Improving PSS performance of Srepok 3 power plant peer optimization

Abstract

The excitation system in a power plant is a critical subsystem that determines the generator’s electrical output. It is responsible for regulating the terminal voltage according to load variations and for indirectly controlling the generator’s active power delivered to the grid. Within the excitation system, an indispensable component is the automatic voltage regulator (AVR), which adjusts the field current to maintain the desired terminal voltage. In addition to the AVR, the power system stabilizer (PSS) provides a supplementary control signal to the AVR, thereby enhancing overall system performance by generating a damping torque that suppresses low-frequency electromechanical oscillations (typically 0.1¸2.0 Hz). These oscillations, if insufficiently damped, cause the generator rotor to experience small but persistent vibrations, leading to mechanical “growling” and accelerated wear, thus shortening the service life of mechanical components. This paper describes the operation of the excitation–turbine control system for hydropower generators equipped with a PSS, using data from the Srepok 3 Hydropower Plant operated by Buon Kuop Hydropower Company in Dak Lak Province, Viet Nam. The study focuses on a single generating unit with a capacity of 110MW. Srepok 3 is a medium-sized hydropower station located on a steep mountainous slope, where the large hydraulic head provides significant damping through the penstock, ensuring stable pressure conditions.