| Abstract |
In this paper, the authors deal with the closed-loop behaviour of frequency controlled DC-DC series resonant converters using standard regulators. A preliminary study, using a small signal modelling method, pointed out that the dynamic behaviour of this converter strongly depends on the operating point. This work revealed different behaviour areas, whose boundaries are function of the ratio between the output filter and the resonant circuit capacitors. We propose to use these results to determine a control structure considering the type of specifications which implicitely precises the operation zone. A theoretical study allows to predict the evolution of the closed-loop performances in the presence of a varying operting point. In particular, the apparition of instabilities is explained. Thus, the robustness and the limits of this linear control are evaluated, yielding general rules to select the adapted regulator in view of the desired closed-loop performances. These theoritical results are compared to experimental results. |
