Ferranti effect
nounEtymology First observed during the installation of underground cables in Sebastian Ziani de Ferranti's 10,000 volt distribution system in 1887.
1
An increase in voltage occurring at the receiving end of a long transmission line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load is disconnected. The capacitive line charging current produces a voltage drop across the line inductance that is in-phase with the sending end voltages considering the line resistance as negligible.
- The Ferranti effect is much more pronounced in underground cables, even in short lengths, because of their high capacitance.