Energy and Thermal Management Simulation of an Advanced Powertrain

Transcription

1 Energy and Thermal Management Simulation of an Advanced Powertrain Armin Traußnig VIRTUAL VEHICLE Research Center COMET K2 Competence Center - Initiated by the Federal Ministry of Transport, Innovation & Technology (BMVIT) and the Federal Ministry of Economics & Labour (BMWFI). Funded by FFG, Land Steiermark and Steirische Wirtschaftsförderung (SFG)

2 Agenda 1 Introduction and Overview Overview VTMS Simulation System Partitioning for Simulation Simulation environment 2 Co-Simulation Part Models Heat Release and Fuel Consumption Engine Friction Cooling / Lubrication Circuit Engine Thermal Network Vehicle and Drivetrain ECU Model 3 Exemplary Simulation results 4 Summary & Outlook VIRTUAL VEHICLE 2

3 1 Introduction and Overview VIRTUAL VEHICLE 3

4 Overview VTMS Simulation Objectives CO2 Reduction Evaluation of CO2 Reduction measures (El. Auxiliaries, Control Strategies) Proposed Approach Simulation of the complete Vehicle System Co-Simulation of detailed Submodels to consider all interactions Today s Challenges Prediction Quality and accuracy CO2 Reduction Potentials in the range of 1-3% High demands on Simulation model integrity to predict influence of measures Integration of Control Units Major influence on fuel consumption Flexibility in ECU Parameter sets (e.g.: Different countries and stages of development) Static representation is not sufficient Nonlinearities due to switching and hysteresis behavior Physical detailing Accuracy VIRTUAL VEHICLE 4

5 System Partitioning for Simulation F Boundary Conditions Engine Control Unit E A Powertrain B Heat Release & FC C Engine Friction D Cooling and Lubrication Thermal Network VIRTUAL VEHICLE 5

6 Simulation environment Coupling via ViF in-house co-simulation platform ICOS Typically ~100 Simulation variables are exchanged Different time step and solver for each model Engine Friction Engine Control Unit Powertrain Heat Release & FC Cooling and Lubrication Thermal Network VIRTUAL VEHICLE 6

7 2 Co-Simulation Part Models VIRTUAL VEHICLE 7

8 (A) Heat Release and Fuel Consumption Objectives Heat release model Modeling of heat transfer between working gas and combustion chamber walls, outlet channel and turbocharger Separation heat flow calculation for individual components Fuel consumption model Calculation of fuel consumption dependent on engine state Modeling Q Mathematical model fit DoE: Wall f n, IMEP, IGA,, Tcool, Tch _ air, Twall,... VIRTUAL VEHICLE 8

9 (B) Engine Friction Objectives Consideration of all relevant partial friction components Validity of the model in broad speed and temperature range Heat release and FMEP Modeling Empirical model fit (DoE) based on: Strip-Down measurements Engine drag warm-up FMEP, Q f ( T, Torque, n, ) frict part VIRTUAL VEHICLE 9

10 (C) Cooling / Lubrication Circuit Objectives 1D thermohydraulic representation of Fluid network Heatflow: Engine structure coolant, oil Heatrejection oil coolant Heatrejection coolant air Cylinder Head Modeling Heat transfer Fluid<->Solid via empirical correlations Calculation of fluid temperatures via discretization of fluid volumes into lumped masses Crank Case Engine Auxiliaries Engine Bypass HX T fluid f ( Tstructure, Tambient, m fluid ) Coolant Pump Physical modeling of pressure drops p f ( T fluid, m fluid ) Thermostat VIRTUAL VEHICLE 10

11 (D) Engine Thermal Network Objectives Temperature distribution in Engine structure Modeling Discretization of engine structure into lumped masses Discretization: ~20 lumped masses ~25 conduction resistances ~10 heat sources (Heat release model) ~10 heat bridges (Cooling/Lubrication) Physical temperature model based on geometry : T mass f ( Tgas, Tstructure, Tcool, Toil, Tambient, m cool, m oil, m air ) VIRTUAL VEHICLE 11

12 (E) Vehicle and Drivetrain Objectives Driver and Driving cycle definition Vehicle driving resistances Engine Torque calculation Gear selection Modeling Longitudinal dynamics in AVL CRUISE Gearbox and auxiliary losses integrated via Temperature dependent models or maps VIRTUAL VEHICLE 12

13 (F) ECU Model Objectives Reproduce thermal management relevant signals Reproduce dynamic behavior of relevant ECU functions Flexible adaption of Soft ECU to new calibration data set Integration into non real-time simulation environment Heat Release & FC Engine Friction Engine Control Unit Cooling and Lubrication Powertrain VIRTUAL VEHICLE 13

14 (F) ECU Model - Modeling SW Docu + calibration data set Engine speed Accelerator pedal position Coolant temperature Oil temperature Vehicle speed Gear Indicated pressure (IMEP) Ambient temperature Ambient pressure Secondary air (on/off) reduced ECU + Engine dynamics Lambda Ignition angle Cam Phaser Mass air flow Fuel pressure Valve lift Multiple injection Internal torque VIRTUAL VEHICLE 14

15 (F) ECU Model Torque path modeling Real ECU Torque Path Very complex ECU function Many involved systems High effort to rebuild Simplified modeling approach: Simulated Powertrain Torque (BMEP) and Friction Torque Powertrain BMEP + IMEP Engine Control Unit FMEP Engine Friction VIRTUAL VEHICLE 15

16 3 Exemplary Simulation Results VIRTUAL VEHICLE 16

17 Exemplary Simulation results NEDC coldstart Measurement Simulation Cylinder head hot side Cylinder head cold side VIRTUAL VEHICLE 17

18 Exemplary Simulation results Overview Fuel consumption VIRTUAL VEHICLE 18

19 Exemplary Simulation results NEDC Start/Stop Investigation: on (red) / off (blue) Simulation VIRTUAL VEHICLE 19

20 Exemplary Simulation results NEDC Start/Stop Investigation: on (red) / off (blue) D= 3% VIRTUAL VEHICLE 20

21 4 Summary & Outlook VIRTUAL VEHICLE 21

22 Summary & Outlook Simulation Quality and accuracy Good accuracy in fuel consumption and Temperature calculation Evaluation of thermal management measures possible One Full vehicle model covers all cycles and boundary conditions ECU model No real time Environment required Representation of all thermal management relevant functions Dynamic behavior is covered sufficiently Exchange of different ECU data sets Outlook Offline precalibration of ECU functions (e.g.: map Thermostat) Evaluation of new Thermal Management functions Evaluation of predictive Thermal Management measures VIRTUAL VEHICLE 22

23 Armin Traußnig VIRTUAL VEHICLE Research Center VIRTUAL VEHICLE 23

24 VIRTUAL VEHICLE 24