VIAVISION SHAPING THE FUTURE OF MOBILITY. e Carbon Hybrid Plug-in Efficient Economical cal Mobile Aerodynamic Monocoque ocoque

Transcription

1 March 2013 VOLKSWAGEN SHAPING THE FUTURE OF MOBILITY t Safe Carbon Hybrid Plug-in Efficient Economical Mobile Aerodynamic Monocoque E-mo ium-ion battery Polycarbonate trendsetting Innovative Lightweight CFRP Streamlined One l Battery management system Storable Low-carbon emission E-vehicle Research Developm ies Prototype Mobility Electric mobility Light Safe Carbon Hybrid Plug-in Efficient Econom bile Aerodynamic Monocoque E-motor Lithium-ion battery Polycarbonate trendsett ovative Lightweight CFRP Streamlined One litre car Battery management system Storable L bon emission E-vehicle Research Development Series Prototype Mobility Electric mobility Li e Carbon Hybrid Plug-in Efficient Economical cal Mobile Aerodynamic Monocoque ocoque E-motor Lithi battery Polycarbonate onate trendsetting etti ting Innovative ve Lightweight CFRP Streamlined ed One litre tery management nt system Storable Low-carbon emission E-vehicle Research Development Se totype Mobility Electric mobility ity Light Safe Carbon Hybrid Plug-in Efficient Economical Mo odynamic Monocoque E-motor Lithium-ion ium-ion battery Polycarbonate trendsetting et ng Innova tweight CFRP Streamlined ed One litre ltre car Battery tery management system Storable Low-car ssion E-vehicle Research Development Series Prototype Mobility Electric mobility ity Light S bon Hybrid Plug-in Efficient Economical Mobile Aerodynamic Monocoque E-motor Lithi battery Polycarbonate ate trendsetting etting Innovative ve Lightweight CFRP Streamlined One litre tery management system Storable Low-carbon emission E-vehicle Research Development Se totype Mobility Electric mobility Light Safe Carbon Hybrid Plug-in Efficient Economical omical Mo odynamic Monocoque ocoque E-motor or Lithium-ion battery Polycarbonate trendsetting tting Innova tweight CFRP Streamlined One litre car Battery tery management system Storable Low-car ssion E-vehicle Research Development en Series Prototype Mobility Electric mobility ity Light S bon Hybrid Plug-in Efficient Economical omical Mobile Aerodynamic Monocoque E-motor Lithi battery Polycarbonate at trendsetting etti Innovative Lightweight CFRP Streamlined One litre tery management me system Storable Low-carbon emission si E-vehicle Research earch Development Se totype Mobility Electric mobility Light Safe Carbon Hybrid Plug-in Efficient ficient Economical omical Mo odynamic Monocoque E-motor Lithium-ion battery Polycarbonate trendsetting tting Innova tweight CFRP Streamlined One litre car Battery management agement system stem Storable Low-car ssion E-vehicle Research Development Series Prototype Mobility Electric mobility Light S bon Hybrid Plug-in Efficient Economical Mobile Aerodynamic Monocoque E-motor Lithiumtery Polycarbonate trendsetting Innovative Lightweight CFRP Streamlined One litre car Batt agement system Storable Low-carbon emission E-vehicle Research Development Series Protot bility Electric mobility Light Safe Carbon Hybrid Plug-in Efficient Economical Mobile Aerodyna nocoque E-motor Lithium-ion battery Polycarbonate trendsetting Innovative Lightweight C eamlined One litre car Battery management system Storable Low-carbon emission E-veh earch Development Series Prototype Mobility Electric mobility Light Safe Carbon Hybrid Plug The XL1 Shows How

2 Sources: page 5: PRTM Management Consulting (as of 2011), page 7: Mennekes; Siemens (both as of 2013), page 11: Ilmenau University of Technology; Institut für Luft- und Kältetechnik Stuttgart (both as of 2012) Index Driving Innovation 2 Dr. Ulrich Hackenberg Contemporary Vehicle Manufacturing 3 The Way We Drive Today Intelligent Drive 4 TwinDrive Technology Storable 6 Electricity for E-Cars and Hybrids Taken Lightly 8 New Materials Low Weight Contoured 10 Aerodynamics in Car Manufacturing Streamlines 11 Air and Other Resistances Imprint Edited by Volkswagen Aktiengesellschaft Konzernkommunikation Brieffach 1972, Wolfsburg Phone: +49 (0)5361/ Fax: +49 (0)5361/ V.i.S.d.P. (Person responsible according to the German press law) Stephan Grühsem, Leiter Konzernkommunikation; Pietro Zollino, Leiter Produktkommunikation Marke Volkswagen Editorial staff: Susanne van den Bergh, Stefanie Huland, Carina Reez Volkswagen: Michael Franke Contact: redaktion@viavision.org Published by Verlag Rommerskirchen GmbH & Co. KG Mainzer Straße 16-18, Rolandshof Remagen Phone: +49 (0)2228/ Printed by L.N. Schaffrath GmbH Marktweg 42-50, Geldern All images in this issue are approved for reprint, citing as their source. Driving Innovation Dr. Ulrich Hackenberg, Member of the Board of Management of Volkswagen Brand with responsibility for Research and Development. Volkswagen has worked intensively for many years on a production ready, one litre car has the effort been worth it? Sometimes it is necessary to go to the limits of technological feasibility. Only then can the synergies and potential for subsequent large scale production be reviewed and assessed. Volkswagen has proved with the XL1 that it is possible to develop a one litre car, that is ready for series production. Some of the technologies developed for the XL1 will be put to use in different series in the future. The genetic code of the XL1 power train, for example, will be transferred to the Golf BlueMotion TwinDrive. What role will the plug-in hybrid play as a drive concept in the future? Our plug-in hybrid is called TwinDrive and leads the way to economical and environmentally friendly mobility. Aside from purely electric cars, highly efficient combustion engines, some, in combination with electric drives will be with us over the next decades. The two technologies are combined efficiently in the TwinDrive and allow for a wide range of driving modes, from pure e-drive to a sporty performance hybrid. What conditions are necessary in order to achieve quick acceptance of these technologies? Electric and plug-in concepts will only prevail in the market if the necessary technical interfaces are standardised. Concerning the connector technology, European manufacturers have now agreed on the so-called Type 2 connector. However, the development of a corresponding charg ing infrastructure is equally important. To achieve general acceptance of these technologies, we need public charging stations in all major areas of life; in front of supermarkets, in car parks and residential complexes. 2

3 MARCH 2013 Contemporary Vehicle Manufacturing The Way We Drive Today Ferdinand Piëch had a clear vision: an everyday use one litre car by Volkswagen. The time has come, the XL1 will soon hit the streets. From the efficient TwinDrive plug-in technology and the basic aerodynamic shape, to the light and also secure materials for the body the XL1 shows the way we drive today. 2002: L1 Consumption: Emissions: Output: Top speed: Weight: 0.99 litres per 100 kilometres 26 grams CO 2 per kilometre 6.3 kilowatts 120 kilometres per hour 290 kilograms The 2002 research vehicle focused primarily on two things: low consumption and low weight. It was powered by a mild hybrid with an optimised, one cylinder, diesel internal combustion engine, the body was made of carbon fibre. Back then the seats for both occupants were arranged in a row for aerodynamic reasons. 2009: L1 Consumption: 1.38 litres per 100 kilometres Emissions: 36 grams CO 2 per kilometre Output: 20 or 29 kilowatts Top speed: 160 kilometres per hour Weight: 380 kilograms In this second, near-production study the driver and passenger still sat in a row. The L1 was already powered, however, by a full hybrid power train with both combustion and electric motors. 2013: XL1 Consumption: 0.9 litres per 100 kilometres Emissions: 21 grams CO 2 per kilometre Output: TDI: 35 kilowatts, e-motor: 20 kilowatts Top speed: 160 kilometres per hour Weight: 795 kilograms The current XL1 has a TwinDrive with a TDI engine, dual-clutch transmission and electric motor and packs the highest effi ciency into the smallest space. The electric range is up to 50 kilometres. The entire, suitable for everyday use, shape of the XL1 is subject to aerodynamic requirements. The wider front allows the occupants to sit next to each other. Extremely lightweight carbon fibre materials and side windows made of polycarbonate not only save weight, they also ensure safety. 3

4 Intelligent Drive TwinDrive Technology Not all hybrids are equal. While all vehicles with that name combine at least two different types of drive how this interaction takes place in detail, however, is different depending on the type (see glossary). The plug-in hybrid by Volkswagen is called TwinDrive and combines the advantages of a highly efficient internal combustion engine with those of a high-performance, zero-emission electric drive. The high voltage battery built in the XL1 allows for an electric range of up to 50 Kilometres. The battery can be charged, not only during braking by energy recuperation and generator operation while driving, but also by an external power source. The power train in the XL1: Lithium-ion battery High voltage lead Hybrid module with 2 cylinder TDI engine, 7 gear dual-clutch gearbox and e-motor The drive train of the XL1 is constructed as a plug-in parallel hybrid. This means that both the internal combustion engine and electric motor can power the vehicle individually, but also together. In joint operation mode, the internal combustion engine is supported as required by the electric motor. During braking, the electric motor acts as a generator and charges the battery via energy recuperation. On demand, the clutch allows decoupling of the internal combustion engine and thus purely electric driving. The genetic code of this power train will be transferred to the Golf BlueMotion TwinDrive which will be produced in series in 2014 and, when required, can be integrated into other series through the modular transverse matrix. 4

5 MARCH 2013 Glossary Hybrid drives distinguished by range of functions: Recuperation Start-Stop Boost Function Recuperation Start-Stop Purely Electrical Drive Boost Function Recuperation Start-Stop Purely Electrical Drive Boost Function Recuperation Start-Stop Micro hybrid (start/stop): Micro hybrids are startstop systems which are operated in the voltage range of 12 to a maximum of 48 volts and have a recuperation function. Due to the low voltage level and the generator technology used, the performance of the system is limited. Mild hybrid: Mild hybrids have a higher power and voltage level and a lot more energy can be recovered during braking through recuper ation, compared to a micro hybrid. The internal combustion engine and electric motor are situated on the same shaft. By the simultaneous use of electric and combustion engines during acceleration, additional power (boost function) can be provided. Full hybrid: Full hybrids with a sys tem voltage greater than 100 volts have higher performance than mild hybrids. Electric driving is possible at a limited range and limited speed. In order to reduce consumption and to avoid drag losses, the combustion engine is disconnected by a decoupler when driving electrically and during recuperation. Plug-in hybrid: The plug-in hybrid electric drive has an even higher performance during pure electric driving than a full hybrid. A special feature of these systems is the ability to recharge the battery via the power grid. Their electric range depends on the energy content of the battery systems used. Hybrid drives distinguished by construction type Parallel hybrid: The electric motor generates additional motor or generator torque on the same shaft as the combustion engine that can be used for the boost or charging function respectively. For electric driving or recuperation the combustion engine can be decoupled from the drive and restarted in electric driving mode. The power of the combustion engine and electric motor are introduced directly into the gearbox. This requires a downstream, automatic, multi-speed transmission. Projected sales of types of drives: (in millions) 56 Petrol and diesel cars Hybrid vehicles Serial hybrid: Serial hybrids have two electric motors, one electric motor that works with the internal combustion engine on the same shaft and converts mechanical energy into electrical power as a generator. The energy generated in this way is fed to the second electric motor which powers the vehicle. Because of the power and torque characteristics of the electric motors, no multi-speed gearbox is required for continuous driving operation. Because the energy is converted twice, which is associated with a loss of electrical efficiency, this drive has not yet been established in cars Mixed hybrid/power split hybrid: A hybrid of parallel and serial hybrid with two electric motors. The electric motors and the combustion engine are connected via planetary transmission. The power of the combustion engine is divided through the transmission. Part of this power goes directly to the wheels. Another, larger part is converted into electrical power using an electric motor. The electrical power is then in turn fed into the second electric motor and the high voltage battery, depending on driving conditions and load requirements It is estimated that in the coming years worldwide sales of cars with hybrid drives will increase significantly. 5

6 Storable Electricity for E-Cars and Hybrids Electric vehicles and plug-in hybrids always raise the same question: what kind of batteries are efficient and robust enough for use in cars and then how to ensure that they are always charged sufficiently? A lot of resources go into research regarding new storage technologies to guarantee a high storage capacity with low weight and long life. Lithium-ion Battery in the XL1: Lithium-ion: The negative electrode of lithium-ion batteries contains graphite as the storage material; the positive electrode lithiummetal oxide. Lithium-ion batteries are used in many areas, for example in cell phones and laptops. In-vehicle use, however, makes much higher demands on the batter ies. + high energy and power density + high level of efficiency + low self-discharge + relatively fast charging process Weight: 68 kilograms Capacity: 5.5 kilowatt hours Cells: 60 Casing: CFRP Voltage: 220 Volts Cooling: Water high costs due to expensive material use, sophisticated manufacturing processes and safety electrics Cooling necessary depending on the structure of the battery system The battery cells used in the XL1 are part of the modular transverse matrix and will also be put to use in other Group vehicles. To achieve a high power density, the battery is integrated in the cooling circuit of the XL1. The housing made of Carbon Fibre Reinforced Polymer (CFRP) is used to optimise the weight and volume, and in addition the battery is safely integrated into the monocoque. The battery is maintenance-free and designed to last a vehicle s lifetime. 6

7 MARCH 2013 Infrastructure and Standardising By 2020, according to the plans of the government of Germany, one million electric vehicles will be driving on German roads. So far, there are slightly more than 52,000 including hybrids. Four arguments stand in the foreground when it comes to their lack of prevalence: high cost, the limited range of battery-powered vehicles, the lack of standardisation of the charging interface and the lack of charging infrastructure. The range of the batteries is being intensively researched. In the field of standardisation, progress is being made. For example, the European Commission has agreed on uniform connector technology for AC and DC charging and put a legislative process in motion at the beginning of This plug has up to seven contacts depending on the power level, two of which function as data lines via which the electric vehicle and the charging point can exchange information. This enables future integration of electric vehicles into a smart grid or to charge the battery in a public space, for example in car parks. At home the charging is also unproblematic thanks to retrofittable, special loading outlets the so-called wallboxes. The charging infrastructure has a lot catching up to do: Germany s 14,000 petrol and diesel stations stand opposite only about 3,000 AC charging stations. Communication Ground Picture: Mennekes Neutral lead Current phase 1 Current phase 2 Current phase 3 The Type 2 connector, here shown in the AC version, is planned to become standard by no later than 2017 for all electric cars which are sold in Europe. A DC version of the Type 2 connector is being prepared for standardisation. The combo Type 2 connector is used for fast DC charging. Both connectors are part of the Combined Charging System and can be plugged into the vehicle using the same charging socket. Battery Management Systems A battery management system is an electronic control unit that is used for monitoring and controlling battery systems. It determines the charge level and performance and protects the cells from over charging or deep discharge. In addition it controls the uniform state of charge of the cells in the battery system and provides a temperature suitable for operation by cooling or heating. The battery management system monitors the high voltage safety of the vehicle and checks the battery system for possible errors. 7

8 EFFIZIENTE MOBILITÄT Material properties in comparison: The acronym CFRP stands for Carbon Fibre Reinforced Polymer. Behind this is hidden a composite of several layers of carbon fibre fabric woven, or non-woven, embedded in a synthetic resin. This material is particularly suitable for the production of a safety cell, the so-called monocoque, because it is extremely light and at the same time extremely rigid. In a crash, a monocoque provides maximum security with optimum lightweight construction. Elastic Modulus: (in gigapascals) Taken Lightly New Materials Low Weight In a conventional car the body accounts for around 40 percent of the total weight. This makes it the ideal starting place to employ new materials to save weight and ultimately fuel, and thus also reduce CO 2 emissions. In the case of the XL1 one litre car, the bulk of the body consists of a monocoque, a self-supporting safety cell made of Carbon Fibre Reinforced Polymer (CFRP). Due to its mechanical properties, this is an excellent lightweight material. The weight of the XL1 s entire body only accounts for 29 percent of its total weight. The XL1 s assembly components weight compared to a compact class car: (in kilograms) Car XL Components made of CFRP are particularly stiff in the direction in which the fibres run. They can barely be stretched or bent Strength: (in megapascals) CFRP Steel Aluminium Chassis Equipment and Electronics CFRP is particularly resistant to deformation or breakage in the direction of the fibres Specific Weight: (in grams per cubic centimetre) Car body Drive train 1,5 7,8 2,7 With its low specific density, CFRP is very light compared to aluminium and steel. Without a driver the XL1 weighs in at only 795 kilograms. Compared to the average diesel compact car that weighs 1,306 kilograms, this represents a saving of almost 40 percent. 8

9 MÄRZ MARCH 2013 EFFIZIENTE EFFICIENT MOBILITÄT MOBILITY The XL1 s CFRP Monocoque: The monocoque of the XL1 is both a safety cell and a supporting vehicle structure at the same time. It is made of carbon fibre reinforced plastic and weighs only 89.5 kilograms. The integrated roll-over protection and lateral crash elements in the floor area, among other features, ensure safety. The side impact protection in the doors is clearly visible. Windows Side windows made of polycarbonate weigh 33 percent less than conventional windows. If panes of glass were used, they would have a weight of 7.8 kilograms. The polycarbonate windows installed in the XL1 add up to just 5.2 kilograms. Power Steering The XL1 can do without power steering because the axle loads were significantly reduced. The XL1 s mechanical steering weighs 5.1 kg; the steering of a series production car weighs in at 15 kilograms. In addition to the 66 percent weight reduction, a positive result is that the XL1 s steering has no additional power requirements. Seats Weight can be saved even in the seats with the use of CFRP. Lightweight, padded bucket seats with covering are installed which do not require the usual mechanisms for backrest and height adjustment. The weight of a CFRP bucket seat is only 11.6 kg making it about half the weight of a conventional seat. 9

10 Contoured Aerodynamics in Car Manufacturing Car manufacturing is a matter of aesthetics, stability and safety. Air resistance is also a focus because it affects the consumption of the car. The vehicle is slowed down by the air stream this effect is familiar to anyone who has ever ridden a bike into a headwind and had to pedal with greater force. A car must constantly displace the air that slows its movement during driving. By how much depends on its streamlining. The Aerodynamics of the XL1: Low-resistance basic shape: Round front Round and smooth roof Strongly sloping roof Narrow rear Removal of conventional side mirrors Reduction of air turbulence: Fairing over the rear wheel housing Use of relatively narrow tyres Air displacers and air dispersers on the wheels reduce the air flow in front of and behind the wheels Air vortex generators on the front wheels prevent the air stream from getting caught in the wheels housing Full underbody fairing Diffuser: the backwards rising part of the underbody reduces the total rear area Attica: A groove below the rear lights reduces air resistance Cooling air duct: The cooling air is passed through the engine compartment so that no cooling air vents are necessary on the sides or the underbody The evolution of the Golf s C d value Golf MK1 C d value: 0.42 Golf MKIV C d value: 0.31 Golf MKVII C d value: The C d value of the new Golf MKVII is lowered to under

11 MARCH 2013 Streamlines Air and Other Resistances The air resistance of a vehicle is given in the drag coefficient. This value is unitless, is expressed in numerals, and for cars usually lies in the range between 0.2 and 0.4 the lower it is, the more aerodynamic the vehicle. It is composed of various parameters which are usually measured in a wind tunnel. C d value: 0.03 F d c d = F d A * * v 2 2 is the resistance of a vehicle and is often colloquially referred to as drag. In addition to the direct air displacement which an area produces, braking effects caused by air turbulence and friction on the vehicle surface also play a role. The higher the resistance of the vehicle, the more the air slows down the car. It is determined in a wind tunnel with a so-called force and moment weighing scale. (Unit: newton) C d value: C d value: 1.2 The penguin has the most aerodynamic shape. For Formula 1 cars there is another consideration, namely, down force is vital. This is particularly important when it comes to driving into corners quickly, without losing contact with the road. F d v stands for the car s driving speed. (Unit: kilometres per hour) is the air density. It indicates how much air mass is contained in a certain volume and is calculated via temperature and pressure. (Unit: kilograms per cubic metre) v A stands for the front surface of the car, air is displaced around this area. In order to determine the size of that area, the car is illuminated from the front and the silhouette measured on a screen behind the car. (Unit: square metre) A 11

12 March 2013 VOLKSWAGEN SHAPING THE FUTURE OF MOBILITY t Safe Carbon Hybrid Plug-in Efficient Economical Mobile Aerodynamic Monocoque E-mo ium-ion battery Polycarbonate trendsetting Innovative Lightweight CFRP Streamlined One l Battery management system Storable Low-carbon emission E-vehicle Research Developm ies Prototype Mobility Electric mobility Light Safe Carbon Hybrid Plug-in Efficient Econom bile Aerodynamic Monocoque E-motor Lithium-ion battery Polycarbonate trendsett ovative Lightweight CFRP Streamlined One litre car Battery management system Storable L bon emission E-vehicle Research Development Series Prototype Mobility Electric mobility Li e Carbon Hybrid Plug-in Efficient Economical cal Mobile Aerodynamic Monocoque ocoque E-motor Lithi battery Polycarbonate onate trendsetting etting Innovative ve Lightweight CFRP Streamlined ed One litre tery management nt system Storable Low-carbon emission E-vehicle Research Development Se totype Mobility Electric mobility ity Light Safe Carbon Hybrid Plug-in Efficient fici Economical omical Mo odynamic Monocoque E-motor Lithium-ion ium-ion battery Polycarbonate trendsetting ng Innova tweight CFRP Streamlined ed One litre ltre car Battery tery management system Storable Low-car ssion E-vehicle Research Development Series Prototype Mobility Electric mobility Light S bon Hybrid Plug-in Efficient Economical Mobile Aerodynamic Monocoque E-motor Lithi battery Polycarbonate ate trendsetting etting Innovative ve Lightweight CFRP Streamlined One litre tery management system Storable Low-carbon emission E-vehicle Research Development Se totype Mobility Electric mobility Light Safe Carbon Hybrid Plug-in Efficient Economical omical Mo odynamic Monocoque ocoque E-motor or Lithium-ion battery Polycarbonate trendsetting tting Innova tweight CFRP Streamlined One litre car Battery tery management system Storable Low-car ssion E-vehicle Research Development en Series Prototype Mobility Electric mobility ity Light S bon Hybrid Plug-in Efficient Economical omical Mobile Aerodynamic Monocoque E-motor Lithi battery Polycarbonate at trendsetting etti Innovative Lightweight CFRP Streamlined One litre tery management me system Storable Low-carbon emission si E-vehicle Research earch Development Se totype Mobility Electric mobility Light Safe Carbon Hybrid Plug-in Efficient ficient Economical omical Mo odynamic Monocoque E-motor Lithium-ion battery Polycarbonate trendsetting tting Innova tweight CFRP Streamlined One litre car Battery management agement system stem Storable Low-car ssion E-vehicle Research Development Series Prototype Mobility Electric mobility Light S bon Hybrid Plug-in Efficient Economical Mobile Aerodynamic Monocoque E-motor Lithiumtery Polycarbonate trendsetting Innovative Lightweight CFRP Streamlined One litre car Batt agement system Storable Low-carbon emission E-vehicle Research Development Series Protot bility Electric mobility Light Safe Carbon Hybrid Plug-in Efficient Economical Mobile Aerodyna nocoque E-motor Lithium-ion battery Polycarbonate trendsetting Innovative Lightweight C eamlined One litre car Battery management system Storable Low-carbon emission E-veh earch Development Series Prototype Mobility Electric mobility Light Safe Carbon Hybrid Plug With an average consumption of 0.9 litres per 100 kilometres the XL1 is below the original target: the first one litre car in mass production. Two motors provide the most modern form of transportation: the TwinDrive hybrid technology combines the advantages of the combustion engine and electric drive.