“…Sahu et al [15] proposed a hybrid firefly algorithm (FA) and pattern search (PS) optimized fuzzy-PID controller for load frequency control (LFC) of multi-area power systems. Sahu et al [16] examined a teaching-learning based optimization algorithm-based fuzzy-PID controller for automatic generation control of a multi-area power system. The fuzzy-PID control algorithm finds the relationship between three parameters (Kp, Ki, and Kd), error (e), and the rate of change in the error (∆e) based on fuzzy math theory, the fuzzy language variable, and fuzzy logic reasoning [6,19].…”