A Purely Mechanical Energy Storing Concept for Hybrid Vehicles
The paper contains the design and simulation of a purely mechanical system for storing energy during vehicle deceleration, which can be utilized during subsequent acceleration (regenerative braking). A continuously variable transmission (CVT) regulates the energy transfer, energy storage is accomplished by means of a spiral spring and additional use of a planetary transmission. The transmission ratio of the CVT is adapted by a combined feed-forward and feed-back control. A computer simulation for a vehicle with an overall mass of 1500kg, and an energy storage capacity of 30kJ was performed for different driving cycles. In a typical urban stop and go situation the proposed device will save up to 0.72kg fuel per 100km and the overall efficiency analysis together with simple design, easy recycling, and long life expectance, showed a clear advantage over other hybrid concepts for frequent stops and accelerations.
INTELLIGENT CONTROL SYSTEM USED FOR INCREASING THE ENERGY EFFICIENCY OF THE ELECTRIC VEHICLES-REDUCED SCALE MODEL -
The actual constraints related to the air pollution, fuel and energy consumption became essential aspects considered while improving the performances of the classic vehicles and developing the new generation of mild hybrid electric vehicles and electric vehicles. Also, assuring the dynamism of the vehicle became an important goal that need to be assessed by the automotive industry. Nowadays, one of the main focuses of the automotive researchers is developing innovative power supplies and composed storage devices able to assure the dynamism of the vehicles thus facilitating the transition from the classic internal combustion engine (ICE) vehicles to the new generation of mild hybrid electric vehicles (HEV) and electric vehicles (EV). A solution for the actual constraints can be a combined energy and power supply system composed of storage devices characterized by different time constants. The present paper is focused on describing a physical reduced scale prototype of an electric vehicle and its control strategies able to satisfy better the requirements for increasing the energy efficiency of the implemented and tested system. In this paper the role of the used storage devices and of the control strategies are emphasized. Also, the architecture of the system, the experiments performed and the preliminary results are described. INTRODUCTION Generally, batteries are used as main power supply, especially for EV, but their cyclability and functional constraints related to the current provided and the operating range of temperature are improving slowly compared to the consumer’s requests because of the high cost of the technology. Lately, new storage devices such as fuel cells and capacitors / supercapacitors are used by the automotive industry to increase the energy efficiency and the storage and generating capabilities, constraints that have to be assessed in the case of the new generation of HEV and EV (1). A solution for the actual constraints can be represented by a combined energy and power supply system composed of devices with different time constants, such as: batteries, supercapacitors, fuel cells and their intelligent control system able to optimize the power flow of the electric engine, to monitor and to increase the lifetime and the performances of the ensemble (2), (3). The capabilities and the power flow reserves of the energy sources increase the dynamicity of the vehicles. Moreover, the role of the regenerative braking in conjunction with the rapid release storage devices is essential for urban traffic in order to increase the energy efficiency of the ensemble (4). In the present paper a physical reduced scale prototype of an EV is described. The prototype is intelligently started and is able to recover a part of the kinetic energy from the braking process, to store it in capacitors and to use it to supply the auxiliary loads. The role of the capacitors and of the implemented and tested control strategies able to satisfy better the requirements of the starting and regenerative braking processes are emphasized. Also, the structure of the system, the experiments performed and the preliminary results are described.
Correlation of the Upper Cretaceous White Chalk (Turonian to Campanian) in the Anglo-Paris Basin
Using key lithological, biostratigraphic and geophysical borehole-log markers a correlation of the Upper Cretaceous Chalk stratigraphies across the whole Anglo-Paris Basin has been achieved. A common lithological marker bed stratigraphy applies and key fossil markers (inoceramids, Micraster and Echinocorys ) are consistently related to the same lithological markers throughout the basin. The major lithological changes consistently occur at the same levels but are not necessarily equally strongly developed. The magnificent dip section along the French Channel coast between the Somme and the Seine, and the inland sections at Precy-sur-Oise and Verlin (Loiret) illustrate the influence of long-lived tectonic lines on Chalk sedimentation history recognised by: (i) rapid thickness variations; (ii) channel flooring hardgrounds and associated anomalous bedding dips: (iii) stratigraphically anomalous infills of channels which may be metres to kilometres across; (iv) redeposited chalks containing abundant Bathichnus paramoudrae ; (v) tectonically induced slumps and slides with flint and chalk shatter beds (palaeoseismic horizons). These features are found along may axes including the Anticlinal du Bray at Precy and Dieppe, the Anticlinal de Margny-les-Compiegne at Nourard le-Franc and Le Treport (the Bresle Valley Axis) and the Fecamp and Verlin fault systems. The ‘events’ recognised along these axes link with similar events recognised in Sussex (e.g. Kingston Anticline), on Portsdown, at Culver Cliff, Isle of Wight (Sandown Pericline) and on the Weymouth Anticline (White Nothe). Such events are common in the high Turonian, low Coniacian, basal Santonian, and the low and mid Campanian. The recurrence of key marker beds dominated by a particular trace fossil association or sequence, Bathichnus-Thalassinoides suevicus-Zoophycos associated with major changes in lithology, micro and macro-fauna indicates more widespread ‘oceanographic’ cycles of transgression and regression related to Atlantic opening.