Data-driven Critical Short-Circuit Ratio for On-line Stability Evaluation of Wind Farms

Recent works have proposed short-circuit ratio (SCR) based on online stability monitoring methods for wind farms regarding small-signal stability. However, the online assessment for a minimum value of SCR or critical short-circuit ratio (CSCR) is equally essential since the SCR of stable wind farms should be greater than the CSCR. To this end, the paper proposes a data-driven CSCR evaluation method based on data from the frequency-domain admittance measurement of wind farms. The analytical relationship between CSCR and the frequency-domain admittance is theoretically proved. On this base, the CSCR can be estimated using the eigenvalues of admittance data in the sub-/sup-synchronization frequency range. Simulations verify the effectiveness of the proposed method.