Oscillatory Characteristics of Turbo-Type Synchronous Generators under Automatic Voltage Regulation

The behavior of synchronous generators under small disturbances is significantly shaped by their excitation systems, particularly the automatic voltage regulator (AVR). While numerous studies have investigated the influence of AVR dynamics on the electromechanical oscillations of hydro-type generators, the specific characteristics and responses of turbo-type synchronous machines remain less explored. This paper focuses exclusively on turbo-type generators, which differ notably from hydro units in terms of electromagnetic properties, inertia, damping, and operational context. Through modal analysis and dynamic simulations, the interaction between the AVR control loop and local oscillation modes is examined. The findings reveal how AVR parameters affect oscillatory performance and provide insight into stability margins for high-power turbo-generator units. This contributes to a more nuanced understanding of excitation control in large-scale thermal power systems.