UQM Technologies has delivered a hybrid electric cargo van powered by a reduced electromagnetic emission (EMI) propulsion system and generator.The company is to complete a hybrid electric shuttle bus, also modified to incorporate reduced EMI systems, in May. Both vehicles are part of a fleet of eleven Ford 350 chassis-based hybrid electric cargo vans and shuttle buses operated at Robins Air Force Base under the management of the Advanced Power Technology Office (APTO).

EMI refers to electromagnetic phenomena arising from the movement of electric current and voltage including to or from electric motor/generators and power electronic inverters. In electrically-propelled vehicles, electromagnetic emissions can cause interference with other electronic equipment onboard the vehicle or in the immediate vicinity of the vehicle.

For military vehicles, the generation of an electromagnetic signature presents additional challenges, many related to vulnerability.

The UQM low-EMI propulsion system and generator reduces the EMI emissions from the baseline system by more than 40 dB across most of the testing spectrum. In addition to reducing EMI emissions through conventional enclosures and concentric cables, EMI emission reductions were achieved through a proprietary commutation technique in the UQM motor controller that reduces the harmonic content of the system.

This will be the first reduced-EMI hybrid in the fleet.