Table 11 Specifications of the analyzed system's transient response for scenario B.

From: Frequency regulation in a hybrid renewable power grid: an effective strategy utilizing load frequency control and redox flow batteries

Controller structures

Considered dynamic response of (\({\Delta \mathbf{f}}_{\mathbf{a}\boldsymbol{ }})\)

Considered dynamic response of (\({\Delta \mathbf{f}}_{\mathbf{b}\boldsymbol{ }})\)

Considered dynamic response of (\({\Delta \mathbf{P}}_{\mathbf{t}\mathbf{i}\mathbf{e}}\))

PD-PI-optimized via HHO3

\({O}_{sh}\)= 28.742

\({O}_{sh}\)= 28.814

\({O}_{sh}\)= 4.082

\({U}_{sh}\) =  − 7.54

\({U}_{sh}\) =  − 6.32

\({U}_{sh}\) =  − 4.036

FO-(PD-PI)-optimized via MRFO3

\({O}_{sh}\)= 17.572

\({O}_{sh}\)= 17.774

\({O}_{sh}\)= 2.559

\({U}_{sh}\) =  − 5.395

\({U}_{sh}\) =  − 1.539

\({U}_{sh}\) =  − 2.45

Fuzzy-PID + (T \({I}^{\lambda }{D}^{\mu }\))-optimized via COA

\({O}_{sh}\)= 8.115

\({O}_{sh}\)= 8.082

\({O}_{sh}\)= 1.129

\({U}_{sh}\) =  − 2.334

\({U}_{sh}\) =  − 0.7005

\({U}_{sh}\) =  − 1.167

  1. All values are multiplied by (\({10}^{-3}\)).