Optimization of a low weight electronic differential for LEVs

It is presented a performance analysis of an Electronic Differential (ED) system designed for Light Electric Vehicles (LEVs). We have developed a test tricycle vehicle with one front steering wheel and two rear fixed units is a same axis with a brushless DC integrated in each of them. Each motor has an independent controller unit and a common Arduino electronic CPU based that can plan specific speeds for each wheels as curves are being traced. Different implementations of sensors (input current/torque, steering angle and speed of the wheels) are discussed related to hardware complexity, and performance obtained based on speed level requirements and slipping on the traction wheels.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Dynamics of Torque-Speed Profiles for Electric Vehicles and Nonlinear Models Based on Differential-Algebraic Equations

The so-called μ — λ curves, where is the slip ratio and μ is the normalised traction force or the friction index, are nonlinear functions of the velocity of the vehicle and the wheel rotational velocity. Despite their predominant use in the literature, linear approximations of such curves may fail to predict correctly key characteristics of vehicle performance efficiency such as torque-speed profiles. Although attempts to model these characteristics in the context of slip phenomena have been made before, to our best knowledge a general model with respect to the vehicle velocity, the wheel rotating velocity, the slip ratio, the traction force, and the torque, has never been formulated and solved as a coupled nonlinear problem based on a system of differential-algebraic equations arising naturally in this context. In this paper, such a model is formulated, solved numerically, and some results of numerical simulation of driving an electric vehicle on di®erent surface conditions are presented

A specific photovoltaic panel for an ultra-light electric vehicle focused on urban mobility

Nowadays, electric vehicles are considered the best alternative to achieve sustainable urban mobility. However, the extended implementation is conditional to a sufficient number of charging stations and the design of a new power grid distribution. Indeed, the vehicle model that dominates the current market, electric or thermal motors, is ten times heavier than its useful weight (occupant plus luggage), so it is not efficient in the way it uses the energy. In this article, an ultra-light electric vehicle with his own photovoltaic generator is proposed as an adequate vehicle prototype for sustainable mobility. This kind of vehicle does not need many charging stations and, because of that, the implantation is less complex than for other commercial vehicles. To verify this proposal, a specific photovoltaic panel was designed, manufactured and evaluated for this kind of vehicles. It can reach a specific power of 27.24 W/kg in STC, higher than commercial solar panels. An experimental study in a wind tunnel was conducted in order to know the influence of the photovoltaic generator in the drag coefficient, and to calculate the performance of the vehicle in an urban circuit. The most important results are that the vehicle, at STC, can circulate at a maximum speed of 35 km/h, without the need to charge the battery from the grid. For the same conditions, if the vehicle circulates at the maximum speed allowed in urban circuits, 50 km/h, it would have a range of 200 km per kWh charged from the grid.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Desarrollo de un panel fotovoltaico específico para un vehículo eléctrico ultraligero enfocado a la movilidad urbana

En la actualidad, los vehículos eléctricos son considerados como la mejor alternativa para la consecución de una movilidad urbana sostenible. No obstante, su implantación a gran escala está supeditada a la instalación de un número suficiente de estaciones de recarga y a un rediseño de la red de distribución de corriente eléctrica. Además de esto, el modelo de automóvil que domina el mercado actual, ya sea eléctrico o de combustión interna, se caracteriza por tener un peso diez veces superior al de la carga útil (personas más equipaje) que suele transportar, por lo que es muy poco eficiente en el uso de la energía. En este artículo proponemos un vehículo eléctrico ultraligero dotado de su propio generador fotovoltaico como prototipo de vehículo adecuado para conseguir una movilidad urbana sostenible. Este tipo de vehículos no necesitan de una amplia red de estaciones de recarga, por lo que su implantación a gran escala es mucho menos compleja. Para verificar la propuesta, se ha diseñado, construido y evaluado un panel fotovoltaico específico para este tipo de vehículos que alcanza una potencia específica de 27,24 W/kg en condiciones estándar, valor muy superior a la de los paneles fotovoltaicos comerciales. Se ha realizado un estudio experimental en el túnel de viento con el objetivo de conocer la influencia del generador fotovoltaico en el coeficiente aerodinámico del vehículo y de esta forma poder calcular las prestaciones del vehículo en un entorno urbano. Los resultados más importantes son que el vehículo, en condiciones estándar de irradiancia, puede circular a una velocidad máxima de 35 km/h sin necesidad de recargar energía de la red eléctrica. En estas mismas condiciones, si el vehículo circula a la máxima velocidad permitida en ciudad, 50 km/h, alcanzaría una autonomía de 200 km por cada kWh de energía recargado de la red eléctrica.Universidad de Málaga. Campus Internacional de Excelencia Andalucía TECH. Proyecto de Innovación Educativa de la Universidad de Málaga PIE13_01

Integrated battery charger for electric scooter

The paper deals with a battery charger integrated into the traction hardware of an electric scooter, for recharging the scooter batteries by means of a single-phase AC source. A mechanical switch and a rectifier bridge are the only additional components required to transform the electric scooter powetrain into a PFC battery charger, suitable for current-controlled or voltage-controlled recharge. The AC current is controlled at unitary power factor with no harmonic distortion. Switching harmonics are also drastically reduced by means of phase-interleaving. The battery charge is regulated according to the requests of the Battery Monitor System (BMS) that is embedded into the battery packs. The effectiveness of the integrated battery charger is demonstrated here on an electric scooter with high voltage Li-Ion battery (260V) and DC/DC/AC power conversion scheme. The integrated PFC charger concept is also valid for electric vehicles with AC traction drives based on a direct DC/AC conversion scheme, as demonstrated throughout the paper

Integrated battery charger for electric scooter

The paper deals with a battery charger integrated into the traction hardware of an electric scooter, for recharging the scooter batteries by means of a single-phase AC source. A mechanical switch and a rectifier bridge are the only additional components required to transform the electric scooter powetrain into a PFC battery charger, suitable for current-controlled or voltage-controlled recharge. The AC current is controlled at unitary power factor with no harmonic distortion. Switching harmonics are also drastically reduced by means of phase-interleaving. The battery charge is regulated according to the requests of the Battery Monitor System (BMS) that is embedded into the battery packs. The effectiveness of the integrated battery charger is demonstrated here on an electric scooter with high voltage Li-Ion battery (260V) and DC/DC/AC power conversion scheme. The integrated PFC charger concept is also valid for electric vehicles with AC traction drives based on a direct DC/AC conversion scheme, as demonstrated throughout the paper

Hardware Architecture and Configuration Parameters of a Low Weight Electronic Differential for Light Electric Vehicles with Two Independent Wheel Drive to Minimize Slippage

This article presents a design and performance analysis of an Electronic Differential (ED) system designed for Light Electric Vehicles (LEVs). We have developed a test tricycle vehicle with one front steering wheel and two rear fixed units in the same axis with a brushless DC (BLDC) motor integrated in each of them. Each motor has an independent controller unit and a common electronic Arduino CPU that can plan specific speeds for each wheel as curves are being traced. Different implementations of sensors (input current/torque, steering angle and speed of the wheels) are discussed related to their hardware complexity and performance based on speed level requirements and slipping on the traction wheels. Two driving circuits were generated (slalom and circular routes) and driven at different speeds, monitoring and recording all the related parameters of the vehicle. The most representative graphs obtained are presented. The analysis of these data presents a significant change of the behaviour of the control capability of the ED when the lineal speed of the vehicle makes a change of direction that passes 10 Km/h. In this situation, to obtain good performance of the ED, it is necessary to include sensors related to the wheels. Document type: Articl

Grinding and fine finishing of future automotive powertrain components

The automotive industry is undergoing a major transformation driven by regulations and a fast-paced electrification. A critical analysis of technological trends and associated requirements for major automotive powertrain components is carried out in close collaboration with industry – covering the perspectives of OEMs, suppliers, and machine builders. The main focus is to review the state of the art with regard to grinding, dressing, texturing and fine-finishing technologies. A survey of research papers and patents is accompanied by case studies that provide further insights into the production value chain. Finally, key industrial and research challenges are summarized

In situ diagnostics and prognostics of wire bonding faults in IGBT modules for electric vehicle drives

This paper presents a diagnostic and prognostic condition monitoring method for insulated-gate bipolar transistor (IGBT) power modules for use primarily in electric vehicle applications. The wire-bond-related failure, one of the most commonly observed packaging failures, is investigated by analytical and experimental methods using the on-state voltage drop as a failure indicator. A sophisticated test bench is developed to generate and apply the required current/power pulses to the device under test. The proposed method is capable of detecting small changes in the failure indicators of the IGBTs and freewheeling diodes and its effectiveness is validated experimentally. The novelty of the work lies in the accurate online testing capacity for diagnostics and prognostics of the power module with a focus on the wire bonding faults, by injecting external currents into the power unit during the idle time. Test results show that the IGBT may sustain a loss of half the bond wires before the impending fault becomes catastrophic. The measurement circuitry can be embedded in the IGBT drive circuits and the measurements can be performed in situ when the electric vehicle stops in stop-and-go, red light traffic conditions, or during routine servicing

The Jet Propulsion Laboratory Electric and Hybrid Vehicle System Research and Development Project, 1977-1984: A Review

The JPL Electric and Hybrid Vehicle System Research and Development Project was established in the spring of 1977. Originally administered by the Energy Research and Development Administration (ERDA) and later by the Electric and Hybrid Vehicle Division of the U.S. Department of Energy (DOE), the overall Program objective was to decrease this nation's dependence on foreign petroleum sources by developing the technologies and incentives necessary to bring electric and hybrid vehicles successfully into the marketplace. The ERDA/DOE Program structure was divided into two major elements: (1) technology research and system development and (2) field demonstration and market development. The Jet Propulsion Laboratory (JPL) has been one of several field centers supporting the former Program element. In that capacity, the specific historical areas of responsibility have been: (1) Vehicle system developments (2) System integration and test (3) Supporting subsystem development (4) System assessments (5) Simulation tool development