New Designs of Electric Vehicles - Case Study Example

New Designs of Electric Vehicles Name: Course: Instructor: Institution: Date of Submission: TABLE OF CONTENTS TABLE OF CONTENTS 2 1.0.Introduction 3 2.0.Design of Electric Vehicles 3 2.1.Calculations of Power for the EV 5 2.2.Motors of New Designs of Electric Vehicles 8 2.3.Batteries 9 2.4.Braking 11 3.0.Critical Challenges of Electric Vehicles 12 4.0.Example of Electric Vehicles in Use and their Architectures 12 5.0.Advantages of the Electric Vehicles 13 6.0.Conclusion 14 7.0.References 15 8.0.APPENDICES 16 1.0. Introduction Electric vehicles are the future generation of car designs in the world due to the increased efficiency the vehicles possess. This is in relation to better environmental benefits such as reduced noise pollution. The electric vehicles have an increased power regulation process, which is a key advantage in energy efficiency. The present gasoline/diesel vehicle has numerous disadvantages such as the high emissions, noise pollution, high consumption of power and lack of power regeneration among others. These impacts are perceived in the world generally, mainly through climate change and increased global warming. Thus, based on these facts the electric vehicles will be the future vehicles to be used by coming generations. The electric cars already exist, though not dominantly in use mainly due to the high price and the disadvantage of long time battery charging as will be shown in the text below. The project evaluates some of the new designs of electric vehicles that exist to enhance understanding of the basics of electric vehicles. It also presents the designs of electric vehicles, the critical disadvantages and challenges of the vehicles, and the advantages of the vehicles, which satisfy why the electric vehicles are the future models in the car industries. 2.0. Design of Electric Vehicles Designing electric vehicles is dependent on several factors such as the electric machine, transmission of power, battery and other power electronics. The electric vehicles (EV) get their electricity from sources such as solar energy, wind energy, and power stations among others. Some of the electric vehicles on the road include Mercedes Benz Smart, Tesla, Nissan FEVII, and Nissan Altra among others. Figure 1: Electric Vehicle: Mercedes Benz Smart The range of the vehicle is dependent on the energy stored in the battery. Main considerations of the car include the electric system efficiency, charging time of the battery, and range of the vehicle. The engine needs to be suffieicntly compact through the design o f the vehicle optimizing space for the engine to be housed in the axle (Mercedes Benz, 2017). The electricity control components of the EV derive from electrical energy (or any other source of energy being used) to charge the battery of the vehicle. When the battery is charged, it is stored in the inverter or motor. The inverter is used to drive the motor of the vehicle, thus powering the vehicle. When the battery is charged, the power is converted using the DC-DC converter while using the computer of the vehicle and other electronics (Taranovich, 2011). The batteries that are commonly used for the EV include the lead-acid batteries, Lithium ion, and NiMH among others. The common motors that the EV use include the DC motors, induction motors, DC brushless motors, and the reluctance motor among others. Thus, the design of the electrical vehicle begins through determining the source of energy, how to convert the electrical energy to the power to drive the motor using the inverter. The EV electronics should also consider the lighting of the vehicle, the motor, inverters and other drives such as the DC distribution (Mercedes Benz, 2017). 2.1. Calculations of Power for the EV The main factor/component to consider when evaluating the design of the EV is the maximum speed, torque speed, the weight of the vehicle, which influences speed. Also, the motor and controllers used among others (Ehsani, Gao, Gay, & Emadi, 2005). The designs begin through firstly identifying the power calculations of the new design EV, which determine the characteristics and design of other factors. That is; the given power calculations are used to select the battery and motor of the vehicles among other electronic modules (Seth & Bob, 2009). The powertrain of the EV design during development of the vehicle should ensure the weight and volume of the vehicle are reasonable, to ensure the prices of the cars are fair to consumers for purchases to be made (Santos, Pais, Ferreir, Ribiero, & Matos, 200). The speed of the EV vehicles is reflected to be low when compared to gasoline/diesel vehicles. The low speed stipulates that the rolling resistance of the vehicle should be well-thought-out, as it is relative to the weight of the vehicle. Thus, the lower the weight of the vehicle, the more efficient the vehicle in terms of speed and energy consumption. Thus, the design of the EV shows that the lighter the vehicle, the more efficient it is (Seth & Bob, 2009). Figure 2: Design of wheel drive trains for EV where the electric motor is at the centre The accurate power necessities of an EV cannot be determined unless some forms of Matlab simulations (or others) are used. However, the power calculations must be conducted to start designing the vehicle. As presented above, the most important factor considered is the aerodynamic drag force and rolling resistance, as they compete against the vehicles motion. Thus, through coast down tests, the vehicles speed on the neutral gear is perceived, which determines the condition of the vehicle. Thus, most of the new designs use the following power calculations regarding the rolling resistance and drag aerodynamics force to design new EV. The graph below presents that speed reduced as time moved forward. At about 0 seconds the speed of the vehicle was around 58km/h while at 30 seconds the speed had decreased to 14km/hour. Graph 1: Coast down test for EV New Designs The rolling resistance of vehicles can also be calculated using the formula below. The aerodynamic drag force is calculated using the formula below Where F (N) = force µ = the rolling resistance coefficient m = mass given in kg (of the vehicle) g = the constant factor of gravitational (m/s2) α = inclination angle ρ = air density (g/m2) Cd =aerodynamic coefficient of the drag force A = the cross sectional area of the front part of the vehicle (m3) v = vehicles velocity (km/h) vo = headwind vehicle velocity (km/h) Thus, the rolling resistance and aerodynamic drag force calculations give the power calculations that are used to determine other important factors of the EV such as the motor or controller to be used for the vehicle. The results are used through the equation given below Where p presents the power load in the vehicle, v similarly presents the vehicles velocity while F gives the force load on the vehicle. The information is used to generate the graph that is used in designing the new EV since it shows the power constantly needed to sustain a given speed for the vehicle. The graph below presents an example of a graph used to design a new electric vehicle with a cross sectional of 1m2 and mass of 680. Graph 2: New design of EV with a mass of 680 and cross sectional area of 1m2 The graph above presents that to maintain a speed of 75km/h the ideal power needed would be 10kW while at a speed of 80, the needed power would be 14.5kW. Thus, in calculating the power calculations of a new design of the EV, other factors are easily identified and selected for implementation during the architecture of the vehicle (Santos, Pais, Ferreir, Ribiero, & Matos, 200). 2.2. Motors of New Designs of Electric Vehicles The main motors used for electric vehicles are the DC or AC motors. The DC motors use about 96 to 192 volts of power to run. The main limitation of the DC motors is that the motors can only be used for short periods due to heat building up. On the other hand, AC motors have high advantages of high speed output, better torque, size and weight. Fgure 3: AC Motor The electric vehicles controller helps in controlling the motor voltage, which is dependent on the potentiometer output that leads to controlling the speed of the motor as well. The AC controller uses about 6sets of transistors, which helps with an input power of 300 volts when using the DC motors while the AC produces 240 volts (Ehsani, Gao, Gay, & Emadi, 2005). The drive motors for new EV designs have to reach a torque speed, which is considered maximum at the first revolution. The advantage of the AC motor is that it does not require the application of a start period to reach an idling speed (Taranovich, 2011). Thus, the design of the EV motor stipulates that complex transmissions are not required to run the vehicle. Graph 3: Torque development in EV The new designs of EV presents the engine of the vehicle which needs the idling speed to develop a torque at the first revolution, which increases with increase in the engine speed (Santos, Pais, Ferreir, Ribiero, & Matos, 200). The engine also necessitates the transmission of some gear ratios, where the torque speed is distributed through the clutch for motion (Seth & Bob, 2009). The transmission process is irrelevant in electrical vehicles due to the polarity of the electrical motor. 2.3. Batteries The main battery that is currently being used for the new designs of electric vehicles is the lead battery. The battery charges slowly, it is very heavy, bulky and has a short life, despite the high cost of the batteries. Thus, despite being a new design for the EV, it is not the best option. Thus, the main battery that is considered a better option for the EV is the NiMH, which is also highly expensive, but has a long life, and can run for longer periods compared to the lead acid battery (Condon, 2017 ). Some of the important factors to consider about the batteries selection for the EV are shown below. Table 1: Battery selection considerations for the Electric Vehicles Charging of the batteries can be conducted through a charging grid, where some chargers monitor the voltages of the battery and also show the data regarding the temperature of battery and flow of current, which lowers the time used to charge the battery. When the charger of the EV is working, the outlet voltage is either 240/120 volts for the AC motor and controller (Ehsani, Gao, Gay, & Emadi, 2005). The electric vehicle comprises of several battery strings, which are identical to each other but not compleely matched. Therefore, a weaker battery consumes more energy due to the increase in recharging episodes (Ehsani, Gao, Gay, & Emadi, 2005). When a battery is recharged many times, it becomes weaker leading to the life deteroriation of the battery as it becomes inoperable. To increase the life cycle of weak batteries, they should be overcharged so that the weak cells can fully charge. For a charger that shows the charging process of a battery, the following information is useful to ensure the weak cells are overcharged for a longer life cycle and driving range for the vehicle. Figure 4: Battery Charging Information (important for weak batteries to ensure overcharging occurs) The batteries are used for other actions such as the airbags power, windows power, computers, fans, headlights and others. Thus, the controller of the motor logic should ensure the battery used in the design of the vehicle meets the anticipated needs to run the vehicle’s applications including maintaining the anticipated vehicle and torque speed besides other auxiliary uses. 2.4. Braking The electric vehicles use regenerative braking in connection with the conventional friction braking (Ehsani, Gao, Gay, & Emadi, 2005). The motor of the vehicle is mainly used as a generator that captures the kinetic energy the car consumes, and converts the energy to additional electrical power that can be used to recharge a battery (Volkswagen, 2013). 3.0. Critical Challenges of Electric Vehicles Driving range of the vehicles is limited. Despite the availability of air conditioning, it is inefficient since it does not support the long range of the vehicles. That is; the air conditioning does not support the long range of the batteries (Santos, Pais, Ferreir, Ribiero, & Matos, 200). The cars take a long time to be charged (Taranovich, 2011). When compared to common gasoline vehicles, which only consumed a few seconds or a minute refuelling, the EV mainly requires hours to fully recharge. Since they consume electrical power, the electric vehicles need to be recharged, which takes a longer time. Thus, when the battery is almost dead and one needs to go somewhere, the vehicle would not be an option, which is a key imitation that may hinder the dominant usage of the vehicles despite the many benefits it offers (Seth & Bob, 2009). The cost of the vehicles is very high. For instance, the cost of the motor and battery is expensive, which makes the EV expensive compared to other existing cars. 4.0. Example of Electric Vehicles in Use and their Architectures The vehicle presented is from the TESLA brand. The vehicle uses a lithium ion battery, which generates about 375 volts of power to the motor. Thus besides the basic needs of the car, the battery power is used for air conditioning, cooling and heating systems in the vehicle (Condon, 2017 ). The battery stores about 53kWh. The battery used for this electric vehicle is beneficial since it has a long life cycle of about 10 years. The motor of the vehicle is a 4-pole phase AC motor with a maximum torque of 350Nm at 0rpm, and a maximum speed of 13500 rpm. 5.0. Advantages of the Electric Vehicles One of the mainly recognized advantages of the electric vehicles is the increased energy efficiency. For instance, a gallon of biodiesel helps a diesel car to go about 66 miles (Seth & Bob, 2009). However, when the same gallon of diesel is converted to electrical energy, it has about 21.9kWh, which means that the vehicle can range to about 96 miles since 1kWh propels the vehicles by about 4.4miles. Thus, the electric vehicles are beneficial when fully charged in increasing the efficiency of energy. The energy efficiency is also favourable in that the costs of running an EV compared to gasoline cars is relatively low. The EV motors have a longer life cycle compared to the gasoline vehicles (Seth & Bob, 2009). Additionally, the EV also have the key advantage of zero emissions. Given the current situation in the world regarding global warming due to emissions and climate change, the electric vehicle is the best option since it eliminates emissions. It can help manage the global warming effect (Taranovich, 2011). Furthermore, the vehicles are environmentally friendly, which is also linked to the low sound pollution they cause. Thus, the vehicles are important in mitigating climate change effects and increasing the consumption of raw materials such as solar energy. The vehicles help countries in attaining the given international limits regarding emissions, while leading to the development of low emissions zones (Mercedes Benz, 2017). The world is also facing a challenge of limited oil reserves, which stipulates that oil to sustain gasoline vehicles may become scarce and expensive compared to EV. 6.0. Conclusion Electric vehicles are definitely what the future holds in terms of vehicle improvements. Thus, it is important that businesses and other vehicle industries consider improving the EV batteries to meet the needs of private individuals. Lithium polymer is one of the batteries that should be improved to meet future needs of the people. For instance, methods of storing energy could be improved such as developing double layered capacitors among others. Based on the information provided above, the battery with high voltage is a key component of the new EV powering the generator, brake system, power transmission and the high voltage vehicle air conditioning. The efficiency of the EV is highly related to the life, efficiency, and energy of a battery besides other power calculations. 7.0. References Condon, J. (2017 ). Volkswagen's New Design Language May Show the Future of Electric Vehicle Forms: Demands of Electric Vehicles Necessitate Taller Cars with Shorter Overhangs. The Drive, 1-1 Retrieved from:http://www.thedrive.com/tech/7216/volkswagens-new-design-language-may-show-the-future-of-electric-vehicle-forms. Ehsani, M., Gao, Y., Gay, S. E., & Emadi, A. (2005). Modern Electric, Hybrid Electric, and Fuel Cell Vehicles - Fundamentals, Theory, and Design. New York: CRC Press LLC. Mercedes Benz. (2017, 2 2). Mercedes-Benz. Retrieved from Vehicle Architecture with Open Space: https://www.mercedes-benz.com/en/mercedes-benz/next/e-mobility/vehicle-architecture-with-open-space/ Santos, R., Pais, F., Ferreir, C., Ribiero, H., & Matos, P. (200). Eletric Vehicle - Design and Implementation Strategies for the Power Train. RE&PQJ, 552-558. Seth, L., & Bob, B. (2009). Build your own electric vehicle . New York: McGraw Hill. Taranovich, S. (2011). Engineer Shares how to Build an electric vehicle from the ground up: Design Choices. EDN Network, 1-1 Retrieved from: http://www.edn.com/design/automotive/4368192/Engineer-shares-how-to-build-an-electric-vehicle-from-the-ground-up--Design-choices. Volkswagen. (2013). Basics of Electric Vehicles Design and Function. Service Training: Self Study Program 820233, 1-57. 8.0. APPENDICES Read More