Toyota - Prius - Miscellaneous Documents - 1993 - 2020

Toyota’s Hybrid Technology Yoshihiro Onomura General Manager, Planning & Administration Dept. Hybrid Vehicle Engineering Management Div. 1 1. Birth of the world’s first mass produced hybrid: the Prius 2 The Challenge of car-making for the 21st century: Prius development 3 Toyota started development of Prius in 1993, autumn The theme that was given to the project team at that time: • Create the 21st century car • Change the vehicle development method Project name: “Ｇ２１” 3 The Challenge of car-making for the 21st century: Prius development The mission of Prius was to create an entirely new concept vehicle to meet 21st century needs = outstanding fuel economy Maintain or enhance good usability or comfort of conventional vehicles, but also simultaneously respond to the Challenges of motorized society in the 21st century Overcome energy resources / environmental issues Realize outstanding fuel economy 4 The Challenge of car-making for the 21st century: Prius development Prius achieved far better fuel economy than original target Original target Ideal target 1.5 times better fuel economy (Extension of existing technology) Target too low to develop the vehicle for the future 2 times better fuel economy Not just do “What we can”, but do “What we should” Mass production of the hybrid vehicle Prius Conventional vehicle 1.5L (Gasoline) 28.0km/L 14.0km/L (Japanese 10-15 test mode) 5 The Challenge of car-making for the 21st century: Prius development Dec. 1997 Sales of Prius had Begun World’s first mass produced hybrid vehicle 6 2. What are Hybrids? 7 Feature of Toyota’s Hybrid Vehicles Hybrid vehicles have two power sources; Gasoline engine and electric motor which bring about greater efficiency Gasoline engine Gasoline engine vehicle Electric motor Electric vehicle Gasoline engine ＋ Electric motor 8 Feature of Toyota’s Hybrid Vehicles By combining the benefits of gasoline engines and electric motors, hybrid vehicles offer excellent driving performance and eco-friendliness 9 Feature of Toyota’s Hybrid Vehicles When Hybrid vehicles are in EV mode, only the electric motor works and therefore, no CO2 emissions. No CO2 emissions while EV mode 10 Feature of Toyota’s Hybrid Vehicles Also, hybrid vehicles save energy recovered from braking 11 Feature of Toyota’s Hybrid Vehicles HVs use two or more distinctive types of power to enhance fuel efficiency and environmental performance through recovery and re-using of energy First Prius (1997) : Gas Station (1) The world’s first mass Battery Motor produced HV (2) Power sources – the Engine Fuel Tank internal combustion engine and electric motor (3) Battery is the power buffer which allows regenerated power during braking to be re-used (4) Achieve high level of fuel efficiency and low-emissions with 2 power sources and battery 12 Driving energy in conventional vehicles Energy needed for driving is often not in the high-efficiency area + Energy Energy needed for driving vehicle Engine High-efficiency operating area Constant running Stop Time Deceleration - 13 Energy management of Toyota’s Hybrid System In hybrid vehicles, battery supports engine for the less-efficiency operation area, and also store energy for less energy consuming drive Battery + Driving Energy Supply necessary energy ３ Surplus Energy Storage High-efficiency operating area Energy ２ １ Engine power Re-generating Energy ４ （maximum efficiency） Engine stop STOP START Full throttle Eng stop Battery Battery+Eng Constant speed Braking Eng Battery charge 5 14 How Toyota’s Hybrid System works When starting and light-load driving, electric motor drives the wheels by using electricity from the battery Starting and light-load driving 15 How Toyota’s Hybrid System works When normal driving, the engine power is split into 2 portions, 1) for driving the wheels, 2) for feeding generator/motor to supplement engine power Excess electricity during light-load driving is charged to battery Normal driving 16 How Toyota’s Hybrid System works When in full acceleration mode, battery supplies more power to drive the electric motor. Full acceleration 17 How Toyota’s Hybrid System works When decelerating and braking, regenerative braking recharges the electricity from motor to battery Decelerating and braking 18 How Toyota’s Hybrid System works The amount of charged electricity has reduced, the engine drives the generator to recharge the battery Battery-charging 19 Why Toyota’s Hybrid System is fuel efficient Toyota’s Hybrid technology realizes high fuel efficiency compared to gasoline engine cars Fuel efficiency improvement City Mode Vehicle: Prius-class model 2 Regenerative braking Idling stop Engine use in fuel efficient area ・ EV driving mode (start driving, light-load driving) ・ Engine use in fuel efficient area (normal driving) Engine improvement 1 Advantages of hybrid vehicle 0 20 Gasoline AT Gasoline HV Why Toyota’s Hybrid System is fuel efficient Toyota’s hybrid vehicles are “strong hybrid” vehicles that combine the use of a high efficient gasoline engine and a high output electric motor/generator. 21 Why Toyota’s Hybrid System is fuel efficient The difference between Strong HV and Mild HV is that Strong HV has the EV drive function Classification by function of hybrid systems Hybrid Improvement of fuel efficiency Strong EV Drive Mild Motor Assist Regenerative Braking Engine Stop 22 High fuel efficiency Better Strong HV fuel efficiency is much better than that of Mild HV (Japan Crown HV) 23 High fuel efficiency and better cost performance Strong Hybridｓ are relatively more costly, but have high fuel efficiency and are more cost effective Fuel Efficiency high Hybrid Cost (Price) high 24 Low emissions: Carbon dioxide (CO2) Hybrid vehicles can contribute to the reduction of CO2 emission High Gasoline CO2 emission (g/km) Diesel Gasoline HV LS600h RX450h Prius GS450h Camry HV Yaris HV Prius PHV Vehicle weight (tons) Heavy EC mode 25 Low emissions: Nitrogen oxide (NOx), Carbon dioxide (CO2) HVs manage both lower emissions(NOx) and lower CO2 CO2 (g/km) *New European Driving Cycle Gasoline Diesel Low CO2 Tank to wheel Europe C-segment (NEDC* mode) HV Clean Tank to wheel NOx (g/km) 26 Low emissions: Hydrocarbon (HC) The more HVs there are on the road, the atmosphere becomes cleaner Cleaner air* HC concentration (ppm) Polluted air Roadside HC concentration Vehicle emission HC concentration 27 *Concentration levels of HC in the air in urban areas is reduced. High driving performance HVs realize the dual functions of high driving performance and fuel efficiency JC08 Mode Fuel Efficiency （km/L） 45 ☆ 4th Prius (1.8L) 40 35 Better 30 25 Quick ３rd Prius (1.8L) ２nd Prius (1.5L) Other HV(1.3L) 20 Premio 2.0L 15 Camry 2.4L 10 5 Collora 1.5L 3 3.5 4 4.5 5 5.5 6 Mid range acceleration 40-70km/h （sec） 28 Benefit of Toyota’s HV In addition to high fuel efficiency and low emissions, hybrid vehicles have strong power and quietness as characteristics High fuel efficiency Low emissions Power Quietness 29 Benefit of Toyota’s HV: Power 30 Benefit of Toyota’s HV: Quietness 31 ３. Evolution in the Fourth-generation Prius 32 Fourth-Generation Prius: Fuel efficiency improvement Prius has improved its fuel efficiency over the generations 33 Fourth-Generation Prius: Fuel efficiency improvement 25.2% improvement was made from previous Prius and powertrain has contributed to 18.2% of improvement. 34 Fourth-Generation Prius: Fuel efficiency improvement Engine efficiency improvement and reduction in energy loss of HV electric units are the key improvements in powertrain. 1. Engine efficiency improvement ～Advancement of TNGA Engine～ 2. Drastic energy loss reduction of HV electric units 3. Synergy effect between 1. and 2. as system fig．Breakdown of powertrain fuel efficiency improvement 35 Fourth-Generation Prius: Advance fuel efficiency technology To achieve the high fuel efficiency, not only the HV system, but aerodynamics has been improved as well ＜Low fuel consumption＞ ■Improved 2ZR-FXE engine ・Maximum thermal efficiency of 40% ■New Hybrid System development ■World-class aerodynamic performance ・Cd*：0.24 （Camry : 0.28) ・Flat under floor ・Grill shutter *Drag coefficient 36 ４. Reliability Evaluation 37 Durability and safety of HVs Many taxis use HVs because of their durability and fuel efficiency In Austria 38 Durability and safety of HVs Many used HVs are imported into Sri Lanka, Myanmar, Mongolia, etc. as second hand vehicles which shows long life of vehicles Myanmar Sri Lanka Mongolia 39 Batteries Durability Management For good durability, hybrid electric vehicles control SOC and temperature of battery SOC (%) Range of the State of charge (SOC) Cellular phone HV 500,000km Worse (Deterioration) Battery capacity Ni-MH Battery Durability in Market No Deterioration Up to 500,000km Taxis 100,000 200,000 300,000 400,000 Running distance (km) 40 Example of reliability evaluation Hybrid vehicles are evaluated with all the same reliability test as conventional vehicles transformation Strength fatigue Multi spindle bench Rough road ・ ・ water Specific environment temperature Low temp. room Floodway ・ Electromagnetic Interference immunity emission 41 Anechoic chamber Example of the reliability evaluation of battery Batteries unique to Hybrid vehicles are evaluated through many reliability tests 1. Charge and discharge durability Inside of thermostat room 2. Durability vibration vibration machine with thermostat room controller wiring condition 3. Inspect collected parts from the market 4. Battery control management 42 Laboratory evaluation Ensuring market suitability by conducting battery evaluation tests; simulating the real-world environment Charge and discharge controller: simulate actual current current（A） Temperature and humidity room: simulate actual environment （ex） simulate mountain drive and others time（second） Inside of temperature and humidity testing room discharge Power supply battery charge 43 Vibration test simulated uneven rough road conditions Toyota conducts vibration tests on batteries by simulating the various road conditions around the world Triaxial vibration machine with thermostat room Controller Inside of the thermostat room ★evaluate functional quality and damage by simulating vibration and temperature of actual vehicle Vibration machine 44 Battery drop evaluation Battery test example: Drop battery from great heights 45 Battery drop evaluation 46 Water leak evaluation Battery test example: Water immersion 47 Water leak evaluation 48 TODAY for TOMORROW 49