A study on a energy management of EDLC for unbalanced input voltage three level inverter

There are still several technical problems with batteries for electric vehicles (EVs), such as short life of batteries on board, and less driving distance. An unbalanced input voltage three level inverter have been studied for a traction system for battery and EDLCs (Electric Double Layer Capacitors) hybrid EVs. This system is expected to reduce the loss and mass compared to a system with DC/DC chopper. When applying EDLCs as energy storage device, the energy management is essential through the whole operation of the motor because the energy density of EDLC is not so high and it can be charged only by the regenerative brake. In this paper, a method to manage energy of EDLC is proposed and it is examined by 1kW class experimental system.