Analysis of Turbine-Generator Shaft System Mechanical Torque Response based on Turbine Blade Modeling

터빈 블레이드 모델링을 통한 터빈 발전기 축 시스템의 기계적 토크 응답 분석

Park, Ji-Kyung;Chung, Se-Jin;Kim, Chul-Hwan

  • Received : 2015.03.11
  • Accepted : 2015.08.12
  • Published : 2015.09.01


Turbine-generator torsional response is caused by interaction between electrical transient air-gap torque and mechanical characteristics of turbine-generator shafts. There are various factors that affects torsional interaction such as fault, circuit breaker switching and generator mal-synchronizing, etc. Fortunately, we can easily simulate above torsional interaction phenomena by using ElectroMagnetic Transient Program (EMTP). However, conventional EMTP shows the incomplete response of super- synchronous torsional mode since it does not consider turbine blade section. Therefore, in this paper, we introduced mechanical-electrical analogy for detailed modeling of turbine-generator shaft system including low pressure turbine blade section. In addition, we derived the natural frequencies of modeled turbine-generator shaft system including turbine blade section and analyzed the characteristics of mechanical torque response at shaft coupling and turbine blade root area according to power system balanced/unbalanced faults.


Mechanical-electrical analogy;Mode frequency;Turbine blade;Turbine-generator shaft system;Torsional response