Application control configurations for parallel connection of single-phase energy conversion units operating in island mode

This paper presents the design and implementation of controllers for parallel connection of single phase energy conversion units, for applications in island mode operation. Orders to comply with this objective, two control configurations are implemented having as reference to the output voltage of droop scheme. These controllers are: two degrees of freedom control plus repetitive controller and proportional integral ‑ proportional controller plus resonant controller. With these control configurations is intended maintain amplitude, waveform and frequency of the voltage signal and attend increases linear and nonlinear load in island mode operation of a single phase energy conversion unit. That is, with these control strategies is achieved that several inverters connected in parallel to a microgrid can operate as sources of tension carving up the active and reactive power demanded by the load.