Contribution of GCSC to regulate the frequency in multi-area power systems considering time delays: A new control outline based on fractional order controllers

Abstract

This paper addresses the application of the gate controlled series capacitor (GCSC) in coordination with automatic generation control (AGC) for providing better dynamic responses in interconnected multi-area power systems. A novel controller scheme called Hybrid controller for modeling the GCSC is proposed. The proposed control model consists of a fractional-order proportional-integral-derivative (FOPID) controller and a tilt-integral-derivative (TID) one. Optimized coefficients of the controllers are obtained by applying the Sine-Cosine algorithm (SCA). The delay in communication links as a common feature in wide area control of power systems may cause instability problem. So, a robust stability criterion is presented to estimate the maximum delay time which allows an AGC scheme embedded with the GCSC damping controller to retain stable. Comprehensive discussions are presented on a deregulated two-area power system and a traditional three-area one. Simulation results confirm that the proposed Hybrid controller is capable to achieve better dynamic responses and provide better coordination between the GCSC and AGC in comparison to the other coordinated controllers including PID-based GCSC-AGC, TID-based GCSC-AGC, and FOPID-based GCSC-AGC ones. Eventually, the sensitivity analysis is accomplished to assess the robustness property of the proposed controller against the variations of the parameters.