Adson Bezerra Moreira

Evaluation of active frequency drift anti-islanding methods with a single-phase grid-tie photovoltaic inverter

The increasing number of distributed generators connected to the distribution grids requires islanding detection methods that guarantee the disconnection of generators during grid faults and unintentional island situations. Many anti-islanding techniques have been developed to satisfy this necessity. This paper evaluates two frequency-drift anti-islanding methods used with a single-phase grid-tie photovoltaic (PV) inverter.

Design, optimization and analysis of the axial C-core Switched Reluctance Generator for wind power application

Switched reluctance generator (SRG) has been covered in several researches in the last two decades. These kind of machine is very promising for wind power application due to their low cost, high efficiency and high power density per volume. On the other hand, lots of researches are dedicated to the study and project of traditional SRG (radial flux). This article presents the electromagnetic design and optimization of the Axial Switched Reluctance Generator with C Core (C-SRG) using finite element method. Moreover, in order to better analyze the dynamic behavior of the C-SRG, a co-simulation was developed using the software Maxwell 3D and Simplorer. The simulation results indicate that the methodology adopted was suitable and can be applied to C-SRG electromagnetic design.

Evaluation of active anti-islanding methods based on the ABNT NBR IEC 62116 and IEEE STD 929-2000 standards

In this paper two active anti-islanding methods are evaluated and compared according to the ABNT NBR 62116 and IEEE STD 929-2000 standards. These standards specify voltage and frequency trip time settings and trip magnitudes. The first method is the active frequency drift with positive feedback and the second one is the active frequency jump that is based on phase-locked loop perturbation. The latter distorted less the power injected into the utility grid and had a better time response to detect grid faults. Besides, it was able to obey the two standards, different from the first one that was able to follow just the second standard.

Application Of The Power Control For Wind Power Generation And Current Harmonic Filter With Dfig

This paper describes a new proposed wind power system which controls the active and reactive generated power as well as performs filtering of the grid currents harmonic components. The harmonic compensation is achieved by an algorithm applied for grid side converter in the presence of a non-linear three-phase load in the point of common coupling. This technique when correctly used improves the power quality. The machine side converter controls the active and reactive power that is delivered to the grid by vector control with the stator field orientation. A design methodology of the controllers used in these techniques is presented. Simulation and experimental results confirmed the effectiveness of the proposed system. 

Analysis of the Sandia Frequency Shift (SFS) islanding detection method with a single-phase photovoltaic distributed generation system

The number of photovoltaic distributed generators introduced into electricity distribution systems is increasing worldwide. Safety measures must be taken for the correct operation of these new distributed generators so as to prevent uncontrolled and undesired power injections into the grid and possible damages to equipment and personnel. This paper describes an anti-islanding detection method used for prevention against unintentional islanding of the distributed generator. The main focus is the study, implementation and analysis of the Sandia Frequency Shift method based on the IEEE 929-2000 standard.

Active frequency drift with positive feedback anti-islanding method for a single phase two-stage grid-tied photovoltaic system

The amount of distributed generators connected to the utility grid has been growing every year. With this in mind, it is necessary to use methods that can detect islanding conditions in a faster way and that do not decrease the quality of the energy provided by the utility grid. This paper focuses on the design and simulation of a single phase grid-tied photovoltaic system using an active frequency drift with a positive feedback anti-islanding method (AFDPF).