http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

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.<<ETX>>

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

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.

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

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.

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

A sparse auto-encoder-based deep neural network approach for induction motor faults classification

Discrimination between an internal fault and a magnetizing inrush current has been recognized as a power transformer protection problem, since can cause malfunction of a differential relay. To overcome this problem the paper proposes a new approach for transformer differential protection. This approach is based on the Park transformation of the differential currents. Using this technique each harmonic that must be used for the protection will be converted in a dc component. So, one of the advantages of this approach is that the proposed algorithm does not require a very high computational effort. The evaluation of this technique is performed by a Matlab/Simulink-based simulator. From the obtained results it is possible to verify that the relay can correctly discriminates magnetic inrush from an internal fault.

A Transformer Differential Relay Based on a Multiple Park Transformation

The three-level active neutral point clamped converter (ANPC) allows to overcame the problem of unequal loss distribution among semiconductor devices that appears in the classical neutral point clamped converter NPC. Another advantage of this power converter is that it can operate under faulty conditions. In this paper the study of the ANPC using a voltage sliding mode controller for a vector modulator under a semiconductor open fault is presented. The approach allows keeping the voltage of the neutral point balanced under a fault condition. Simulation results are presented in order to verify the effectiveness of the proposed control strategy under the fault condition mode.

http://ieeexplore.ieee.org/iel7/6963792/6980494/06980651.pdf

Fault tolerant operation of active neutral point clamped multilevel converters using a voltage sliding mode controller

Control transition mode from voltage control to MPPT for PV generators in isolated DC microgrids

With the growing popularity of mobile devices, several projects for mobile learning courses have been developed. Those equipments allow a superior portability and accessibility of the learning courses. In this context, the present paper focuses on the development of a mobile learning framework for an analog electronics course. This course was designed as a supplementary mean to the classic analog electronics courses. The course project consists of several interactive multimedia modules. At the end of each module, students have several oriented questions to answer. The set of answers, in SMS format, gives feedback to the teacher about the learning process. Another module, that is under development, is responsible for storing and managing the answers in a server, where all the results from students are processed in a competitive learning based methodology application.

/pdf/development-of-a-mobile-learning-framework-for-an-analog-1z6fg5eten.pdf

Development of a mobile learning framework for an analog electronics course

This paper presents a three-phase on-board integrated battery charger for electric vehicles (EVs). This charger is designed for EVs that uses six-phase machines. Moreover, this charger was designed to connect to the inverter with reduced switches, as is the case of the nine-switch inverter. The input of the charger will operate as a three-phase power factor correction (PFC) converter with Buck-Boost characteristics. In this scheme, all windings of the motor are used as DC inductors of the charger. A detailed analysis of the proposed on-board integrated battery charger will be presented. On the other hand, an associated fast and active current controller is also proposed to ensure the unit power factor of the rectifier. The feasibility, characteristics and validation of theoretical deductions will be confirmed through several simulation tests.

V. Fernao Pires

Papers

A Transformer Differential Relay Based on a Multiple Park Transformation

Fault tolerant operation of active neutral point clamped multilevel converters using a voltage sliding mode controller

Control transition mode from voltage control to MPPT for PV generators in isolated DC microgrids

Development of a mobile learning framework for an analog electronics course

A Three-Phase On-Board Integrated Battery Charger for EVs with Six-Phase Machine and Nine Switch Converter