Performance of FACTS and energy storage devices in a multi area wind-hydro-thermal system employed with SFS optimized I-PDF controller

This paper presents automatic generation control of an unequal three area interconnected wind-hydro-thermal system incorporating flexible AC transmission system (FACTS) and energy storage devices. Non-linearities such as boiler dynamics and generation rate constraints are considered to get an insight into realistic power systems. A novel secondary controller named as the integral minus proportional derivative controller with first order filter effect (I-PDF) is proposed for the system. A new heuristic optimization technique called stochastic Fractal Search (SFS) is used for the optimization of the controller gains and other parameters. The comparison of system dynamics using some controllers such as integral (I), proportional-integral (PI), and proportional-integral-derivative (PID), and I-PDF reveals the superiority of the latter. The performance comparison of some FACTS devices such as static synchronous series capacitors, thyristor controlled phase shifter (TCPS), and unified power flow capacitors in the presence of I, PI, PID, and I-PDF controllers is done for damping out frequency oscillations. The results explore promising performance using TCPSs and I-PDF controllers. Also, investigation on integration of some energy storage devices such as capacitive energy storage and Redox Flow Batteries (RFBs) results in further damping and better system performance in terms of peak deviation and settling time. The response profile seems more convincing with RFBs. Sensitivity analysis reveals that the SFS optimized I-PDF controller obtained at nominal conditions in the presence of TCPS and RFB are good enough to widely change the system conditions and parameters.