Identification of a Hammerstein model for DC/DC converters operating in CCM

This paper deals with a method for identification of a Hammerstein model of DC-DC converters operating in continuous conduction mode (CCM). This model has the duty cycle and the output voltage as input and output, respectively; it consists of a static nonlinearity and a linear and timeinvariant model. The aim of the modeling the system by means of a Hammerstein model is due to its capability of describing the converter in a range of steady-state operating points instead of a desired well defined operating point as occurs for the small-signal models which are the more common mathematical description to approach the study of the converters themselves. The nonlinear characteristic of the Hammerstein model is constructed by determining ii certain number of its input-output couples using the results of measures carried out at the steady-state for constant inputs. The linear model is identified using results of a transient corresponding to a suitable two-values PRBS sequence whose values are chosen among the above input-output couples of the nonlinearity. The identification of the Hammerstein model is carried out using experiments carried out in PSpice environment.