Optimized Direct Power Control for Single Phase Grid-connected Inverters

Abstract

The growth of power plants based on renewable energies connected to the distributed grids and MicroGrids (MGs), has raised the challenges to maintain good power quality and stability. Where, power electronics switching frequency may generate a large amount of harmonics. Thus, this work assesses a single-phase inverter control’s based on the Direct Power Control (DPC). The grid synchronization technique has been performed based on Quadrature Signal Generator (QSC) and a Frequency Looked Loop (FLL) with FLL gain normalization owing to its capability to enhance the generated orthogonal voltages and to estimate the grid frequency. Moreover, the DC voltage is maintained stable trough a DC voltage regulator. To improve the generated power quality, Particle Swarm Optimization (PSO) based PID is performed and compared to PSO based PI. To investigate the DPC’s performances, a simulation of the overall system is performed and presented along with harmonics spectrum analysis of the voltage and the injected current.