Computer aided control optimization of power converters

The paper describes an improved automatic technique for the dynamic modelling of PWM DC-DC converters. It makes easier and more accurate the control optimization. Since the operating ranges of the load current and of the input voltage are generally wide, the usual recourse to a single linear model provides an information inadequate, in many cases. Such insufficiency is heavy when different operating modes are involved, f i. DCM/CCM, whose dynamic performances can be very dissimilar. The proposed technique makes reference to a full set of models in the ranges of the input variables. Automatic modelling in the state space discrete time, by means of suitable software tools, cuts the drawback of implementing a large number of models. It gets the full set of the dynamic descriptions in a short time and provides a bundle of frequency responses as shown in the Fig. 1s. The case of a phase-shift controlled PWM converter is studied. The open loop frequency responses are provided first, with indications for the feedback optimization. After assigning the feedback compensation networks the closed loop behaviour over the whole operating range is shown. The compliance of the model forecasts with the real life is very good.