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.

Control of Bidirectional Quadratic DC-DC Converters for Storage Support of DC Power Grids

Abstract: Many applications require a DC bus supporting connections to several renewable energy sources, storage systems and loads. However, due to the intermittent nature of renewable energy sources and load variations it is essential to stabilize the voltage of the DC bus. Usually a battery is used to support the DC bus voltage, but their continuous charge and discharge cycling will affect his lifetime. Thus, the use of a storage system based in supercapacitors provides an interesting alternative to stabilize the DC power grid. In this context, this work presents a study of a storage system based in supercapacitors combined with a bidirectional quadratic DC-DC converter to support the DC bus. A full design of the controllers for the quadratic converter is also presented. The behaviour of the system will be tested through several simulation results.

Neural network based identification of hand movements using biomedical signals

Abstract: This paper proposes a methodology that analysis and classifies the EMG and MMG signals using a linear neural network to control prosthetic members. Finger motions discrimination is the key problem in this study. Thus the emphasis is put on myoelectric signal processing approaches in this paper. The EMG and MMG signals classification system was established using a linear neural network and it is presented the comparison with the classification based on the LVQ neural network. Experimental results show a promising performance in classification of motions based on both MMG and EMG signals.

Fault detection and diagnosis of six-phase voltage source inverter using trajectory mass current center

Abstract: This paper presents a new fault detection and diagnosis method for a six-phase voltage source inverter (VSI). The proposed method is based on an equivalent six dimension of a current trajectory mass center of the VSI output currents. This approach allows detecting and identifying the faulty power switch. The proposed approach results in a fast and reliable fault detection method. The performance of a proposed technique, are confirmed through several simulation and experimental results.

An 8/6 SRM Drive with a Multilevel Topology Based on a Cross-Switched Configuration

Abstract: SRM drives based on multilevel power electronic converter presents several advantages, like reducing the switching frequency and improve the operation of the motor under high speed. In this way, several multilevel power converter topologies have been developed for the SRM drives. In line with this, this paper proposes a new multilevel power converter topology for the 8/6 SRM drive. The topology was developed with the purpose to reduce the number of power semiconductors, without reducing the performance of the motor. The proposed topology was designed in a way that uses crossover switches. The operation of the power converter topology in all of their modes is analyzed in a detailed way. The verification of the global system performance (drive and motor) is realized by the implementation of simulation studies. Indeed, through these studies it is verified that at low speed operation the switching frequency is reduced, but maintaining the application of the maximum voltage during the magnetization and demagnetization process.

Multi-level conversion : high voltage choppers and voltage-source inverters

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.<>

Recent Advances in the Design, Modeling, and Control of Multiphase Machines—Part II

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.

Overview of Control Systems for the Operation of DFIGs in Wind Energy Applications

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.