The article discusses the coordinated effect of the vanadium redox flow battery (VRFB) and thyristor control phase shifter (TCPS) on combined automatic load frequency control and automatic voltage regulator of three area hydrothermal systems incorporating renewable sources. Solar thermal power plant, dish-Stirling solar thermal system, and geothermal power plant are integrated into Area-I, Area-II, and Area-III, respectively. Suitable generation rate constraint and governor dead-band are considered for both thermal and hydro plants. A new fuzzy logic-based cascaded controller named fuzzy proportional-derivative with filter coefficient cascaded with proportional-integral-derivative with filter coefficient (CFPDN-PIDN) is proposed as a secondary controller and its performance is compared with the PIDN and CPDN-PIDN controllers. Various controller parameters are optimized by the artificial flora algorithm. Simulation results reveal that the CFPDN-PIDN controller outperforms the PIDN and CPDN-PIDN controllers. Two types of control schemes are used to regulate the TCPS's phase angle variation: Type-I is a first-order lag transfer function, while Type-II includes a washout filter and lead-lag compensator along with Type-I. Analysis shows that the Type-I control strategy is better than Type-II. VRFB charging/discharging is regulated using high-pass filter (HPF) and dead-band (DB) control schemes. Investigation reveals that the BD scheme provided better system dynamics than the HPF scheme. Moreover, the system performance degrades with very high or low state-of-charge values. Further, using the best control schemes for both VRFB and TCPS, the system's dynamic performance was superior to that of the individual one. Finally, the robustness of the proposed control approach is validated through sensitivity analysis.