Salp swarm algorithm-based optimal load frequency control of hybrid renewable power systems with communication delay and excitation cross-coupling effect

This paper proposes a new application of the salp swarm algorithm (SSA) to fine-tune the gains of proportional-integral-derivative (PID) controllers of load frequency control (LFC) of a multi-area hybrid renewable nonlinear power system. To analyze the system nonlinearity, a dead-band is implemented in the governor model, a generation rate constraint is employed with the turbine model, and a communication delay time of phase measuring unit devices is carried out in the secondary automatic LFC loop. An exact model is established to take into consideration the effect of cross-coupling between the excitation control system and LFC loop. A single and multi-objective functions are performed to test the validity of the proposed controllers. To obtain a more realistic study, real wind speed data are involved in the wind farm model and real sun irradiations for a photovoltaic system that captured from a field test are incorporated to check the validity of the SSA-PID controllers under power system nonlinearities and renewable energy sources variability and uncertainties. The effectiveness of SSA-PID controller is compared with other optimization methods based-PID controller under several operating conditions. With the proposed controller, the LFC dynamic responses of multi-area hybrid nonlinear power systems shall be further enhanced.