Current distribution control of converters connected in parallel

Two schemes of current distribution control in a system of power converters connected in parallel, master-slave and central-limit controls, are analyzed from system block diagrams to determine steady-state distribution errors. The performance characteristics of distributive power systems using these two control techniques are presented. The comparison between the system performances with and without these distribution controls is discussed. The results of a FORTRAN program written to simulate the responses of two buck converters connected in parallel are described. It is shown that the master-slave technique provides good current distribution but no control in the output current overshoots that occur in the output of the master converter. The central-limit current distribution control is shown to provide tight control to all currents in the converters towards the central-limit reference signal that is the weighted average of the total current to the shared load. Therefore the central-limit technique is regarded as superior to the master-slave technique.<>