POWERTRAIN DESIGN GROUP MEETING #3 ADVISOR 2.0 Sachin Kumar Porandla Advisor Dr. Wenzhong Gao

Outline Need for simulation tools What is ADVISOR Working Principle ADVISOR GUI Simulation of HEV Limitations References

Need for Simulation tools Many configurations / energy management / control strategies Analytical solution is difficult Prototyping and testing is expensive & time consuming Optimization can be arduous task since there are literally hundreds of parameters affecting its performance

ADVISOR ADVISOR = Advanced VehIcle SimulatOR -- simulates conventional, electric, hybrid (series, parallel, fuel cell) vehicles ADVISOR was created in 1994 to support DOE Hybrid program in NREL. Part of a larger system analysis effort from NREL and DOE Commercialized from 2002, available from AVL Powertrain Engineering Inc., Plymouth, Michigan. Downloaded by over 4000 people around the world

ADVISOR operates in the MATLAB/Simulink environment Advisor contd... ADVISOR operates in the MATLAB/Simulink environment -- Matlab is chosen for its programming ability, modeling flexibility, optimization toolbox and visualization tools Vehicle data is provided in Matlab files (m files) and models are developed in Simulink (calculations) Empirical model using drivetrain component performances Graphical User Interface (GUI), allows the user to model any type of ICE/EV/HEV by easily changing the vehicle configuration and parameters without having to modify the Simulink block diagrams.

ADVISOR will allow the user to answer questions like: Advisor contd… ADVISOR will allow the user to answer questions like: Was the vehicle able to follow the speed trace? How much fuel and/or electric energy were required in the attempt? How does the state-of-charge of the batteries fluctuate throughout a cycle? What were the peak powers delivered by the drivetrain components? What was the distribution of torques and speeds that the piston engine delivered? What was the average efficiency of the transmission? Predicts fuel economy, emissions, accel. performance and grade sustainability and optimization

Working Principle Advisor is a backward facing model with limited forward facing capabilities In backward-facing calculations, no driver behavior is required. The user must input the driving pattern, a velocity profile, called the speed trace. The force required to accelerate the vehicle is calculated and translated into torque. This procedure is repeated at each stage from the vehicle/road interface through the transmission, drivetrain,etc., until the fuel use or energy use is calculated In forward-facing calculations, the user inputs the driver model, then the simulator generates throttle and brake commands that are changed into engine torque, which is passed to the transmission model and passed through the drivetrain until a tractive force is computed.

Principle contd… HEV model backward-facing model pass torque, speed, and power requirement up the drivetrain forward-facing model pass available torque, speed, force and power through the drivetrain represent model (data processing modules) contains all data processing elements, such as “Sum” and “Product” blocks and look-up tables, necessary to model

ADVISOR GUI 2 1 3 1. User can select his own vehicle configuration & components using drop- down menus user can modify variables in the variable list autosize: accel’n/grade constraints and optimizing drivetrain components 2. Graphical representation of the powertrain selected 3. Shows the performance information of the comp- onents (efficiency contours, emission contours and batteries 2 1 3

GUI contd… autosize window accel’n options grade options

GUI contd… 1 2 3 1. User can select a drive- cycle/test procedure, no. of cycles etc. Declare initial conditions soc correction for HEV 2. Gradeability and accel’n requirements parametric analysis can be done 3. Views drive cycle selected and associated statistics/description 1 2 3

GUI contd… Results Screen 6 5 1 2 3 4 1. Shows the fuel econ., gasoline equivalent and distance covered 2. Emission data 3. Accel’n and Gradeability 4. Warnings: if the trace is not met or failed in performance criteria 5. Plot control 6. Graphs: max. 4 plots 6 5 1 2 3 4

Simulation of a Hybrid Electric vehicle A default parallel HEV is simulated. The parameters can be obtained by just inserting ‘parallel’ in ‘drivetrain config’ menu box Objective is to minimize the engine size, meeting the constraints Constraints 0 – 60 mph <= 12 s 40 – 60 mph <= 5.3s 0 – 85 mph <= 23.4s distance in 5 s >= 140 ft time in 0.25mi <= 20s max. accel. Rate >= 17 ft/s2 max. speed >= 90mph gradeability = 6% at 55mph Meets the constraints at 41 kW

Simulation of a Hybrid Electric vehicle meets constraints at 40 kW meets constraints at 39 kW

Simulation of a Hybrid Electric vehicle meets constraints at 38 kW Fails to meet the grade- constraints at 37 kW Minimum size of engine for this config. Can be 38 kW

Limitations analysis tool, and not originally intended as a detailed design tool Component models are quasi-static, and cannot be used to predict phenomena with a time scale of less than a tenth of a second or so Physical vibrations, electric field oscillations and other dynamics cannot be captured using ADVISOR, however recent linkages with other tools such as Saber, Simplorer, and Sinda/Fluint allow a detailed study of these transients in those tools with the vehicle level impacts linked back into ADVISOR

References Wipke, K., Cuddy, M., Burch, S., “ADVISOR 2.1: A User-Friendly Advanced Powertrain Simulation Using a Combined Backward/Forward Approach,” IEEE Transactions on Vehicular Technology: Special Issue on Hybrid and Electric Vehicles. (8/99) Wipke K. et. al, “ADVISOR 2.0: A Second-Generation Advanced Vehicle Simulator for Systems Analysis,” NREL NAEVI ’98 paper presented in Phoenix, AZ. (12/98) ADVISOR 2002 documentation K. M. Stevens, “ A versatile computer model for the design of the design and analysis of electric and hybrid drivetrains,” Master’s thesis, Texas A&M Univ., 1996. J. Larminie and J. Lowry, “Electric vehicle technology explained,” John Wiley & Sons, Ltd., England, 2003