Digital Implementation of Harmonic and Unbalanced Load Compensation for Voltage Source Inverter to Operate in Grid Forming Microgrid

Voltage source inverter (VSI) is a good candidate for grid forming microgrid because it provides constant amplitude, frequency, and sinusoidal shape voltage at point of common coupling (PCC). As the separated from utility grid, quality PCC easily affected by type load. To ensure power in operation, three-phase VSI providing automatic compensation unbalanced or nonlinear load presented this paper. maintain certain level, Fast Fourier Transform (FFT) algorithm embedded proportional-resonant (PR) controller to mitigate total harmonic distortion (THD) PCC. In meantime, any change magnitude that caused could be reduced as well. further enhance transient response with load, predictive current (PC) integrated into PR controller. All control strategies are implemented digital approach. The effectiveness proposed controls verified through experiments on testbed stand-alone system.