Method for detecting shafting torsional oscillation mode of generator set

Abstract

The invention relates to a method for real-time monitoring and calculation of the subsynchronous oscillation mode from the generating set side when the subsynchronous oscillation occurs in the power plant and the power system, and discloses a method for combining the main filter, the start-up filter and the narrow-band rejection filter bank to obtain the subsynchronous oscillation mode. The method of the torsional vibration mode of the shafting of the turbo-generator set, which calculates the change dw of the rotational angular velocity of the shafting of the generator through the speed pulse of the speed sensor installed on the shafting of the generator set, and passes through the main filter and the narrow-band blocking filter The combined broadband filter bank algorithm calculates and obtains the instantaneous value of each mode of the shafting torsional vibration of the generator set with linear phase shift; the dw signal is combined with the starting filter and the narrow-band blocking filter as the mode starting condition. This method is used in a subsynchronous damping controller of a turbogenerator set capable of suppressing subsynchronous oscillation.

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...

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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

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