A robust load-sharing control scheme for parallel-connected multisystems

Parallel connection of inverters or converters is one useful method for sol ving the high power requirements. However, a load-sharing problem among par allel-connected systems is not an easy task, since crosstalk may take place among the subsystems. We develop a general methodology for solving the loa d sharing problem using the master-slave concept. In synthesizing the input to the slave system, we utilize system-dynamics-dependent filters. With th e proposed method, we can equally distribute the load, or can give a certai n offset (in load) to a specific subsystem. To show the usefulness of the p roposed control scheme, we perform a simulation study with two practical sy stems: a current-balancing control in parallel-connected pulsewidth modulat ion converters and a speed and tension control for a bridle roll system in a steel mill.