Method for detecting shafting torsional oscillation mode of generator set appended with field excitation damp controller

Abstract

The invention relates to a method for monitoring and calculating a subsynchronous oscillation mode from an electric generating set in real-time when a power house and an electric power system generate subsynchronous oscillation (SSO) and discloses a method for obtaining a shafting torsional oscillation mode of a steamer electric generating set through combining a main filter, a starting filter and a narrow band wave-resistance filter. The method works out the change of a rotary palstance (dw) of an electric generating shafting through a rotary speed pulse of a rotary speed sensor arranged on the electric generating set shafting and works out an instant value of each mode of the electric generating set shafting torsional oscillation with linear phaseshift through the combination algorithm of a broad band filter combined by the main filter and the narrow band wave-resistance filter; a dw signal is combined with the narrow band wave-resistance filter by passing through the starting filter to be a mode starting condition. The method can be used for restraining the subsynchronous oscillation (SSO) steamer electric generating set into a subsynchronous oscillation damp controller (SSODC).

Description

technical field [0001] The invention relates to the monitoring, analysis, protection and control of the subsynchronous oscillation in the power system and the torsional vibration of the steam turbine generator set in the thermal power plant. Background technique [0002] Subsynchronous oscillation (SSO) is a very harmful special oscillation mode of power system, and its oscillation frequency is 2-48Hz. The causes of subsynchronous oscillation are more complicated, usually including: power plants supply power to the grid through long-distance transmission lines, transmission lines use series compensation technology (including controllable series compensation TCSC) to increase transmission power, Grid power supply and transmission system using power electronics technology. [0003] The harm of subsynchronous oscillation is manifested in the occurrence of electromechanical transient oscillation on the side of the power plant, and the mechanical energy and electric energy gener...

AI Technical Summary

Problems solved by technology

[0003] The harm of subsynchronous oscillation is manifested in the occurrence of electromechanical transient oscillation on the side of the power plant, and the mechanical energy and electric energy generate torsional vibration in the shafting of the generator. It is precisely because the frequency of the torsional vibration and the mechanical frequency of the shafting of the generator set are very close, resulting in The frequency of the mechanical characteristics of the shaft system resonates, which will cause great harm to the shaft system of the generator set, and eventually lead to a major safety accident that the shaft system of the generator set will be twisted

[0004] At present, domestic power plants and power systems do not have special installations or technical means to identify and detect subsynchronous oscillations or shafting torsional vibrations (subsynchronous oscillations of the power grid appear as torsional vibrations of unit shaftings in power plants), and many unidentified incidents have occurred in China. Causes of Accidents of Turbo-Generator Shafting Twisted

Images