Shaft Torsional Fatigue Life Expenditure Evaluation Of 1000MW Class Turbine-Generators Of SEC-SIEMENS

1000MW class turbine-generator of SEC-SIEMENS type is the first unit manufactured with the largest capacity in fossil power market in China. The withstanding ability against the impact of electrical disturbances and torsional fatigue life expenditures are quite necessary to be studied for such a unit.The research results of current standards and criteria are analyzed and the design criteria of torsional natural frequencies and permissible fatigue life expenditures for turbine-generator units are summarized firstly in the thesis.The shaft train is then equivalently modeled as two to three hundreds of uniform cylinder elements with additional moment of inertia based on original data of different format from Siemens program.The torsional natural frequency and mode shape of shaft train are calculated based on the equivalently modeled data which is verified, and the torsional natural frequency is evaluated whether to meet the criteria or not.The program MANDISP 2007 is used, and the transient torsional torque and torsional fatigue life expenditures of 1000MW class turbine-generator shaft train under different disturbances and impact of electrical disturbances are calculated and analyzed. The investigated system is a single-machine and infinite-bus power system and different faults at generator terminals and transmission lines are considered for 1000MW class turbine-generators with brushless excitation and static excitation.The torsional fatigue life expenditures of shaft train are calculated under typical disturbances, by considering impact of different short circuit capacity of the power system and different impedance of the set-up transformer. And the comparison results are concluded on account of influence of power system parameters.The research work of the thesis is of practical value and can be acted as guidance for the localization and manufacturing of SEC-SIEMENS type 1000MW class turbine-generator units.