Novel Implementation and Comparison of Active and Reactive Power Flow Control Methods in a Single Phase Grid-Connected Microgrid

Grid-connected inverters are essential microgrid components that interface a common dc bus, fed by several distributed resources, to the ac loads. This article presents different methods to control active and reactive power flow from the ac source in a single phase microgrid when it operates in grid-connected mode. A novel mixed-frame control strategy is presented and its performance evaluated using different methods to produce the orthogonal axis components. The different strategies are presented and compared with respect to their performance in the presence of harmonics in the main ac grid. Physics-based models and simulated plots are presented and validated by experimental waveforms measured on a laboratory prototype.