and hourly simulated/observational data. Results show that the most significant improvements are associated with the IBC dataset and the data assimilation scheme used. Thus, the results show that the assimilation procedures coupled with the new ERA-5 reanalysis dataset reduce significantly the errors of the wind speed and direction, especially the normalized mean square error. This reduction, depending on the different calibration setup, can be above 50%. The new Atlas confirms the previous indicators, Portugal presents a high wind power potential, especially for deep offshore regions.

2019Journal article

Open access

Meteorological forecast data: Coupling NWP and CFD Modeling. Merging the datasets: Deliverable D2.2

Publication . Couto, António

ABSTRACT: The work presented in this deliverable was developed by LNEG and R&D NESTER as part of the R&D activities of the project OPTIGRID - Methodology for the dynamic line rating analysis and optimal management of power networks. According to the plan activities of Tasks 2.1 and 2.4, the main objective of this deliverable is to present the methods applied to obtain the meteorological forecast data need to feed the models developed in this project and it merges all the datasets to be used in each case study. According to the work plan, and as reported in the deliverables from Task 4, three case studies were defined for: A) a region with large distributed wind capacity; B) a region with large photovoltaic (PV) potential and limited grid capacity; and C) market splitting occurrence in MIBEL due to congestion in the interconnections. For these regions the meteorological forecast data, used during this project, were obtained using a numerical weather prediction model and computational fluid dynamic model coupling approach. The numerical weather prediction (NWP) model is used to forecast the hourly spatial meteorological data (e.g., wind speed and direction, temperature) during 2018 with a maximum spatial resolution of 3 km. This model is calibrated regarding its physical parametrizations and initial/boundary conditions, among others.

2021-09Report

Open access

Development of DLR analysis and power system models: Deliverable D3.1

Publication . Algarvio, Hugo; Duque, Joaquim; Couto, António

ABSTRACT: This deliverable presents the work developed by LNEG as part of the R&D activities of the project OPTIGRID - Methodology for the dynamic line rating analysis and optimal management of power networks. According to the plan activities of Tasks 3.1 and 3.2, the main objective of this deliverable is to integrate the mathematical model for the Dynamic Line Rating (DLR) analysis in the optimal power flow model for a generic AC power system, previously developed in LNEG. The main limiting factor for the transmission capacity of overhead lines (OHLs) is usually defined by a thermal constraint. For OHLs several effects are present, some with a positive contribution while others can lead to the potential congestion of the electrical networks. The seasonal line rating (SLR) methodology, traditionally used by the system operators to ensure that the grid does not operate over the maximum pre defined conductor temperature, determines the line’s ampacity from constant weather conditions using: 1) seasonal basis information or 2) conservative weather conditions. These conditions usually underestimate the real transmission capacity of OHLs. Thus DLR analysis allows assessing more realistic current limits for the power lines could present a method to deal with potentially congested electrical networks enabling the optimal integration of distributed renewable power generation.

2021-07Report

Open access

Validation of transmission network and MIBEL data: Deliverable D2.1

Publication . Couto, António; Algarvio, Hugo

ABSTRACT: The work presented in this deliverable was developed by LNEG and R&D NESTER as part of the R&D activities of the project OPTIGRID - Methodology for the dynamic line rating analysis and optimal management of power networks. According to the plan activities of Tasks 2.2 and 2.3, the main objective of this deliverable is to present the transmission network and the Iberian electricity market (MIBEL) data gathered and validated to use in each case study. According to the work plan, and as detailed reported in the deliverables from Task 4, three case studies were defined: 1) a region with large distributed wind capacity; 2) a region with large photovoltaic (PV) potential and limited grid capacity.; and 3) market splitting occurrence in MIBEL due to congestion in the interconnections - Figure 1. For these regions, during this project, the high voltage network topology and its electrical characteristics (e.g., cables, resistance, reactance, and susceptance) were collected. The power generation, the loads in the regions under analysis were also obtained. Finally, to address the third case study, the interchange capacity (import and export) available and the bids of the day-ahead and intra-day markets at those hours are also gathered and analysed.

2020-07Report

Open access

Pre-Solve Methodologies for Short-Run Identification of Critical Sectors in the ACSR Overhead Lines While Using Dynamic Line Rating Models for Resource Sustainability

Publication . Algarvio, Hugo

ABSTRACT: Most transmission system operators (TSOs) use seasonally static models considering extreme weather conditions, serving as a reference for computing the transmission capacity of power lines. The use of dynamic line rating (DLR) models can avoid the construction of new lines, market splitting, false congestions and the degradation of lines in a cost-effective way. The operation of power systems is planned based on market results, which consider transactions hours ahead of real-time operation using forecasts with errors. The same is true for the DLR. So, during real-time operation TSOs should rapidly compute the DLR of overhead lines to avoid considering an ampacity above their lines' design, reflecting the real-time weather conditions. Considering that the DLR of the lines can affect the power flow of an entire region, the use of the complete indirect DLR methodology has a high computation burden for all sectors and lines in a region. So, this article presents and tests three pre-solve methodologies able to rapidly identify the critical sector of each line. These methodologies solve the problem of the high computation burden of the CIGR & Eacute; thermodynamic model of overhead lines. They have been tested by using real data of the transmission grid and the weather conditions for two different regions in Portugal, leading to errors in the computation of the DLR lower than 1% in relation to the complete CIGR & Eacute; model, identifying the critical sector in significantly less time.

2025-04Journal article

Open access