CANNOCK CHASE U3A SCIENCE & TECHNOLOGY GROUP. Hybrid, Electric and Fuel Cell Cars: How they work July 2015

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1 HybridElectricCarsRevG.ppt Barry K. James June 2015 CANNOCK CHASE U3A SCIENCE & TECHNOLOGY GROUP Hybrid, Electric and Fuel Cell Cars: How they work July 2015

VEHICLE TYPES (AVAILABLE TODAY) Conventional petrol, diesel or LPG (IC) engine One fossil fuel energy source, toxic emissions (except LPG) Performance maintained throughout tank of fuel Approx 300+

2 VEHICLE TYPES (AVAILABLE TODAY) Conventional petrol, diesel or LPG (IC) engine One fossil fuel energy source, toxic emissions (except LPG) Performance maintained throughout tank of fuel Approx 300+ miles per tank of fuel Pure electric (EV) Rechargeable battery is the only energy source Approx miles per battery charge Long battery charge can take around 8 hours+ Braking will generate power to charge the battery Batteries will probably need replacing during life Hybrid, petrol/electric (HEV) e.g Zoe Leaf GM Volt Smart Tesla Combination of fossil fuel and battery power Types include Plug-in and non plug-in Can usually use in pure electric, IC engine, or both electric and IC together modes e.g. Usually a short range in electric only mode Prius Braking will generate power to charge the battery Auris Lexus

3 WHAT S IN A PURE ELECTRIC CAR (EV)? Smart 55kW, 120 Nm, 12,000 rpm, Vdc Drivetrain (EV engine) Motor 3 phase brushless HV Battery Pack with cell management, control and cooling. Neodimium magnets. Single Li-ion Cell 3.7V nominal Power modules & control DC to DC converter For 12V system Inverter power control

4 PURE EV POWER & CONTROL CIRCUIT

WHAT S IN THE HV LITHIUM ION BATTERY Can be 100+ cells PACK Safety circuit breakers Every cell is monitored for temperature and voltage constantly.

5 WHAT S IN THE HV LITHIUM ION BATTERY Can be 100+ cells PACK Safety circuit breakers Every cell is monitored for temperature and voltage constantly. The battery temp and charge state can affect car performance. Voltage charged: 400V+ dc Voltage discharged: 240V For a 400HP motor: Current = 1200A! Huge weight and cost! Other older battery types include: Cooling Nickel Metal Hydride (NiMH) Nickel Cadmium (NiCd) Power monitoring sensor

6 WHAT DRAINS THE HV BATTERY? Main traction motor(s) Heater (EVs are 90% + efficient, petrol 30%, diesel 50%) Air conditioning Power steering, heated screens Lighting, instrumentation, wipers Brake vacuum pump Cooling pumps for Inverter, Motor & HV battery ABS, traction and stability control Power and battery controllers, engine management 400VDC to 12VDC converter for above (Charger on board)..so the battery won t last long if the weather is hot or cold

7 BEWARE: LITHIUM ION BATTERIES Lithium Ion batteries getting overheated creates thermal runaway Never short out lithium batteries or let them get overheated in use. Also used in laptops and phones!

COMPARISON OF ENERGY STORAGE METHODS Petrol Energy Cost Life 12000 Wh/kg $30 / kw 5000 hours

UltraCapacitors (Lots of instant power, Fast charge) Energy Cost Life 5 Wh/kg (low) High Limitless

8 COMPARISON OF ENERGY STORAGE METHODS Petrol Energy Cost Life Wh/kg $30 / kw 5000 hours Lithium Ion Battery Pack Energy Cost Life 120 Wh/kg $1000 / kw 500 cycles (2500hours) UltraCapacitors (Lots of instant power, Fast charge) Energy Cost Life 5 Wh/kg (low) High Limitless cycles Conclusion Petrol has 100 times the energy of a battery (range). Batteries only cost a few pence per mile to run.

THE INVERTER POWER CONTROL Typical power switching

1400A capability IGBT module Processing control To

diameter (75mm2) To motor (3) To HV Battery (2)

9 THE INVERTER POWER CONTROL Typical power switching module x A capability IGBT module Processing control To car controls Power cables to this module can be 20mm diameter (75mm2) To motor (3) To HV Battery (2) Current sensor, monitoring and control (4 off) Toyota Prius Power controller IGBT 3 Phase power to motor

10 CHARGING A PURE EV Type 1: Slow 3kW Home ac charge point Street charge point Type 2: Fast 7kW+

11 DRIVING A PURE EV Very quiet, maximum acceleration from rest. One gear for whole speed range: easy to drive. Low cost/mile. Power may reduce when battery is low. Low and high battery temp causes power reduction. Battery needs cooling. Good for city centre reduction in CO2; Zero emission. Short trips only due to low range, so probably a second car. High acceleration and high speeds use a lot of energy. Use of ancilliaries (AirCon, heater) will deplete the battery. Braking will recharge the battery (slightly). Called regenerative braking. Trailing throttle will also generate. Charging battery a long process for another 60 + miles. High voltage lithium battery pack is used. Limited life.

12 Inverter: 280kW 14kW loss 24kg EXCITING AUDI R8 E-TRON REAL PERFORMANCE NOT A MILK FLOAT! Battery 500kg Motors: 12,200rpm 820Nm R8 e-tron 0-62mph 4.6s 155mph 465bhp

13 HYBRID CARS Ampera Prius BMW i3 Volvo Yaris Lexus

14 WHAT S IN A HYBRID CAR 2 electric motors and power controllers coupled to an IC engine, a power splitter, and HV battery. Power control Battery, motors and power controllers will be smaller than a pure EV. Toyota Prius Drivetrain 2 Types of Hybrid: Plug-in (PHEV) Non- plug-in (HEV)

15 HYBRID ENERGY DISPLAY Electric only drive (depletes battery) Braking (Regen) charges battery IC engine drive only uses petrol IC engine AND electric doubles torque

16 DRIVING A HYBRID CAR Starting from standstill: Usually electric only until ~5mph which depletes the battery, then IC engine starts. The generator will start the IC engine when required to avoid battery depletion. Heavy acceleration should start IC engine and use motor simultaneously for increased torque and power (parallel mode).

17 DRIVING A HYBRID CAR Normal Under running: normal driving, the IC engine will power the car. Heavy throttle pedal can parallel motors and engine. IC engine will recharge battery via the generator, but uses fuel to do it in a HEV. PHEV can be charged from mains. Foot off throttle (trailing throttle) or braking will regenerate electricity to charge battery. Regenerative braking will feel like engine braking. Mechanical brakes can have less wear with regenerative braking.

18 HYBRID CAR CONCLUSIONS Pros and Cons Hybrid has no advantage on motorway if no braking occurs (same as IC but carrying more weight). Maximum acceleration from rest using motors. Emissions not much different from standard IC car. Fuel economy not much different from standard IC car. Heavy battery, motors and power controllers. Non-plug-in hybrids have to use fuel to charge the battery. Engine acts as a range extender for the battery, so no need to charge. Same range as petrol car. Cost of car is high compared to standard petrol. Allowable for congestion charge cities.

19 WHY DO WE NEED TO RECOVER ENERGY FROM BRAKING? Fuel efficiency in hybrid cars. Braking will recover a small amount of energy to charge battery. Small battery charging opportunities for pure electric cars when braking. Energy collection for use in hybrid race cars Braking collects energy Driver selects when to use the energy for acceleration. (KERS in F1 collected energy for a 6 second burst of 60hp).

20 Race Car Hybrid (KERS) System (Japanese race series) RACE CAR

21 NEXT TEA ANYONE? THE FUTURE OF ELECTRIC AND RANGE EXTENDERS.The Fuel Cell.

22 CONCLUSIONS ON HYBRID & ELECTRIC CARS Battery energy does not last long for pure EVs Long battery recharge time for pure EVs Batteries may need replacing over life of car Pure EVs can be expensive to buy Pure EVs are cheaper to run than petrol or diesel Zero emission not really true just shifted elsewhere Hybrids not much advantage on motorways Hybrids expensive with extra equipment Hybrids give little or no improvement in running costs over a standard diesel So, what about a Alternative fuel to extend range?

23 FUEL CELL CARS THE ULTIMATE COMBINATION? H2 + 1/2O2 = H2O + Elec Hydrogen dispensing Proton Exchnage Membrane (PEM) Maybe !

24 TYPES OF FUEL CELL Alkaline Electrolyte Phosphoric Acid Acid KOH, Used in the Apollo spacecraft. electrolyte, 40% efficient, buses in CA. Proton Exchange Membrane (PEM) Permeable plastic electrolyte like cling film, platinum, 200F, most likely for cars. Solid Oxide Calcium, zirconium or sodium electrolyte, 1800F, domestic Molton Carbonate Potassium or lithium carbonate electrolyte, 1200F, utilities Reformers: Can convert methanol but not zero emission

CONCLUSIONS ON FUEL CELLS Cost Very Complication Very high presently complicated control required Fuel Requires hydrogen infrastructure for

25 CONCLUSIONS ON FUEL CELLS Cost Very Complication Very high presently complicated control required Fuel Requires hydrogen infrastructure for zero emission Requires reformer for methanol (not zero emission) Timeframe Probably 2025 onwards to get cost down But seems ideal combination

26 ACKNOWLEDGEMENTS ANY QUESTIONS? Some internal photos and 3D views courtesy of Zytek Electric Vehicles, Lichfield, UK, Daimler Mercedes Smart Vehicles and VAG Audi. Other pictures courtesy of the Internet.

27 TOPICS CALENDAR November: Using an Internet Browser and security for banking online. December: No meeting January: A Famous Scientist study. Leonardo DaVinci. February: facts. Energy. The practical truth about solar PV panels and power March: Practical Session 1. Soldering, Components, Kits construction; crystal radio, clock, solar car April: May: Cancelled June: Using Microsoft PowerPoint July: Aug: A Famous Scientist 2: Guglielmo Marconi and radio. Sept: Introduction to 3D Graphics (movies) Practical Session 2. Soldering, Components, Kits construction; crystal radio, clock, solar car The Electric & Hybrid Car. The workings inside the engine and battery of pure electric and hybrid cars.

28 FUTURE SESSION IDEAS The use and benefit of technology (PC s, Cameras/Photography, Tablets, Music MP3, etc) Scientific and Engineering achievements of interest. Famous Scientists or Engineers (Brunel, Marconi, Faraday) DVDs of Railways, Industrial Age, Air transport, Road transport, Buildings (Eiffel, Bridges), Waterways. Own interests, diagrams, photos. Group visits (JCB, Jaguar, Jodrell Bank, BBC, Transport museum, Chasewater engine sheds, Space Centre, RAF Cosford?) Electronics practical projects and workshops (Soldering, Components, Raspberry Pie, Picaxe)

29 PICAXE PROJECTS Anyone look at the Picaxe or Revolution Education websites? Any project ideas? How about 2 robot teams competing for the best obstacle course program? How about making a weather station or kit? Any more suggestions?

Is there really anything wrong with it? Generation II 2007 Toyota Prius 311,000 miles

Is there really anything wrong with it? Generation II 2007 Toyota Prius 311,000 miles Always make sure that the HV Disconnect is removed! Always use the proper protective equipment! 1,000 volt gloves Battery