Improved vehicle-to-home (iV2H) operation mode: experimental analysis of the electric vehicle as off-line UPS

This paper presents experimental results of electric vehicle (EV) operation as an off-line uninterruptible power supply (UPS). Besides the traditional grid-to-vehicle and vehicle-to-grid modes, this paper presents an improved vehicle-to-home operation mode. This new operation mode consists of the detection of a power outage in the power grid and the change of the EV battery charger control to operate as an off-line UPS. When the power grid voltage is restored, the voltage produced by the on-board EV battery charger is slowly synchronized with the power grid voltage before a complete transition to the normal mode. This paper presents results of two algorithms to detect a power outage: the root mean square (rms) calculation method based on half-cycle of the power grid voltage, and the rms estimation based on a Kalman filter. The experimental results were obtained in steady and transient state considering two cases with the EV plugged in at home:when charging the batteries and without charging the batteries. This paper describes the EV battery charger, the power outage detection methods, and the voltage and current control strategies.- This work was supported by the Fundacao para a Ciencia e Tecnologia (FCT) in the scope of the projects under Grant PEst-UID/CEC/00319/2013. The work of V. Monteiro was supported by the Doctoral Scholarship through the Portuguese FCT Agency under Grant SFRH/BD/80155/2011. The work of B. Exposto was supported by the Doctoral Scholarship through the Portuguese FCT Agency under Grant SFRH/BD/87999/2012.info:eu-repo/semantics/publishedVersio

Smart charging system of the electric vehicle CEPIUM

In this paper is presented the development of a smart batteries charging system for the Electric Vehicle (EV) CEPIUM, aiming the integration of EVs in the future Smart Grids. The main features of the developed charging system are the mitigation of the power quality degradation and the bidirectional operation, as Grid-to-Vehicle (G2V) and as Vehicle-to-Grid (V2G). The batteries charging process is controlled by an appropriate control algorithm, aiming to preserve the batteries lifespan. During the charging process (G2V), the consumed current is sinusoidal and the power factor is unitary. Along the discharging process (V2G), when the equipment allows delivering back to the electrical power grid part of the energy stored in the batteries, the current is also sinusoidal.FEDER Funds - Operational Programme for Competitiveness Factors (COMPETE)Fundação para a Ciência e a Tecnologia (FCT) - PTDC/EEA-EEL/104569/2008, MITPT/ EDAM-SMS/0030/2008

Smart charging management for electric vehicle battery chargers

This paper proposes a smart battery charging strategy for Electric Vehicles (EVs) targeting the future smart homes. The proposed strategy consists in regulate the EV battery charging current in function of the total home current, aiming to prevent overcurrent trips in the main switch breaker. Computational and experimental results were obtained under real-time conditions to validate the proposed strategy. For such purpose was adapted a bidirectional EV battery charger prototype to operate in accordance with the aforementioned strategy. The proposed strategy was validated through experimental results obtained both in steady and transient states. The results show the correct operation of the EV battery charger even under heavy load variations.Fundação para a Ciência e Tecnologia within the Project Scope: PEst - OE/EEI/UI0319/201

Comparison of charging systems for electric vehicles and their impact on electrical grid

This paper presents a comparison of four types of on-board batteries charging systems for Electric Vehicles (EVs) and Plug-in Hybrid Electric Vehicles (PHEVs), and their impact on the power quality of the electrical power grid. In the comparison are analyzed the features, the characteristics and the operation of each charging system, aiming their controllability and their impact on the electrical grid, mainly considering the Total Harmonic Distortion (THD) of the consumed current and the power factor. Besides the normal mode of operation to charge the batteries, denominated Grid-to-Vehicle (G2V), in this paper is also discussed the possibility of operation as Vehicle-to-Grid (V2G), in which the batteries of the Electric Vehicle return part of the stored energy back to the electrical grid. The operation of the batteries charging systems for EVs is shown through simulations and experimental results.FEDER Funds - Operational Programme for Competitiveness Factors (COMPETE)Fundação para a Ciência e a Tecnologia (FCT) - PTDC/EEA-EEL/104569/2008, MITPT/EDAM-SMS/0030/200

A novel architecture of a bidirectional bridgeless interleaved converter for EV battery chargers

This paper presents a novel architecture of a bidirectional bridgeless interleaved converter for battery chargers of electric vehicles (EVs). The proposed converter is composed by two power stages: an ac-dc converter that is used to interface the power grid and the dc-link, and a dc-dc converter that is used to interface the dc-link and the batteries. The ac-dc converter is an interleaved bridgeless bidirectional boost-type converter and the dc-dc converter is a bidirectional buck-boost-type converter. The proposed converter works with sinusoidal grid current and with high power factor for all operating power levels, and in both grid-to-vehicle (G2V) and vehicle-to-grid (V2G) operation modes. In the paper is described in detail the proposed converter for EV battery chargers: the circuit topology, the principle of operation, the power control theory, and the current control strategy. Several simulation results for both G2V and V2G operation modes are presented.Fundação para a Ciência e Tecnologia (FCT

Requoting the arcades. Walter Benjamin’s idle robbers

By contrasting Walter Benjamin’s fragmentary theory of quotation to the different ways his work has itself undergone quotation thus far, a new insight can be gained into the perception of the materiality and visuality of texts. The so-called Passagen-Werk, the project on the Parisian Arcades which Benjamin pursued for more than ten years until the end of his life, is the overflowing, yet voided space where this crossing takes place

A novel concept of unidirectional bridgeless combined boost-buck converter for EV battery chargers

This paper presents a novel concept of unidirectional bridgeless combined boost-buck converter for electric vehicles (EVs) battery chargers. The proposed converter is composed by two power stages: an ac-dc front-end converter used to interface the power grid and the dc-link, and a dc-dc back-end converter used to interface the dc-link and the batteries. The ac-dc converter is a bridgeless boost-type converter and the dc-dc converter is an interleaved buck-type converter. The proposed converter operates with sinusoidal grid current and unitary power factor for all operating power levels. Along the paper is described in detail the proposed converter for EV battery chargers: the circuit topology, the different stages describing the principle of operation, the power control theory, and the current control strategy, for both converters. Along the paper are presented several simulation results for a maximum power of 3.5 kW.Fundação para a Ciência e Tecnologia (FCT

Rhythm and Structure: Brecht’s Antigone in performance

Brecht’s adaptation of Sophocles’ Antigone in 1948 was openly a political gesture that aspired to the complete rationalization of Greek Tragedy. From the beginning, Brecht made it his task to wrench ancient tragic poetry out of its “ideological haze”, and proceeded to dismantle and eliminate what he named the “element of fate”, the crucial substance of tragic myth itself. However, his encounter with Hölderlin's unorthodox translation of Antigone, the main source for his appropriation and rewriting of the play, led him to engage in a radical experiment in theatrical practice. From the isolated first performance of Antigone, a model was created – the Antigonemodell – that demanded a direct confrontation with the many obstacles brought about by the foreign structure of Greek tragedy as a whole. In turn, such difficulties brought to light the problem of rhythm in its relation to Brecht’s own ideas of how to perform ancient poetry in a modern setting, as exemplified by the originally alienating figure of the tragic chorus. More importantly, such obstacles put into question his ideas of performance in general, as well as the way they can still resonate in our own understanding of what performance is or might be in a broader sense

Comparison of current-source and voltage-source shunt active power filters for harmonic compensation and reactive power control

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 focuses on the Total Harmonic Distortion (THD) and RMS values of the compensated currents, and in the Total Power Factor (TPF) of the installation.Fundação para a Ciência e a Tecnologia (FCT

Assessment of a battery charger for electric vehicles with reactive power control

Batteries of Electric Vehicles (EVs) and Plug-in Hybrid Electric Vehicles (PHEVs) have a large potential not only to provide energy for the locomotion of these vehicles, but also to interact, in dynamic way, with the power grid. Thereby, through the energy stored in the batteries, these vehicles can be used to regulate the active and the reactive power, as local Energy Storage Systems. This way, EVs can contribute to help the power grid to regulate the active and reactive power flow in order to stabilize the production and consumption of energy. For this propose should be defined usage profiles, controlled by a collaborative broker, taking into account the requirements of the power grid and the conveniences of the vehicle user. Besides, the interface between the power grid and the EVs, instead of using typical power converters that only work on unidirectional mode, need to use bidirectional power converters to charge the batteries (G2V - Grid-to-Vehicle mode) and to deliver part of the stored energy in the batteries back to the power grid (V2G - Vehicle-to-Grid mode). With the bidirectional power converter topology presented in this paper, the consumed current is sinusoidal and it is possible to regulate the power factor to control the reactive power, aiming to contribute to mitigate power quality problems in the power grid. To assess the behavior of the presented bidirectional power converter under different scenarios, are presented some computer simulations and experimental results obtained with a prototype that was developed to be integrated in an Electric Vehicle.Fundação para a Ciência e a Tecnologia (FCT) - FCOMP-01-0124-FEDER-022674, PTDC/EEAEEL/ 104569/2008, MIT-PT/EDAM-SMS/0030/2008.FEDER Funds, through the Operational Programme for Competitiveness Factors (COMPETE