GKN's ActiveConnect all-wheel drive system as an energy-efficient - PowerPoint PPT Presentation

GKN's ActiveConnect all-wheel drive system as an energy-efficient solution for electrified vehicles Christoph Schmahl | 9/10.05.2019 1

AWD Systems in the Age of Electrification AWD Systems in the Age of Electrification Electrified AWD vehicles are becoming increasingly popular AWD is realized by an electrified secondary axis, which leads Significant growth expected in the HEV/BEV to dual motor systems with front hybridized HEV and with BEV market with East/West configuration 40 35 30 Volume [M units] 25 20 15 10 5 0 2020 2025 2030 Year Example: BEV with dual motor AWD AWD - HEV/BEV East/West AWD - conventional AWD - conventional & HEV/BEV - North/South GKN Internal Analysis, 2018 2

Mechanical AWD System as Alternative Approach Dual motor systems: Electric vehicle with dual Conventional vehicle with Two separate drive units lead to high costs, motor AWD system mechanical AWD system low efficiency and mobility disadvantages AWD systems in conventional vehicles: Mechanical drivetrain architecture allows use of a single source of propulsion power GKN’s ActiveConnect AWD system allows to Electric vehicle with mechanical AWD system combine the best of both worlds to achieve high vehicle efficiency cost reduction enhanced mobility and driving dynamics low engineering and integration effort 3

ActiveConnect: How much AWD is needed? AWD demand Road data acquisition Test vehicles Road profiles 100% 75% 75% 86% 91% Demand Disconnected 100% AWD 50% Active AWD 25% 25% 14% 9% 0% Snow Country City Autobahn low-µ high-µ high-µ high-µ Most of the time AWD is not required! 4

GKN ActiveConnect-AWD Technology Increased efficiency with ActiveConnect Twinster technology improves driving performance Twinster PTU Disc RDU Clutches Throttle on – torque bias to outer wheel Booster to mitigate under-steer (Single Clutch RDU) Modular Design Dog Clutch rotating parts parts on down time Throttle off – Active AWD increased locking torque Disconnected AWD (both wheels) to mitigate over-steer 5

GKN ActiveConnect-AWD Technology Increased efficiency with ActiveConnect Twinster technology improves driving performance Twinster PTU Disc RDU Clutches Throttle on – torque bias to outer wheel Booster to mitigate under-steer (Single Clutch RDU) Modular Design Dog Clutch rotating parts parts on down time Throttle off – Active AWD increased locking torque Disconnected AWD (both wheels) to mitigate over-steer 6

Basis Vehicles for Efficiency Simulation Simulation of three different BEV AWD concepts regarding the energy consumption: Single motor with mechanical Dual motor AWD (permanent) Dual motor AWD (EDD) ActiveConnect AWD • • • No disconnect Front axle with disconnect Mech. AWD with ActiveConnect • • • Permanent AWD Efficiency optimized disconnect Speed dependent disconnect • • • Motor: 50 kW front / 50 kW rear Motor: 50 kW front / 50 kW rear Motor: 100 kW front Schematic illustration of clutch Vehicle parameter: • Mass 1885 kg • Front area 2,6 m² • Drag coefficient 0,33 7

Growth Laws of Electric Machines The ratio of power to efficiency of electrical machines is determined by the so-called growth laws [1] Scaling up an electric machine by the factor k in all it’s linear dimensions results in an increase [1] – of power by the factor k 4 – of volume by the factor k³ – of energy losses by the factor k³ With increasing motor power the efficiency and the ratio of power to costs improves [1] [1] Spring, E. Elektrische Maschinen: Eine Einführung Springer Berlin Heidelberg, 2009 Efficiencies of totally enclosed 4-pole induction motors [2] [2] Pyrhonen, J. et al. Design of Rotating Electrical Machines Wiley, 2008 Conclusion: Replacing two low powered electrical machines with one high powered electrical machine results in improved efficiency and cost savings 8

Powertrain Efficiency (Example) Single motor with ActiveConnect AWD RDU - Disconnect High motor efficiency Dual motor AWD Load independent losses of single Low motor efficiency gearbox and inverter Double load Low drag loss of PTU and RDU in independent losses of disconnect gearbox and inverter PTU - Disconnect PMSM + Inverter (P max =50 kW) PMSM + Inverter (P max =50 kW) 100 72% 82% 87% 88% 72% 82% 87% 88% 100 74% 83% 87% 89% 88% 88% 90 90 74% 83% 87% 89% 88% 88% 75% 84% 88% 90% 90% 88% 80 75% 84% 88% 90% 90% 88% 80 Torque [Nm] 70 76% 85% 89% 90% 91% 88% 88% Torque [Nm] 76% 85% 89% 90% 91% 88% 88% 70 77% 86% 89% 90% 91% 91% 88% 86% 60 60 77% 86% 89% 90% 91% 91% 88% 86% 77% 86% 90% 91% 91% 92% 91% 87% 50 77% 86% 90% 91% 91% 92% 91% 87% 50 40 77% 85% 90% 91% 91% 92% 91% 89% 87% 86% 86% 77% 85% 90% 91% 91% 92% 91% 89% 87% 86% 86% 40 76% 84% 90% 90% 91% 91% 91% 90% 89% 88% 86% 86% 30 30 76% 84% 90% 90% 91% 91% 91% 90% 89% 88% 86% 86% 20 72% 81% 87% 89% 89% 89% 89% 88% 88% 87% 87% 85% 72% 81% 87% 89% 89% 89% 89% 88% 88% 87% 87% 85% 20 10 68% 73% 83% 85% 84% 84% 84% 82% 83% 83% 82% 82% 68% 73% 83% 85% 84% 84% 84% 82% 83% 83% 82% 82% 10 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 Gearbox Speed [rpm] Speed [rpm] Gearbox Gearbox PMSM + Inverter (P max =100 kW) 80% 88% 90% 92% 200 81% 88% 91% 92% 180 160 82% 89% 91% 93% 92% Torque [Nm] 83% 89% 92% 93% 93% 91% 140 83% 90% 92% 93% 94% 93% 90% 120 100 84% 90% 92% 93% 94% 93% 92% 90% 89% 84% 90% 92% 93% 94% 93% 93% 92% 90% 88% 80 60 84% 89% 92% 93% 93% 93% 93% 92% 91% 90% 86% 40 83% 89% 90% 91% 92% 93% 93% 92% 91% 91% 89% 89% 79% 85% 87% 88% 89% 89% 90% 90% 89% 88% 87% 87% 20 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 Rotational Speed [rpm] 9

Powertrain Efficiency (Example) Single motor with ActiveConnect AWD RDU - Disconnect High motor efficiency Dual motor AWD Load independent losses of single Low motor efficiency gearbox and inverter Double load Low drag loss of PTU and RDU in independent losses of disconnect gearbox and inverter PTU - Disconnect PMSM + Inverter (P max =50 kW) PMSM + Inverter (P max =50 kW) 100 72% 82% 87% 88% 72% 82% 87% 88% 100 74% 83% 87% 89% 88% 88% 90 90 74% 83% 87% 89% 88% 88% 75% 84% 88% 90% 90% 88% 80 75% 84% 88% 90% 90% 88% 80 Torque [Nm] 70 76% 85% 89% 90% 91% 88% 88% Torque [Nm] 76% 85% 89% 90% 91% 88% 88% 70 77% 86% 89% 90% 91% 91% 88% 86% 60 60 77% 86% 89% 90% 91% 91% 88% 86% 77% 86% 90% 91% 91% 92% 91% 87% 50 77% 86% 90% 91% 91% 92% 91% 87% 50 40 77% 85% 90% 91% 91% 92% 91% 89% 87% 86% 86% 77% 85% 90% 91% 91% 92% 91% 89% 87% 86% 86% 40 76% 84% 90% 90% 91% 91% 91% 90% 89% 88% 86% 86% 30 30 76% 84% 90% 90% 91% 91% 91% 90% 89% 88% 86% 86% 20 72% 81% 87% 89% 89% 89% 89% 88% 88% 87% 87% 85% 72% 81% 87% 89% 89% 89% 89% 88% 88% 87% 87% 85% 20 10 68% 73% 83% 85% 84% 84% 84% 82% 83% 83% 82% 82% 68% 73% 83% 85% 84% 84% 84% 82% 83% 83% 82% 82% 10 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 Gearbox Speed [rpm] Speed [rpm] Gearbox Gearbox PMSM + Inverter (P max =100 kW) 80% 88% 90% 92% 200 81% 88% 91% 92% 180 160 82% 89% 91% 93% 92% Torque [Nm] 83% 89% 92% 93% 93% 91% 140 83% 90% 92% 93% 94% 93% 90% 120 100 84% 90% 92% 93% 94% 93% 92% 90% 89% 84% 90% 92% 93% 94% 93% 93% 92% 90% 88% 80 60 84% 89% 92% 93% 93% 93% 93% 92% 91% 90% 86% 40 83% 89% 90% 91% 92% 93% 93% 92% 91% 91% 89% 89% 79% 85% 87% 88% 89% 89% 90% 90% 89% 88% 87% 87% 20 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 Rotational Speed [rpm] 10

Efficiency Simulation Results 20 Basis drive cycle: WLTP Simulation with a range of different PMSM Disconnection thresholds have been Energy Consumption [kWh/100km] 19 established below 40 km/h Potential energy savings by ActiveConnect AWD: ~ 9 % vs. permanent dual motor system Typical disconnection threshold 18 ~ 6 % vs. dual motor system with EDD (v < 40 km/h) -9 % -6 % 17 16 AWD - AWD with FWD only 30 km/h 50 km/h 70 km/h 100 km/h 120 km/h AWD only Permanent EDD Disconnect threshold Dual motor system Single motor with mechanical ActiveConnect system (Battery: 60 kWh) 11

Cost Comparison Cost benefit by ActiveConnect AWD vs. Dual Motor System vs. Dual Motor System Cost benefit is achieved by single motor with permanent AWD with Front Axle EDD concept due to 13% – reduced number of complex drive components 9% 8% – generating drive power by one central 4% motor Cost estimate based on current market ActiveConnect with ActiveConnect with prices Twinster RDU Booster RDU – Inverters, motors, transmissions and ActiveConnect-AWD evaluated – Cost of wiring, cooling and potential battery modification not considered ActiveConnect Inverter Transmission Motor AWD System (PMSM) 12 12