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V. Fernao Pires

Bio: V. Fernao Pires is an academic researcher from INESC-ID. The author has contributed to research in topics: Inverter & Fault (power engineering). The author has an hindex of 18, co-authored 154 publications receiving 1457 citations. Previous affiliations of V. Fernao Pires include Technical University of Lisbon & University of Lisbon.


Papers
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Proceedings ArticleDOI
01 Jan 2013
TL;DR: In this paper, a three-phase nine switch inverter for a grid-connected photovoltaic (PV) system is presented, where a sliding mode controller associated to vectorial modulator is used to control this power converter.
Abstract: In this paper it is presented a three-phase nine switch inverter for a grid-connected photovoltaic (PV) system. The structure of this power converter is based on the classical three-phase voltage source inverter. However, it requires three extra bi-directional switches and presents a multilevel characteristic. Thus, reducing switching frequency and/or inverter ac voltages with reduced THD are obtained. To control this power converter a sliding mode controller associated to vectorial modulator is used. The performance of the proposed PV system is verified by time-domain simulation studies.

6 citations

Journal ArticleDOI
TL;DR: A new approach for the practical learning of power system relaying is presented, which consists of a computer‐based testing system of relay‐operating characteristic that is possible to understand the performance and limitations of different protective relay systems and to test a real relay disoperation.
Abstract: Teaching power system relaying is a fundamental issue in a power system high-level course. However, for an effective instruction of this topic an experience with real equipments can be considered as fundamental. To achieve this purpose, in this paper a new approach for the practical learning of power system relaying is presented. This consists of a computer-based testing system of relay-operating characteristic. Different relay types and developed specific software are also an important piece of the laboratory practice. Using this system it is possible to understand the performance and limitations of different protective relay systems and to test a real relay disoperation. The benefit of using this system is not available through traditional lectures and textbooks. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 20: 19–28, 2012

6 citations

Book ChapterDOI
15 Apr 2013
TL;DR: An on-line system for detection and diagnosis of electrical faults in induction machines based on computer-aided monitoring of the supply currents and Principal Component Analysis (PCA) is presented.
Abstract: Nowadays in industry there many processes where human intervention is replaced by electrical machines, especially induction machines due to his robustness and performance. Although, induction machines are a high reliable device, they are also susceptible to faults. Therefore, the study of induction machine state is essential to reduce human and financial costs. It is presented in this paper an on-line system for detection and diagnosis of electrical faults in induction machines based on computer-aided monitoring of the supply currents. The main objective is to detect and identify the presence of broken rotor bars and stator short-circuits in the induction motor. The presence of faults in the machine causes different disturbances in the supply currents. Through a stationary reference frame, such as αβ-vector transform it is possible to extract and manipulate the results obtained from the supply currents using Principal Component Analysis (PCA).

6 citations

Proceedings ArticleDOI
01 Jan 2009
TL;DR: In this paper, the MATLAB/SIMULINK modeling for a stand-alone energy system supported by totally renewable hydrogen production is described and a simplified model that is being used in the renewable energies course at the Electrical Department of the Faculty of Sciences and Technology (Universidade Nova de Lisboa, Portugal).
Abstract: This paper describes the MATLAB/SIMULINK modeling for a Stand-Alone Energy System Supported by Totally Renewable Hydrogen Production. The full modelling of a stand-alone Energy System is a huge task implying heavy computation models with long computation times. Therefore, the full modelling approach cannot be used for teaching purposes. In this way, this paper describes a simplified model that is being used in the renewable energies course at the Electrical Department of the Faculty of Sciences and Technology (Universidade Nova de Lisboa, Portugal).

5 citations

Proceedings ArticleDOI
10 Apr 2018
TL;DR: This study will show the impact of the 3L-Active NPC (3L-ANPC) to the qZS inverters on the efficiency of the system as well as on the distribution of the switching losses.
Abstract: Quasi-Z-source (qZS) inverters have been found very suitable in boost operation applications. As a result, studies have focused on the three-level neutral-point-clamped (3L-NPC) qZS inverters. However, this topology has a shortcoming of loss distribution among the switches. Focus in this article is on the application of the 3L-Active NPC (3L-ANPC) to the qZS inverters. Our study will show the impact of this topology on the efficiency of the system as well as on the distribution of the switching losses. A shoot-through sinusoidal pulse with modulation adapted to the 3L-ANPC was used. A modified modulation was also implemented and tested. Several simulation tests were performed to analyze the adopted topology and modulation strategies.

5 citations


Cited by
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01 Sep 2010

2,148 citations

01 Jan 1992
TL;DR: In this paper, a multilevel commutation cell is introduced for high-voltage power conversion, which can be applied to either choppers or voltage-source inverters and generalized to any number of switches.
Abstract: The authors discuss high-voltage power conversion. Conventional series connection and three-level voltage source inverter techniques are reviewed and compared. A novel versatile multilevel commutation cell is introduced: it is shown that this topology is safer and more simple to control, and delivers purer output waveforms. The authors show how this technique can be applied to either choppers or voltage-source inverters and generalized to any number of switches.<>

1,202 citations

Journal ArticleDOI
TL;DR: The main objective of the two-part survey named ‘Recent Advances in the Design, Modeling, and Control of Multiphase Machines’ is to present relevant contributions to encourage and guide new advances and developments in the field.
Abstract: The main objective of this two-part state-of-the-art paper called “Recent Advances in the Design, Modeling, and Control of Multiphase Machines” is to present latest contributions in the multiphase machines' field. The first part of this paper focuses on the recent progress in the design, modeling, and control, whereas the drive is in healthy operation. This second part presents relevant contributions in two not analyzed fields. The first is in relation with the use of the additional degrees of freedom of multiphase machines and the exploitation of their fault-tolerant capabilities without adding extra hardware. The second one analyzes multiphase generation, particularly in grid-connected wind energy conversion systems and stand-alone applications. Recent progresses are shown and open challenges and future research directions are discussed.

607 citations

Journal ArticleDOI
TL;DR: The control systems for the operation of DFIGs in wind energy applications are reviewed for connections to balanced or unbalanced grids, and sensorless control.
Abstract: Doubly fed induction generators (DFIGs), often organized in wind parks, are the most important generators used for variable-speed wind energy generation. This paper reviews the control systems for the operation of DFIGs and brushless DFIGs in wind energy applications. Control systems for stand-alone operation, connection to balanced or unbalanced grids, sensorless control, and frequency support from DFIGs and low-voltage ride-through issues are discussed.

594 citations

Journal ArticleDOI
TL;DR: Compared with traditional neural network, the SAE-based DNN can achieve superior performance for feature learning and classification in the field of induction motor fault diagnosis.

562 citations