Theoretical and experimental verification of independent control for parallel-connected multi-UPS´s

This paper proposes an independent control for parallel-connected multi UPS´s made of two simple PI controllers for the active and reactive components currents. The phase and the amplitude of the voltage source are the controllable variables here. The current is measured locally and, with the computation of the active and reactive components, the control ensure the synchronization and load sharing. Theoretical analysis and experimental results confirm the efficiency of the control.