Implementation of a Voltage-Based Algorithm for Parallel Connection of Uninterruptible Power Supplies

In this study, a voltage-based method is proposed for parallel connection of uninterruptible power supplies (UPS). In the proposed method, UPSs with the same power can be connected in parallel and power can be increased, resulting in a high-power system. The developed method ensures balanced power sharing between parallel UPSs. Synchronization information is sent analogue between parallel UPSs, UPS load percentage, DC bus voltage values, modulation index and other critical information are transmitted via CAN communication. To verify the proposed parallelization method, three UPSs of 160kVA power are connected in parallel. The PSIM simulation program is used to obtain the output voltage and current waveforms of the UPSs under different operating conditions. In the simulation environment, it is observed that the output voltage is stable and balanced current sharing is performed.