Piecewise Constant Switched Dynamical Systems in Power Electronics

This paper overviews nonlinear dynamics of switching power converters which are common objects in dynamical system theory and power electronics. First, complex dynamics of single switching power converters is discussed. Their nonlinear switching can cause rich chaotic and bifurcation phenomena including complicated superstable periodic behavior in discontinuous conduction mode. Second, paralleled converters with winner-take-all switching is discussed. This system can realize multiphase synchronization relating to current sharing with smaller ripple for low-voltage high-current capabilities. Analysis of the dynamics is performed through simple models having piecewise constant vector field and piecewise linear trajectories. Third, simple hardware implementation method is shown and typical phenomena are confirmed experimentally. Finally some future problems are discussed.