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

This paper presents a new configuration for an uninterruptible power system (UPS) with the integration of a photovoltaic system (PV. Currently, the safest way to supply energy to critical equipment or data processing system is still the use of an online UPS. On other hand, normally it is not required to use the same security for a PV system. This work proposes the integration of these two systems resulting not only in the improvement of the PV system reliability but also of the UPS system. This integration will also result in a multilevel structure for the electronic power converter systems with the inherent advantages of this structure. A control system for the proposed structure will also be presented. Several simulation results will be presented to verify the operation of this hybrid system.

Hybrid PV-UPS system with multilevel structure of power converters and reliability improvment

HVDC transmission systems based on voltage source converters have lately emerged as a good alternative to conventional AC transmission. In these transmission systems multilevel converters have become a promising energy conversion technology. The reliability of the power converters are extremely important since a fault in these equipments may lead to an unavailability for a long period of the transmission system. Thus, this paper will focuses in HVDC dual transmission system under semiconductor failure conditions. As presented in this paper this structure presents interesting characteristics under the point of view the reliability considering a power semiconductor failure. It will present the consequences for the transmission system when there is a semiconductor fault. A study for the change of the modulation system in order to ensure DC link capacitors voltage balance under a fault condition is also presented. Simulation studies are shown in order to confirm the characteristics of the proposed methodology in normal and fault condition mode.

/pdf/study-of-the-hvdc-dual-transmission-system-under-faults-in-1oct87no5f.pdf

Study of the HVDC dual transmission system under faults in the power converters

In this paper, a single stage flyback pfc converter is used as a power supply of a testing distance relay system. The flyback pfc converter topology, operation and control are presented. A fast and robust sliding mode control of the input current is also presented. The sliding mode controller enables also high power factor and nearly sinusoidal input current. The dc output voltage of the converter is controlled by a proportional integral (PI) controller. Simulation and experimental results from a laboratory prototype are presented and discussed.

A Single Stage Flyback PFC Converter for Testing Distance Relay Systems

DC microgrids initiated the change of a paradigm regarding the concept about electrical distribution networks, especially in the context of the distributed generation associated with renewable energies. However, this new reality opens a new area of research, in which several aspects must be carefully studied. Indeed, the bipolar design is one of the principal dc microgrid configurations considering its characteristic wiring. Although holding many promising advantages, the bipolar dc microgrid has a tendency toward voltage and current imbalances due to the unequal distribution of the loads and generators between the two poles. Thus, specific power electronic-based solutions are required to ensure the balance of these dc microgrids. Within this frame, this article gives a comprehensive review of the multiple architectures and power electronic topologies proposed to mitigate/eliminate this undesired condition. The following provides an insightful classification and discussion with the pros and cons of these solutions. This work can serve as a timely review for researcher/engineers who want to enter the voltage balancing field in the bipolar dc grids and promote the innovation of their power electronics-enabled solutions.

DC–DC Converters for Bipolar Microgrid Voltage Balancing: A Comprehensive Review of Architectures and Topologies

Voltage sags and swells have a severe impact on sensitive loads. To overcome this problem Dynamic Voltage Restores (DVR) are often used. The DVR is very attractive due to its potential for fast dynamic response to sags disturbances. In this paper, a new multilevel power converter structure for the DVR is proposed. This structure uses three single phase inverters and one three-phase inverter. In this way, a power converter with a five level output voltage is obtained. To control the proposed multilevel power converter a sliding mode controller is used. This control system presents important characteristics such as fast dynamic response and robustness to external perturbations. Several computer simulation results are presented in order to verify the proposed DVR structure.

V. Fernao Pires

Papers

Hybrid PV-UPS system with multilevel structure of power converters and reliability improvment

Study of the HVDC dual transmission system under faults in the power converters

A Single Stage Flyback PFC Converter for Testing Distance Relay Systems

DC–DC Converters for Bipolar Microgrid Voltage Balancing: A Comprehensive Review of Architectures and Topologies

Dynamic voltage restorer using a multilevel converter with a novel cell structure