Power Stability Enhancement of SCIG and DFIG Based Wind Turbine Using Controlled-SMES

Abstract

Several installed electrical power systems have a traditional type of wind power (WP) generators called squirrel cage induction generator (SCIG). However, SCIG is not the best type of WP in which it has a harmful impact on the stability of power systems. Therefore, with the increase in the loads especially at transient events, the SCIG will lead to system instability. Hence, it is necessary to increase the penetration level of WP by using more efficient generators, such as the doubly-fed induction generator (DFIG). At transient events such as increasing in the loads causes fluctuation of frequency and voltage of power systems. So, it is necessary to use controlled energy storage units to improve the stability of WP. The system used for studying consists of a grid connected to 25 kV bus through a step-down transformer and transmission line supplied initially by SCIG-based WP then supported by DFIG to increase penetration level and covers the increase in the loads. The superconducting magnetic energy storage (SMES) units are proficient in response, efficiency, and lifetime in contrast to other categories of energy storage systems, which make it a favored option for renewable energy. If SMES is combined with DFIG and SCIG, it increases the energy capacity of the total system. The SMES-controller is based on fuzzy logic control (FLC). The models of SMES, SCIG-based WP, and DFIG-based WP are demonstrated with MATLAB/SIMULINK, and the results illustrate the success of the proposed control to minimizing the voltage and frequency fluctuations during the transient events. Also, the model illustrates that the performance of DFIG on voltage and frequency stability is better than that of SCIG.