Research on Mechanism and Damping Control Strategy of DFIG-Based Wind Farm Grid-Connected System SSR Based on the Complex Torque Method

The subsynchronous resonance (SSR) of a double-fed induction generator (DFIG) and its suppression method are studied in this paper. SSR may be aroused by the interaction between series-compensated transmission lines. This paper proposes an expression electrical damping for assessing stability based on complex torque method. is derived linearizing DFIG model at operating point. When mechanical neglected, can used to calculate whether positive or negative judge stability. quantitatively analyze impact wind speed, compensation degree, parameters rotor speed controller rotor-side converter Furthermore, control (SDC) strategy designed suppress SSR. SDC optimized particle swarm optimization (PSO) damping. Finally, above research verified PSCAD/EMTDC time-domain simulations. results show that decreases with decrease increase series proportional coefficient, integral coefficient converter. oscillation DFIG.