A Nonlinear Control Law for Achieving Some Good Output Properties of_??_uk Converters

It is well known that the state space averaging models of _??_uk converters are obtained as bilinear systems. Since the stability and output regulation problems of bilinear systems are complicated, most previous works which deal with the _??_uk converters in the state space are confined to the analysis of linear approximated systems (small signal model). However a control law for small signal model dose not generally guarantee the global stability but the partial stability of the system. A new control law based on the bilinear large signal model is proposed for achieving output regulation of _??_uk converters. The control law is derived from directly applying the Lyapunov stability theory to the bilinear large signal model. The actual realization of this control law might have some difficulties compared with the other ones proposed previously, because it is given as a solution of the differetial equations for the state and input variables. However the closed loop system is expected to possess the robust stability achieving an excellent output regulation for any changes of reference, load and source voltage.