Identification of Generalized Short-Circuit Ratio for On-Line Stability Monitoring of Wind Farms
Linbin Huang, Huanhai Xin, Zhiyi Li, Ping Ju, Hui Yuan, Guanzhong Wang
Abstract
Unstable power oscillations may arise in wind farms under weak grid conditions. Recent works have shown that the power grid strength can be quantified by generalized short-circuit ratio (gSCR) to analytically evaluate the stability of multi-device systems. On this basis, this letter provides a solution to the identification of gSCR based on data from phasor measurement units (PMUs), which facilitates the on-line stability monitoring of wind farms. We demonstrate that the interior nodes of a wind farm can be eliminated by Kron-reduction and the gSCR can be estimated by solely using voltage and current data of wind turbines. Our method is also applicable to monitor the stability of multiple wind farms. Simulations validate the effectiveness of our method.