DOE Researchers Testing Integrated Inverter for Use in Fuel Cell Vehicles
April 7, 2004
In traditional internal combustion (gasoline) engines, the compressors for heating, ventilating, and air-conditioning (HVAC), as well as water/oil pumps, are typically belt-driven. In fuel cell-powered vehicles, these belt-driven components will likely be replaced by electrical motor drives, each of which requires an inverter for proper operation.
An Oak Ridge National Laboratory research and development project funded by the U.S. Department of Energy's FreedomCAR and Vehicle Technologies Program is looking into integrating those auxiliary inverters so they can drive multiple motors. Integration would allow sharing of some of the power semiconductor switches, control circuit, and other components, resulting in a lower-cost, smaller-volume drive system.
In the current effort, the Oak Ridge researchers are developing an integrated inverter for the traction motor drive and HVAC compressor drive. Figure 1 shows a block diagram of this integrated inverter, designed for driving a traction motor and an auxiliary motor. The main motor is a typical three-phase motor, but the auxiliary motor is a two-phase motor. This configuration saves two switches, their associated gate drive circuits, and one dc bus capacitor. Other savings come from the shared gate drive power supply and DSP control circuit.
The Oak Ridge team recently tested the configuration shown in Figure 1 in a simulation study; results confirmed the operation of the integrated inverter drive. Figure 2 shows the simulation results. A proof-of-concept setup is being assembled and lab testing will begin once the setup is completed.