Adaptive filter based sub-synchronous oscillation damping strategy for doubly-fed induction generators

To address the technical challenge that the conventional sub-synchronous oscillation (SSO) damping strategy for doubly-fed induction generator can only suppress SSO in a specific frequency band for series compensated network, this paper proposes an Adaptive Filter Based SSO Damping (AF-SSOD) strategy for Doubly-fed Induction Generators. The AF-SSOD controller consists of a filter-based SSO Damper (SSOD) suppressing module to extract and whittle down the amplitude of the dominant SSO frequency bands, a frequency identification module to obtain real-time dominant SSO frequency by Kaiser window enhanced Fast Fourier transformation (FFT) as well as a frequency locking module to update the central frequency of SSOD, achieving the high adaptability of SSO suppression under various operating conditions. The key parameters of AF-SSOD are analyzed and optimized via small signal analysis (SSA). Finally, simulation verification and comparisons are carried out, showing that AF-SSOD can effectively suppress SSO in different frequencies with satisfactory robustness and superior performance over existing SSO suppressing strategies.