General Synergetic Control Strategies for Arbitrary Number of Paralleled Buck Converters Feeding Constant Power Load: Implementation of Dynamic Current Sharing

The inability of linear controls to predict dynamic behavior of nonlinear system leads to chaotic behavior of the system and sometimes could result in a system collapse. The advantage of synergetic control design is that it results in an analytical control law that reduces the dynamic order of the system, compensates for system nonlinearity by a particular choice of coefficients, and ensures asymptotic stability of the closed loop system. Our paper presents generalized control strategies for the system of an arbitrary number of paralleled buck converters feeding a constant power load. Using these generalized control strategies we develop a family of control strategies for a particular system of two buck converters covering a range of operating regimes. We show the impact on system dynamics of several different coordination algorithms that control transition between strategies. Finally, we describe how including a current limiting feature into the control decreases electrical stress on the switching components and we put forward a load estimator that simplifies the control strategies