A novel ZVS bidirectional Cuk converter for dual voltage systems in automobiles

The automotive industry is heading towards a higher electrical voltage system of 42 V for next generation vehicles. In the interim, there will be dual voltage systems which would require a bi-directional dc-dc converter to regulate power flow between the 42 V and 14 V buses. Cuk converter with integrated magnetics has the advantage of zero ripple in both input and output currents, and also can handle power in both directions. This paper proposes a simple zero voltage switching scheme for the Cuk converter using only passive components. ZVS is effective at all loads, including reverse power flow, and thus improves the overall converter efficiency. The paper discusses the design methodology for the zero-ripple converter and the synthesis of the ZVS scheme. Computer simulations are used to verify the design.