Stability Analysis of Grid-connected PV Farms with High Switching Frequency Power Electronics

High Switching Frequency Power Electronic (HSFPE) have a different dynamic behavior than conventional power electronics since HSFPE with faster switching allows an increased controller cross-over frequency. This paper assesses the dynamic characteristics of solar PV farms with a large number of HSFPE while connecting to weak grids. This is done by first obtaining closed-loop small-signal models of HSFPE and then adopting the Impedance Stability Criterion. It is demonstrated, through time- and frequency-domain analysis, that PV farms with HSFPE have far better dynamic characteristics and stability margins. Therefore, it is envisioned that future solar PV farms with HSFPE will suffer less from stability issues.