Robust Load Frequency Control Using Fractional-order TID-PD Approach Via Salp Swarm Algorithm

Abstract

To preserve frequency and tie-line power flow within a tolerable range in modern intricate and renewable energy sources (RES) integrated power system, an intelligent, expert, and robust load frequency control (LFC) scheme is requisite. This paper proposes a new load frequency control (LFC) approach using a dual-stage controller composed of fractional-order tilted-integral-derivative (TID) and integer-order proportional-derivative (PD) controllers. The recently developed salp swarm algorithm has tuned the parameters of the controller. The proposed scheme exhibits robustness and fast disturbance rejection performance because the tilted-integral-derivative controller is structured in a fractional-order framework, and transient response is improved due to the proportional-derivative controller. The overall activity of the LFC has been further upgraded by incorporating the flexible AC transmission system (FACTS) device namely thyristor-controlled phase shifter (TCPS) unit and energy storage system called redox flow battery (RFB) units. The proposed control approach is applied to diverse types of multi-area multi-source power systems with thermal, hydro, and wind turbine units along with nonlinear functions namely generation rate constraint (GRC), governor dead band (GDB), and communication delay (CD). The simulation results yield improved frequency regulation activity with and without TCPS and RFB using the proposed control approach when compared with the recently developed LFC approaches. Sensitivity analysis also established the robustness of the proposed control approach.