Effect of Coupling on Input-Output Voltage relations in DCM of SIDO Boost Converters

A single input dual output with a coupled inductor (CI-SIDO) converters can generate two outputs from only one available input. The literature shows that these CI-SIDO converters offer several advantages, including reduced losses and component count compared to single output SISO converters. The presence of inversely coupled inductors further reduces the physical size of the core by the flux cancellation in the core. This paper analyses the CI-SIDO boost. It combines two conventional boost converters with a common input and inversely coupled inductors. The continuous conduction mode (CCM) of the CI-SIDO converters are preferred. In CCM, the voltage relations and the control of CI-SIDO boost is not load dependent. However, during operation, anyone boost converter may enter the discontinuous conduction mode (DCM) due to the reduction in loads. This paper analyses the voltage relations of CI-SIDO boost converter when one boost enters DCM keeping the other boost in CCM. The effect of load current change and input voltage change on the voltage relations are also analyzed. Simulations verify the analytical expressions in Matlab/Simulink.