Friday, December 31, 2010

Hybrid Cars(Toyota Prius)...................

Have you ever moved your car to the petrol pump and been shocked by the high price of gas? Is it going to be a common expression due to unstoppable and unpredictable price hike of fuels.However in such condition you will be thinking of  buying a car which delivers more mileage and is easy on the pocket.The answer to your question is going to be Hybrid cars, which is going to be one of the most promising propulsive method in near future.
In this article we will understand the working of hybrid technology, and take a closer look at the recently launched Toyota Prius.


  • What is hybrid vehicle? A vehicle which is powered or propelled by two power sources is a hybrid vehicle. For e.g mo-ped is a hybrid vehicle i.e mo means it is powered by a engine and ped alternately it is also powered by pedal effort of human. Any vehicle which combines two type of power sources.Railway engines,submarines,mining trucks are examples of hybrid vehicles.As far as the hybrid cars are concerned they are propelled by a gasoline and electric motor.

  • Gasoline(Petrol) power and electric power, both individually have some shortcomings.Their are some specific requirements for a car to be useful for a person.
      1.Drive for at least 500kms before refuelling.
      2.Refuelling should be convenient and fast.
      3.Speed of the car should be able to cope up with traffic. 
                
        A gasoline powered car meets the above requirements, but produces pollution which is unsuitable for the nature.In comparison a electric car does not emit any smoke, but has a very small driving range along with a slower driving speed.
        Thus a ideal choice would be a combination of these two powering systems.

  • Gasoline-Electric structure 

        

            The main components of the system:-
         
       1.Gasoline engine-The hybrid car has a gasoline engine which is found in  most of the cars, however the engine here is of a smaller capacity and tuned to deliver high efficiency and low pollution.
       
       2.Fuel Tank-Fuel tank as it is known is the storage for the gasoline in the car, but the interesting fact is that petrol has more energy density than energy of batteries.It takes about 1000 pounds of batteries to develop power of just 4 liters of petrol.
      
     3.Electric motor-The electric motor on a hybrid car is very sophisticated. Advanced electronics allow it to act as a motor as well as a generator. For example, when it needs to, it can draw energy from the batteries to accelerate the car. But acting as a generator, it can slow the car down and return energy to the batteries.
      
     4.Generator-The generator is similar to an electric motor, but it acts only to produce electrical power. It is used mostly on series hybrids.
     
     5.Batteries-The batteries in a hybrid car are the energy storage device for the electric motor. Unlike the gasoline in the fuel tank, which can only power the gasoline engine, the electric motor on a hybrid car can put energy into the batteries as well as draw energy from them.


     6.Transmission-The transmission on a hybrid car performs the same basic function as the transmission on a conventional car. Some hybrids, like the Honda Insight, have conventional transmissions. Others, like the Toyota Prius, have radically different ones.


  • Type of Hybrid systems.
     1. Parallel hybrid system-It contains a battery pack which supplies power to the motor which in turn supplies power to the transmission system, and the  transmission system turns the wheels, along with the batteries the engine also powers the car, thus engine and batteries both can simultaneously power the vehicle.
      
       


     2.Series hybrid system-Series hybrid system is a contrast of parallel hybrid system, here only one type energy producing system can power the vehicle. It contains a extra component in the form generator, the generator performs two functions, it either charges the battery or powers the motor to power the vehicle. The generator is turned by the engine.





      Hybrid systems are invented to harness the power of the car from two    different sources increasing the efficiency of the car and also reducing the emissions by a considerable amount.



  • Toyota prius a thorough green car manufactured by Toyota, has been launched in india a few months back and is priced with Rs 27 lacs. 















                                                                                                                                               Toyota has a unique hybrid technology known as HYBRID SYNERGY DRIVE,  which propels the vehicle. Functionally it is a combination of a series-paralle hybrid system.Toyota has been using it inits hybrid vehicle range, including Lexus(sold in USA). 


Hybrid synergy drive replaces the standard transmission system used in normal cars with a different transmission system called as E-CVT(Electrnically controlled  Continuously Variable Transmission) which replaces the traditional gears with normally belts and pulleys, the advantage of the later is, that in a normal gearbox we have fixed number of gear ratios(GEAR RATIO IS THE RATIO OF THE SIZE OF TWO GEARS WHICH ARE IN MESH WITH EACH OTHER, WITH WHICH DIFFERENT SPEEDS AND TORQUE CAN BE OBTAINED DEPENDING UPON THE SIZE OF THE GEARS, AND THE NO OF TEETH ON THEM) while in a E-CVT the ratios are nearly infinite, thus the vehicle can get a more number of speed and torque ratios within the limit of CVT.


When the vehicle is turned-on with the "start" button, it is ready to drive immediately with the electric motor, before the internal combustion engine is started. The delay between starting the car and starting the internal combustion engine is approximately seven seconds. A button labelled "EV" maintains Electric Vehicle mode after start up and under most low-load driving conditions. This permits driving with low noise and no fuel consumption, and is advertised as a "quiet" option for short journeys, for example in residential areas at night, in the Asia manual. The car automatically reverts to normal mode if the battery becomes exhausted, i.e it switches the petrol engine on. 


Hybrid synergy drive technology also includes technology like REGENERATIVE BRAKING. Regenerative braking technology converts the heat dissipated while braking into other form of energy to charge the batteries.




The hybrid cars are made for more efficiency than acceleration of the car,considering the mileage figures of the car, they are significantly more than a car of its size and weight.

The mileage specification of the car are not tested as per the indian driving cycle, but the UK specification mentions that the car has a mileage of city driving as 60.3 mpg, which is equivalent to 25 Kmpl, highway driving as 27kmpl, in a combined petrol and electric mode.


In a nut shell it justifies that, hybrid technology is one of the most promising mode of alternative energy power source. The technology is being developed still, which will further boost the mileage and the performance of the vehicle.Companies like GM,HONDA are also working on the technology and have launched their respective vehicles.


Specification:-
Gas engine: Inline 4-cylinder DOHC, 1,497 cc
Peak Horsepower: 70 hp at 4,500 rpm
Peak Torque: 82 lb.-ft. at 4,200 rpm
Fuel Tank Capacity: 45 lts

ELECTRIC MOTOR - Permanent Magnet, 
Capacity: 6.5 amperes
Peak Torque: 258 lb./ft. (350.0 Nm) 0-400 rpm

BATTERY PACK
Peak Horsepower: 25 kW (34 hp)
Nominal Voltage: 274 volts

EXTERIOR DIMENSIONS
Length: 4460mm
Width: 1745mm
Height: 1510mm
Wheelbase: 2700mm
Weight: 1400 kg
Seating Capacity: 5

No comments:

Post a Comment