Modelling and identification of a DC-DC boost converter operating in discontinuous conduction mode

This paper proposes a grey-box modelling approach for a laboratory based DC-DC boost converter operating in discontinuous conduction mode, where use is made of recorded input-output data, rather than physical relationships. Because the nonlinear steady-state characteristic of the converter can be described by a static nonlinearity, whilst operating point dependent dynamics can be captured by a bilinear structure, it is proposed to use a Hammerstein-bilinear structure (HBS). A set of such HBS models at individual operating points is identified and combined into a single model through an interpolating Gaussian blending function that in effect allows for the entire range of operation to be covered. The proposed HBS approach is compared and validated against a state-dependent parameter model on an independent set of data.