IPRO 326 - Spring 2003 Hybrid Electric Vehicles: Simulation, Design, and Implementation
Team Goals Understand the benefits and pitfalls of hybridizing Gasoline and Diesel parallel hybrid SUVs Conduct an extensive analysis of simulations involving the Toyota Prius and Honda Civic for comparison to known results Determine what extent the use of ultra-capacitors improves the efficiency of hybrid vehicles and model an ultra-capacitor in parallel with an energy source Lay the simulation and design groundwork for hybrid electric vehicle SUV conversion at IIT to begin next semester
Introduction to Hybrid Electric Vehicles Presenter: Pavel Reytikh
What is a HEV? Hybrid electric vehicles (HEVs) combine the internal combustion engine of a normal vehicle with the battery and electric motor of an electric vehicle. This results in an increase in the fuel economy when compared to conventional vehicles. Also offers the extended range and rapid refuelling that consumers expect from a normal vehicle, with most of the energy and environmental benefits of an electric vehicle. Can be used in a wide range of applications, from personal transportation to commercial hauling. 2 sources of power: series and parallel
Series HEV Configuration Accelarator pedal Brake pedal Controller Internal Combustion Engine Generator Machine Controller Electric Machine Transmission Differential Battery ICE charges batteries or powers electric motor which drives the transmission
Parallel HEV Configuration Accelarator pedal Brake pedal Controller Internal Combustion Engine Transmission Differential Battery Machine Controller Electric Machine ICE and electric motor can both drive the transmission
Electrical Power System HEVs contain a small electric motor Acts as a generator as well Uses battery energy to accelerate car Uses generator properties to slow car and recharge batteries HEVs contain batteries Used to power the electric motor Recharged each time the brakes are pressed The electric component of the car takes over when driving in slow traffic or when you stop frequently The electric motor can be used with the gas engine when accelerating the car
Gasoline Power System The HEV has the same internal combustion engine as a regular car Slightly smaller it isn t doing as much work as in a regular car because the electric motor is able to take over in certain circumstances More efficient because of the size The internal combustion engine is used during faster driving or when accelerating (to pass, climb a hill, or get on the highway) Hybrids have a transmission that performs the same job as in non-hybrid cars
What is ADVISOR? ADVISOR is an ADvanced VehIcle SimulatOR that simulates the performance of hybrid electric, conventional, electric, and fuel cell vehicles. Calculates the fuel economy, emissions released, acceleration times, and much more for a given drive cycle. Created the U.S. Department of Energy's (DOE) Office of Transportation Technologies' (OTT) Hybrid Vehicle Program
What is UDDS? UDDS stands for Urban Dynamometer Driving Schedule AKA The U.S. FTP-72 (Federal Test Procedure) cycle 60 UDDS Drive Cycle 50 speed (mph) 40 30 20 10 0 0 200 400 600 800 1000 1200 1400 time (sec) Tests vehicles over the following parameters: Duration: 1369 seconds Distance: 7.45 miles (12 km) Averages Speed: 19.6 mph (31.5 kph) Maximum Speed: 56.7 mph (91.2 kph)
Toyota Prius and Honda Civic Research and Simulation Presenter: Pavel Reytikh
Toyota Prius 1.5 L, 70 hp ICE 44 hp electric motor 52 city/45 highway mpg Can achieve speeds of 15 mph on electric motor alone Optimized for city driving
Honda Civic 1.3 L, 85 hp ICE 13.4 hp electric motor 48/47 mpg (CVT) 46/51 mpg (MT)
Results Comparison CYCLE PRIUS CIVIC (MT) CIVIC (CVT) UDDS 48.4 49.6 48.3 MANHATTAN 27.2 24.7 24.2 SKELETON 31.3 36.7 33 HWFET 65.6 62.7 61.1 BUSRTE 18.5 20.3 20.7 *All numbers are miles per gallon.
Gasoline Sport Utility Research and Simulation Presenters: Jason Tyrus and Ryan Long
Gasoline Sport Utility Vehicle Specifications Engine: Saturn 1.9L (95kW) DOHC SI Engine Energy Storage: Hawker Genesis 12V26Ah10EP Motor: Westinghouse 75kW AC induction motor/inverter Transmission: Model of GM 4L60E Automatic Transmission and Final Drive
Simulation Control Strategy Parallel Hybrid Electric Vehicle Configuration Charge Sustaining - Battery State of Charge must remain above 0.5 Optimized Battery Control Strategy 5 UDDS Cycle Simulations Power of Vehicle remains constant
Representative Small SUV Based on: Jeep Liberty Sport Toyota Rav4 Base Ford Escape XLS Nissan Xterra XE Saturn VUE Chevrolet Tracker HT Base Drag Coefficient 0.40 Frontal Area (m 2 ) 2.79 Vehicle Height (m) 1.75 Front Weight Fraction 0.6 Wheelbase (m) 2.62 Total Mass (kg) 1547 Total Mass (lb) 3411 Total Power (hp) 175 Total Power (kw) 130 Glider Mass (kg) 896.6984 Ground Clearance (m) 0.2068 Center of Gravity Height (m) 0.72
Small SUV Simulation Results Fuel Economy and % Improvement vs. Hybridization Factor for 130 kw Small SUV 50 45 Fuel Economy (mpg) % Improvement 40 35 30 25 20 15 10 5 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Hybridization Factor Best hybridization factor is 0.5 Above HF of 0.7, cannot maintain state of charge 44.9% improvement over conventional
Performance of Small SUV Gradeability vs. Hybridization Factor for 130 kw Small SUV 25 21.5 20 18.7 18 16.1 Gradeability (%) 15 10 13.7 11.3 8.8 8.9 5 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Hybridization Factor
Representative Medium SUV Based on: Toyota 4Runner SR5 Honda Pilot EX-L Lexus LX470 Jeep Grand Cherokee Nissan Pathfinder SE Dodge Durango SLT GMC Envoy Drag Coefficient 0.45 Frontal Area (m 2 ) 2.9 Vehicle Height (m) 1.8 Ground Clearence (m) 0.214 Avg. Height (m) 0.744 Front Weight Fraction 0.5 Wheelbase (m) 2.8 Total Mass (kg) 2,100 Total Mass (lb) 4,630 Total Power (hp) 245 Total Power (kw) 183
Medium SUV Simulation Results Fuel Economy and Percent Improvement vs. Hybridization Factor for 245 kw Medium SUV 60 Fuel Economy (mpg) % Improvement 50 40 30 20 10 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Hybridization Factor Best hybridization factor is 0.5 51.4% improvement over conventional
Performance of Medium SUV Gradeability vs. hybridization Factor for 245 kw Medium SUV 25 20 20.1 17.2 Gradeability (%) 15 10 14.9 12.6 10.1 7.7 5 5.4 3 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Hybridization Factor
Representative Large SUV Representative Drag Coefficient 0.41 Frontal Area (m 2 ) 3.37 Vehicle Height (m) 1.92 Front Weight Fraction 0.6 Wheelbase (m) 3.06 Total Mass (kg) 2644 Total Mass (lb) 5830 Total Power (hp) 282 Total Power (kw) 210 Based on: Cadillac Escalade, Land Rover Range Rover, Ford Expedition, Ford Excursion, GMC Yukon, Hummer H2, and Toyota Land Cruiser
Large SUV Simulation Results Fuel Economy and Percent Improvement vs. Hybridization Factor for 210 kw Large SUV 60 Fuel Economy % Improvement 50 40 30 20 10 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Hybridization Factor The best hybridization factor is 0.5 50.4% improvement over conventional
Performance of Large SUV Gradeability vs. Hybridization Factor for 210 kw Large SUV 25.0 21.0 20.0 17.9 15.6 Gradeability (%) 15.0 10.0 13.3 10.8 8.2 5.8 5.0 3.3 0.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Hybridization Factor
Diesel Sport Utility Research and Simulation Presenter: Ian Albert
Diesel Sport Utility Vehicles Diesel engines are more efficient than gasoline engines and achieve better fuel economy. Current Hybrid Vehicles run on gasoline, investigate the effect of hybridization of a diesel SUV. Combine the benefits of diesel and Hybrid electric vehicles to get improved fuel economy from the vehicle. Evaluate ADVISOR s capability to simulate diesel hybrid electric vehicles
Representative Vehicles 2003 FORD EXCURSION 2003 TOYOTA RAV 4 The models used in ADVISOR are based on the manufacturers data for the FORD EXCURSION and TOYOTA RAV 4. Approximations are made for data that is not available from the manufacturers. The FORD EXCURSION represents a large SUV and the TOYOTA RAV4 represents a small SUV.
Goals of Simulation Achieve best fuel economy for each hybridization factor by varying the number of battery units Minimum state of charge is 0.5 Speed, gradeability and acceleration performance are not taken into consideration Simulation is done with a parallel drivetrain configuration where the output power is the sum of the power of the electric motor and internal combustion engine
Results of Small SUV simulations Fuel Economy and % improvement vs. Hybridization Factor for small SUV 120 115.91 100 97.73 86.36 80 75.76 60 40 20 13.2 40.15 18.5 53.03 20.2 63.64 21.6 23.2 24.6 26.1 28.5 Mileage ( MPG ) % Improvement 0 0.00 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Hybridization Factor Tabulated data is available in the report
Acceleration Performance of Small SUV 0-60 Mph time for Small SUV (Lower is better) 25 20 time (s) 15 10 0-60 mph (s) 5 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Hybridization Factor (HF)
Results of Large SUV Simulation Fuel Economy and % Improvement vs. Hybridization Factor for Large SUV 50 45 40 39.47 44.74 42.11 48.03 35 30 27.63 31.58 34.87 25 20 15 15.2 23.68 18.8 19.4 20 20.5 21.2 22 21.6 22.5 Mileage ( MPG ) % Improvement 10 5 0 0.00 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Hybridization Factor Tabulated data is available in the report
Acceleration Performance of Large SUV 0-60 Mph time for Large SUV (Lower is better) 35 30 25 time ( seconds ) 20 15 10 0-60 Mph time 5 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Hybridization Factor
Conclusion of Diesel SUV Simulations As hybridization factor increases, acceleration performance decreases and fuel economy increases Increasing the battery units affects the performance but does not affect the fuel economy Greater fuel economy gains for small SUV as compared to large SUV For HF < 0.5, good performance For HF 0.5, good fuel economy Performance of SUVs can be optimized
Ultra-Capacitor Research and Simulation Presenter: Carson Baisden
Energy Source Problem A single energy source usually has a trade off of maximum storage versus power flow Specific energy (storage) Specific power (deliver) Charge/ Discharge efficiency Life Expectancy Battery 10-100 W-h/Kg <1000W/Kg 50-85% 3 years Ultra-capacitor 5-10 W-h/Kg <10,000W/Kg 85-98% 10 years Harness the benefits of the Battery and UC together to improve the energy density, life expectancy, and cost. Maintain or improve upon the characteristics of the vehicle. Combine the two sources in a parallel configuration.
ADVISOR s model to couple the Battery and UC Power Requested SOC / Power Available Battery Power Delivered from Battery Power Requested from Power Bus DC/DC Converter Max Limit of Converter Σ Power Delivered to Power Bus Power Requested SOC / Power Available Ultracapacitor Power Delivered from Ultracapacitor
Source Currents
Comparing Currents Battery Alone Battery (w/ UC) UC (w/ Battery) Max Current (A) 27.6 13.8 94.6 10 year cost ~$7800 ~$6450
Simulation Results Conventional (Non-Hybrid) Battery Source Optimal UC & Battery Source VEHICLE PARAMETERS Battery 18 Cells/ Energy Storage N/A 26 Cells UC 35 Cells SIMULATION RESULTS Conv. Bat % change of the UC/Bat Source vs: Fuel Economy (MPG) 32 37.4 38.3 19.69% 2.41% Acceleration 0-60 mph (sec) 11.2 8.9 8.9-20.54% 0.00% Grade-ability @ 55MPH 16.5 20.5 19.4 17.58% -5.37% Max Speed (MPH) 111.9 118.4 111.1-0.71% -6.17% EMMISIONS: HC 0.851 0.561 0.56-34.20% -0.18% CO 2.99 3.172 2.931-1.97% -7.60% Nox 0.463 0.482 0.476 2.81% -1.24% Drive Cycle (UDDS), vehicle size (small), parallel configuration, engine, motor (HF=41%), etc. is held constant only the energy source is varied.
Advantages of an Ultracapacitor Battery s current when with the UC is decreased and makes it steadier than the Battery s current without the UC Smaller battery can be used More efficient Decreased cost Life of battery potentially increased Capacitor produces needed current burst that provide for an adequate fuel economy, acceleration, etc.
Future Plans Run extensive simulations on Jeep Liberty in preparation for actual SUV conversion to hybrid beginning next semester Verify computer-simulation and design results from this and previous IPRO teams experimentally on actual Jeep Liberty next semester Implement design results and convert actual conventional Jeep Liberty to hybrid Publish 3 technical papers concerning Gasoline Hybrid SUVs and Diesel SUVs
Questions? Refer to Final Progress Report or check us out at: http://www.iit.edu/~ipro326s03 *Refer to Final Progress Report for Complete Result Tables, Charts, and Analysis