Generator split-phase protection

• Autorzy: Kim S. , Finney D. , Fischer N. , Kasztenny B.
• Języki publikacji: EN

Abstrakty

EN

The stator winding of a hydrogenerator is often made up of coils with multiple turns in the same slot. It is therefore possible for faults to develop between adjacent turns on the same phase (turn-toturn faults). These faults cannot be detected by the stator differential protection because there is no difference between the neutral- and terminal-side currents. Split-phase protection, an overcurrent element responding to the difference between the currents in the winding parallel branches, is typically provided to detect these faults. Ideally, the split-phase element should be sensitive enough to detect a single shorted turn. Despite the fact that the current in this turn can be six to seven times the machine nominal current, the current seen by the split-phase protection can be quite small, in the order of one-twentieth of the generator full-load current. In addition, a spurious split-phase current can be measured due to current transformer (CT) errors, saturation during external faults in particular. Therefore, primary considerations in the application of split-phase protection are the method of measuring the difference in the currents between the parallel branches and the proper selection of the CT used for this purpose.

Słowa kluczowe

EN

protective relaying; stator differential protection; split-phase protection

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Present Problems of Power System Control
• Rocznik: 2012
• Tom: Nr 2
• Strony: 5--40
• Opis fizyczny: Bibliogr. 8 poz., rys. 27

Twórcy

autor

Kim S.

autor

Finney D.

autor

Fischer N.

autor

Kasztenny B.

• Ontario Power Generation

Bibliografia

• [1] DeHAAN J., Electrical Unbalance Assessment of a Hydroelectric Generator With Bypassed Stator Coils, proceedings of the IEEE International Conference on Electric Machines and Drives, Seattle, WA, May 1999.
• [2] FINNEY D., KASZTENNY B., Mc CLURE M. and BRUNELLO G., Self-Adaptive Generator Protection Methods, proceedings of the IET 9th International Conference on Developments in Power System Protection, Glasgow, United Kingdom, March 2008.40 S. KIM et al.
• [3] IEEE Tutorial on the Protection of Synchronous Generators, 1995.
• [4] JONES K. W., Addressing Window Type Transformer Proximity Errors, proceedings of the 59th Annual Conference for Protective Relay Engineers, College Station, TX, April 2006.
• [5] RHUDY R. G., SNIVELY H. D. and WHITE J. C., Performance of Synchronous Machines Operating With Unbalanced Armature Windings, IEEE Transactions on Energy Conversion, vol. 3, no. 2, pp. 391–397, June 1988.
• [6] SILLS H. R. and McKEEVER J. L., Characteristics of Split-Phase Currents as a Source of Generator Protection, Transactions of the American Institute of Electrical Engineers, Part III: Power Apparatus and Systems, vol. 72, no. 2, pp. 1005–1016, January 1953.
• [7] WALKER J. H., Large Synchronous Machines: Design, Manufacture, and Operation. Oxford University Press, 1981.
• [8] Voith Hydro, Micalastic ®Insulation for High Voltage Hydro Generators, 2009. Available: http://www.voithhydro.com