Synergetic control for m-parallel connected DC-DC buck converters

Abstract

A promising new approach, synergetic control theory, based on ideas of self-organization, is used to design control for the general case of m parallel-connected DC-DC buck converters serving resistive load. A general nonlinear synergetic PI control algorithms are derived using averaged models of the system. Using the general control laws, two particular cases are considered. They are two and three parallel-connected DC-DC buck converter systems. It is shown that the derived controls suppress unmeasured piecewise constant disturbances, nullify errors of current sharing among parallel connected converters, and ensure exponential asymptotic stability. It is pointed out that by change of control law parameters it is possible to choose between master-slave and democratic system operation regimes. Matlab/Simulink simulations of the closed loop performance are performed and characteristics of synergetic control design are discussed. Thus, it is shown that the approach allows designers to derive analytical control laws that ensure exponential asymptotic stability for nonlinear, high dimensional, and multiconnected systems.