Fast Frequency Support from Doubly Fed Induction Generators in Coordination with Super-conducting Magnetic Energy Storage Systems

Continuous growth of wind energy systems and increased wind penetration levels pose challenges in power system stability. Popular Wind Turbine Generators (WTGs) such as Doubly Fed Induction Generators (DFIGs) desired to have inertial response close to conventional synchronous generators to improve system inertia. Several strategies have been proposed to release the kinetic energy stored in the rotor of WTGs and provide an inertial response to the grid. However, after the inertial response, there is a possibility of secondary frequency dip and frequency oscillations. The extent of such undesirable events depend on the penetration level of the wind energy systems in the grid and the DFIG reserve which provided for inertial support. This paper proposes a control strategy to enable inertial response from DFIGs in coordination with Super-conducting Magnetic Energy Storage Systems (SMES) with minimized secondary effects. The simulation results show that the system succeeded in reducing the secondary dip and preventing the frequency oscillations during power system disturbances.