Floating voltage fuel cell drive system

Fuel cell technology, with its advantages of high energy density, fast refuel, and possibility to produce from renewable energy, becomes a promising solution for electric vehicles. However, the output voltage of fuel cells is variable (up to 30%) with the load current. Thus, a conventional fuel cell drive system requires a two-stage converter topology with a ‘constant voltage’ DC bus in between.  The first-stage is a DC-DC converter to regulate the output of the fuel cells to the constant DC voltage. The second-stage is a 3-phase DC/AC drive inverter to generate AC power for the motor. The DC voltage is usually maintained by Li-ion batteries. The capacity of the batteries depends on the power matching of the fuel cells and the motor.

The technical challenges to be addressed in the project include: (1) how to maintain the required power output of the motor with the floating DC voltage; and (2) how to dimension the energy storage for given fuel cell power and motor power.


Partner organizations

  • Volvo Cars (Private, Sweden)
  • Powercell (Private, Sweden)
Start date 01/01/2018
End date The project is closed: 31/08/2018

Published: Thu 31 May 2018.