Investigation on TCSC Parameters and Control Structure for SSR Damping in DFIG-Based Wind Farm

The most common method to increase the transmittable power is to insert a fixed series capacitor into a transmission line. But unfortunately, it was noted that the system stability is inversely proportional to the compensation level. This phenomenon is called a sub-synchronous resonance (SSR). SSR has a detrimental influence on the system's safety and stability. Thyristor controlled series capacitor (TCSC) is one of the most methods used for damping SSR and improving system stability. In this paper, appropriate values of TCSC parameters are identified. The ratio of TCSC inductive reactance to the TCSC capacitive reactance, TCSC impedance characteristic, the ratio of the TCSC capacitive reactance to the capacitive reactance of the fixed series capacitor, and different synchronization signals are studied. Additionally, the TCSC constant power control based on the P and PI controllers are compared. In order to analyze the SSR phenomenon in a doubly fed induction generator (DFIG)-based wind farm connected to TCSC, IEEE first benchmark model (FBM) is modified. MATLAB software is utilized to demonstrate the results.