Electrical Vehicles
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This document provides an overview of electric vehicles, including their history, components, design considerations, manufacturing process, and advantages over gasoline-powered vehicles. It discusses how electric vehicles first emerged in the late 1800s but declined as gasoline vehicles improved. Recent concerns over pollution and limited resources have led to a resurgence in electric vehicle research and development. The key components of an electric vehicle include batteries, electric motors, motor controllers, and charging systems. Vehicle design must consider factors like weight, battery type and placement, and drivetrain configuration.
Electrical Vehicles
- 2. Content • Background • History • Components • Materials • Electric Vehicle Configuration • Design • Manufacturing Process • Optimization • Charging System • Electric vs Gasoline • Energy Efficiency • Conclusion
- 3. Background Unlike the gas-powered automobile, the electric automobile did not easily develop into a viable means of transportation Why? - The easily mass-produced gasoline-powered automobile squelched interest in the project - Technologies that support a reliable battery and the weight of the needed number of batteries elevated the price of making an electric vehicle
- 4. Background Although - Research waned from 1920-1960 and worries about environmental issues of pollution and diminishing natural resources reawakened the need of a more environmentally friendly means of transportation. - Automotive electronics have become so sophisticated and small that they are ideal for electric vehicle applications.
- 5. History In 1837, Robert Davidson of Scotland appears to have been the builder of the first electric car
- 6. History During the late 1890s, United States roads were populated by more electric automobiles than those with internal combustion engines.
- 7. History The history of the electric car is related with the history of the development of the battery. Why were they popular? They were clean, quiet, and easy to operate However - The industry improved the gasoline-powered vehicle so much so that competition was nonexistent. - Between 1920 and 1960, the low price of combustion engine vehicles made disappear almost every electric car companies.
- 8. History In the 1960’s, interest in the electric car rose again due to the escalating cost and diminishing supply of oil and concern about pollution generated by internal combustion engines The resurgence of the electric car in the last part of the 20th century has, however, been fraught with technical problems. During the 90’s, some electrical cars were brought to the market but batteries were the weakness of this electric car because they needed to be replaced every two years, doubling the vehicle's cost
- 9. History Nowadays, automotive electronics have become so sophisticated and small that they are ideal for electric vehicle applications. Batteries are more efficient and capable so every car firm has its own line of electric cars.
- 10. Components Here we have the main components of an Electrical car: - Electric Motor: Every electric car needs a motor. They can use AC or DC electricity. - Motor Controller: The purpose of the motor controller is to adjust the speed at which the motor spins. - Throttle Pot Box: Is a small part that connects to your stock throttle cable. When you push on your throttle, the pot box sends a signal corresponding to the amount of pressure you’re putting on the pedal to the controller which then sends the proper power to the motor.
- 11. Components - Batteries: Batteries are the source of energy of the car. As fuel is for combustion vehicles. The type of batteries will affect performance and range. - DC/DC Converter: The DC/DC converter takes the voltage of your main (traction) battery pack and reduces it to 12V which keeps your 12V battery charged.
- 12. Components Complete scheme of componentes:
- 13. Electrical circuit scheme: Components
- 14. Materials - The electric car's skeleton is made of aluminum to be both strong and lightweight. - Seat frames and the heart of the steering wheel are made of magnesium, a lightweight metal - The body is made of an impact-resistant composite plastic that is recyclable.
- 15. Materials - Electric car batteries consist of plastic housings that contains metal anodes and cathodes and fluid called electrolyte - The motor or traction system has metal and plastic parts that do not need lubricants - Plastics, foam padding, vinyl, and fabrics form the dashboard cover, door liners, and seats.
- 16. - The tires are rubber, but, unlike standard tires, these are designed to inflate to higher pressures so the car rolls with less resistance to conserve energy. - Materials that provide thermal conservation reduce the energy drain that heating and air conditioning impose on the batteries. Materials
- 17. Electric Vehicle Transmission Power Unit (motor/controller) Fuel (batteries) Regenerative Brakes (energy returns to batteries)
- 18. Electric Vehicle
- 20. Design To design an electric vehicle, it is important to match the motor-drivetrain combination to the body style selected. Various factors can influence the design of an electric vehicle such as the cost and weight of components and accessories, among others.
- 21. Design-Weight • Research the structural strength and loading capacity of any vehicle under consideration. Electric components may add weight to a vehicle, especially if choosing lead acid batteries. This affects: Handling, and front end alignment, Suspension component sizes (springs, shock absorbers, brakes) Suspension mounts (may need to be reinforced). • There is a diminishing rate of return as we add batteries – eventually the power of extra batteries is used up by moving their extra weight. Limit battery weight to 33% - 45% of total vehicle weight.
- 22. Weight Comparisson Front-to-rear Weight Distribution Trade-off
- 23. Design - AC vs. DC Systems • AC systems offer better performance but at higher cost. • AC cars consume 0.11 to 0.18 kW-hr / kilometer, while DC cars consume about 0.25 kW-hr / kilometer. • AC systems can use batteries that are rated at lower kW-hr capacity. • However, most AC systems use higher voltages than DC systems so there is no overall savings in battery pack weight and size. • Regenerative braking is easier to implement in AC systems. • DC system failures can allow sudden runaway (full uncontrollable power to the motor). • AC systems can use smaller diameter cables. • AC motors and controllers must be more tightly matched than DC motors and controllers. • Generally, AC motors are more reliable than DC motors.
- 24. Design - AC vs. DC Systems AC Motor Single speed transmission Light weight Less expensive 95% efficiency at full load More expensive controller Motor/controller/inverter is more expensive DC Motor Multi-speed transmission Heavier for same power Higher cost 85-89% efficiency at full load Simple controller Motor/controller - lower cost
- 25. Design-Batteries • The battery pack is the heart of an electric vehicle. • Batteries that store energy and power the electric motor are a science of their own in electric car design, and many options are being studied to find the most efficient batteries that are also safe and cost effective. • Many different battery types exist, e.g., lead-acid, nickel-metal hydride, lithium ion, etc. • However, today the lithium ion is the preferred choice due to its relatively high specific energy and power. • An electric motor that converts electrical energy from the battery and transmits it to the drive train.
- 26. Design-Chargers • Two varieties of chargers are needed. • A full-size charger for installation in a garage is needed to recharge the electric car overnight, but a portable recharger (called a convenience recharger) is standard equipment for the trunk so the batteries can be recharged in an emergency or away from home or a charging station. • For safety, an inductive charger was created for electric cars with a paddle that is inserted in the front end of the car. It uses magnetic energy to recharge the batteries and limit the potential for electrocution.
- 27. Design-Transmission • Electric motors produce high torque almost down to zero rpm, so why add the extra weight of a transmission? • The reason is that at low rpm, especially while starting, electric motors consume a lot of battery power. • Also, one gear ratio becomes a compromise between top speed and hill climbing ability. • A transmission can also provide reverse; otherwise we need extra contactors and wiring. AC systems may not need transmissions.
- 28. Design-Acessories • Lights, turn signals and the horn were designed for 12 V DC so an auxiliary system is required. • Heat, air conditioning, power brakes and power steering reduce battery range. • Devices that used engine vacuum now need a pump. If using resistive heating, wire the ventilation fan to keep the element from burning out.
- 29. Manufacturing Process - Body shop The body for the electric car is handcrafted at 3 work stations • First: Parts of the aluminum space frame are put together in sections called subassemblies that are constructed of prefabricated pieces that are welded or glued together. As the subassemblies for the undercarriage of the car are completed, they are bonded to each other until the entire underbody is finished. • Second: The subassemblies for the upper part of the body are also bonded to make larger sections. The completed sections are similarly welded or glued until the body frame is finished. The body is added to the underbody. • Third: The roof is attached. Like other parts of the exterior, it has already been painted. The underbody and the rest of the frame are coated with protective sealants, and the finished body is moved to the general assembly area.
- 30. Manufacturing Process - General Assembly 1. The first set of the electric car's complex electronics are put in place. 2. The interior is outfitted. Flooring, seats, carpeting, and the console and dash are placed in the car. 3. The air conditioning, heating, and circulation system is inserted, and the system is filled. 4. The battery pack is added. The T-shaped unit is seated by lifting the heavy pack using a special hoist up into the car. 5. The windshield is installed and other fluids are added and checked. The door systems (complete with vinyl interiors, arm rests, electronics, and windows) are also attached, and all the connections are completed and checked. 6. The alignment is checked and adjusted, and the under-body panel is bolted into place. The process concludes with the last, comprehensive quality control check.
- 31. Optimization • Weight and climbing and acceleration • Aerodynamic drag and wind • Rolling and cornering resistance • Drivetrain system
- 32. The Charging System • Any electric car that uses batteries needs a charging system to recharge the batteries • To pump electricity into the batteries as quickly as the batteries will allow • To monitor the batteries and avoid damaging them during the charging process • It takes about 12 kilowatt-hours of electricity to charge the car after a 80-kilometer trip.
- 33. Car Charger
- 34. Fuel Costs 12 10 8 6 4 2 Fuel cost ¢/mile Gasoline vehicle Electric vehicle
- 36. Energy Efficiency - Internal combustion engines are relatively inefficient at converting on-board fuel energy to propulsion as most of the energy is wasted as heat - On the other hand, electric motors are more efficient in converting stored energy into driving a vehicle - Some of the energy lost when braking is captured and reused through regenerative braking
- 37. Energy Efficiency - Typically, conventional gasoline engines effectively use only 15% of the fuel energy content to move the vehicle - Diesel engines can reach on-board efficiencies of 20% - Electric drive vehicles have on-board efficiency of around 80%
- 38. Energy Efficiency - Approximately 20% of power consumption is due to inefficiencies in charging the batteries - Electric vehicles generate very little waste heat and resistance electric heat may have to be used to heat the interior of the vehicle
- 39. Conclusion – The Future - Electric cars are critically important to the future of the automobile industry and to the environment. - Consumption of decreasing oil supplies, concerns over air and noise pollution, and pollution caused (and energy consumed) by abandoned cars and the complications of recycling gasoline-powered cars are all driving forces that seem to be pushing toward the success of the electric car
Editor's Notes
- #30: The glue is an adhesive bonding material, and it provides a connection that is more durable and stiffer than welding.