Harmonic Performance Differences under Non-ideal Grid between Grid-Following and Grid-Forming Converters

Renewable energy generation devices need power electronic converters to be connected to the grid. Presently, the grid-following converter (GFL) and the grid-forming converter (GFM) are used in the electric power system for grid-connection control. As renewable energy progresses, power electronics play a growing role in power systems, leading to increased complexity in harmonic generation. The sinusoidal pulse width modulation (SPWM) and dead time can lead to the output of converter harmonics. Meanwhile, the grid voltage background harmonics also respond to the converter harmonics. Given the structural differences between GFL and GFM, there are differences in their harmonic outputs and responses. In this paper, the differences in the effects of control parameters, dead time, and background harmonics on the grid-connected current harmonics of GFL and GFM are analyzed. Finally, through a data-driven analysis, the simulation results validate the proposed harmonic performance differences between GFL and GFM.