Effect of X/R ratio of the power system on Dynamic stability of Photovoltaic Power Plants

This paper studies the effect of the X/R ratio of the ac grid on the dynamic stability of PV power plants. For this purpose, it is necessary to obtain the dynamic model of the PV system. In this paper, by linearizing the nonlinear model of different PV parts around a stable operating point, and by augmenting them, we determined the transfer function of the whole PV system. Using this transfer function, we calculate the eigenvalues of the PV system for various X/R ratios. The results of the eigenvalue analysis show that the X/R ratio affects on the dynamic stability of the PV system. To validate the accuracy of the results of eigenvalue analysis, the dynamic performance of our system is investigated using time-domain simulations. For this purpose, a grid connected PV system is simulated using EMTD / PSCAD software and its small-signal behavior is investigated by applying a small signal disturbance. The results of the time-domain simulation indicate that changing the X/R ratio varies the frequency and amplitude of system fluctuations. Which these results are consistent with the results of eigenvalue analysis.

کلیدواژه ها:

Photovoltaic System ، X/R ratio ، Dynamic Stability ، Eigenvalue analysis ، Transfer function ، Laplace.