SSCI performance of DFIG with direct controller

Mathematical analysis indicates that stator output power of doubly fed induction generator (DFIG) could be directly controlled by the output voltage of rotor-side converter (RSC). Thus, a direct stator-power controller (DPC) could be induced. Furthermore, rotor speed can be directly controlled by RSC with direct rotor-speed controller (DSC). When the rotor speed is selected as a feedback of RSC controller, the equivalent impedance of RSC could be decreased sharply. Under this condition, DFIG will supply little energy for series resonance caused by fixed series compensation. This results in that DFIG with DSC is insusceptible to subsynchronous control interaction (SSCI). Updating DLP into DSC could be selected as a solution of existing SSCI. Eigenvalue analysis and time-domain simulations prove the effectiveness of DSC in mitigating SSCI.