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Research is funded by the Department of Energy
The FreedomCAR project will develop a variable timing controlled, high-efficiency, soft-switching inverter for a wide range of input voltages and loads so that the inverter can be operated with an engine coolant temperature of 105ºC. The project is funded by the Department of Energy, and FEEC is the project leader. Azure Dynamics and Powerex are team members, who are responsible for motor control and soft-switching module development, respectively. The Gen-1 soft-switching inverter has been developed and tested with a dynamometer successfully at different coolant temperatures and load conditions. It demonstrates efficiency as high as 99%. A Gen-2 soft-switching inverter is under development for integration improvements, and an in-vehicle test will be conducted.
  • Battery Voltage: 200V - 450Vdc
  • Peak Power: 55kW
  • Peak Torque: 240Nm
  • Continuous Power: 30kW
  • Coolant Temperature: 105ºC
  • Inverter Efficiency: 98.5% - 99%
Key Technologies:
  • A variable timing controlled soft-switching inverter for switching loss reduction
  • A hybrid soft switch module for conduction loss reduction
  • A low thermal impedance module with integrated heat sink for high temperature operation
  • A highly integrated soft-switch module for low-cost inverter packaging
  • Modeling and simulation for design optimization
  • Testing the soft-switching inverter with existing EV platform and dynamometer for EMI and efficiency performance verification

System Block Diagram

Inverter-Motor-Dynamometer Test System Setup

5kW soft-switching inverter

Measured efficiency reaches 98.5% under 0.83 power factor conditions


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