Projeto e implementação de método para conexão paralela de UPSs com compartilhamento de potência

Abstract

This work presents the design and experimental implementation of a complete paralleling method to be used for parallel single-phase UPSs connection. There is a algorithm that performs a phase/frequency droop, and a new method to work with or without data communication among the inverters. When communication is working, a new algorithm is used, inserting a variable virtual resistance in the output, along with active power sharing, obtaining a low output voltage THD (Total Harmonic Distortion) value and good power sharing. Without communication a constant virtual resistance is inserted, increasing the output THD with non-linear load, but still allowing a good active power sharing. The advantage is to obtain a good performance operation with communication, but, in case of communication failure, the system still works providing more reliability. The implementation have a electronic load emulation algorithm, with purpose to execute factory tests, based in the same parallelism algorithm, just changing some variables.