Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
Publications

Publications by CPES

2024

Optimal Sizing and Energy Management of Battery Energy Storage Systems for Hybrid Offshore Farms

Authors
Varotto, S; Trovato, V; Kazemi-Robati, E; Silva, B;

Publication
2024 IEEE 22ND MEDITERRANEAN ELECTROTECHNICAL CONFERENCE, MELECON 2024

Abstract
This paper investigates the financial benefits stemming from the potential installation of battery energy storage systems behind the meter of a hybrid offshore farm including wind turbines and floating photovoltaic panels. The optimal investment and operation decisions concerning the energy storage system in the hybrid site are assessed by means of a mixed integer linear programming optimization model. The operation is also subject to technical constraints such as limitations on the connection capacity and ramping constraints imposed by the grid operator at the point of common coupling. Three design configurations for the battery system are analysed: I) offshore with the hybrid farm, II) onshore where the grid connection point is, III) both offshore and onshore. The results indicate the financial value of installing battery storage units, and other benefits deriving from this investment, as the reduction of curtailment.

2024

A Two-Phase Approach for the Electrical Layout Optimization of the Offshore Wind Farms

Authors
Castro, RM; Silva, B; Kazemi-Robati, E;

Publication
2024 IEEE 22ND MEDITERRANEAN ELECTROTECHNICAL CONFERENCE, MELECON 2024

Abstract
Due to the current focus on offshore renewable energies worldwide, more capacity of them is expected in the future. The electrical layout design considerably affects overall implementation cost of these offshore power plants as well as the losses of energy inside the farms. Considering the increasing size of offshore wind farms, it is necessary to develop more robust and computationally efficient methods to design the electrical layout of these farms. In this work, a two-phase approach is proposed for the optimization of the electrical layout of the offshore wind farms; the proposed framework aims at the minimization of the ohmic losses and the cost of the cables. To solve the optimization problem, Simulated Annealing (SA) is applied in this study. A tool is also developed using Python programming language to implement the framework for the optimization of the electrical layout of the offshore farms. The proposed method is then applied to a farm with 100 turbines and an overall rated capacity of 1GW. The results approved the accuracy of the two-phase approach in finding the optimal electrical layout as well as the high efficiency in terms of the computational burden.

2024

Offshore Wind Farm Black Start With Grid-Forming Control

Authors
Prakash, PH; Lopes, JP; Silva, B;

Publication
2024 IEEE 22ND MEDITERRANEAN ELECTROTECHNICAL CONFERENCE, MELECON 2024

Abstract
This paper introduces a detailed procedure for executing a black start service from an offshore wind farm (OWF) through the integration of grid-forming (GFM) control. The proposed strategy involves exploiting a grid-forming battery energy storage system (BESS) to deliver black start service within an OWF equipped with grid-following wind turbines. Controller modelling, and operation methodology are explained. To illustrate the efficacy of the suggested control and operation principles, the study employs an OWF as a case study. Simulation analyses are conducted using the Matlab/Simulink software to demonstrate the viability of the presented strategy.

2024

Black Start of an Off-grid Offshore Wind Farm with Grid Forming Converter

Authors
Prakash, H; Lopes, P; Silva, B;

Publication
IET Conference Proceedings

Abstract
This paper presents a comprehensive procedure for conducting a black start service from an offshore wind farm (OWF) by integrating grid-forming (GFM) control. The proposed strategy utilizes a grid-forming battery energy storage system (BESS) to provide black start service within an OWF that is equipped with grid-following wind turbines. The paper elaborates on the modeling of controllers and the operational methodology taking wind variability during the black start procedure. To showcase the effectiveness of the proposed control and operation principles, the study utilizes an OWF as a case study. Simulation analyses are performed using Matlab/Simulink software to validate the feasibility of the proposed strategy. © Energynautics GmbH.

2024

Comparison between LightGBM and other ML algorithms in PV fault classification

Authors
Monteiro, P; Lino, J; Araújo, RE; Costa, L;

Publication
EAI Endorsed Trans. Energy Web

Abstract
In this paper, the performance analysis of Machine Learning (ML) algorithms for fault analysis in photovoltaic (PV) plants, is given for different algorithms. To make the comparison more relevant, this study is made based on a real dataset. The goal was to use electric and environmental data from a PV system to provide a framework for analysing, comparing, and discussing five ML algorithms, such as: Multilayer Perceptron (MLP), Decision Tree (DT), K-Nearest Neighbors (KNN), Support Vector Machine (SVM) and Light Gradient Boosting Machine (LightGBM). The research findings suggest that an algorithm from the Gradient Boosting family called LightGBM can offer comparable or better performance in fault diagnosis for PV system.

2024

Switched reluctance motor core loss estimation with a new method based on static finite elements

Authors
Melo, PS; Araújo, RE;

Publication
COGENT ENGINEERING

Abstract
Core loss estimation in switched reluctance motor is a complex task, due to non-linear phenomena and non-sinusoidal flux density waveforms. Several methods have been developed for estimating it (e.g. empirical, and physical-mathematic models), each one with merits and limitations. This paper proposes a new method for core losses estimation based on Finite Element Method Magnetics software. The main idea is using the machine phase-current harmonics as input for estimating core losses. In addition, a comparative study is carried out, where the proposed approach is faced up to a different one, based on Fourier decomposition of the flux density waveforms in the machine sections. In order to systematically analyze and compare the applied estimation cores loss techniques, a case study of a three-phase 6/4 SRM for different simulation scenarios is introduced. The outcomes of both methods are discussed and compared, where core loss convergence is found for limited speed and load ranges.

  • 8
  • 330