Abstract
This paper investigates the structure, energy efficiency, and dynamic characteristics of a hybrid gas turbine system operating on biogas and integrated with a water-based thermal energy storage unit. The proposed system combines the electrical power generation capability of a gas turbine with a thermal accumulator, enabling efficient simultaneous utilization of electrical and thermal energy. A nonlinear mathematical model of the system is developed, incorporating the dynamics of the rotor, combustion chamber, and thermal storage unit. The model is linearized in the vicinity of the nominal operating point and represented in state-space form. Transient processes resulting from changes in fuel flow rate are analyzed using numerical simulation. The results demonstrate that hybridization preserves the mechanical stability of the system while introducing an additional slow thermal loop. The integration of a water thermal accumulator enables effective recovery and storage of exhaust gas heat, significantly increasing the overall efficiency of the system. The study confirms that the hybrid gas turbine installation exhibits multi-scale dynamic behavior, making the application of multi-loop or cascade control strategies appropriate. The proposed hybrid system represents a promising solution for autonomous and distributed energy systems operating on biogas.