A Quadruple Active Bridge converter as the storage interface in the more electric aircraft

The More Electric Aircraft (MEA) concepts aims at increasing the penetration of electric systems on the aircrafts. In this framework, the electrical power distribution system (EPDS) is of high importance. Increasing the electrical subsystem while limiting the overall weight is one of the major challenges for the MEA. This problem can be addressed by a proper energy storage system that allows increasing the utilization of the generators. This paper proposes the use of a Quadruple Active Bridge (QAB) converter, already adopted in other fields, to interfaces different storage technologies to the aircraft DC bus. This solution would replace multiple DC/DC converters, increasing the power density, but presents difficulty in the power flow control and in the possible efficiency deterioration in the case of asymmetrical operation. A novel control, based on current feed-forward and power decoupling is proposed to this aim and simulations shows the effectiveness of the solution. A laboratory prototype is used to confirm that the asymmetrical operation, where each port processes a different amount of power, does not imply a marked reduction of efficiency.