Superconducting Magnetic Energy Storage Unit for Increasing Stability of a Wind Power Generation System

A superconducting Magnetic Energy Storage (SMES) system includes a high inducting coil that can act as a constant source of direct current. A high temperature SMES (HTS) unit connected to a power system is able to absorb and store both active and reactive power from this system and to release these powers into this system in the demand periods. These injected powers can be controlled by adjusting the power conversion system of SMES by changing both the duty cycle of the dc-dc chopper switches and its operation modes. In this paper, an efficient design based on an SMES unit controlled by the combined the artificial neural network (ANN) and adaptive control method is presented to improve transient stability by regulating the dc link voltage and to damp and reduce the voltage and frequency fluctuations that are always associated with wind power generator. The authors propose using an SMES as an interface device between the wind power farm and the power grid connected through the DC Link capacitor to rapidly stabilize the voltage and frequency fluctuations in the power system. The system behavior is tested with three different faults/events for both voltage and frequency fluctuations of wind power supply with and without applying the SMES unit. The results show that both voltage and frequency stabilities are significantly increased when the SMES unit is applied in these three events.