Handmade series direct-current motor

Using common materials, it is possible to build a variety of very simple - and yet functioning - electric devices. These devices can be used to verify Electromagnetism fundamentals. Electric currents within magnetic fields originate forces and that is the basic principle of operation of electric motors. This paper describes a universal series motor made with iron bars, insulated copper wire, two small brass plates, insulating tape, six screws and a couple of hoops. The motor is fed with a personal computer 12V DC switched power supply. Rotor speed can achieve several rotations per second

Electromagnet and switchboard for slewing crane

This paper presents an electromagnet and a switchboard used on a science fair slewing crane described in a separate paper. The electromagnet can lift 50kg loads. The switchboard includes a transformer that powers the electromagnet. It also contains relays, contactors and inverters that allow the operation of the crane three-phase motors using a single-phase power supply. Crane slewing is limited to an 180º angle, for safety reasons. Pressing an emergency button switches off all command circuits. An 8051 microcontroller-based system determines the vertical position of the electromagnet, which cannot be switched off while being on a high position, not even if the emergency button is pressed

Slewing crane with electromagnet

This paper describes a slewing crane with electromagnet, operated by three three-phase induction motors. A switchboard described in a separate paper, which also depicts the electromagnet construction details, drives the motors and the electromagnet. From its seat – mounted on the crane - an operator can make the crane arm slew left or right. The electromagnet can be moved back, forward, up or down. The crane is made of iron, has a height of 3m and a length of 2,5m. Such proportions make it very suitable for science fair events

Real-life comparison between diesel and electric car energy consumption

Vehicle electrification is one of the strategies with higher potential for increasing the efficiency of vehicle powertrains, reducing the dependency on dwindling fossil fuel sources and meeting stringent emissions targets set by policy makers. Despite all the theoretical assessments and manufacturer’s claimed efficiency and emissions records of current vehicles, there is a lack of data concerning real life comparisons of Electric Vehicles (EV) against Internal Combustion Engine (ICE) cars. A test program comparing the energy consumption of an EV and a diesel powered (ICE) car was carried out. Both short (at levelled ground and 6% up hill) and long distance tests were performed for several fixed vehicle speeds. Measurements enabling the assessment of average energy consumption, required power and energy suplied were performed for both vehicles. Results indicate that in terms of vehicle use (Tank to Wheel perspective) the electric powertrain is significantly more energy efficient than the Diesel powertrain, although the difference between the two is less pronounced for higher power events.Fundação para a Ciência e a Tecnologia (FCT) - Project MOBI-MPP (MIT-Pt/EDAM-SMS/0030/2008), SFRH/BPD/51048/2010, SFRH/BPD/89553/2012MIT Portugal Program (EDAM), MOBI-MPP ProjectFEDER - Programa Operacional Factores de Competitividade COMPET

Model predictive current control of a slow battery charger for electric mobility applications

This paper presents a model predictive current control applied to a slow electric vehicle (EV) battery charger. Taking into account the similarities between the power converters inside the EV, it is possible to combine the battery charger and the motor driver in a single integrated converter, thus reducing the weight and volume of the proposed solution, and also contributing to reduce the final price of the EV. Due to the bidirectional power flow capability of the integrated power converter, when working as a slow EV battery charger it can operate in grid-to-vehicle (G2V) mode and in vehicle-to-grid (V2G) mode, contributing to make EVs an important assets in the future smart grids. The integrated power converter working as battery charger operates with sinusoidal current and unitary power factor, contributing to improve the power quality of the electrical grid. This paper provides simulation and experimental results that validate the model predictive control algorithm applied to the proposed integrated power converter working as slow EV battery charger.(undefined)info:eu-repo/semantics/publishedVersio

A case study on the conversion of an internal combustion engine vehicle into an electric vehicle

This paper presents the conversion process of a traditional Internal Combustion Engine vehicle into an Electric Vehicle. The main constitutive elements of the Electric Vehicle are presented. The developed powertrain uses a three-phase inverter with Field Oriented Control and space vector modulation. The developed on-board batteries charging system can operate in Grid-to-Vehicle and Vehicle-to-Grid modes. The implemented prototypes were tested, and experimental results are presented. The assembly of these prototypes in the vehicle was made in accordance with the Portuguese legislation about vehicles conversion, and the main adopted solutions are presented.FCT – Fundação para a Ciência e Tecnologia in the scope of the project: PEst - OE/EEI/UI0319/201

Mobile sensing system for cycling power output control

This paper describes the development of a novel cycling effort control sys-tem that contributes to promote the users’ physical health and mobility. This system controls the motor assistance level of an electric bicycle in order to ensure that the cyclist’s power output remains inside the desired limits, regardless of changes in variables such as the speed of the bicycle or the slope of the terrain. The power output is monitored using a sensor device that provides raw torque and cadence data, whereas a smartphone application processes these data, implements the effort control algorithm and provides the user interface. Modules on the bicycle handle the data acquisition, wire-less communication with the smartphone and driving of the motor assis-tance level. Experimental results validate the effectiveness of the imple-mented power output control system.This work is supported by FCT (Fundação para a Ciência e Tecnologia) with the reference project UID/EEA/04436/2013, and by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941

Digital control of a novel single-phase three-port bidirectional converter to interface renewables and electric vehicles with the power grid

This paper presents the digital control of a novel single-phase three-port bidirectional (STB) converter used to interface renewables from solar photovoltaic (PV) panels and electric vehicles (EVs) with the power grid. Using an appropriated power theory, the STB converter can be used to exchange ener-gy between the PVs, the EVs and the power grid in four distinct modes: (1) The EV receives energy from the power grid (G2V - grid-to-vehicle operation mode) or delivers energy to the power grid (V2G - vehicle-to-grid operation mode); (2) All the energy produced by the PV panels is delivery to the power grid; (3) All the energy produced by the PV panels is delivery to the EV; (4) The EV can receive energy simultaneously from the PV panels and from the power grid (G2V). The currents of the power grid, PV panels and EV are con-trolled through independent predictive current control strategies, which ensure good power quality levels. This paper presents the architecture of the proposed STB converter and the detailed explanation of the digital implementation of the control algorithms, namely, the power theory and the predictive current control strategies. The control algorithms were validated through computational simula-tions and experimental results.Fundação para a Ciência e Tecnologia (FCT); FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER- 006941

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

The impact of poor power quality in solar photovoltaic microgeneration: technical problems and losses of revenue

This paper presents a critical and quantitative analysis of the influence of the Power Quality in grid connected solar photovoltaic microgeneration installations. First are introduced the main regulations and legislation related with the solar photovoltaic microgeneration, in Portugal and Europe. Next are presented Power Quality monitoring results obtained from two residential solar photovoltaic installations located in the north of Portugal, and is explained how the Power Quality events affect the operation of these installations. Afterwards, it is described a methodology to estimate the energy production losses and the impact in the revenue caused by the abnormal operation of the electrical installation. This is done by comparing the amount of energy that was injected into the power grid with the theoretical value of energy that could be injected in normal conditions. The performed analysis shows that Power Quality severally affects the solar photovoltaic installations operation. The losses of revenue in the two monitored installations M1 and M2 are estimated in about 27% and 22%, respectively.CT - Fundação para a Ciência e Tecnologia within scope of the project : PEst- UID/CEC/00319/2013