Modeling of AC-DC power system feeding a controlled buck-boost converter

It is well-known that dynamic models of power converters are normally time-varying because of their switching actions. Unfortunately, the system analysis and design via the time-varying model is very complicated. Therefore, the paper presents the mathematical model of AC-DC power system feeding a controlled buck-boost converter. The proposed model is derived from the combination between the DQ method and the generalized state-space averaging method. These methods are used to eliminate the switching behavior to achieve the time-invariant model suitable for a system analysis and design via the conventional control theory. The intensive time-domain simulations show that the resulting model can provide high accuracies in both transient and steady-state responses compared with the exact topology model.