Electro-thermal models of
automotive inverters
PA Mawby
Electro-thermal modelling of power
electronics
16th March 2009
Background
• Inverter Technology
• IGBTs, diodes are enabling technologies
• Must be considered as part of whole system
• Co-simulation of electrical, thermal systems
• Optimisation to include:
• Device structures
• Circuit design
• Heatsink/packaging design
compact yet accurate
models required
• Assessment of new materials
• SiC/GaN unipolar devices (schottky diode, MOSFET, HEMT)
• Tools to allow comparison with existing Si devices
Hybrid Vehicles
Electric Vehicles
Value Added to Toyota
• Integrated software environment
• for assisting simulation, optimization and testing of power
electronic circuits and power semiconductor devices under
realistic conditions.
• Improved confidence
• that inverter devices and circuits are truly optimized for hybrid
vehicle applications.
• Comprehensive compact models,
• with associated parameter extraction, for circuit simulation and
optimization of Toyota devices and new material devices.
• Tools
• for the investigation into the effects of vehicle load cycles on
device stresses and performance.
Project Overview
• Principal strands:
• Development and validation of a technique for
rapid simulation of inverter losses.
• Development of new material (SiC/GaN) device
compact models to use in inverter simulation.
• Development of 3D thermal models for
heatsinks and packaging.
• These enable:
• Assessment of new material devices and
comparison with Si devices.
• Analysis and optimisation of heatsink and
device design.
Results: On-state
Forward characteristics for diode (left), IGBT (right) with temperature
(solid: simulation, dotted: experiment)
Results: Switching
Recovery current transients vs temperature for diode (left), IGBT (right) at 13A and 40A.