Analysis of interleaved dual boost converter with integrated magnetics: signal flow graph approach

A systematic development of a unified signal flow graph model for an interleaved boost converter with coupled inductor system operating in continuous current mode is presented. This signal flow graph approach provides a means to directly translate the switching converter to its graphic model, from which steady-state and dynamic behaviour of the converter can easily be studied. Development of a unified signal flow graph is explained and derivation of large, small-signal and steady-state models is demonstrated. Converter performance expressions such as steady-state voltage gain, efficiency expressions and small-signal characteristic transfer functions are also derived. Large-signal responses against supply and load disturbances are predicted by programming the corresponding signal flow graph in the TUTSIM simulator. Experimental observations are provided to validate the signal flow graph modelling method. Frequency response characteristics generated from the signal flow method are validated with PSpice simulations. Further, the mathematical models obtained from the signal flow graph modelling are in agreement with those obtained from the state-space averaging technique.