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Prof. Jose Afonso
CMEMS Research Center, University of Minho, Campus of Azurem, 4800-058 Guimaraes, Portugal

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0 Energy Management
0 Internet of Things
0 Smart Homes
0 Wireless Sensor Networks
0 quality of service

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Smart Homes
Internet of Things
quality of service
Mobile Sensing
Energy Management

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Review
Published: 22 August 2021 in Sustainability
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Power grids are evolving with the aim to guarantee sustainability and higher levels of power quality for universal access to electricity. More specifically, over the last two decades, power grids have been targeted for significant changes, including migration from centralized to decentralized paradigms as a corollary of intensive integration of novel electrical technologies and the availability of derived equipment. This paper addresses a review of a disruptive vision of future power grids, mainly focusing on the use of hybrid AC/DC grids and solid-state transformers technologies. Regarding hybrid AC/DC grids in particular, they are analyzed in detail in the context of unipolar and bipolar DC grids (i.e., two-wire or three-wire DC grids), as well as the different structures concerning coupled and decoupled AC configurations with low-frequency or high-frequency isolation. The contextualization of the possible configurations of solid-state transformers and the different configurations of hybrid transformers (in the perspective of offering benefits for increasing power quality in terms of currents or voltages) is also analyzed within the perspective of the smart transformers. Additionally, the paper also presents unified multi-port systems used to interface various technologies with hybrid AC/DC grids, which are also foreseen to play an important role in future power grids (e.g., the unified interface of renewable energy sources and energy storage systems), including an analysis concerning unified multi-port systems for AC or DC grids. Throughout the paper, these topics are presented and discussed in the context of future power grids. An exhaustive description of these technologies is made, covering the most relevant and recent structures and features that can be developed, as well as the challenges for the future power grids. Several scenarios are presented, encompassing the mentioned technologies, and unveiling a progressive evolution that culminates in the cooperative scope of such technologies for a disruptive vision of future power grids.

ACS Style

Vitor Monteiro; Julio S. Martins; João Carlos Aparício Fernandes; Joao L. Afonso. Review of a Disruptive Vision of Future Power Grids: A New Path Based on Hybrid AC/DC Grids and Solid-State Transformers. Sustainability 2021, 13, 9423 .

AMA Style

Vitor Monteiro, Julio S. Martins, João Carlos Aparício Fernandes, Joao L. Afonso. Review of a Disruptive Vision of Future Power Grids: A New Path Based on Hybrid AC/DC Grids and Solid-State Transformers. Sustainability. 2021; 13 (16):9423.

Chicago/Turabian Style

Vitor Monteiro; Julio S. Martins; João Carlos Aparício Fernandes; Joao L. Afonso. 2021. "Review of a Disruptive Vision of Future Power Grids: A New Path Based on Hybrid AC/DC Grids and Solid-State Transformers." Sustainability 13, no. 16: 9423.

Journal article
Published: 07 June 2021 in Energies
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An electric vehicle (EV) usually has two main power converters, namely one for the motor drive system and another for the battery-charging system. Considering the similarities between both converters, a new unified power converter for motor drive and battery charging of EVs is propounded in this paper. By using a single unified power converter, the cost, volume, and weight of the power electronics are reduced, thus also making possible a reduction in the final price of the EV. Moreover, the proposed unified power converter has the capability of bidirectional power flow. During operation in traction mode, the unified power converter controls motor driving and regenerative braking. Additionally, during operation in battery-charging mode, with the EV plugged into the electrical power grid, the unified power converter controls the power flow for slow or fast battery charging (grid-to-vehicle (G2V) mode), or for discharging of the batteries (vehicle-to-grid (V2G) mode). Specifically, this paper presents computer simulations and experimental validations for operation in both motor-driving and slow battery-charging mode (in G2V and V2G modes). It is demonstrated that the field-oriented control used in the traction system presents good performance for different values of mechanical load and that the battery-charging system operates with high levels of power quality, both in G2V and in V2G mode.

ACS Style

Delfim Pedrosa; Vitor Monteiro; Tiago Sousa; Luis Machado; Joao Afonso. Unified Power Converter Based on a Dual-Stator Permanent Magnet Synchronous Machine for Motor Drive and Battery Charging of Electric Vehicles. Energies 2021, 14, 3344 .

AMA Style

Delfim Pedrosa, Vitor Monteiro, Tiago Sousa, Luis Machado, Joao Afonso. Unified Power Converter Based on a Dual-Stator Permanent Magnet Synchronous Machine for Motor Drive and Battery Charging of Electric Vehicles. Energies. 2021; 14 (11):3344.

Chicago/Turabian Style

Delfim Pedrosa; Vitor Monteiro; Tiago Sousa; Luis Machado; Joao Afonso. 2021. "Unified Power Converter Based on a Dual-Stator Permanent Magnet Synchronous Machine for Motor Drive and Battery Charging of Electric Vehicles." Energies 14, no. 11: 3344.

Research article
Published: 02 February 2021 in International Transactions on Electrical Energy Systems
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This article presents a power management system (PMS) designed for smart homes aiming to deal with the new challenges imposed by the proliferation of plug‐in electric vehicles (EVs) and their coexistence with other residential electrical appliances. The PMS is based on a hybrid wireless network architecture composed by a local hub/gateway and several Bluetooth Low Energy (BLE) and Wi‐Fi sensor/actuator devices. These wireless devices are used to transfer information inside the smart home using the Message Queuing Telemetry Transport (MQTT) protocol. Based on the proposed solution, the current consumption of the EV battery charger and other residential electrical appliances are dynamically monitored and controlled by using a configurable algorithm, ensuring that the total current consumption does not cause the tripping of the home circuit breaker. An Android client application allows the user to monitor and configure the system operation in real‐time, a developed Wi‐Fi smart plug permits to measure the RMS values of current of the connected electrical appliance and change its state of operation remotely, and an EV battery charger may be controlled in terms of operating power according to set‐points received from the Android client application. Experimental tests are used to evaluate the quality of service provided by the developed smart home platform in terms of communication delay and reliability. An experimental validation for different conditions of operation of the proposed smart home PMS concerning the power operation of the EV battery charger with the proposed control algorithm is also presented.

ACS Style

Ruben E. Figueiredo; Vitor Monteiro; Joao C. Ferreira; Joao L. Afonso; Jose A. Afonso. Smart home power management system for electric vehicle battery charger and electrical appliance control. International Transactions on Electrical Energy Systems 2021, 31, e12812 .

AMA Style

Ruben E. Figueiredo, Vitor Monteiro, Joao C. Ferreira, Joao L. Afonso, Jose A. Afonso. Smart home power management system for electric vehicle battery charger and electrical appliance control. International Transactions on Electrical Energy Systems. 2021; 31 (4):e12812.

Chicago/Turabian Style

Ruben E. Figueiredo; Vitor Monteiro; Joao C. Ferreira; Joao L. Afonso; Jose A. Afonso. 2021. "Smart home power management system for electric vehicle battery charger and electrical appliance control." International Transactions on Electrical Energy Systems 31, no. 4: e12812.

Journal article
Published: 18 January 2021 in Energies
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Rail power conditioner (RPC) has the ability to improve the power quality in AC railway power grids. This power conditioner can increase the loading capacity of traction substations, balance the active power between the feeder load sections, and compensate for reactive power and current harmonics. At present, there is increasing use of multilevel converter topologies, which provide scalability and robust performance under different conditions. In this framework, modular multilevel converter (MMC) is emerging as a prominent solution for medium-voltage applications. Serving that purpose, this paper focuses on the implementation, testing, and validation of a reduced-scale laboratory prototype of a proposed RPC based on an MMC. The developed laboratory prototype, designed to be compact, reliable, and adaptable to multipurpose applications, is presented, highlighting the main control and power circuit boards of the MMC. In addition, MMC parameter design of the filter inductor and submodule capacitor is also explained. Experimental analysis and validation of a reduced-scale prototype RPC based on MMC topology, are provided to verify the power quality improvement in electrified railway power grids. Thus, two experimental case studies are presented: (1) when both of the load sections are unequally loaded; (2) when only one load section is loaded. Experimental results confirm the RPC based on MMC is effective in reducing the harmonic contents, solving the problem of three-phase current imbalance and compensating reactive power.

ACS Style

Mohamed Tanta; Jose Cunha; Luis A. M. Barros; Vitor Monteiro; José Gabriel Oliveira Pinto; Antonio P. Martins; Joao L. Afonso. Experimental Validation of a Reduced-Scale Rail Power Conditioner Based on Modular Multilevel Converter for AC Railway Power Grids. Energies 2021, 14, 484 .

AMA Style

Mohamed Tanta, Jose Cunha, Luis A. M. Barros, Vitor Monteiro, José Gabriel Oliveira Pinto, Antonio P. Martins, Joao L. Afonso. Experimental Validation of a Reduced-Scale Rail Power Conditioner Based on Modular Multilevel Converter for AC Railway Power Grids. Energies. 2021; 14 (2):484.

Chicago/Turabian Style

Mohamed Tanta; Jose Cunha; Luis A. M. Barros; Vitor Monteiro; José Gabriel Oliveira Pinto; Antonio P. Martins; Joao L. Afonso. 2021. "Experimental Validation of a Reduced-Scale Rail Power Conditioner Based on Modular Multilevel Converter for AC Railway Power Grids." Energies 14, no. 2: 484.

Journal article
Published: 21 December 2020 in ISA Transactions
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In this work, the design and development of a new variable linear power supply, using the LM317 regulator, is proposed. The originality of this power supply is related with the control of the rectifier circuit, which is based on a reference of voltage, superimposed on the output voltage. This reference is used in the control strategy to maintain a constant voltage between the input and the output voltages of the LM317 regulator. Due to this strategy, the heating losses are greatly reduced, allowing to increase the efficiency of the regulator to about 90%, and to reduce the requirements of the cooling system. Moreover, drawbacks of conventional power supplies are mitigated, where the developed variable linear power supply delivers a current of 3 A and a variable output voltage, from 1.2 V to 30 V. The LM317 regulator was modeled by its thermal equivalent structure associated with a heatsink to study the heat transfer problem. The modeling was performed on the Matlab Simulink software, and the theoretical results were validated by a set of experimental tests using the LM317 regulator.

ACS Style

Amira Haddouk; Khaoula Khlifi; Vitor Monteiro; Joao L. Afonso; Hfaiedh Mechergui. Power losses reduction in a variable linear power supply using the LM317 voltage regulator. ISA Transactions 2020, 112, 402 -408.

AMA Style

Amira Haddouk, Khaoula Khlifi, Vitor Monteiro, Joao L. Afonso, Hfaiedh Mechergui. Power losses reduction in a variable linear power supply using the LM317 voltage regulator. ISA Transactions. 2020; 112 ():402-408.

Chicago/Turabian Style

Amira Haddouk; Khaoula Khlifi; Vitor Monteiro; Joao L. Afonso; Hfaiedh Mechergui. 2020. "Power losses reduction in a variable linear power supply using the LM317 voltage regulator." ISA Transactions 112, no. : 402-408.

Review
Published: 01 December 2020 in Energies
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Concerns about greenhouse gas emissions are a key topic addressed by modern societies worldwide. As a contribution to mitigate such effects caused by the transportation sector, the full adoption of electric mobility is increasingly being seen as the main alternative to conventional internal combustion engine (ICE) vehicles, which is supported by positive industry indicators, despite some identified hurdles. For such objective, power electronics technologies play an essential role and can be contextualized in different purposes to support the full adoption of electric mobility, including onboard and offboard battery charging systems, inductive wireless charging systems, unified traction and charging systems, new topologies with innovative operation modes for supporting the electrical power grid, and innovative solutions for electrified railways. Embracing all of these aspects, this paper presents a review on power electronics technologies for electric mobility where some of the main technologies and power electronics topologies are presented and explained. In order to address a broad scope of technologies, this paper covers road vehicles, lightweight vehicles and railway vehicles, among other electric vehicles.

ACS Style

Joao L. Afonso; Luiz A. Lisboa Cardoso; Delfim Pedrosa; Tiago J. C. Sousa; Luis Machado; Mohamed Tanta; Vitor Monteiro. A Review on Power Electronics Technologies for Electric Mobility. Energies 2020, 13, 6343 .

AMA Style

Joao L. Afonso, Luiz A. Lisboa Cardoso, Delfim Pedrosa, Tiago J. C. Sousa, Luis Machado, Mohamed Tanta, Vitor Monteiro. A Review on Power Electronics Technologies for Electric Mobility. Energies. 2020; 13 (23):6343.

Chicago/Turabian Style

Joao L. Afonso; Luiz A. Lisboa Cardoso; Delfim Pedrosa; Tiago J. C. Sousa; Luis Machado; Mohamed Tanta; Vitor Monteiro. 2020. "A Review on Power Electronics Technologies for Electric Mobility." Energies 13, no. 23: 6343.

Journal article
Published: 10 September 2020 in Electronics
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This paper presents the design, implementation, and testing of a wireless communication system for automatic identification of e-bikes and management of their battery charging in the context of dynamic inductive wireless power transfer (DIWPT) lanes. The proposed system checks if an e-bike, uniquely identified by its RFID tag, is authorized to receive energy from the lane coils and acts accordingly. An authentication mechanism was developed based on the use of embedded Wi-Fi boards attached to the coils and communicating with a central HTTP server with a MySQL database. The developed management system also provides other features, such as the recording of the number of lane coils used by each e-bike for billing purposes. The results from experimental tests on a laboratory prototype were used to validate the developed functionalities and assess the quality of service provided by the proposed system.

ACS Style

Jose A. Afonso; Helder G. Duarte; Luiz A. Lisboa Cardoso; Vitor Monteiro; Joao L. Afonso. Wireless Communication and Management System for E-Bike Dynamic Inductive Power Transfer Lanes. Electronics 2020, 9, 1485 .

AMA Style

Jose A. Afonso, Helder G. Duarte, Luiz A. Lisboa Cardoso, Vitor Monteiro, Joao L. Afonso. Wireless Communication and Management System for E-Bike Dynamic Inductive Power Transfer Lanes. Electronics. 2020; 9 (9):1485.

Chicago/Turabian Style

Jose A. Afonso; Helder G. Duarte; Luiz A. Lisboa Cardoso; Vitor Monteiro; Joao L. Afonso. 2020. "Wireless Communication and Management System for E-Bike Dynamic Inductive Power Transfer Lanes." Electronics 9, no. 9: 1485.

Journal article
Published: 25 August 2020 in Energies
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In AC railway electrification systems, the impact of reactive power flow in the feeding voltage magnitude is one aspect contributing to the quality of supply degradation. Specifically, this issue results in limitations in the infrastructure capacity, either in the maximum number of trains and in maximum train power. In this paper, two reactive power compensation strategies are presented and compared, in terms of the theoretical railway infrastructure capacity. The first strategy considers a static VAR compensator, located in the neutral zone and compensating the substation reactive power, achieving a maximum capacity increase up to 50% without depending on each train active power. The second strategy adapts each train reactive power, achieving also a capacity increase around 50%, only with an increase of the train apparent power below 10%. With a smart metering infrastructure, the implementation of such compensation strategy is viable, satisfying the requirements of real-time knowledge of the railway electrification system state. Specifically, the usage of droop curves to adapt in real time the compensation scheme can bring the operation closer to optimality. Thus, the quality of supply and the infrastructure capacity can be increased with a mobile reactive power compensation scheme, based on a smart metering framework.

ACS Style

Vítor A. Morais; João L. Afonso; Adriano S. Carvalho; António P. Martins. New Reactive Power Compensation Strategies for Railway Infrastructure Capacity Increasing. Energies 2020, 13, 4379 .

AMA Style

Vítor A. Morais, João L. Afonso, Adriano S. Carvalho, António P. Martins. New Reactive Power Compensation Strategies for Railway Infrastructure Capacity Increasing. Energies. 2020; 13 (17):4379.

Chicago/Turabian Style

Vítor A. Morais; João L. Afonso; Adriano S. Carvalho; António P. Martins. 2020. "New Reactive Power Compensation Strategies for Railway Infrastructure Capacity Increasing." Energies 13, no. 17: 4379.

Journal article
Published: 04 August 2020 in Energies
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This paper proposes a novel multifunctional isolated microinverter which is able to extract the maximum available power from a solar photovoltaic module and inject it into the power grid, while simultaneously charging a battery energy storage system (BESS). The proposed microinverter integrates a novel DC–DC power converter and a conventional DC–AC power converter. The DC–DC power converter is able to send electrical energy to the secondary side of a high-frequency transformer and to the BESS, using only two power switches. Throughout this paper, the converter topology, the operation modes, the control algorithms, and the development of a laboratory prototype of the proposed microinverter are described in detail. Moreover, simulation and experimental results are presented to demonstrate the feasibility of the proposed solution.

ACS Style

Luis A. M. Barros; Mohamed Tanta; Tiago J. C. Sousa; Joao L. Afonso; J. G. Pinto. New Multifunctional Isolated Microinverter with Integrated Energy Storage System for PV Applications. Energies 2020, 13, 4016 .

AMA Style

Luis A. M. Barros, Mohamed Tanta, Tiago J. C. Sousa, Joao L. Afonso, J. G. Pinto. New Multifunctional Isolated Microinverter with Integrated Energy Storage System for PV Applications. Energies. 2020; 13 (15):4016.

Chicago/Turabian Style

Luis A. M. Barros; Mohamed Tanta; Tiago J. C. Sousa; Joao L. Afonso; J. G. Pinto. 2020. "New Multifunctional Isolated Microinverter with Integrated Energy Storage System for PV Applications." Energies 13, no. 15: 4016.

Review
Published: 01 May 2020 in Energies
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Electric locomotives in AC traction power systems represent a huge single-phase non-linear load and, detrimentally, affect the power quality and the efficiency of the three-phase power grid. Nevertheless, along the last decades, power electronics are being used to mitigate power quality problems in the three-phase power grid. In particular, Rail Power Conditioner (RPC) helps to increase the loading capacity of traction substations and improve the power quality of three-phase power grids. As the main characteristics, an RPC can supply reactive power, suppress current harmonics and overcome currents imbalance of the three-phase power grid. On the other hand, the traction substations may be constituted by different types of power transformers. For instance, single-phase power transformers and open-delta (V/V) power transformers are widely used, while Scott power transformers are less frequently used, since they are more complex and expensive. In this framework, this work presents a review study of RPC topologies, including their operation modes, and a comprehensive comparison between the characteristics of the RPC topologies when using different types of AC traction substations and power transformers. This helps to ensure the correct selection of the RPC topology for a specific application, according to the main structure of the traction substation. Consequently, and based on the established review, it is possible to sort and allocate each RPC topology for limited or wider applications.

ACS Style

Mohamed Tanta; José Gabriel Pinto; Vitor Monteiro; Antonio P. Martins; Adriano S. Carvalho; Joao L. Afonso. Topologies and Operation Modes of Rail Power Conditioners in AC Traction Grids: Review and Comprehensive Comparison. Energies 2020, 13, 2151 .

AMA Style

Mohamed Tanta, José Gabriel Pinto, Vitor Monteiro, Antonio P. Martins, Adriano S. Carvalho, Joao L. Afonso. Topologies and Operation Modes of Rail Power Conditioners in AC Traction Grids: Review and Comprehensive Comparison. Energies. 2020; 13 (9):2151.

Chicago/Turabian Style

Mohamed Tanta; José Gabriel Pinto; Vitor Monteiro; Antonio P. Martins; Adriano S. Carvalho; Joao L. Afonso. 2020. "Topologies and Operation Modes of Rail Power Conditioners in AC Traction Grids: Review and Comprehensive Comparison." Energies 13, no. 9: 2151.

Journal article
Published: 11 April 2020 in Energies
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This paper presents the analysis and experimental validation of a single-phase off-board multi-functional electric vehicle (EV) charging station (MF-EVCS), which has a single ac interface and two dc interfaces. As innovative aspects, the proposed MF-EVCS handles the interface of the ac power grid, the dc interface of a renewable energy source (RES), as well as the dc interface of an EV to perform dc charging or discharging of the batteries (in off-board grid-to-vehicle (G2V) or vehicle-to-grid (V2G) modes). Considering the power grid, the individual operation modes of the RES and the EV interfaces can be considered. Moreover, a combination of these modes is also possible. Besides, the MF-EVCS has as key innovative aspect the possibility of operating as an active power filter (APF), supporting the operation with reactive power and/or selected current harmonics. This possibility can be associated with any of the previous mentioned modes. These new features are framed in two distinct scenarios: in a smart home, where the ac-side current can be determined as a function of the other electrical appliances; in a smart grid, where the ac-side current can be determined as a requisite of the power grid. The proposed power theory, as well as the current control strategies for both ac-side and dc-side of the MF-EVCS, are presented in the paper for all the possible operation scenarios. A laboratory prototype was developed to validate the proposed MF-EVCS and the experimental results confirm its suitability for smart homes.

ACS Style

Vitor Monteiro; Pedro Lima; Tiago J. C. Sousa; Julio S. Martins; Joao L. Afonso. An Off-Board Multi-Functional Electric Vehicle Charging Station for Smart Homes: Analysis and Experimental Validation. Energies 2020, 13, 1864 .

AMA Style

Vitor Monteiro, Pedro Lima, Tiago J. C. Sousa, Julio S. Martins, Joao L. Afonso. An Off-Board Multi-Functional Electric Vehicle Charging Station for Smart Homes: Analysis and Experimental Validation. Energies. 2020; 13 (8):1864.

Chicago/Turabian Style

Vitor Monteiro; Pedro Lima; Tiago J. C. Sousa; Julio S. Martins; Joao L. Afonso. 2020. "An Off-Board Multi-Functional Electric Vehicle Charging Station for Smart Homes: Analysis and Experimental Validation." Energies 13, no. 8: 1864.

Conference paper
Published: 09 April 2020 in Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering
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The huge power requirements of future railway transportation systems require the usage of energy efficient strategies towards a more intelligent railway system. With the usage of on-board energy storage systems, it is possible to increase the energy efficiency of railways. In this paper, a top-level charging controller for the on-board energy storage system is proposed based on a fuzzy logic controller. As an optimization procedure to increase the energy efficiency of such charging controller, a genetic algorithm meta-heuristic is used to automatically tune the fuzzy rules weight. To validate the proposed controller, two sets of rules were defined, one considering only known rules and the other also considering all possible combinations of rules. As global results, the reduction of regenerated energy reached 30%, and the net energy consumption reduction is near 10%.

ACS Style

Vítor A. Morais; João L. Afonso; António P. Martins; Vítor A. Morais. Towards Smart Railways: A Charging Strategy for On-Board Energy Storage Systems. Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2020, 33 -46.

AMA Style

Vítor A. Morais, João L. Afonso, António P. Martins, Vítor A. Morais. Towards Smart Railways: A Charging Strategy for On-Board Energy Storage Systems. Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering. 2020; ():33-46.

Chicago/Turabian Style

Vítor A. Morais; João L. Afonso; António P. Martins; Vítor A. Morais. 2020. "Towards Smart Railways: A Charging Strategy for On-Board Energy Storage Systems." Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering , no. : 33-46.

Conference paper
Published: 01 April 2020 in 2020 IEEE International Conference on Autonomous Robot Systems and Competitions (ICARSC)
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On this paper a vision-based contact- and markerless method for gait evaluation is proposed, and validated in different experimental setups against commercial motion capture systems (Vicon) and inertial gait analysis tools (GaitShoes). While the development goal is its integration on the ASBGo Smart Walker platform, only an inexpensive depth camera is required. It is shown to have reasonable results when computing gait metrics in real time, in different experimental setups, from different walker types, vision hardware and walking scenarios. Performance is evaluated through RMSD values for several gait metrics. Results illustrate that the proposed approach can be a valuable non-invasive, contactless and low cost alternative to gait analysis systems used in clinical rehabilitation environments.

ACS Style

Joao Andre; João Pedro Mendes Lopes; Manuel Palermo; Diogo Goncalves; Ana Matias; Fatima Pereira; Jose Afonso; Eurico Seabra; Joao Cerqueira; Cristina Santos. Markerless Gait Analysis Vision System for Real-time Gait Monitoring. 2020 IEEE International Conference on Autonomous Robot Systems and Competitions (ICARSC) 2020, 269 -274.

AMA Style

Joao Andre, João Pedro Mendes Lopes, Manuel Palermo, Diogo Goncalves, Ana Matias, Fatima Pereira, Jose Afonso, Eurico Seabra, Joao Cerqueira, Cristina Santos. Markerless Gait Analysis Vision System for Real-time Gait Monitoring. 2020 IEEE International Conference on Autonomous Robot Systems and Competitions (ICARSC). 2020; ():269-274.

Chicago/Turabian Style

Joao Andre; João Pedro Mendes Lopes; Manuel Palermo; Diogo Goncalves; Ana Matias; Fatima Pereira; Jose Afonso; Eurico Seabra; Joao Cerqueira; Cristina Santos. 2020. "Markerless Gait Analysis Vision System for Real-time Gait Monitoring." 2020 IEEE International Conference on Autonomous Robot Systems and Competitions (ICARSC) , no. : 269-274.

Journal article
Published: 08 March 2020 in Applied Sciences
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This paper presents a deadbeat predictive current control methodology to reduce the circulating currents in a modular multilevel converter (MMC) when it operates as a rail power conditioner (RPC) in a conventional railway system-based V/V connection. For this purpose, a half-bridge MMC based on half-bridge submodules, operating as an RPC is explained, and the total system is denominated as a simplified rail power conditioner (SRPC). The SRPC in this study is used to compensate harmonics, reactive power, and the negative sequence component of currents. This paper explains the SRPC system architecture, the key control algorithms, and the deadbeat predictive current control methodology. Mathematical analysis, based on the MMC equivalent circuit, is described and the reference equations are presented. Moreover, simulation results of the deadbeat predictive current control methodology are compared with the results of the conventional proportional-integral (PI) controller. This comparison is to verify the effectiveness of the proposed control strategy. Simulation results of the SRPC show reduced circulating currents in the MMC phases when using the predictive control approach, besides accomplishing power quality improvement at the three-phase power grid side.

ACS Style

Mohamed Tanta; J. G. Pinto; Vitor Monteiro; Antonio P. Martins; Adriano S. Carvalho; Joao L. Afonso. Deadbeat Predictive Current Control for Circulating Currents Reduction in a Modular Multilevel Converter Based Rail Power Conditioner. Applied Sciences 2020, 10, 1849 .

AMA Style

Mohamed Tanta, J. G. Pinto, Vitor Monteiro, Antonio P. Martins, Adriano S. Carvalho, Joao L. Afonso. Deadbeat Predictive Current Control for Circulating Currents Reduction in a Modular Multilevel Converter Based Rail Power Conditioner. Applied Sciences. 2020; 10 (5):1849.

Chicago/Turabian Style

Mohamed Tanta; J. G. Pinto; Vitor Monteiro; Antonio P. Martins; Adriano S. Carvalho; Joao L. Afonso. 2020. "Deadbeat Predictive Current Control for Circulating Currents Reduction in a Modular Multilevel Converter Based Rail Power Conditioner." Applied Sciences 10, no. 5: 1849.

Chapter
Published: 21 January 2020 in Electric Vehicles in Energy Systems
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Concerns about climate changes and environmental air pollution are leading to the adoption of new technologies for transportation, mainly based on vehicle electrification and the interaction with smart grids, and also with the introduction of renewable energy sources (RES) accompanied by energy storage systems (ESS). For these three fundamental pillars, new power electronics technologies are emerging to transform the electrical power grid, targeting a flexible and collaborative operation. As a distinctive factor, the vehicle electrification has stimulated the presence of new technologies in terms of power management, both for smart homes and smart grids. As the title indicates, this book chapter focuses on the role of off-board EV battery chargers in terms of operation modes and contextualization for smart homes and smart grids in terms of opportunities. Based on a review of on-board and off-board EV battery charging systems (EV-BCS), this chapter focus on the off-board EV-BCS framed with RES and ESS as a dominant system in future smart homes. Contextualizing these aspects, three distinct cases are considered: (1) An ac smart home using separate power converters, according to the considered technologies; (2) A hybrid ac and dc smart home with an off-board EV-BCS interfacing RES and ESS, and with the electrical appliances plugged-in to the ac power grid; (3) A dc smart home using a unified off-board EV-BCS with a single interface for the electrical power grid, and with multiple dc interfaces (RES, ESS, and electrical appliances). The results for each case are obtained in terms of efficiency and power quality, demonstrating that the off-board EV-BCS, as a unified structure for smart homes, presents better results. Besides, the off-board EV-BCS can also be used as an important asset for the smart grid, even when the EV is not plugged-in at the smart home.

ACS Style

Vitor Monteiro; Jose Afonso; Tiago Sousa; Joao L. Afonso. The Role of Off-Board EV Battery Chargers in Smart Homes and Smart Grids: Operation with Renewables and Energy Storage Systems. Electric Vehicles in Energy Systems 2020, 47 -72.

AMA Style

Vitor Monteiro, Jose Afonso, Tiago Sousa, Joao L. Afonso. The Role of Off-Board EV Battery Chargers in Smart Homes and Smart Grids: Operation with Renewables and Energy Storage Systems. Electric Vehicles in Energy Systems. 2020; ():47-72.

Chicago/Turabian Style

Vitor Monteiro; Jose Afonso; Tiago Sousa; Joao L. Afonso. 2020. "The Role of Off-Board EV Battery Chargers in Smart Homes and Smart Grids: Operation with Renewables and Energy Storage Systems." Electric Vehicles in Energy Systems , no. : 47-72.

Journal article
Published: 07 January 2020 in EAI Endorsed Transactions on Energy Web
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ACS Style

Zakariae Jebroni; Jose Afonso; Belkassem Tidhaf. Smart Home Energy Management System based on a Hybrid Wireless Network Architecture. EAI Endorsed Transactions on Energy Web 2020, 7, 1 .

AMA Style

Zakariae Jebroni, Jose Afonso, Belkassem Tidhaf. Smart Home Energy Management System based on a Hybrid Wireless Network Architecture. EAI Endorsed Transactions on Energy Web. 2020; 7 (25):1.

Chicago/Turabian Style

Zakariae Jebroni; Jose Afonso; Belkassem Tidhaf. 2020. "Smart Home Energy Management System based on a Hybrid Wireless Network Architecture." EAI Endorsed Transactions on Energy Web 7, no. 25: 1.

Journal article
Published: 01 January 2020 in Electronics
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The earliest and simplest impedance compensation technique used in inductive wireless power transfer (WPT) design is the series-series (SS) compensation circuit, which uses capacitors in series with both primary and secondary coils of an air-gapped transformer. Despite of its simplicity at the resonant condition, this configuration exhibits a major sensitivity to variations of the load attached to the secondary, especially when higher coupling coefficients are used in the design. In the extreme situation that the secondary coil is left at open circuit, the current at the primary coil may increase above the safety limits for either the power converter driving the primary coil or the components in the primary circuit, including the coil itself. An approach often used to minimize this problem is detuning, but this also reduces the electrical efficiency of the power transfer. In low power, fixed-distance stationary WPT, a fair trade-off between efficiency and safety must be verified. This paper aims to consolidate a simple design procedure for such a SS-compensation, exemplifying its use in the prototype of a WPT system for automotive light detection and ranging (LiDAR) equipment. The guidelines herein provided should equally apply to other low power applications.

ACS Style

Luiz A. Lisboa Cardoso; Vítor Monteiro; José Gabriel Pinto; Miguel Nogueira; Adérito Abreu; José A. Afonso; João L. Afonso. Design of an Intrinsically Safe Series-Series Compensation WPT System for Automotive LiDAR. Electronics 2020, 9, 86 .

AMA Style

Luiz A. Lisboa Cardoso, Vítor Monteiro, José Gabriel Pinto, Miguel Nogueira, Adérito Abreu, José A. Afonso, João L. Afonso. Design of an Intrinsically Safe Series-Series Compensation WPT System for Automotive LiDAR. Electronics. 2020; 9 (1):86.

Chicago/Turabian Style

Luiz A. Lisboa Cardoso; Vítor Monteiro; José Gabriel Pinto; Miguel Nogueira; Adérito Abreu; José A. Afonso; João L. Afonso. 2020. "Design of an Intrinsically Safe Series-Series Compensation WPT System for Automotive LiDAR." Electronics 9, no. 1: 86.

Conference paper
Published: 01 October 2019 in IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society
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The Modular Multilevel Converter (MMC) has become progressively an attractive solution for the medium-power and the high-power applications, due to its modularity, flexibility of redundancy or scalability, high efficiency and low production of harmonic contents. However, in order to have a reliable and robust MMC system, different concerns should be observed in terms of the converter control complexity and the required effective protection system. In this context, this paper presents a novel hardware protection topology for the MMC half-bridge submodule. The introduced scheme is based on new sensors technology that can be assembled near the power hardware, resulting in less perturbation and a very low signal delay. This allows the protection system to respond quickly to fault situations. The proposed protection scheme of half-bridge MMC submodules is a new contribution given the steadily increasing popularity of the MMC and that just a few scientific publications treat in detail the protection mechanisms of half-bridge submodules for MMC. The experimental results confirm the effectiveness of the proposed scheme after creating the fault overvoltage and overcurrent conditions on one MMC half-bridge submodule.

ACS Style

Mohamed Tanta; Jose Cunha; Vitor Monteiro; Antonio P. Martins; Adriano S. Carvalho; Joao L. Afonso. A Novel Hardware Protection Scheme for a Modular Multilevel Converter Half-Bridge Submodule. IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society 2019, 1, 6043 -6048.

AMA Style

Mohamed Tanta, Jose Cunha, Vitor Monteiro, Antonio P. Martins, Adriano S. Carvalho, Joao L. Afonso. A Novel Hardware Protection Scheme for a Modular Multilevel Converter Half-Bridge Submodule. IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society. 2019; 1 ():6043-6048.

Chicago/Turabian Style

Mohamed Tanta; Jose Cunha; Vitor Monteiro; Antonio P. Martins; Adriano S. Carvalho; Joao L. Afonso. 2019. "A Novel Hardware Protection Scheme for a Modular Multilevel Converter Half-Bridge Submodule." IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society 1, no. : 6043-6048.

Conference paper
Published: 01 September 2019 in 2019 International Conference on Smart Energy Systems and Technologies (SEST)
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This paper presents a comparative analysis of power electronics topologies that can be used to interface dc homes with a 230 V, 50 Hz ac power grid. Dc homes represent an essential asset for smart grids, since energy storage systems and renewable energy sources, such as photovoltaic solar panels, operate in dc, as well as most of the electrical appliances used in domestic scenario. However, since the power grid operates in ac, it is necessary to convert voltage from ac to dc to properly supply a dc home. This conversion can be accomplished in several ways, with different power conversion stages. In this context, this paper analyzes three different possibilities that can be used to perform the interface between the ac power grid and a dc home: (1) ac-dc converter using a low frequency transformer; (2) ac-dc and dc-dc converters using a high frequency transformer; (3) ac-ac and ac-dc converters using a medium frequency transformer. These three possibilities are compared in terms of efficiency, total power factor and total harmonic distortion of the ac power grid. The results were obtained by means of a simulation model based on the internal parameters of the power semiconductors.

ACS Style

Tiago J. C. Sousa; Vitor Monteiro; Julio S. Martins; M. J. Sepulveda; Antonio Lima; Joao L. Afonso. Comparative Analysis of Power Electronics Topologies to Interface dc Homes with the Electrical ac Power Grid. 2019 International Conference on Smart Energy Systems and Technologies (SEST) 2019, 1 -6.

AMA Style

Tiago J. C. Sousa, Vitor Monteiro, Julio S. Martins, M. J. Sepulveda, Antonio Lima, Joao L. Afonso. Comparative Analysis of Power Electronics Topologies to Interface dc Homes with the Electrical ac Power Grid. 2019 International Conference on Smart Energy Systems and Technologies (SEST). 2019; ():1-6.

Chicago/Turabian Style

Tiago J. C. Sousa; Vitor Monteiro; Julio S. Martins; M. J. Sepulveda; Antonio Lima; Joao L. Afonso. 2019. "Comparative Analysis of Power Electronics Topologies to Interface dc Homes with the Electrical ac Power Grid." 2019 International Conference on Smart Energy Systems and Technologies (SEST) , no. : 1-6.

Conference paper
Published: 01 September 2019 in 2019 International Conference on Smart Energy Systems and Technologies (SEST)
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This paper presents the sliding mode control (SMC) applied to an innovative active rectifier. This proposed active rectifier is constituted by a single-switch, and operates with three voltage levels, evidencing a set of advantages when compared with conventional approaches of power factor correction topologies. Taking into account the diversity of applications for this type of power converter, the SMC is used in order to obtain a robust current tracking. Since the active rectifier is controlled according to the ac grid-side current, the error between such current and its reference is determined, and by employing the SMC, this error is minimized during each sampling period with the objective of selecting the state of the single-switch. A comprehensive description about the SMC implementation, supported by the overall operation of the active rectifier, is presented throughout the paper. The obtained computational results for a set of different operating conditions, comprising significant power ranges and sudden variations, confirm the accurate application of the SMC when applied to the proposed single-switch three-level active rectifier. A comparison is also established with other current control, allowing to confirm the precise application of the SMC strategy.

ACS Style

Vitor Monteiro; Tiago J. C. Sousa; Julio S. Martins; M. J. Sepulveda; Carlos Couto; Joao L. Afonso. Sliding Mode Control of an Innovative Single-Switch Three-Level Active Rectifier. 2019 International Conference on Smart Energy Systems and Technologies (SEST) 2019, 1 -6.

AMA Style

Vitor Monteiro, Tiago J. C. Sousa, Julio S. Martins, M. J. Sepulveda, Carlos Couto, Joao L. Afonso. Sliding Mode Control of an Innovative Single-Switch Three-Level Active Rectifier. 2019 International Conference on Smart Energy Systems and Technologies (SEST). 2019; ():1-6.

Chicago/Turabian Style

Vitor Monteiro; Tiago J. C. Sousa; Julio S. Martins; M. J. Sepulveda; Carlos Couto; Joao L. Afonso. 2019. "Sliding Mode Control of an Innovative Single-Switch Three-Level Active Rectifier." 2019 International Conference on Smart Energy Systems and Technologies (SEST) , no. : 1-6.