Small-Signal Model of STATCOM and Its Model Validation

This paper proposes a small-signal model of STATCOM based on theoretical derivation. This theoretical model is obtained by linearization of the DC-Link control loop, Phase-Locked Loop (PLL), reactive power control loop under the weak grid condition. In order to validate the correctness of this small-signal model, an identified model in the form of transfer function matrix is obtained by Output Error with Extended Prediction Model identification method using the data acquired from the nonlinear time-domain simulation. The two developed models are compared using the time-domain simulations conducted in MATLAB/Simulink. Based on the compared results disturbance, the accuracy and applicability of the proposed small-signal model have been discussed.