Load frequency control in modern‐complex‐uncertain power systems (PSs) assumes significance due to their challenging nature of the operation and hence utilisation of robust controllers is indispensable. In the industry, conventional single‐loop controllers may not offer robust behaviour under changed operating conditions. Alternatively, two‐loop cascade fuzzy structured controllers can show significant robust performance in dynamic conditions and best suited in systems having non‐linearities. Hence, a novel optimal cascade fuzzy‐fractional order integral derivative with filter (CF‐FOIDF) controller is utilised for 2‐area thermal and hydrothermal PSs considering various physical constraints from a practical point of view. As physical constraints mandate an energy storage system, hence in this study, batteries of electric vehicles (EVs) are employed to assist power plants to swiftly arrest oscillations in the system frequency following load demands. A combined model of EV fleets is incorporated in the control areas of PSs. Numerous simulations are conducted to authenticate the robustness and excellence of EVs and the suggested control strategy over existing methods.