This paper reveals the virtual L7e vehicle, GRAND TWIZY concept for the first time into an conference. The concept is an academic project and is developed within at the “Alternative Propulsion Systems –Electric and Hybrid Vehicles” Laboratory of the “Automotive Engineering” Research Centre, University of Pitesti, Romania. The main objective of the project is minimal costs development of a L7e concept, starting from the RENAULT TWIZY quadricycle and increasing its habitability, versatility and autonomy, similar to the competitors`. The vehicle design is influenced by four elements: the exterior design, legal requirements, the powertrain components and the vehicle components provided by RENAULT TWIZY. To increase the habitability, the body has been modified in transversal direction, keeping the same wheelbase of the vehicle. This solution allows minimal chassis and body transformations, taking over many mechanical components of the front axle, of the rear axle and the electric powertrain and taking as many body parts as possible, especially from the lateral sides of the original RENAULT TWIZY vehicle. The new body has a new anti-rain system for the doors and heating and ventilation system. This allows extending the period of use in rain conditions and low temperatures (winter). For increasing the versatility the passenger seat is placed on the lateral side of the driver. The rear space can be usable for the placement of luggage or the placement of children's seats. The increasing luggage transport space we have created a space modularized in the passenger`s seat place. For the transport of oversized equipment or luggage it was built a folding outer trunk. In order to increase the autonomy and the additional electricity consumption caused by the heating and the ventilation system for the passenger compartment, a new 48 V traction battery with NMC technology (Nickel Manganese Cobalt) is proposed. It contains elements from the Renault ZOE 50 battery, produced by LG Chem. This battery is charged with a bidirectional charger, able to function “Vehicle to Grid” (V2G), both by cable and wireless. The charging system, was built from a charger-inverter assembly, compatible with lithium-ion batteries. In the case of the proposed wireless charging system, the transfer of station and vehicle energy was made trough by means of a magnetic field that circulates between an emitter (coupled to the 230V-50Hz single-phase alternating current) and a receiver mounted on the vehicle (coupled by charger to the 48 V traction battery). In addition, the traction battery is charged with a photovoltaic cell system located on the roof was provided. This solution was favored by the extension of the roof surface caused by the vehicle. To reduce vehicle mass and increase the reliability of the servitude battery, is propose to replace the 12 V battery with AGM lead technology with a Panasonic DLC (Double Layer Capacitor) battery.

Mr. Vlad-Nicolae Turcescu, University of Pitesti, ROMANIA Mr. Dănuț-Gabriel Olaru, University of Pitesti, ROMANIA Ms. Ana-Maria Arsene, University of Pitesti, ROMANIA Prof. Dr.-Ing. Danut-Gabriel Marinescu, University of Pitesti, ROMANIA