Mechanism Analysis and Controller Design of SMES-Based Power Oscillation Damping

With the feedback rotor speed outer-loop PI control, the mechanism analysis of SMES-based power oscillation damping is derived by the small signal and classical electric torque method in this research. Theoretical analysis shows that adjusting the proportional and integral can equivalently dominate the damping ability and synchronization level. However, the conventional PI may cause the deep charging-discharging so that the power oscillation damping failure. To this end, the proportional integral controller with integral alleviation (PI-IA) controller is designed to address this issue, which not only ensures energy deviation-free of SMES, but also holds the advantage of PI controller. Moreover, the effectiveness of the proposed controller and the validity of the mechanism analysis are performed by the time-domain simulation.