Hybrid Electric Vehicle Modeling

Hybrid-Electric Vehicle, Driveline and Control Systems

GT-SUITE offers a versatile set of tools for the simulation of vehicles with Hybrid-electric (HEV) or electric-only (EV) drivelines, as well as the control systems and control strategies that are key to the operation of these vehicles.   A set of HEV components (electromechanical and energy storage devices) are provided and can be combined with elements of the Vehicle dynamics toolbox and Electrical and Control libraries to create comprehensive and integrated models of HEV or EV vehicles and drivelines.   Such models are indispensible in studies aimed at selection of components, and selection, evaluation, fine-tuning and optimization of control strategies to achieve set design goals, typically fuel economy, emissions and performance for various duty cycles.

The following are the key elements of GT-SUITE which enable modeling of HEV drivelines:

• Electromechanical component models (motor, generator)
• Energy storage (battery)
• Electrical (circuit) modeling elements
• Control/signal processing library
• Torque-splitting devices (transfer case, planetary gear)

Together, these allow modeling of virtually any HEV driveline configuration (series, parallel, power-split or combinations) as well as electric vehicles.   HEV driveline models can model in full detail the master "strategy" controller as well individual device controllers, to simultaneously apply strategies for all common HEV functions:

• Electric launch and transition to IC engine drive
• Regenerative braking, braking load distribution (mechanical vs. electrical)
• IC engine assist
• Battery state of charge maintenance
• Interactions, interdependences and interlocks between the above

GT-SUITE provides both map-based and simplified "electro-mechanical" models of a motor or generator.   In the map-based model, a torque (or mechanical or electrical power) map is user-specified as a function of speed and an "actuator".   In the electro-mechanical model the device is "driven" with an applied voltage and a simple circuit is solved for.   The back-voltage is a function of rotor speed through a multiplier, which by energy conservation principles is also the ratio of torque to current.   The multiplier can be made variable, for example specified as a map/function of speed and current.   A third alternative is the construction of detailed electro-mechanical models using basic mechanical and electrical primitives.   This enables integration of any external circuit models (e.g. for controller, inverter circuits) which control applied voltages to be included in the simulation.

The battery model is based on a simple circuit and is controlled by power request.   The battery open circuit voltage, internal resistance, as well as a Columbic efficiency can be specified as a function of battery state of charge (SOC) and temperature, all separately for charging and discharging.   The model solves for the current and integrates SOC.   A thermal model based on stacked cylindrical cells can be activated by the user to model mean battery temperature, and an interface to a user thermal model is also provided.   Electrical and thermal libraries may also be used together to construct a battery model which can be integrated with models of external circuits.

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For more information contact: (or contact us online)
Gamma Technologies, Inc.  601 Oakmont Lane, Suite 220  Westmont, IL 60559  USA	Tel.  (630) 325-5848  Fax. (630) 325-5849 Email: CAE@gtisoft.com Web: www.gtisoft.com

APPLICATIONS

Engine Performance
Test Pressure Analysis
Exhaust Aftertreatment
Acoustics
SiL, HiL, real-time
Vehicle, driveline
Hybrid Vehicles
Cooling/VTM
Underhood Modules

AC and Rankine
Lubrication and bearings
Fuel Injection
Hydraulics, pneumatics
Valvetrain, camshaft
Cranktrain, crankshaft
Chain, gear, belt drive