SHIVAM.pdf
- 1. ❖TRANSMISSION SYSTEM OF HEV’S. BY:- YASH JOSHI TMHC72 SHIVAM PAWAR TMHC73 Guided by:- m.s.patil.
- 2. introduction • A hybrid electric vehicle (HEV) augments an electric vehicle (EV) with a second source of power referred to as the alternative power unit (APU). • A hybrid can achieve the cruising range and performance advantages of conventional vehicles with the low-noise, low-exhaust emissions, and energy independence benefits of electric vehicles. • Accordingly, the hybrid concept, where the alternative power unit is used as a second source of energy, is gaining acceptance and is overcoming some of the problems of pure electric vehicles.
- 3. What is an hev HEV – Hybrid Electric Vehicle • A vehicle that has two or more energy conversion technologies combined with one or more energy storage units.
- 4. HEV OJECTIVES Objectives the HEV wants to obtain: • Maximize fuel economy • Minimize fuel emissions • Minimize propulsion system cost to keep affordable • Maintain acceptable performance with a reasonable cost • Reduce the conventional car weight
- 5. Hev advantages over conventional engines. • Regenerative Braking. • Reduction in engine and vehicle weight. • Fuel efficiency is increased. • Emissions are decreased. • Cut emissions of global warming pollutants by 1/3 or 1/2. • Reduce the dependency on fossil fuels. • Some states offer incentives with owning an HEV. • ~2 times more efficient than conventional engines.
- 6. HYBRID STRUCTURE • Two types of hybrid vehicle configurations. • 1.parallel hybrids. • 2.series hybrids.
- 7. Parallel hybrids • Fuel tank, which supplies gasoline to t h e engine. • Set of batteries that supplies power to a nelectric motor. • Both the engine and the electric motor c a nturn the transmission at the same time, and the transmission then turns the wheels.
- 8. • When the APU is off, the parallel hybrid runslike an electric vehicle. • When the APU is on, the controller divides energy between the drive train (propulsion) and the batteries (energy storage). • Under acceleration, more power is allocated t othe drive train than to the batteries. During periods of idle or low speeds, more power goes to the batteries than the drive train. • The batteries also provide additional power t othe drive train when the APU is not producing enough and also to power auxiliary systems such as the air conditioner and heater.
- 9. Series hybrid • Similar to an electric vehicle with an on- board generator • The vehicle runs on battery power like a pure electric vehicle until the batteries reach a predetermined discharged level. • At that point the APU turns on and begins recharging the battery. • The APU operates until the batteries are charged to a predetermined level. • APU never directly powers the vehicle
- 10. • The length of time the APU is on depends on the size of the batteries and the APU itself. • Since the APU is not directly connected tothe drive train, it can be run at its optimal operating condition; hence, fuel economy is increased and emissions are reduced relative to a pure IC engine vehicle.
- 11. Components of hev ❑ Electric drive motors. • to provide the power forpropulsion. • converts electric energy to mechanical energy (motion) to drive the hybrid vehicle. • Direct Current Motors, Alternating Current Motors. • The two possible configurations of electric drive motors in a hybrid vehicle. • single electric motor connected to the wheels through adrive train and multiple electric motors, one located at each wheel. ❑ Auxiliary Power Units • Supplies the baseline power required to the vehicle, recharges the batteries and powers accessories such as the air conditioner andheater. • The APU can consist of a mechanical type engine or afuel cell. • Spark Ignition Engine, Compression Ignition Engines, FuelsCells
- 12. • Generators • To convert the mechanical power into electrical power when used in series hybrids. ❑ Energy Storage Systems • Peak power required in hybrid vehicles is m e tby devices like batteries, capacitors or a flywheel. • store energy and readily release it w h e n needed.
- 13. ❑ Regenerative Braking • Some of the energy is converted into electrical energy and stored. • rotational energy of the braking mechanism generates electrical power and stores it in thebatteries. ❑ Control Systems • contains two main components-command and power components. • command component manages and processes the driver’s instructions. • power component chops power flows to control the motor’s power intake.
- 14. fuel cell hybrid vehicle • Electric vehicle equipped with a fuelcell. • Use hydrogen as a fuel and power the electric battery when it is depleted. • In the 21 century, the auto fuel will be replaced b y such regenerative resources as hydrogen and the power system with traditional internal combustion engine will be replaced by hybrid system and finally be replaced by fuel cell power system to realize multi-resources, electric driving and zero emission. • For the fuel cell hybrid electric bus developed, high- pressure PEMFC and high-power NiMH battery pack forms the hybrid system. • In order to obtain the higher fuel efficiency and a v oid the frequent charge & discharge of battery pack, the active control for the fuel cell pack to follow the driver’s pedal and the surplus peak power from NiMH battery pack passively is used.
- 15. • Fuel cell Hybrid Power Train Structure. • Fuel Cell Indirect Powersystem . • FCE is connected with ESS in parallel after DC/DC converter. • better for the optimization and control of the FCE and is an economic selection for the fuel cell vehicle nowadays
- 16. • Fuel Cell Direct Power System. • FCE’s output is directly inputted to DC/AC and the ESS is connected with the FCE’s output in parallel after a bidirectional DC/DC. • FCE outputs power directly into DC/AC, the FCE must have good dynamic response to output enough power quickly to meet the vehicle’s driving performance requirement and good voltage maintained performance to avoid the large voltage drop of bus line and the large torque drop of electric motor. On the other side, the FCE must be overlarge to avoid the possible damage.
- 17. • The main controller receives the pedal signals from the driver. With the values of pedal, speed, the driving power required is calculated by look-up table of motor performance map. • The target power of fuel cell engine is the sum of the driving power and the SOC-regulated power of battery pack. • The target current of the DC-DC converter is real-time calculated by the target driving power divided by the bus voltage. The air compressor’s speed control is based on the target power of fuel cell engine.
- 18. System control srategy • Two kinds of control strategies. ▪ Conventional fuel cell outputpower oriented control strategy • Setting the FCE as the main power sources and controlling the FCE’s output power to follow the vehicle’s driving power requirement at some extent. The FCE is working on nearly for all of the driving time expect for the first cold start and small driving power requirement while battery pack is at high SOC.
- 19. conclusions • Using the concept of Hybridization of cars results in better efficiency and also saves a lot of fuel in today’s fuel deficit world. • A hybrid gives a solution to all the problems t o some extent. • If proper research and development is done in this field,hybrid vehicle,promises a practical,efficient low pollution vehicle for coming era. • One can surely conclude that this concept andthe similar ones to follow with even better efficiency & conservation rate are very much on the anvil in today’s energy deficit world.
- 20. Thank you.