Powertrain Systems. From 12+12V to 48V: a new road map for hybridization. Dr. Ing O. COPPIN - Valeo Powertrain Systems - France.

Transcription

1 Powertrain Systems From 12+12V to 48V: a new road map for hybridization Dr. Ing O. COPPIN - Valeo Powertrain Systems - France May - June 2016 I 1 May - June 2016

2 Agenda Drivers for Hybridization 12+12V & 48v mild hybrid functions Introduction to Boosted Hybrid 4 Hybridization effects on Nox emissions Electrical board net modular architectures Components modularity 12+12V & 48v extending Road-Map Conclusion May - June 2016 I 2

3 Driver for hybridization : CO 2 regulations Main Issue of Hybrid / Electric: COST! Cost of Powertrain ( ) China 2020 (cars only): V Systems 48V Systems Gasoline STT Diesel STT Gasoline 12+12V Gasoline MH 48V Gasol. Mild 100V HEV 300V PHEV 10km PHEV 40km BEV REX Diesel today just represent the upper limit customers are willing to pay To develop in mass-market, Hybrids need to be cheaper : Why 12V+12V and 48V make sense May - June 2016 I 3

4 Hybrid functions Stop & Start Functions HV 48V 12+12V 12V Extended SST & Coasting Energy recovery Supply board net Torque assist Boost May - June 2016 I 4

5 Alternative Boosting : efficiency analysis Mechanical supercharger Electrical supercharger 17,4 100 > 82,6 100 > 100 High mechanical losses, only 82% of generated torque goes to the wheels No Mechanical losses. 100% of the generated torque is transferred to the wheels With e-supercharger there is no friction while boosting. Energy is free while recovered during braking May - June 2016 I 5

6 Interest of alternative boosting Hybrid system Electrical supercharger 25 kw 25kW 5 kw 25kW To get 25kW on the wheels, need ~25 kw from the e-motor. With 300Amps limit, 100V necessary To get 25kW on the wheels, need ~5 kw on the air thanks to combustion COP. With 300Amps limit, 48V is far enough With e-supercharger there is fundamentally efficiency benefit linked to combustion COP For the same power at wheels, the hybrid voltage can be reduced from high voltage to 12 or 48V: The electric system, including batteries, is then far cheaper. May - June 2016 I 6

7 BMEP (bar) Electric Supercharger = instantaneous response Electric supercharger after 0.5s Turbo after 2.0s Turbo engine Turbo after 1.0s Turbo after 0.5s Naturally aspirated engine Engine speed (RPM) The higher the downsizing, the longer the turbo low RPM. The turbo is unable to compensate the lag. Response time is the key parameter May - June 2016 I 7

8 Electric Supercharger 3 main application fields More Power Better Fuel Efficiency Less pollutants Audi RS5 TDI 386HP Valeo NA Democar 8% FE Volvo edrive 450HP Ricardo HyBoost 20% FE Valeo-FEV : Euro6 w/o SCR 48V 12V Diesel May - June 2016 I 8

9 Electric Supercharger - Various Applications Allows downspeeding without response drawback (Valeo Democar 8% Fuel economy) Allows extreme downsizing (Suralhy Democar & Ricardo s HyBoost DemoCar 20% Fuel economy better performances) Allows Miller Cycle operations on NA engine Allows boosted EGR Allows Clean Diesel without SCR Allows low cost hybridization while coupled with regen system (Kia s T- Hybrid concept in Paris 2014) Allows enhanced cylinder disconnection Allows exceptional accelerations on premium sporty vehicles (Audi RS5, Acura NSX) May - June 2016 I 9

10 CO2 / NOx benefit [%] NOx emissions variation [%]* NOx emissions reduction with ibsg Valeo Internal study Acceleration scenario with torque assist C-Segment MPV (1430kg), 1.6L Diesel, 6-Speed MT, no Stop&Start Simulation estimates (warm start) Possibility to tune ibsg between CO2 and NOx -25%* -80%* NOx emissions Speed Fuel consumption BSNOx 30 to 60km/h at 2m/s², in 3 rd gear Benefits from electric assistance (belt starter-generator used at max. torque): Improved vehicle response Engine operated in low NOx regions Possibility to tune CO2 / NOx Tradeoff Driving cycles Reduction of engine high load operation by electric assistance * Valeo estimate, non contractual data, pending applications, will vary per vehicle application Optimization tradeoff: 90% CO2 10% NOx CO2 benefit [%]* NOx benefit [%]* NEDC WLTC RDE-like RDE-like cycle ibsg NOx optimized Conv CO2 emissions variation [%]* May - June 2016 I 10

11 NOx emissions reduction with esc - Valeo based on FEV / Valeo study Engine 2.0L Diesel, Simulation estimation Context: During transient, NOx emissions increases due to the lack of fresh air. By instantaneously increasing the air flow, the esc lower the NOx increase in transient. Simulation conditions: BMEP [bar] Air Mass Flow Engine Configurations: No esc esc electric Power: 1.2 kw; 1.8 kw; 3 kw & 5 kw Test conditions: escs No esc escs No esc From 2 to 10bar 1500rpm EGR rate: from 50 to 28% Delta = 100 K No esc FEV estimation : 10%~20% Nox reduction Results will vary depending on application escs Results: esc increases the air flow during transient. It improves the performances AND reduces the temperature increase (-100 C in this case) which is one main factor on the NOx production * Valeo estimate, non contractual data, pending applications, will vary per vehicle application May - June 2016 I 11

12 Board net requirement : 48V Dual Battery example Reversible StarterGenerator 10-12kW Regen/Boost 48V Network 48V loads Boost DC/DC converter 2,5kW Regen Stabilized 12V Network 12V loads 12V + 48V Basic Set 48V battery pack (Li-ion) 12V Lead acid battery 2 batteries : allows engine stop and address safety issues Dual battery required for regen and boost (coasting compatible) One battery dedicated to safe network (sensitive loads) One battery dedicated to high current managing (regen & boost) Each battery specification adapted to its own use May - June 2016 I 12

13 Electrical board net : modular building 12V -> 48V 12V regen network Optional Piloted switch 12V clean network Reversible Machine Starter + Alternator 12V 12V + 12V Basic Set Starter 12V Battery 1 12V NON Sensitive Loads 12V Battery 2 12V Sensitive Loads 12V regen network Optional Piloted switch 12V clean network Reversible Machine Starter + Alternator 12V 12V + 12V Extented Set Starter 12V Battery 1 12V NON Sensitive Loads esc 12V Battery 2 12V Sensitive Loads 48V regen network DCDC V 12V clean network Reversible Machine 48V 12V + 48V 48V Battery 48V NON Sensitive Loads esc 12V Battery Starter 12V Sensitive Loads May - June 2016 I 13

14 Electrical board net : 48V modular building Reversible StarterGenerator 10-12kW Regen/Boost 48V Network 48V loads Boost DC/DC converter 2,5kW Regen Stabilized 12V Network 12V loads 12V + 48V Basic Set 48V battery pack (Li-ion) 12V Lead acid battery Reversible StarterGenerator 10-12kW PTC Regen/Boost 48V Network Heated WS Active susp. 12V + 48V Extended Board net DC/DC converter 2,5kW Boost Electric supercharger Electric AC compressor Regen 48V battery pack (Li-ion) Stabilized 12V Network 12V Lead acid battery 12V loads May - June 2016 I 14

15 Emachines & Electronics Building Blocks overview 12V 48V 300V Belt Belt Beltless Belt Beltless Hyb Arch (P1) (P1) (P3) Gearbox Motor (P4) Driveline Motor (P1) (P3) Gearbox Motor (P4) Driveline Motor Rotor Type 1 Type 1 Type 1 Type 2 Type 2 Type 2 Type 2 Type 2 Stator Type 1 Type 1 Type 2 Type 2 Type 2 Type 2 Type 3 Type 3 Power module Type 1 Type 2 Type 2 Type 2 Type2 Type 3 Type 3 Type 3 Inverter Type 1 air cooled Type 2 air cooled Type 2 Air/water cooled Type 2 Oil cooled Type 2 Oil cooled Type 3 Air cooled Type 3 Oil cooled Type 3 Oil cooled May - June 2016 I 15

16 % CO2 Reduction 12+12V & 48V Potential Road Map First 12V application : Stop & Start 48V mild hybrid : more power and more energy available First and easier step : belt e-machine. 80 Systems CO2 gains / cost position STT system cost May - June 2016 I 16

17 % CO2 Reduction 12+12V & 48V Potential Road Map An extension to the 12V field : 12+12V gateway to hybrid functions and coasting 80 Systems CO2 gains / cost position STT + Regen + Coasting system cost May - June 2016 I 17

18 % CO2 Reduction 12+12V & 48V Potential Road Map A better cost / CO 2 gain ratio than high voltage systems 48V : An increasing potential with boosted hybrid and power devices electrification A continuous extension : accessories electrification, P3/P4 hybrid architectures, new concepts. 80 Systems CO2 gains / cost position system cost May - June 2016 I 18

19 12V NON Sensitive loads 12V Sensitive loads Conclusion Hybridization: a necessity for CO 2 reduction Cost is always a driver : China 2020 (cars only):106 Affordable cars require simpler / cheaper solutions Scalable solutions for CO 2 reduction level adaptation i-stars Piloted switch Modular Electric Architectures & topology as way to reduce integration cost Start er 12V Battery 1 12V Battery 2 (AGM/NiMH) Extended 12V & 48V mild hybrid systems address basis hybrid functions and allow superior fuel economy for best value equation 100 Boosted 12+12V & 48V hybrid with electric supercharger Extended downsizing and downspeeding New turbo matching field (turbo lag) Pollutants reduction Fun to drive / high power engines 50 0 May - June 2016 I 19

20 May - June 2016 I 20