A Study on the Detection of Asynchronous State of the Synchronous Generator

  • Choi, Hyung-Joo (Dept. of electrical Eng. Korea Midland Power Company(KOMIPO)) ;
  • Lee, Heung-Ho (Department of Electrical Engineering, Cung-Nam National University)
  • Received : 2013.10.14
  • Accepted : 2013.11.02
  • Published : 2013.12.01


This paper includes new protection concepts and practices to avoid mechanical damage of three-phase transformer by asynchronous operation of synchronous generator. this failure is often caused just after synchronous generator was connected to the grid because of a malfunction of the controller or misconnections of the synchronous devices. The results of the studies on the analyzing the phenomenon of asynchronous operation experienced in Korea and rapidly detecting asynchronous state are descrived.


  1. Okamoto, "Why cannot asynchronous operation", Mitsubishi Transactions September 1986, Pp 109-114.
  2. B. R. Hill, "Modern Power Station Practice, Third Edition in 12 volumes, Electrical System and Equipment Volume D" PERGAMON PRESS, pp. 948-985
  3. A. C. Franklin, D. P. Franklin, "The J&P Transformer Book, 11th Editio, A Practical Technology of the power transformer", Butterworths, pp. 666-680.
  4. J. A. Imhof, "Out of Step Relaying for Generators Working Group Report", IEEE Transactions on Power Apparatus and Systems, Vol. PAS-96, No.5, pp. 1556-1564, September/October 1977.
  5. E Clarke, "Circuit Analysis of A-C Power Systems", Vol. I-Symmertical and Related Components, Wiley, 1943.
  6. Hirofumi Akagi, Edson Hirokazu Watanabe, Mauricio Aredes, "Instantaneous Power Theory and Applications to Power Conditioning", WILEY-INTERSCIENCE, pp. 41-47.

Cited by

  1. Influence of Stator Parameter Variation and Phase-Shift Under Synchronizing Out of Phase on Turbine Generator Electromagnetic Field vol.32, pp.2, 2017,
  2. Influence of Rotor Structure on Field Current and Rotor Electromagnetic Field of Turbine Generator Under Out-of-Phase Synchronization vol.53, pp.6, 2017,