Adaptive Sub-synchronous Oscillation Suppression Strategy for Doubly Fed Wind Farm Connected to Series Compensated System

To suppress the sub-synchronous oscillation (SSO) with a wide range of time-varying frequency characteristic of doubly fed wind farm connected to series compensated (DWF + SC) system, this paper proposes a modified adaptive linear element (ADALINE) SSO suppression (MA-SOS) strategy for Doubly fed Induction Generators. Compared to the classical SSO suppression strategies, the MA-SOS controller consists of an ADALINE filter-based SSO suppression (A-SOS) module, a frequency identification module to obtain real-time dominant SSO frequency as well as a frequency locking module to update the reference frequency of A-SOS, achieving the high adaptability of SSO suppression under various operating conditions. With the advantages of simple control structure, easy control implementation and superior filtering effect, MA-SOS is also independent of accurate mathematical model of the system. Finally, simulation verification and comparisons are carried out, showing that MA-SOS can effectively suppress SSO in different frequencies with satisfactory robustness and superior performance over existing classical SSO suppressing strategies.