Thursday, December 23, 2010



   
Objectives
  The client has given a list of objectives which are as follows:
  To travel within the campus for the disabled and help the older people visiting the campus.
  It must also act as shuttle between the college campus and the hostels (boys & girls) for the needy students.
  It must be simple and well furnished.
  It must accommodate 3+1 persons with small luggage space.
  A technological approach from BVB students.

Objective of the engine selection
  Selection of engine to run the generator.
  Engine should run the generator to produce electric. current until the battery is charged.
  Preferred engine should be S.I. (petrol).
  Four stroke is preferred.
  Low maintenance.
Economical

Engine power
  The generators are 70% efficient.
  Engine 1.428 * p
  Where to generate 2k of electricity we need to use 2.856 K.W
  Different engines available in market.
  Still we need to decide whether to use the commercial generator or to prepare full assembly of the generator.


Selection of engine for hybrid vehicle
  If we select series hybrid then, engine is used to generate electricity.
  In Parallel connection engine used drive the vehicle as well as to generate the electricity.
Other combinations of hybrids are there they are complicated.

  Reasonable Efficiencies to use for cycle comparisons
Electric Motor (Peak) η = 95%
• Transmission Efficiency (0.95) = 1)-(Rη
• Battery Efficiency (Regen) η = 75-85%
• Battery & Generator Efficiency (Regen) η = 50-55%
• Battery & Motor Efficiency (Accel) η = 80%
• Solar Cell Efficiency η = 15%
• IC Engine (Peak Efficiency) η = 30%
• Flywheel Efficiency (Storage and Conversion Average) η = 70

Simple calculation
  Power required to run the vehicle.
  Paero=(12.86*10-6)*cdAV(V+Vo)2
  Prr=(2.72*10-3)*Crr*M*V
  Paero=0.7914kW
  Prr=1.3056kW
  Pgr=0.335 kW
  Total  power = 2.432284 kW
  From above  data 50% is the loss in conversion from  mechanical  to electrical  and from  battery to mechanical .
  Power required is =  Ptotel+1/2 Ptotel
  Power required =3.64827 kW 

Conclusion
  From the above calculation we come to know that power required running series hybrid is 3.648 kW.