A structural index to affect the operation life of steam turbine generators

作者：Lin Chi Hshiung^*

来源：International Journal of Circuit Theory and Applications, 2008, 36(8): 923-938.

DOI：10.1002/cta.474

• turbine generator
• single-phase-to-ground fault
• torsional vibration
• fatigue
• electromechanical analogy

Since there is a largest occurrence probability among power line faults, the single-phase-to-ground fault (1P-G fault) plays a non-negligible role on fatigue life of a turbine generator unit. It is found in this paper that the system frequency disturbance is the principal one to arouse torsional vibrations on turbine mechanism under a I P-G fault, which is different from the unidirectional one for a three-phase-to-ground fault (3P-G fault). By analyzing the turbine-generator-exciter-blade model using the electromechanical analogy, it is further found that the structural index of K(GEN-TURB)/H(GEN) ratio governs the response sensitivity, to Such a disturbance. That means the larger the ratio is, the severer the torsional vibrations induced will be. According to this result, it call be deduced that the coming generation of turbine generator units would get more sensitive to the 3P-G fault because the tendency is toward reducing the inertia of generators.

• 出版日期2008-12