PowerPoint Presentation: SEMINAR ON REGENERATING BRAKE SYSTEM PowerPoint Presentation: Definition: Regenerative braking is a system in which the electric motor that normally drives a hybrid or pure electric vehicle is essentially operated in reverse (electrically) during braking or coasting. Instead of consuming energy to propel a vehicle, the motor acts as a generator that charges the onboard batteries with electrical energy that would normally be lost as heat through traditional mechanical friction brakes. As the motor “acts in reverse,” it generates electricity. The accompanying friction (electrical resistance) assists the normal brake pads in overcoming inertia and helps slow the vehicle. PowerPoint Presentation: WORKING How Regenerative Braking Systems Work Regenerative braking is something that is becoming a modern standard for vehicles of all descriptions as what was before just wasted energy used to slow a vehicle down is now being captured for re-use by the vehicle, making it more efficient . image courtesy of Toyota PowerPoint Presentation: REGENERATIVE BRAKING IS USED ON HYBRID GAS/ELECTRIC AUTOMOBILE Regenerative braking is used on hybrid gas/electric automobiles to recoup some of the energy lost during stopping. This energy is saved in a storage battery and used later to power the motor whenever the car is in electric mode. PowerPoint Presentation: How to design the regenerative brakes in the vehicles Step 1 – Objective: Establish a reusable energy source in a vehicle. Step 2 – Establish User Requirements - Must contain resistors and electric motors. -Must be able to produce enough energy to maintain energy consumption in a standard vehicle. -Must contain an electric and internal combustion motor -Must stay within price range of an average income consumer. -Is it a conservative means of braking compared to traditional braking? Step 3 – Constraints -Must withstand high temperatures as well as hard braking. -Must be effective in all weather conditions. -Does it need special maintenance care? -How available is this special feature on current vehicles? -Vehicle must run on alternative fuel and multiple batteries. -How high is the cost of this upgraded feature? -What is its compatibility with other hybrids with electric motors? Step 4 – Establish functions – Functionally responsive -Efficiency of regenerative braking must be as effective as traditional braking. -Must be efficient and effective in producing enough electricity back into electric motor for reuse. . PowerPoint Presentation: Step 5 – Conceptual design Materials: Electric motor -Internal combustion engine -Construction and size of electric motor -Assembly parts and maintenance care items to maintain feature. Step 6 – Generating Alternatives -Power that electric motor produces -Traditional braking system -Switching to standard brakes for increased friction on hard braking maneuvers (results in increased wear on standard brake pads versus regenerative braking which does not use brake pads.) Step 7 – Preliminary Design Model or Build and Analyze Design. Criteria: Increased or equivalent braking compared to traditional. -Withstand environmental changes -Affordability and Availability -Must meet user requirements. Step 8- Test and Evaluate Design -Continuous strain and tests on electric motor due to braking -Apply to all conditions, sizes, and weights. -Effectiveness with standard-sized vehicles PowerPoint Presentation: Step 9 – Detailed Design Refine and Optimize -Do alternatives sound like a better approach? -Minor improvements must be done to fix performance of electric motors if failure. Step 10 – Design Communication Regenerative braking uses electricity to create torque from electric motors which are powered by alternative fuel and batteries. When the vehicle’s brakes are applied, the electric motor reverses and then converts the torque already created from momentum of vehicle and uses this to create electricity which will be used to accelerate the vehicle after gas has been applied. This is very effective in stop-and-go situations such as urban driving. PowerPoint Presentation: Advantages: Full use of the energy recovery potential (serial recuperation concept) Optimal for hybrid vehicles as well as electric and fuel cell vehicles The basic concept and the proven components of the conventional brake Are mostly retained Optimum pedal feel selectable by the vehicle manufacturer Low noise, almost no pedal vibrations in ABS mode Improved crash behavior Networking adaptability to further vehicle control systems Disadvantages The main disadvantage of regenerative brakes when compared with dynamic brakes is the need to closely match the electricity generated with the supply. With DC supplies this requires the voltage to be closely controlled and it is only with the development of power electronics that it has been possible with AC supplies where the supply frequency must also be matched (this mainly applies to locomotives where an AC supply is rectified for DC motors). PowerPoint Presentation: Limitations Traditional friction -based braking is used in conjunction with mechanical regenerative braking for the following reasons: The regenerative braking effect drops off at lower speeds, therefore the friction brake is still required in order to bring the vehicle to a complete halt, although malfunction of a dynamo can still provide resistance for a while. Physical locking of the rotor is also required to prevent vehicles from rolling down hills. The friction brake is a necessary back-up in the event of failure of the regenerative brake. Most road vehicles with regenerative braking only have power on some wheels (as in a 2WD car) and regenerative braking power only applies to such wheels, so in order to provide controlled braking under difficult conditions (such as in wet roads) friction based braking is necessary on the other wheels.