132 documents found, page 1 of 14
Asymmetric impedance model for grid-forming converters with droop control
Pérez-Estévez, Diego; Ríos-Castro, Diego; Fernández-Abraldes, Pablo Marino; Monteiro, Vítor Duarte Fernandes; Pinto, J. G.; Afonso, João L.This article introduces an impedance model for a grid-forming (GFM) converter with droop control (Droop-GFM converter) connected to a weak power grid. The proposed model offers a more accurate and simpler alternative to the conventional minor-loop criterion and the generalized Nyquist stability criterion for studying the stability of a Droop-GFM converter, as it accounts for loading effects and uses only two tr...
A review on power electronic converters for modular BMS with active balancing
Miranda, João P. D.; Barros, Luis A. M.; Pinto, J. G.Electric vehicles (EVs) are becoming increasingly popular due to their low emissions, energy efficiency, and reduced reliance on fossil fuels. One of the most critical components in an EV is the energy storage and management system, which requires compactness, lightweight, high efficiency, and superior build quality. Active cell equalization circuits such as those used in battery management systems (BMS) have b...
DC-DC power converter for high power solar photovoltaic system
Miranda, João P. D.; Rodrigues, Duarte M. N.; Barros, Luis A. M.; Pinto, J. G.Worldwide there is an enormous dependence on fossil fuels to produce electricity. Burning fossil fuels results in CO2 emission into the atmosphere, causing a negative environmental impact. In order to mitigate these problems, there is a need to integrate renewable energy sources into the power grid, namely solar photovoltaic (PV) energy. Power electronics converter solutions for solar PV module interface are va...
Balancing the active power of a railway traction power substation with an sp-RPC
Barros, Luis A. M.; Martins, António P.; Pinto, J. G.The railway system is one of the safest, most efficient, and environmentally friendly means of land transport for people and goods. However, as the demand for mobility has increased, the current railway system has shown some weaknesses, requiring an increase in catenary power in order to be able to supply power to longer trains and faster locomotives, as well as to increase rail traffic. This paper proposes a c...
New topology of a hybrid, three-phase, four-wire shunt active power filter
Freitas, Stefani; Oliveira, Luis Carlos; Oliveira, Priscila; Exposto, Bruno; Pinto, J. G.; Afonso, João L.With a view to reducing harmonic content in electrical power systems, and, consequently, improving power quality level, filters and other harmonic compensation devices are widely used. In the category of filters, they can be distinguished into two classes that are related to the operating mode, active or passive, both widely known and applied in electrical power grids and in the most diverse industry sectors. I...
Development of a Modular Multilevel Cascade Converter based on full-bridge subm...
Rego, João; Pereira, Fábio Lúcio; Barros, Luis A. M.; Martins, António P.; Pinto, J. G.The Modular Multilevel Cascade Converters (MMCC) present themselves as one of the solutions for high power and high voltage applications. Modularity and low voltage stress in each semiconductor are some of the features of this solution. This paper presents a study with experimental results concerning an MMCC composed by three full-bridge submodules with a common DC-bus and with low frequency cascaded transforme...
Comparative analysis between different approaches for single-phase PLLs
Monteiro, Luis; Pinto, J. G.; Monteiro, Vítor Duarte Fernandes; Couto, Carlos; Afonso, João L.This paper presents a comparative analysis between two distinct synchronizing circuits, which are usually applied as the core of control algorithms for single-phase power quality applications. One of these synchronizing circuits corresponds to a single-phase Phase-Locked Loop (PLL), implemented in α-β coordinates (αβ-PLL), whereas the other one corresponds to the Enhanced PLL (E-PLL). The major contribution of ...
A comprehensive review on modular multilevel converters, submodule topologies, ...
Barros, Luis A. M.; Martins, António P.; Pinto, J. G.The concept of the modular multilevel converter (MLC) has been raising interest in research in order to improve their performance and applicability. The potential of an MLC is enormous, with a great focus on medium- and high-voltage applications, such as solar photovoltaic and wind farms, electrified railway systems, or power distribution systems. This concept makes it possible to overcome the limitation of the...
A comprehensive comparison of voltage and current control techniques for three-...
Fernandes, Daniel F. S.; Costa, Rui F. O.; Barros, Luis A. M.; Pedrosa, D.; Afonso, João L.; Pinto, J. G.Converting electrical energy from direct current to alternate current, or vice versa, is one of the most frequently performed tasks in today’s electrical systems. The Voltage Source Inverter (VSI) is the most widely used topology to accomplish this task. This paper compares the performance of three control algorithms for voltage source inverter (VSI) with PI, PR and MP control algorithms were applied for voltag...
An islanded microgrid to increase quality of life and support agricultural acti...
Coelho, Sérgio; Monteiro, Vítor Duarte Fernandes; Pinto, J. G.; Monteiro, A. Caetano; Mahanjane, Uranio S.; Chilundo, Rosa J.; Martins, Júlio S.This paper deals with the design, sizing, and validation of an islanded microgrid to aid agricultural activities of rural communities, in which a water pumping system (WPS), a set of dc electric loads, and an energy storage system (ESS) are powered by solar photovoltaic (PV) panels. In this regard, four operation modes are considered and validated by performing computer simulations, namely: (i) solar PV panels ...