Fractional order fuzzy control of hybrid power system with renewable generation using chaotic PSO

- Centralized control scheme is proposed for frequency control of a hybrid power system.
- Fractional order fuzzy PID controller outperforms the PID and fuzzy PID structures.
- Controllers are tuned with chaotic map adapted particle swarm optimization.
- Stochastic variation in load and renewable generation are considered for simulation.
- Nonlinear effects, disconnection of components and system perturbation are handled.

This paper investigates the operation of a hybrid power system through a novel fuzzy control scheme. The hybrid power system employs various autonomous generation systems like wind turbine, solar photovoltaic, diesel engine, fuel-cell, aqua electrolyzer etc. Other energy storage devices like the battery, flywheel and ultra-capacitor are also present in the network. A novel fractional order (FO) fuzzy control scheme is employed and its parameters are tuned with a particle swarm optimization (PSO) algorithm augmented with two chaotic maps for achieving an improved performance. This FO fuzzy controller shows better performance over the classical PID, and the integer order fuzzy PID controller in both linear and nonlinear operating regimes. The FO fuzzy controller also shows stronger robustness properties against system parameter variation and rate constraint nonlinearity, than that with the other controller structures. The robustness is a highly desirable property in such a scenario since many components of the hybrid power system may be switched on/off or may run at lower/higher power output, at different time instants.