6. Electric car According toCALSTART, the advanced transportation consortium in California, 70% of anelectric vehicle’s component parts may be different from a gasoline-poweredvehicle 53. The electric vehicle has various unique components compared tocombustion engine cars even while both the components perform the samefunction.
Most important difference is the number of moving parts present inelectric vehicles that is significantly lesser on comparison with the IC enginetype. The motor of the electric vehicle is the only moving part. Fewer movingparts are direct advantage for the electric vehicles, as it requires much lessintensive maintenance and lesser breakdowns when compared to its IC enginecounterpart. The traditional vehicles demands a lot through maintenancestarting from oil change, coolant change, filter replacements etc.
6.1 The major components of an electric vehicle Figure 8: Electric vehicle components 1156.1.1 The Electric Motor The electricmotor is the power-delivering component of the electric car. It converts theelectric energy supplied to it into mechanical rotation to drive the vehicle.The type of motor used is three-phase synchronous motor powered by athree-phase alternating current.
The stator of this electric motor is wound in threecoils, and the rotor contains several permanent magnets. When electricity issupplied to the coils sequentially it generates the rotating electrical field intern rotating the rotor containing the permanent magnet. The electricmotor does not produce any emission or noise making it environmentallyfriendly. It is easier to achieve greater control over the electric motor, asthe response is very quick and efficient to produce good acceleration andtorque. Electric motors deliver their nominal power over a broad range of rpm.The maximum torque is available across the lower rpms’ drops once the motorreaches high speeds. The direction of rotation is also selectable with thedirection of current supplied in the stator. This eliminates the need fortransmission or a clutch.
Compared to Internal combustion engine, Electricmotors have simple design with only the rotor as the moving part. 57 6.1.2 The High-Voltage Battery The battery isthe heart of the vehicle. The high voltage battery’s function is to supplydirect current to the control unit that converts the current to alternatingcurrent and transfers to the electric motor. The batteries have to be competent to deliver a power inthe order of 100kW and be able to fit inside the limited space with lessweight.
All over the world extensive research work is made towards theadvancement of the battery technology. The U.S. government has stronglysupported the research activities to advance batteries technologies through theDepartment of Energy: Grants of 2 billion dollars are given to accelerate themanufacturing and development of the next generation of U.S. batteries and EVs54.
European Commission and governmental organizations in Europe and JapaneseMinistry of Economy are also continuously supporting the research for thebatteries. Currently the battery technologies for cars follow 2 major platformnickel metal hydride (NiMH) and lithium ion (Li-ion). The Lithium ion type hasthe potential of having higher specific energy and energy density; making it tobe the most effective platform for the future of battery technology andexpected to be adopted in wide scale.
5557 6.1.3 Control unit for battery regulation andcharger The battery canonly hold direct current while the motor needs alternating current to run. Theexternal charging points also have alternating current. The Control unit doesthe job of converting the external three phase alternating voltage into aconstant direct voltage to charge the battery.
It also converts the directvoltage from the battery into a 3-phase alternating voltage for the electricmotors. 57 6.1.4 Braking system Apart from thetraditional mechanical/ hydraulic brake system the electric cars have a secondarybrake system for regenerative braking.
The braking system generates electricityfrom the electric motor during braking and deceleration. The generatedelectricity is recovered and is used to charge the high-voltage battery. Thisregenerative braking contributes to the high efficiency of the electricvehicles especially in stop and go city traffic conditions.
57 6.1.5 Cooling system The temperatureacutely affects the performance of the battery.
The battery also generates alot of heat during its operation. The function of the cooling system is to keepthe battery at ideal temperature conditions to facilitate best performance ofthe battery and protecting the battery from permanent damage. The coolingsystem in addition to cooling, also heats the cells in case the ambienttemperature is lower than ideal. The ideal operating temperature for thebattery is a temperature range of 5 to 45°C.
Three common methods are followedin electric car cooling system. One method is convection by letting airflowover the battery. Second method the dielectric oil is made to flow over thebattery to collect the heat and transfer the heat outside through a heatexchanger. Third is cooling by circulation of water-based coolant. Typicallythe auto makers are adapting to either the second or third method i.e.
Coolingbased on dielectric oil or water-based coolants. 56 6.1.
6 Transmission The Pure electricvehicles do not need a traditional transmission with gears, as the electricmotor is capable of handling all the needs of transmission by itself. Thecontrols available to the driver in the selector lever have 3 positions:Neutral, Drive forward, Drive reverse. The speed of the car can be variedthrough the level of voltage supplied to the motor and can be directly and accuratelychanged using the accelerator pedal. 57 From the abovecomponent structure we can understand that the degree of parts that changebetween IC engine and electric cars are huge.
The parts of the electric car arenot comparable with the parts of the traditional car this makes the supplierexpertise of manufacturing combustion engine parts futile. The new parts are tobe developed from the scratch by the supplier base to move the industry intoelectro mobility. In this thesis,we are going to explore the impact of suppliers who supply the engine and powertrain parts of the traditional car.
These suppliers will have the major impactas compared to other part suppliers such as the body part, paint, glass orlights who have the option to modify their production systems without majorchanges to cater the electric vehicles. However, the engine part suppliers facingthe discrete technology change will have to be able to produce electricalpowertrain parts that are completely out of their portfolio. They are in thecross roads of time that can make them obsolete.