Method and system for monitoring large disturbance transient impact torsional vibration of turbine-generator shaft system

Abstract

The invention belongs to the technical field of monitoring of torsional vibration of a turbine-generator shaft system, and particularly relates to a method and system for monitoring large disturbance transient impact torsional vibration of the turbine-generator shaft system. The method comprises the steps of carrying out simulation calculation on shaft system torsional vibration caused by large disturbance of a power system under the coordination effect of an electromechanical network, establishing the correspondence between the maximum value of the electromagnetic torque of a generator and the fatigue life loss of the shaft system under large disturbance of the power system, setting a damage alarm threshold value and a tripping halt protection threshold value, calculating the electromagnetic torque of the generator according to the three-phase current and voltage of the generator, sending a damage alarm signal or a tripping halt protection signal in time when the safety of a generator set is threatened, and finally carrying out shaft system torsional vibration dynamic response calculation on the torsional vibration fault so as to accurately estimate the damage degree and the remaining life of the shaft system. By means of the method, on-line monitoring, analysis and protection of torsional vibration caused by the large disturbance fault of the power system be achieved, and accurate calculation of the fatigue life loss caused by torsional vibration of the turbine-generator shaft system can be achieved at the same.

Description

technical field [0001] The invention belongs to the technical field of torsional vibration monitoring of a shaft system of a steam turbine generator set, and in particular relates to a method and a system for monitoring a large disturbance transient impact torsional vibration of a shaft system of a steam turbine generator set. Background technique [0002] The torsional vibration of the shafting of the turbogenerator can be divided into transient shock torsional vibration and subsynchronous oscillation and other resonance torsional vibration according to its excitation mechanism. Sudden electromechanical disturbances such as automatic reclosing, non-synchronous grid connection, instantaneous symmetrical and asymmetrical short circuits, and line switch switching operations may generate short-term impact torques and form short-term impact shaft torsional vibrations. Although this torsional vibration lasts for a short time, under unfavorable matching conditions, it is still pos...

AI Technical Summary

Problems solved by technology

Although this kind of torsional vibration is not long, under unfavorable matching conditions, it is still possible to generate alternating torsional stress that is too high for the shafting of the unit to bear, resulting in one-time damage, or the accumulation of torsional vibration fatigue loss

[0003] When the shafting of the turbogenerator set undergoes transient shock-like torsional vibration under a large disturbance fault in the power system, the torsional vibration amplitude shows a characteristic of sudden increase and then gradually attenuation. It is difficult to accurately filter out the relative angular displacement signal of torsional vibration with band-pass filter, so it is not suitable to use modal superposition method for further analysis and calculation

At the same time, under the large disturbance fault of the power system, the transient impact torsional vibration of the turbine generator shaft system is very harmful. If such torsional vibration cannot be detected in time, the damage alarm or tripping protection action can be made, which may cause the shaft system of the unit to be damaged. great damage

The existing monitoring and analysis methods cannot quickly and accurately locate and analyze the torsional vibration of the shaft system, and the method also needs to be further improved and improved

Images