Science is always wrong. It never solves a problem without creating ten more. We need science to help us solve all the problems we wouldn’t have if there were no science. George Bernard Shaw

ELECTROMECHANICAL DRIVE SYSTEMS Dr. Bartłomiej Ufnalski | [email protected] | Electric(al) Drive Division

The lecture and the laboratory are passed based on two mini-projects and on the bonus points from exercises (i.e. activity during laboratory+lecture meetings). The final grade is a weighted average of these marks. Lectures will be combined with hands-on training in a dedicated teaching laboratory equipped with a Matlab/Simulink/PLECS simulational environment. This means that lectures are interactive and you can get bonus points during all our meetings for being active. The typical meeting will include 30 mins of solving problems during lecture-like part, just to create ten times more problems during 60 mins laboratory-like part. And don’t worry – I’ll be at your service to help you create these problems.

BATTERY ELECTRIC VEHICLE (BEV) POWERTRAINS

Fot.: Internet

The very first „serious” battery electric car

Carriage Built in 1830s Uses Non-Rechargeable Batteries Robert Anderson built a crude electric carriage in the 1830s using non-rechargeable batteries. It eventually became the rechargeable Detroit Electric (1907 - 1939) which in one test run achieved a 211.3 mile range and a top speed of 20 MPH. It was mainly marketed to women who didn’t want to bother with hand cranking an engine.

Production of the electric automobile, powered by a rechargeable lead acid battery, began in 1907. For an additional $600.00 an Edison nickel-iron battery was available from 1911 to 1916. The cars were advertised as reliably getting 80 miles (130 km) between battery recharging, although in one test a Detroit Electric ran 211.3 miles (340.1 km) on a single charge. Top speed was only about 20 miles per hour (32 km/h), but this was considered adequate for driving within city or town limits at the time. The company production was at its peak in the 1910s selling around 1000 to 2000 cars a year. From: Wikipedia

Fot.: Internet

„MASS” PRODUCTION AT THE BEGINNING OF XX CENTURY

BEV AS EVERYDAY USE PRODUCT (TARGETED AT HOUSEWIVES) Fot.: Internet

BEV SPEED RECORD ESTABLISHED IN XIX CENTURY

Fot.: Internet

La Jamais Contente ("The Never Satisfied") was the first vehicle to go over 100 km/h (62 mph). It was an electric vehicle with a light alloy torpedo shaped bodywork, although the high position of the driver and the exposed chassis underneath spoiled much of the aerodynamics. The land speed record of 105.882 km/h was established, according to sources, on April 29 or May 1, 1899 at Achères, Yvelines near Paris, France. The vehicle had two direct drive Postel-Vinay 25 kW motors, running at 200 V drawing 124 Amperes.

BEV DEVELOPMENT STOPPED FOR OVER 50 YERS! WHY? Reason 1. Radiator (1895)
no more problems with ICE overheating. Reason 2. Mass production of the Ford Model T (1908-1927)
cheaper than available BEVs. Reason 3. Electric starters (Cadillac Model 30, 1912)
no more broken arms (crank can cause serious injuries if engine kicks back)
women are no longer afraid of using cars. Reason 4. DC grid vs. AC grid. And the winner is… AC grid + no rectifiers
users are unable to charge batteries in their cars. In general: substantial developments making ICE cars more userfriendly and technical barriers like lack of effective speed controllers for electric motors made BEV less- or even noattractive solution.

Henney Kilowatt Max speed ca. 100km/h Range ca. 100km

Although the Kilowatt is described by some sources as "the first transistor-based electric car", the speed controller uses a combination of relays and diodes to switch the batteries and motor windings in different configurations for different speeds, not transistors.

Fot.: Internet

Fot.: Internet

FIRST BEV WITH „POWER ELECTRONIC CONVERTER” (1960)

WHO KILLED THE ELECTRIC CAR?

Battery: ca. 25kWh Ni-MH Range/vmax: ca. 200km / 130km/h Energy consumption: 125 Wh/km Front-engined, FWD, no gearbox, 3-phase AC induction motor, 100kW

http://en.wikipedia.org/wiki/General_Motors_EV1 + YouTube

Fot.: Internet

EV1 (General Motors) – the first mass produced BEV of the modern era. Over 1100 EV1s were produced (1996-1999) and 800 units were leased. In 2002 the program was cancelled, all cars on the road were repossessed and crushed (some of them with deactivated powertrains were delivered to museums and educational institutes. Users were disappointed or even devastated (Don’t Crush Campaign). WHY? Some hints can be found in 2006 full-length documentary „Who killed the electric car?”.

WHERE WE ARE TODAY (SPORT CARS) Tesla Roadster 2 [www.teslamotors.com] – in production from 2007, ca. 400/year (quantity similar to Porsche Carrera GT). Motor: asynchronous 3f 4p, air-cooled, 375V Max power: 215kW @ 4400-6000rpm Max RPM: 14000 Fot.: Internet

Torque: 400Nm @ 0-5100rpm Single speed fixed gear. Acceleration: 60mph (96.5km) in 3.7secs Top speed: 125mph (201km/h) Battery: lithium-ion battery with 6,831 individual cells

Range: 244 miles (392km)

Capacity: 53kWh (450kg), coolant pump Expected battery life: 7 years or 100,000 miles (new one will cost you 36 000 USD)

Nearest dealer: Munchen/Germany

Full charge: about 3.5 hours at 240V and 70A

Price: 110 000 USD

WHERE WE ARE TODAY (SPORT CARS) Mitsubishi Lancer Evolution MIEV (2005 concept car)

Fot.: Internet

Motors: 4 PMSM in-wheel outer-rotor 1500rpm Max power: 50kW per wheel Torque: 518Nm Top speed: 180km/h Range: 250km

Battery: lithium-ion Capacity: 24 moduls 95Ah @ 14.8V each (ca. 33kWh)

Fot.: Internet

IN-WHEEL MOTORS AND DRIVES

Michelin

Siemens

Fot.: Internet

Protean

Mitsubishi

Honda

… and many more.

WHERE WE ARE TODAY (SPORT CARS)

Fot.: Internet

Dodge Circuit EV (2009 working prototype, project cancelled)

Motor: 200kW, 650Nm Top speed: 190km/h Range: 240-320km Acceleration: 0-60mph in less than 5 secs

Chrysler unveiled the working prototypes of this all-electric vehicle and announced plans to bring it to market in the United States by 2010. But in May 2009 Autocar claimed the project was cancelled and in November Fiat SpA disbanded Chrysler's ENVI electric car division and dropped its models from future product plans. Source: Wikipedia

WHY ELECTRIC MOTOR IS A PERFECT CHOICE FOR SPORT CAR

Reason 1. Electric motor outdoes internal combustion engine in terms of torque-speed characteristics. Electric motor can deliver full torque at zero speed. Combustion engine delivers no torque at zero speed! Reason 2. Why bother about second reason? In sport cars it’s all about torque and power!

POWER CONSUMPTION IN BEV Installed capacity / vehicle range (standardized driving cycle) Tesla: 136 Wh/km Mitsubishi Lancer MIEV: 132 Wh/km Volvo C30 BEV: 24kWh/150km = 160 Wh/km Ford Focus BEV: 23kWh/120km = 190 Wh/km Mitsubishi iMIEV: 16kWh/160km = 100 Wh/km Renault Kangoo ZE: 20kWh/150km = 130 Wh/km Renault Fluance ZE: 24kWh/160km = 150 Wh/km Tips and tricks: • If battery pack nameplate says e.g. 24kWh (e.g. 80Ah @ 300V), it does not mean that you can use up to 24kWh of energy per charge. • DoD (Depth of Discharge) is factory limited to achieve longer life-time. Effective capacity can be limited even to half of the nameplate one. • Performance of the battery depends on temperature and discharge current (typically capacity is declared for 0.5C current and 25 degree Celsius, which is not the case in city traffic conditions and/or winter time).

STARTER BATTERY IN ICEV VS. BEV’S BATTERY PACK – WEIGHT, VOLUME Typical starter battery for a passenger car: 50Ah * 12V = 600Wh (15kg, lead-acid). Let’s assume that „our” BEV needs 150 Wh/km and tha we want to travel 160km per charge and deep discharge is available. We need 24kWh=24000Wh. 24000/600 = 40 lead-acid batteries weithing ca. 600 kg!!! 20cm x 17cm x 22cm x 40 gives e.g. 1m x 1.36m (5 x 8) x 22cm. One can use SLA (gel or AGM lead-acid batteries) to slightly improve energy density but it does not solve the problem of mass/distance factor. The most common solution: lithium (Li-ion) batteries. Tips and tricks: • Specific energy [MJ/kg] for lead-acid batteries is at the level of 0.15, for lithium chemistry ca. 3 times higher. You can reduce mass to about 200kg and still travel 160km. • Lithium chemistry needs BMS (Battery Management System). • Li-ion battery packs (cells + BMS) are relatively expensive. Mass production will certainly reduce cost per stored kWh. Nowadays 7kWh spare battery pack for SAM Re-Volt will cost you ca. 30 000 PLN.

Li-ion vs. NiMH Lithium-ion cells can store up to three times more energy (per kg) and generate twice the power of the nickel-metal hydride batteries. Vehicle range DOES NOT grow linearly with mass of installed battery, because overall mass of vehicle also grows.

AIV Sable ICV = aluminum intensive vehicle; a very light weight Mercury Sable (Ford Motor Company) body with a conventional internal combustion engine). Source: www.cleancaroptions.com

Source: www.elipsavehicle.com

WHAT’S HAPPENING NOW IN OUR BACKYARD?

Production vehicle Elipsa from Radom Motors: 2 BLDC 2kW (RWD) Vmax: 26km/h Range: 70-130km Battery: 8 traction batteries (Trojan, acid) Price: ca. 30 000 PLN

Source: www.re-volt.com.pl

WHAT’S HAPPENING NOW IN OUR BACKYARD?

Production car Sam RE-Volt from Pruszkow (Cree, Switzerland) Motor: PMSM 3f 16 KM (12kW) Vmax: 90km/h Range: 100km Bateria: Li-Ion 7kWh

Price: 75 000 PLN gross !!! (including battery ca. 30 000 PLN)

Concept car Romet 4E (Electric, Economic, Ecologic, Easy) BLDC motors: 60V or 72V Power: 2x2,7 KM (2x2 kW), total: 5,4 KM (4 kW) Battery: lead-acid or Li-ion: 10 kWh Range: ca. 100 km Planned price: 6000 - 7000 euro

Source: www.motors.romet.pl

WHAT’S HAPPENING NOW IN OUR BACKYARD?

WHAT’S HAPPENING NOW IN OUR BACKYARD?

Prototype car ELV001 (www.marr.pl) Max speed: 110km/h Max range: 150km @ 50km/h and 10 C deg. Consumption approx.: 130 Wh/km PMSM Motors: 15kW Battery: Li-polimer KOKAM: 19.5kWh @ 130V Power electronics: 2x Semikron SKAI

WHAT’S HAPPENING NOW IN OUR BACKYARD – CHARGING INFRASTRUCTURE AND RENTAL/LEASING PROGRAMS e+ electricmobility.pl: -

develops charging points network in Warsaw

-

offers parking stations for car charging, individual charging points, car leasing or rental, insurance, assistance and service.

Their fleet includes (November 2011) Mitsubishi i-MiEV and Tazzari ZERO (www.tazzari-zero.com/eng/Made_in_Italy) BEVs:

Source: www.samochodyelektryczne.org

BEV „MASS” PRODUCTION IN 2011/2012

Source: www.revaindia.com

REVA G-Wiz z Indii [RECC in Bangalore, currently the world's leading electric car manufacturing company, 30 000 cars/year]

Range/vmax: ca. 160km / 100km/h Battery: Li-ion, 72 V, 14 kWh Motor: 3 phase AC induction motor, 25 kW, 92 Nm 2001-2007: DC motor, lead-acid battery 2008: AC motor, lead-acid battery (300kg, 8 x 6V), complete kerb (curb) weight ca. 700kg 2009: AC motor, lithium-ion battery (200kg) + solar panel, kerb weight ca. 600kg 2011: Sport version – REVA NXG: 200km, 130km/h The biggest electric car factory. Price: ca. 10 000 EUR (acid) / 15 000 EUR (Li-Ion).

BEV „MASS” PRODUCTION IN 2011/2012 Nissan Leaf (Leading, Environmentally friendly, Affordable, Family car)

Range: 160km Battery: 24kWh, 140Wh/kg, 300kg with control module Price: 35 000 EUR

More info: www.nissanusa.com/leaf-electric-car

BEV „MASS” PRODUCTION IN 2011/2012 Mitsubishi i-MiEV (Mitsubishi innovative Electric Vehicle) in Japan, sold as Peugeot iOn or Citroen C-Zero in Europe.

Fot.: Internet

Range/vmax: ca. 160km (for Japan 10-15 mode) / 130km/h Battery: Li-ion, 16kWh @330V Motor: 3 phase AC synchronous motor, 47 kW, 180 Nm [The production version of the i MiEV does not have in-wheel motors like the many MIEV concepts shown before.]

Consumption: 100 Wh/km

BEV „MASS” PRODUCTION IN 2011/2012

… and many others. Almost every „big” car manufacturer has prototype or production BEV planned to be sold in 2012.

CHARGING INFRASTRUCTURE

• Standard charge on a standard plug: 230V/16A available from domestic supplies, on-board charger or on-wall charger – you will need several hours to recharge your battery (suitable for charging in your garage during nighttime). • Fast charge: external high power charger (400V/36A) – charging points/stations available e.g. in parking places – you will need e.g. 15min/50km. • Quickdrop (e.g. Renault Fluence Z.E. and Better Place battery switch network) – battery swap station – you will have to wait e.g. 3min (comparable in terms of waiting time to classical gas filling station).

MYTHBUSTER Travelling by BEV is much cheaper than by ICEV. Is it true? BEV: 5 PLN / 100km (only electric energy cost) ICEV: 35 PLN / 100km (gasoline cost) Choosing BEV you save 30 PLN per 100km and 10 000 PLN per year (assuming 30 000 km per year). After 7 years and 200 000km you „save” 70 000 PLN. Probably your battery life-time will be shorter but let’s favor BEV. E.g. Nissan Tiida (ICEV) costs 70 000 PLN whereas similar Nissan Leaf (BEV) will cost 140 000 PLN. Conclusion: travelling by BEV is not much cheaper than by ICEV nowadays. This will be true if mass-produced battery packs become cheaper than todays semi-mass-produced battery packs.

WHAT IS MORE ECO AND WHAT IS LESS ECO IN BATTERY ELECTRIC VEHICLE? ECO-Car earns its name due to: - zero-emission in cities (incl. no significant noise emission), - high well-to-wheels efficiency if energy comes from renewables (e.g. wind or solar farms), - regenerative (recuperative) braking – you don’t waste all kinetic energy during braking Be aware that BEV is rather less ECO if we consider that: - almost all electric energy in PL comes from conventional power plants (BEV only shifts pollution from roads to power plants) BUT at the same time it’s easier to handle this pollution on the power plant side than on the end-user side, - electrochemical battery is difficult (i.e. energy-consuming) in recycling BUT its recycling is a must and should be subsidized.

LIMITED RANGE OF BEV - WHAT CAN BE DONE ABOUT THIS? Is it possible to have e.g. pure electric travelling range at the level of tens of km and additional hundreds of km on ICE? Of course! This solution is not cheap but very tempting. Solution 1. You can equipe BEV with additional electric generator driven by ICE and you will end up with Extended-Range EV (EREV). Solution 2. You can redesign existing HEV solution to have bigger battery and introduce possibility to charge it from external source. You will end up with Plug-in HEV (PHEV). It’s easier to do this with series HEV, due to lack of mechanical link between ICE and road wheels.

Toyota Prius PHEV

Chevrolet Volt EREV

www.opel-ampera.com

Examples of production EREVs/PHEVs:

www.chevrolet.com/volt-electric-car

www.toyota.com/prius-plug-in

Both solutions give in fact the same output: EREV = series PHEV.

Opel Ampera EREV

DRIVETRAINS/POWERTRAINS (SELECTED TOPOLOGIES) Of course an electric one!

Does it make any sense? Is it technically justified?

BEV POWERTRAIN – A VERY BASIC ONE

BEV POWERTRAIN – A CONCEPT

DC/DC battery step-up/down chopper and 3-level converters.

BEV POWERTRAIN – A CONCEPT

Part of a main converter as a component of battery charging system.

BEV POWERTRAIN – A CONCEPT

Main converter as a battery charging system.

BEV POWERTRAIN – A CONCEPT

Machine windings as a filter in battery charging system.

SERIES PHEV POWERTRAIN

HYBRID ENERGY SOURCE What’s the difference between hybrid electric vehicle and „non-hybrid” electric vehicle with hybrid energy source/storage (HES)? Hybridization of the electric vehicle refers to combining an ICE and one or more electric motors. Hybridization of the electric energy source/storage for BEV refers to combining two different electric energy storages/sources in one design. Of course one can also imagine PHEV with HES. Notice that: performance of lithium batteries deteriorates in low temperatures (e.g. exploatation in winter time) and with current (bigger currents mean lower efficiency and shorter life-time). Driving a car, especially in city traffic, means freqient accelerating and braking. In ideal case lithium battery pack should work delivering average power. Additional storage (with higher efficiency, longer cycle-life, higher power density) should be employed to store energy recovered during regenerative braking and to deliver this anargy back to the motor during acceleration. Ultracapacitors can be a solution!

ELECTROCHEMICAL CELL VS. ULTRACAPACITOR (UCAP, SUPERCAPACITOR) Compare: - gravimetric energy density - volumetric energy density - gravimetric power density - volumetric power density - cycle-life - performance deterioration with falling temperature - price per Wh Answer following questions: - Why today’s ucaps are not suitable as a main energy storage for BEV? - Why today’s electrochemical cells are not suitable for loads that draw high currents, e.g. 1C and more?

Fot.: www.a123systems.com

Fot.: www.maxwell.com

HYBRID ENERGY SOURCE

M.Michalczuk ECO-Mobility Project

HYBRID ENERGY SOURCE

M.Michalczuk ECO-Mobility Project

HYBRID ENERGY SOURCE

Braking

Constant speed

Braking

Constant speed

Braking

Accelerating

Accelerating

M.Michalczuk ECO-Mobility Project

Accelerating

WHY HYBRID (ELECTROCHEMICAL BATTERY + ULTRACAPACITORS) ENERGY STORAGE?

- to make regenerative braking more efficient and, in turn, to extend driving distance (especially in traffic jams), - to extend battery lifetime, - to make electric cars even more ECO - it’s green because it saves energy (see above) and reduces number of battery replacements (see above).

HES – SOME PROS IN NUMBERS

25oC Range

ECE15

Heavy traffic

Battery ES Hybrid ES

Battery ES

Hybrid ES

77.5 km

85.45 km

68.66 km

75.24 km

Power losses

7.05 %

4.91 %

7.47%

5.05 %

Capacity loss

5.40 %

4.52 %

6.14%

4.95 %

Range

42.10 km

77.49 km

37.46 km

65.45 km

Power losses

12.72 %

6.13 %

12.86 %

6.73 %

Capacity loss

1.50 %

1.21 %

1.70 %

1.33 %

50 000km

0oC

37 000km

m=1200kg EBatt=8kWh EUcap=0.05kWh M.Michalczuk ECO-Mobility Project

KERS (KINETIC ENERGY RECOVERY SYSTEM) – MORE SOLUTIONS Assumption: 1500kg GVWR (gross vehicle weight rating), 54km/h=15m/s This gives: approx. 170kJ of kinetic energy Assumption: constant deceleration 3m/s/s (wet asphalt) Peak power: 1500kg * 15m/s * 3m/s/s = 67.5kW Solution 1. Electrochemical battery (e.g. LiFePO4): 40Ah, 300V, 12kWh more than 40MJ. Power density could be insufficient: 1C gives 12kW. Peak current at the level of 6C. Possible (Thynder Sky / Winston Battery WB-LYP40AHA has 3C continuous current capability and 20C maximal 5s in 1 min current capability). It’s not healthy and efficient but could be done. Solution 2. Ultracapacitors (e.g. Maxwell Technologies 75V Module BMOD0094 P075 B02): 25kg, 265kJ, 3Wh/kg, peak power 120kW @75V (72kW @45V), over 1000 000 duty cycles, 515mm x 263mm x 220mm. Solution 3. Flywheel (e.g. Flywheel Capacitor from Flybrid Systems): 27kg, 530kJ, 60kW, 60000rpm.

SOLAR PANELS ON THE ROOF Some car manufacturers offer solar (PV = Photovoltaic) panels on the roof as an option to claim being even more green than pure BEV. Let’s discuss this solution. Roof surface area = ca. 2 square meters. In our latitudes one can get ca. 100kWh per 1 square meter of PV per year (ca. 250Wh per day). Energy consumption ca. 100Wh per 1km. 2 hours long trip in sunny day and no shadows caused by trees, buildings, etc. And you extend vehicle range by… less than 1km (less than 1%). This doesn’t change the fact that a car with PV panel on its roof looks very fancy.

BEV INTERIOR HEATER One can try to use energy stored in the battery. It’s not a good idea. Why? Typical battery pack for A- or B-segment car: 15-25kWh This gives e.g. 150km vehicle range and 2-3 hours possible trip time. During cold winter days (e.g. -10 C deg.) you will need 3-5kW to keep comfortable temperature. This can reduce you range by half. Most production BEVs are not „all-electric”. They are equipped with heaters, e.g. Volvo C30 Electric has bio-ethanol tank (ca. 15 liters). Such solutions are also known from ICEVs. See e.g. Webasto parking heaters.

www.webasto.pl

…-BY-WIRE SOLUTIONS Aviation: Fly-by-wire (FBW), Fly-by-light (optical fiber) Automotive: Drive-by-wire (DbW, by-wire, x-by-wire) • Steer-by-wire • Accelerate-by-wire • Break-by-wire • … Let’s discuss pros and cons of these solutions. Why car engineers tend to eliminate hydraulic and mechanic systems and replace them with electronic ones? Why they tend to break mechanical link between a human (driver) and a vehicle?

wire

Fot.: Internet

It’s brainstorm time!

LET’S BUILD A BEV IN A GARAGE HEV/PHEV/BEV-oriented motors, batteries and power electronics (off-the-shelf examples)

…

1. Liquid cooled modules: SKAI from Semikron HybridPACK2 from Infineon

2. In-wheel motors:

… Active Wheel from Michalin

Protean Electric

eCorner from Siemens

…

3. Battery packs with BMS: SCiB from Toshiba

4. BEV/HEV control systems solutions:

A123 Systems

…

Texas Instruments Developers Kits

FORECASTS It is forecasted that in 2025 electric cars or plug-in hybrid cars will have approx. 50% market share at new cars in highly developed countries [1] with PHEV to BEV share ratio at the level of 4. There are governmental plans to put one million EVs on U.S. roads by 2015. More moderate forecasts say about 750 000 EVs only on U.S. roads and PHEVs are supposed to play key role in achieving this goal [2], [3], [4]. [1] Kalmbach R., Bernhart W., Kleimann P.G., Hoffmann M., Automotive landscape 2025 - Opportunities and challenges ahead, Roland Berger Strategy Consultants, rolandberger.com (2011), 1-88 [2] Voelcker J., One Million Plug-in Cars by 2015?, IEEE Spectrum, 48 (2011), n.4, 11-13 [3] Bedi G., Brylawski M.,at al., Plug-in Electric Vehicles: A Practical Plan for Progress, The Report of a Transport Electrification Panel (TEP), Indiana University (2011), 1-78 [4] The U.S. Department of Energy, One Million Electric Vehicles By 2015, February 2011 Status Report (2011), 1-11

HANDBOOKS AVAILABLE ON-LINE (BG.PW.EDU.PL) EngNetBase, CRC Press, Elsevier and many others: 2002: Electric vehicle battery systems 2002: Handbook of batteries (3rd ed.) 2003: Electric vehicle – technology explained 2003: Electric and hybrid vehicles – design fundamentals 2004: Vehicular electric power systems 2008: Build your own electric car (2nd ed.) 2009: Modern electric, hybrid electric, and fuel cell vehicles (2nd ed.) Tips and tricks: • 10 years in battery technology is like 10 years in computer technology – if you want to stay up to date on battery developments search for publications from recent 2 years! Ten years old handbooks are good to study principles but won’t let you know about state-of-the-art in battery packs for vehicles. • To understand articles you should be familiar with many acronyms. Here are some of them: BEV, HEV (series and parallel), PHEV, EREV, ICE, ICEV, ZEV, EV, KERS (surprise, surprise!), V2G (surprise, surprise!).

THANK YOU FOR YOUR ATTENTION dr. Bartłomiej Ufnalski | [email protected] | Electrical Drive Division

Warsaw University of Technology Faculty of Electrical Engineering Institute of Control and Industrial Electronics