This paper identifies the most promising electric power system (EPS) architecture for a future more electric aircraft based on reviews and evaluations of both system weight and stability feature of the existing EPS architectures. When comparing the overall system weight of different architectures, various aspects, including voltage generation, wiring system, ground operation, power conversion, and complexity of integrating alternative energy sources, are considered. After choosing the possible candidates among all the possible architectures by using weight-saving criterion, stability features for the initially selected candidates are further evaluated. Necessary simulation studies are carried out in MATLAB/Simulink to prove the correctness of stability study. Finally, the one both good at weight saving and with the highest stability region is deemed as the most promising EPS architecture for future MEAs.

Investigation on the Selection of Electric Power System Architecture for Future More Electric Aircraft

Boosting the Multifunctional Properties of MnCo2O4-MnCo2S4 Heterostructure for Portable All-Solid-State Symmetric Supercapacitor, Methanol Oxidation and Hydrogen Evolution Reaction

The energy and power requirements of a class of on-the-road electric vehicles are developed, and acceleration and speed characteristics of such vehicles in urban traffic are discussed. Curves of average speed under different conditions of traffic are presented, as are curves of average power required during acceleration, average power required during cruising, and peak power required. A dc drive system for propulsion of such a vehicle and an ac drive system appropriate for such an application are described. The two kinds of system are then compared, on an economic as well as a technical basis. A procedure for designing an electric vehicle is outlined, pertinent fields in which research and development are needed are listed, and a reference list on electric vehicles is included.

Considerations in the design of drive systems for on-the-road electric vehicles

The paper reviews improvements made in the design and manufacture of battery-powered vehicles and their components during the past ten years or so. Batteries, controllers, motors, chargers and transmission systems are discussed, and a brief commentary is made on the effects of modern tyre equipment on vehicle performance. Comparisons are made in some instances with earlier designs of vehicles and components. Many new vehicles have been designed to cover applications made necessary by the competitive nature of modern commerce, and some of these are illustrated and described. The now familiar chaotic road conditions in our cities and towns are worsening, and the advantages of battery electric traction in reducing noise and atmospheric pollution have led to a reappraisal of electric cars and other forms of public transport. Some recent designs are discussed.

Recent developments in battery electric vehicles

1,085,517. Three-wheeled vehicles; vehicle doors. AUSTIN CROMPTON PARKINSON ELECTRIC VEHICLES Ltd. Sept. 9, 1966 [Oct. 1, 1965], No. 41880/65. Headings B7H ard B7J. Two of the wheels 2, 3, of which one at least is steerable, of a battery-electric road vehicle are each built integrally with a traction motor and gearing assembly and are equidistant from and on one side of the longitudinal vertical median plane of the vehicle and the other wheel (4) (Fig. 2, not shown) is on the other side of the plane and equidistant from the centres of the wheels 2, 3. A side-hinged frontal door 8 provides access to the front seat, a sliding door 12 behind the wheel 4 provides access to the rear seat, and a panel 6 provides access to the batteries.

Battery Electric Road Vehicles

Primary and secondary batteries and fuel cells all convert chemical energy directly into electricity. Primary batteries, of the type used for hand torches, provide only very small units of power. Secondary batteries or accumulators supply amounts of power up to several hundred kilowatts and fuel cells have been proposed for even larger units. These systems differ basically from the well known electromechanical methods of producing electricity, i.e. those in which an electric machine is driven by a steam turbine or an internal-combustion engine. The latter involve a heat cycle subject to the limitations of the Carnot cycle. Direct electrochemical conversion devices have no such limitation, and the energy can be produced at an efficiency more than double that of the electromechanical systems mentioned.The widest application of storage batteries is for portable sources of power. In spite of the high density of lead, the main raw material in the lead/acid system, this battery is predominant in this field. Some reasons for this are given. Typical discharge and charge characteristics are shown. The real advances in various types of lead/acid batteries made during the past 15 years or so in the output per unit weight and volume are discussed. For car starter batteries the improvement amounts to nearly 20%, for traction batteries about 35%, for some stationary applications well over 150% and for aircraft batteries over 25%.Some of the basic principles of fuel cells are described, and the performance of practical working units is discussed. The characteristics of batteries and fuel cells are compared.

Developments in electrochemical energy-conversion devices, batteries and fuel cells

So extensive is the use of storage batteries, that the capacity of those mounted in motor vehicles in Britain alone exceeds the present total output from nuclear power stations. The employment of these batteries is limited, however, by their weight and size and by the time that must be spent in recharging. Development of fuel cells, which do not suffer from these limitations, may lead to the practicability of high-performance electric cars.

M. Barak

Papers

Developments in electrochemical energy-conversion devices, batteries and fuel cells

Developments in electrochemical energy-conversion devices, batteries and fuel cells