999 resultados para Electric contactors


Relevância:

20.00% 20.00%

Publicador:

Resumo:

There are two significant issues facing road transport in the medium to long term: the depletion of cheap oil reserves and the need to reduce carbon emissions. A long term solution for passenger cars could be the introduction of battery electric vehicles (BEVs). However, one of the main problems associated with the current generation of BEVs is their short range relative to conventional internal combustion engine (ICE) cars.

To investigate this issue, a long range battery electric vehicle, the UltraCommuter (UC), was constructed by the University of Waikato in partnership with HybridAuto Ltd. This paper describes the development, modelling and testing of the UC and its performance in the 2007 World Solar Challenge.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Personal passenger transport faces several challenges in the coming decades: depletion of cheap oil reserves, increasing congestion, localised pollution, the need for reduced carbon emissions and the long term goal of sustainability. One way of solving some of these problems could be to introduce comfortable, energy efficient, battery electric vehicles.

Currently, hybrid vehicles have been presented as a means to reducing the transportation related oil demand. New developments in materials and technologies have made them, cleaner and safer as well as more fuel efficient. However, hybrids will only prolong the use of oil until alternatively fuelled vehicles are developed.

One long term alternative is the battery electric vehicle (BEV). A BEV designed to be light, aerodynamic with high efficiency drive train and latest battery technology would have a performance comparable to a typical internal combustion engine vehicle (ICEV). Recent developments in virtual engineering, rapid prototyping and advanced manufacturing might enable low-cost development of niche market BEV’s designed and built in New Zealand for export markets.

This work examines the collaborative development of a twin seat BEV using new materials and latest technologies by the University of Waikato’s Engineering Department and a group of NZ and foreign companies. The car will be used to research the potential of BEVs and will also compete in the Commuter Class of the World Solar Challenge in 2007.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper investigates whether low technology driver-only, battery electric commuter vehicles are feasible for New Zealand. Personal passenger transport faces several challenges in the coming decades: depletion of cheap oil reserves, increasing congestion, localised pollution, the need for reduced carbon emissions and the long term goal of sustainability. One way of solving some of these problems could be to introduce low cost, comfortable, energy efficient, driver-only electric vehicles. These would still give the driver a weatherproof, safe and comfortable means of commuting, but at a fraction of the energy and running costs of conventional petrol/diesel cars. To help assess their viability, the performance and energy use of the E-POD electric commuter vehicle is used as a benchmark. The work shows that such a vehicle could be made cheaply, using readily available technology with a range of 180km and a top speed of over 90km/h. The chassis could be made from natural fibre composite materials that might reduce significantly the embedded energy required for its manufacture. The electricity taken from the grid to charge the batteries could be replaced by electricity generated from grid connected photovoltaic panels mounted on the garage roof of the vehicle owner.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The modelling and simulation approach is employed to develop an intelligent energy management system for hybrid electric vehicles. The aim is to optimize fuel consumption and reduce emissions. An analysis of the role of drivetrain, energy management control strategy and the associated impacts on the fuel consumption with combined wind/drag, slope, rolling, and accessories loads are included.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fuel efficiency in a hybrid electric vehicle requires a fine balance between usage of combustion engine and battery power. Information about the geometry of the road and traffic ahead can have a great impact on optimized control and the power split between the main parts of a hybrid electric vehicle. This paper provides a survey on the existing methods of control and energy management emphasizing on those that consider the look-ahead road situation and trajectory information. Then it presents the future trends in the control and energy management of hybrid electric vehicles.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

 It is well known that the one of the main problems concerning battery electric vehicles (BEVs) is their short range compared to conventional petrol and diesel vehicles. In this work the technical factors that will enable long range BEVs are investigated. The concept of Compounding Factors is presented and shows that if certain parameters can be met then BEV’s can have a comparable performance to conventional petrol cars. The development and initial testing of a long range BEW prototype is presented and discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

It has been demonstrated that considering the knowledge of drive cycle as a priori in the PHEV control strategy can improve its performance. The concept of power cycle instead of drive cycle is introduced to consider the effect of noise factors in the prediction of future drivetrain power demand. To minimize the effect of noise factors, a practical solution for developing a power-cycle library is introduced. A control strategy is developed using the predicted power cycle which inherently improves the optimal operation of engine and consequently improves the vehicle performance. Since the control strategy is formed exclusively for each PHEV rather than a preset strategy which is designed by OEM, the effect of different environmental and geographic conditions, driver behavior, aging of battery and other components are considered for each PHEV. Simulation results show that the control strategy based on the driver library of power cycle would improve both vehicle performance and battery health.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

RATIONALE: To determine whether the potential for previous termpollennext term fragmentation is increased during thunderstorms by exploring the previous termeffectsnext term of previous termelectricnext termprevious termfieldsnext term, with magnitude as found in the outdoor environment.

METHODS: Fresh previous termpollennext term grains were collected from bermudagrass flowers. A light microscope was modified with the addition of an previous termelectricnext termprevious termfieldnext term generated from a DC source (0-20 V) that was applied to the stage. Water was added to test for previous termpollennext termprevious termrupturenext term and to assess previous termpollennext term viability.

RESULTS: Bermuda grass previous termpollennext term did not previous termrupturenext term within 1 h of contact with water. Only after exposure to an previous termelectricnext termprevious termfieldnext term did Bermudagrass previous termpollennext term show a considerable amount of rupturing immediately upon immersion in water. The higher the voltage the previous termpollennext term is exposed to before coming into contact with water, the higher the percentage of previous termrupturenext term of the previous termpollennext term. previous termElectricnext termprevious termfieldsnext term, generated in the laboratory and of magnitude found during thunderstorms, affected the previous termpollennext term after as little as a 5 s exposure. The highest percentage of previous termrupturenext term occurred after exposures of at least 10 s: 80% previous termrupturenext term occurred after 10 s exposure at 10kVolts/m. This previous termeffectnext term is sustained for at least 15 min.

CONCLUSIONS: Thunderstorm regularly generate previous termelectricnext termprevious termfieldsnext term up to 5 kV/m in strength, and can reach 10kV/m, and cover several km in distance. The magnitude of the previous termelectricnext termprevious termfieldsnext term that affects the previous termpollennext term grains in the laboratory is low enough to be commonly found in the outdoor environment during thunderstorms. These previous termelectricnext termprevious termfields prime previous termpollen grains for more rapid release of allergenic particles.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Light scattering from small spherical particles has applications in a vast number of disciplines including astrophysics, meteorology optics and particle sizing. Mie theory provides an exact analytical characterization of plane wave scattering from spherical dielectric objects. There exist many variants of the Mie theory where fundamental assumptions of the theory has been relaxed to make generalizations. Notable such extensions are generalized Mie theory where plane waves are replaced by optical beams, scattering from lossy particles, scattering from layered particles or shells and scattering of partially coherent (non-classical) light. However, no work has yet been reported in the literature on modifications required to account for scattering when the particle or the source is in motion relative to each other. This is an important problem where many applications can be found in disciplines involving moving particle size characterization. In this paper we propose a novel approach, using special relativity, to address this problem by extending the standard Mie theory for scattering by a particle in motion with a constant speed, which may be very low, moderate or comparable to the speed of light. The proposed technique involves transforming the scattering problem to a reference frame co-moving with the particle, then applying the Mie theory in that frame and transforming the scattered field back to the reference frame of the observer.