Axial strategy for ultraprecise single point cutting of V-grooves Case 1: constant chip thickness

47th SME North American Manufacturing Research Conference, NAMRC 47, June 10-14, 2019, Pennsylvania, US

Reduction of cutting forces by elliptical vibration in multi-pass ultraprecise single point axial cutting of V-grooves

48th SME North American Manufacturing Research Conference, NAMRC 48 (Cancelled due to COVID-19

Strategies for Ultraprecise Single Point Cutting of V-grooves

V-groove microstructures have found numerous functionalization applications in mechanical, electronic, photonic, biomechanical and optical components. However, despite their wide use, the manufacturing processes associated with their fabrication are limited to axial strategies with a constant depth of cut that do not allow the control of the cutting force and cutting time, and therefore leading to significant micro-burrs as well as an inability to fabricate high aspect ratio grooves. The current thesis addresses this problem with the development of three cutting strategies that make use of a single point cutting process. The study to be detailed herein includes analytical, numerical and experimental approaches with respect to cross-sectional area calculations, tool path planning, finite element modelling as well as experimental measurements of the cutting force and surface roughness. The results revealed that a relationship exists between the number of passes/depth of cut and the magnitude of cutting force as measured along the feed direction as well as the existence of a relationship between chip thickness and surface quality. The developed cutting strategies proved to be efficient in manufacturing of symmetrical V-groove microstructures and augmented the field of micromachining with alternative cutting strategies

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

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