Online analysis method for turbonator shafting fatigue damage caused by subsynchronous oscillation

Abstract

The invention relates to an online analysis method for the turbonator shafting fatigue damage caused by the subsynchronous oscillation, which confirms the subsynchronous oscillation amplitude by actually sensing the phase voltage and the phase current. A four-stage synchronous electric motor model is adopted to confirm the change process of the electromagnetic torque of an electric motor; a turbonator shafting continuous quality model is adopted to confirm the change process of the shafting transient state torque; a finite element method is adopted to build a partial dangerous section physical model so as to confirm the maximum fatigue damage section; and a high-cycle fatigue damage norm is adopted to confirm the shafting fatigue damage value. A fatigue damage database is built to store the calculating data of each process so as to confirm the online analysis method for the turbonator shafting fatigue damage caused by the subsynchronous oscillation. The invention can be used for analyzing the turbonator shafting fatigue damage caused by subsynchronous oscillation on line, enhances the evaluation level for the electric network subsynchronous and the electric generating set correlation and effect, and effectively avoids the electric generating set fatigue damage and accumulation caused by the subsynchronous oscillation.

Description

technical field [0001] The invention relates to steam turbine power generation equipment and a fatigue calculation and analysis method for the steam turbine power generation equipment, in particular to a steam turbine power generation equipment interconnected with a long-distance large-capacity power transmission system and a fatigue calculation and analysis method for the steam turbine power generation equipment. Background technique [0002] Modern large-scale power systems are composed of large-scale long-distance transmission lines, various power electronic equipment and various large-capacity generator sets. Power electronic equipment such as series capacitor compensation and controllable series capacitor compensation in the power grid, as well as high-voltage direct current transmission systems, have become possible inducing factors for machine-grid coupling oscillations. In recent years, with the rapid increase of my country's power system and installed capacity of po...

AI Technical Summary

Problems solved by technology

These power plants have large scale and many units, and the new units have large capacity, most of which are supercritical and ultra-supercritical turbogenerator units. The vibration damping is small, and the attenuation is slow after torsional excitation

Therefore, the torsional vibration of the shafting of large turbogenerators needs to be paid more attention to. When the torsional vibration amplitude is large, it will cause local stress concentration in the shafting and cause fatigue damage to the shafting. Such shafting damage accidents have occurred in foreign countries.

Several accidents in China have the possibility of accumulation of shafting fatigue damage caused by subsynchronous oscillation. Due to the relatively simple mechanical fatigue analysis tools used in the field, the fatigue damage and accumulation of shafting caused by subsynchronous oscillation cannot be well evaluated.

Images