Encontrados 19 documentos, a visualizar página 1 de 2
Comparison of current-source and voltage-source shunt active power filters for ...
Pinto, J. G.; Exposto, Bruno; Monteiro, Vítor; Monteiro, Luís F. C.; Couto, Carlos; Afonso, João L.This paper presents the comparison between two three-phase Shunt Active Power Filters (SAPFs), one with Current-Source Inverter (CSI) and the other with Voltage-Source Inverter (VSI), which are used to compensate current harmonics and to control reactive power. The control algorithm of both SAPFs is based on the Instantaneous Reactive Power Theory (p-q Theory). The comparison here presented fo...
Instantaneous p-q power theory for control of compensators in micro-grids
Watanabe, E. H.; Afonso, João L.; Pinto, J. G.; Monteiro, Luís F. C.; Aredes, M.; Akagi, H.The main objective of this tutorial is to present the basic concepts on the instantaneous p-q Theory and them show its applicability for controlling switching converters connected in a micro-grid. These converters can be used for connecting renewable energy sources (solar, wind, and others) to the micro-grids or for harmonic, reactive power or unbalance compensation, and even for voltage regulation. The ...
Compensation algorithms based on the p-q and CPC theories for switching compens...
Monteiro, Luís F. C.; Afonso, João L.; Pinto, J. G.; Watanabe, E. H.; Aredes, M.; Akagi, H.The main objective of this paper is to com-pare the applicability and p erformance of a switching compensator when it is controlled by algorithms derived from the pq–Theory and from the Current’s Physical Components Power Theory (CPC-Theory) considering a micro-grid application. Compensation characteristics derived from each one of these set of power definitions are highlighted, and simulation results o...
Comparisons between synchronizing circuits to control algorithms for single-pha...
Carneiro, H.; Monteiro, Luís F. C.; Afonso, João L.This paper presents a comparative analysis between synchronizing circuits applied to control algorithms for single-phase active converters. One of these synchronizing circuits corresponds to the single-phase PLL (Phase Locked Loop), implemented in α-β coordinates, whereas the other one corresponds to the E-PLL (Enhanced PLL). These synchronizing circuits are compared in several aspects as processing and settlin...
A comparative analysis of cascaded-multilevel hybrid filters applied in power t...
Merçon,Alexandre G.; Encarnação,Lucas F.; Monteiro,Luís F. C.; van Emmerik,Emanuel L.; Aredes,MaurícioPassive filters, commonly used to attenuate non-characteristic harmonics in High Voltage Direct Current (HVDC) systems, stay at risk of disconnection from the system due to overcurrent problems. A possible solution to solve the problems involving high harmonic levels would be the use of pure active filters. However, this alternative is unpractical due to the high power of the transmission systems. This paper pr...
A control strategy for a three-phase four-wire shunt active filter
Ferreira, Filipe; Monteiro, Luís F. C.; Afonso, João L.; Couto, CarlosThis paper presents a control strategy for a three- phase four-wire shunt active filter. The shunt active filter is a custom-power device capable to compensate, in real time, harmonics, unbalances and power factor in an electrical installation. In this work the power circuit is based on a three-leg IGBT inverter, with the dc-link composed by two capacitors connected in split. Thus the neutral point is con...
Detecting abnormalities in endoscopic capsule images using color wavelet featur...
Lima, C. S.; Barbosa, Daniel; Tavares, Adriano; Ramos, Jaime; Monteiro, Luís F. C.; Carvalho, LuísThis paper presents a system to support medical diagnosis and detection of abnormal lesions by processing endoscopic images. Endoscopic images possess rich information expressed by texture. Texture information can be efficiently extracted from medium scales of the wavelet transform. The set of features proposed in this paper to encode textural information is named color wavelet covariance (CWC). CWC coefficient...
Classification of endoscopic capsule images by using color wavelet features, hi...
Lima, C. S.; Barbosa, Daniel; Tavares, Adriano; Ramos, J.; Monteiro, Luís F. C.; Carvalho, LuísThis paper presents a system to support medical diagnosis and detection of abnormal lesions by processing capsule endoscopic images. Endoscopic images possess rich information expressed by texture. Texture information can be efficiently extracted from medium scales of the wavelet transform. The set of features proposed in this paper to code textural information is named color wavelet covariance (CWC). CWC coeff...
Single-phase shunt active filter with digital control
Pinto, J. G.; Neves, Pedro; Pregitzer, Ricardo G.; Monteiro, Luís F. C.; Afonso, João L.This paper presents a single-phase shunt active filter designed to minimize problems related to power quality in electrical systems. The power stage of the active filter is based on a two-leg full-bridge inverter, with a single capacitor in the dc side, and a filter inductor in the ac side. The control system is based on the instantaneous power theory in the α-β-0 reference frame (pq-theory), derived to be appl...
3-phase 4-wire shunt active power filter with renewable energy interface
Pinto, J. G.; Pregitzer, Ricardo G.; Monteiro, Luís F. C.; Afonso, João L.This paper presents a three-phase four-wire Shunt Active Filter that compensates power quality problems and can also interface renewable energy sources with the electric grid. The inverter stage of the active filter is based in a two level four leg inverter and its control is based in the Theory of Instantaneous Reactive Power (p q Theory). The filter is capable of compensating power factor, unbalance, and curr...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||