- Ferranti effect
The
Ferranti Effect is a rise in voltage occurring at the receiving end of a longtransmission line , relative to the voltage at the sending end, which occurs when the line is charged but there is a very light load or the load is disconnected.This effect is due to the voltage drop across the line inductance (due to charging current) being in phase with the sending end voltages. Therefore both capacitance and inductance are responsible for producing this phenomenon. [ [http://www.ku.edu.np/ee/rb/Handouts_COEG301&303/Ferranti%20Effect.pdf Ferranti Effect handout, University of Kansas] ]
The Ferranti Effect will be more pronounced the longer the line and the higher the voltage applied. [ [http://www.ipst.org/TechPapers/2001/IPST01Paper117.pdf Line-Charging Current Interruption by HV and EHV Circuit Breakers, Carl-Ejnar Sölver, Ph. D. and Sérgio de A. Morais, M. Sc.] ] The relative voltage rise is proportional to the square of the line length. [ [http://www.ipst.org/TechPapers/2005/IPST05_Paper050.pdf A Knowledge Base for Switching Surge Transients, A. I. Ibrahim and H. W. Dommel] ]
Due to high capacitance, the Ferranti Effect is much more pronounced in underground cables, even in short lengths. [ [http://www.geocities.com/cindulkar/notes4.html#_Hlk481122583 Electrical Machines & Power Systems, C. S. Indulkar] ]
References
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