Hybrid Vehicles in Sustainable Motorsport

1. Hybrid Vehicles in Sustainable Motorsport Stephen Lambert

2. Overview • Project Introduction • Customer Requirements • Initial Survey • Conjoint Analysis • Results • Hybrid Architectures • Simulation Design • Architecture Selection • Battery Power Selection

3. Introduction • Motorsport industry worth over £2.9 billion • A further £1.7 billion in sponsorship, PR etc • Carbon emissions and climate change • Industry under pressure to be more green • Technical innovation should move to road • Hybrid vehicles have the potential to; • Reduce vehicle emissions • Increase overall vehicle power

4. UK Niche Vehicle Manufacturers • Approx 200 UK vehicle manufacturers • Same as the rest of the world put together • Mostly sports/racing cars • High power to weight ratio • Small R&D budget • Sustainable technologies • Misunderstood or viewed with suspicion • Formula 1 - KERS

5. Westfield Sportscars • Typical small British Manufacturer • 3 models • Mainly Lotus Seven Type vehicle • Used both for road and racing • Clubman racing • Affordable • Custom classes • Sell toys, not cars

6. Project Vision • Design a hybrid powertrain for motorsport • Increase the vehicle’s performance • Fast development platform • Hybrid system should be vehicle independent • Hybrid system is independent of vehicle platform • Westfield Sportscars initially • Hybrid system is independent of IC engine • Hybrid should retrofit • Play Station Generation • Push to pass / F1

7. Initial Survey • Administered via internet • Simple multiple choice survey • Asked to: • Rate 14 attributes between 1 and 10 • Rate 9 optional extras between 1, 9 and DW • All attainable through hybrid/electric drivetrain • 249 responses over two week period

8. Initial Survey - Attributes - Results

9. Initial Survey - Attributes - Results

10. Initial Survey - Extras - Results

11. Conjoint Analysis Ask people what they want, and they say, “the best of everything.” Ask what they would like to spend; they say, “as little as possible.”

12. Conjoint Analysis • Simple Surveys • Fail to capture consumer trade-offs • Trade-offs may underlie consumer choice • Conjoint Analysis • Provides more realistic approach • Presents attributes as a product • Participant asked to compare and rank products • Results used to produce market simulator • Predict new product consumer choice

13. Conjoint Analysis • Administered via internet • Participants compared two products • Twenty times • Products consist of; • Acceleration Time • Price • Fuel Economy • Drivetrain • Engine Power

14. Conjoint Analysis

15. Engine Power

16. Acceleration Time

17. Fuel Economy

18. Drivetrain

19. Price

20. Attribute Importance Attribute Importance = (Attribute Utility Rage / Total Attribute Utility Range) x 100%

21. Market Simulator • Uses individual results • Every participant simulated • Compares two products • Outputs comparative market share • Compare against current product • Leads to product price sensitivity

22. Simulation

23. Simulation - Results

24. Hybrid Architectures • Series • Parallel • Combined (Series-Parallel) • Powersplit

25. Fuel ICE Gen ESD M/G Wheels Series • 3 energy converters needed • Added weight is not going to increase performance • Not suitable for use in a racing car

26. Fuel ICE Wheels ESD M/G M M Parallel • Energy flow • Maximum acceleration • Parallel Hybrid • Increases available engine torque • Post Transmission Parallel • Drive through gear changes

27. M M M Parallel - cont • Through the Road Parallel • Drive through gear changes • Added traction • Four Wheel Drive Post Transmission • Drive through gear changes • Added traction

28. Fuel ICE Gen Wheels ESD M/G M M Combined • Energy flow • Maximum Acceleration • Added complexity in control • Post Transmission Combined • Increase available engine torque • Drive through gear changes

29. M M M M M Combined - cont • Separate Axle Combined • Increase available engine torque • Drive through gear changes • Added traction • Four Wheel Drive Combined • Increase available engine torque • Drive through gear changes • Added traction

30. Powersplit • Powersplit hybrid • Usually based around planetary gear set • Requires major modification of transmission • Does not fulfil project requirements

31. Model Design • Models acceleration event (0-60mph) • Front engine – rear wheel drive layout • Engine and clutch model, with 1st order engine lag, flywheel and clutch inertia • Drivetrain, transmission and final drive, connected by flexible shafts, modelled as spring/dampers. • Non linear tyre model with longitudinal slip • Full body vehicle model with air resistance and angle of inclination • Weight transfer between front and rear axles • Driver model, designed to achieve maximum acceleration • Three electric motors connected to the engine, rear axle and front axle

32. Model Validation

33. Architecture Selection • Run with same motor specifications • 75kW, 240Nm, 59kg, 8000rpm max speed • Geared to reach 120mph • Acceleration run, 0 - 60mph • Simulated in new model Westfield • 1.6l Turbo Petrol Engine • Launched at Autosport International in January

34. Architecture Selection

35. Architecture Selection

36. Architecture Selection • Architectures use 1,2 or three motor sets. • Additional motor sets add cost • Hybridisation Factor • HF = PEM/(PEM+PICE) • Benefit Factor • BF = (1-(THYBRID/TSTANDARD))/HF • (P = Power (kW), T= 0 – 60mph Time (s))

37. Benefit Factors

38. Battery Pack Power • Battery weight to be a minimum • Vehicle dynamics • Energy storage to be a minimum • Too much will be detrimental to enjoyment • Cost to be low • Batteries represent majority of system cost • Power should be high • How low can the battery pack power be?

39. Battery Pack Power

40. Conclusions • 2 Surveys carried out • Shown market potential for hybrid racing car • Through the road hybrid architecture • Maximum acceleration increased by 30% • Give best performance increase for cost • Battery pack can be decreased by 30% • Only 3.3% increase in acceleration time

41. Thank you Questions