Fatigue Life Prediction of Rotor Slot-Dovetails in Pumped Storage Generator/Motor Considering Transient Loading

Abstract

For fatigue life prediction, the maximum stress calculated by the structural static analysis is used as load calculation in normal continuous operating conditions, which is not valid in time-varying performing situations. This article proposes a fatigue life prediction method considering repetitive time-varying and asymmetrical stresses as a stress spectrum for calculation loading to predict the accumulative fatigue life for the rotor slot-dovetails of the pumped storage generator/motor (PSGM) under multiple transient situations. The structural transient analysis is performed to calculate the time-varying stress caused by the centrifugal force. Then, the total stress is obtained by superimposing the centrifugal stress with the thermal stress caused by temperature difference, which is used as the loads for fatigue life calculations. Through fatigue life calculation in each condition, the numbers of cycles to failure and the initial sites of impending failures are determined. By the cumulative fatigue damage rule, the practical operating data is to predict the service life. By this prediction method, the fatigue fracture sites are in the slot-dovetail, and the minimum service life is estimated.

Keywords:

• pumped storage generator/motor, rotor residual life, structural transient analysis, cumulative fatigue damage rule, transient loading, time-varying performing situations, thermal stress, electromagnetic stress, finite element method

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (51577106).

Notes on contributors

Xiongfeng Huang

Xiongfeng Huang was born in Hubei Province, China. He received the Ph.D. degree from School of Automation, Huazhong University Science and Technology in 2015. He is currently working with the Hubei Key Laboratory of Cascaded Hydropower Stations Operation & Control, China Three Gorges University. His major fields of interests include numerical analysis of electromagnetic field and multi-physics coupling and its application in engineering.

Hongxing Fan

Hongxing Fan was born in Zhejiang province, China, in 1995. He received the B.S. degree from School of Automation and Electrical Engineering, Zhejiang University of Science and Technology, in 2017. He is currently working toward the M.S. degree in Electrical Engineering at China Three Gorges University. His research interests include the advanced design and intelligent operation of electrical equipment.

Dongyuan Liu

Dongyuan Liu was born in Anhui Province, China, in 1993. He received the M.S. degree from College of Electrical Engineering and New Energy, China Three Gorges University, in 2017. He is currently working with the Luan Power Supply Company, State Gird Corporation of China. His major fields of interests include numerical analysis of electromagnetic field and multi-physics coupling and its application in engineering.

Yujiao Zhang

Yujiao Zhang was born in Hubei Province, China. She received the Ph.D. degree from School of Electrical Engineering, Wuhan University in 2012. She is currently working with the Hubei Key Laboratory of Cascaded Hydropower Stations Operation & Control, China Three Gorges University. Her major fields of interests include numerical analysis of electromagnetic field and multi-physics coupling and its application in engineering.

Lan Jiang

Lan Jiang was born in Hubei Province, China, in 1986. He received the M.S. degree from the College of Civil Engineering, Guizhou University in 2012. He is currently working toward the Ph.D. degree in civil engineering at Hunan University, China. His research interests include disaster prevention and mitigation and optimization design of power engineering structure, and dynamic performance of engineering structures.