access icon free Investigation of hydro-governor parameters’ impact on ULFO

The ultra-low-frequency oscillation (ULFO) problem reappears in China recently, but its specific mechanism is not so clear. Although the hydraulic governor system is confirmed as the source of ULFO, the parameters’ impacts are not studied thoroughly. This study investigates the specific impact of the important parameter of governing system in different control modes based on the complex coefficient torque method including the parameters of regulator, actuator and the turbine in hydraulic governing system. The damping torques under different situations are illustrated when parameters and control modes change, and the ultra-low-frequency-band dynamic characteristics of hydro generator are obtained. The simulations match well with the theoretical analysis, and the suggestions are made for parameter settings at last. The findings of this study are significant for ultra-LFO elimination. Moreover, it can also help designers and operator identify the most influential parameters and develop effective control strategies.

Inspec keywords: damping; hydroelectric generators; hydroelectric power stations; frequency control; eigenvalues and eigenfunctions; torque; oscillations; time-domain analysis; power system dynamic stability; power generation control

Other keywords: ultra-low-frequency-band dynamic characteristics; control modes change; specific impact; hydraulic governing system; influential parameters; parameter settings; ultra-LFO elimination; ultra-low-frequency oscillation problem; different control modes; damping torques; actuator; specific mechanism; effective control strategies; hydro generator; hydraulic governor system; complex coefficient torque method; hydro-governor parameters; ULFO

Subjects: Control of electric power systems; Power system control; Mathematical analysis; Mathematical analysis; Hydroelectric power stations and plants; Frequency control

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