Overvoltages in a finite-length underground cable by multiple reflections of transient voltages
- Tennessee Technological Univ., Cookeville, TN (United States)
A transient voltage, such as a lightning surge or a switching surge, travels unimpeded along an overhead power line until it encounters a junction with another line. A major portion of this voltage is then reflected back to the overhead line; a significantly reduced voltage wave is transmitted along the second line if the latter is an underground cable because of the markedly low surge impedance of the cable compared with that of the overhead line. If the other end of the cable is terminated in a high impedance, such as a transformer or an electrical machine, then successive reflections at the two ends of the cable would produce high voltage along the cable, endangering its dielectric system as well as that of the terminal apparatus. A surge arrester across the terminal apparatus will protect the apparatus, leaving the cable and the sending-end terminal unprotected. Lightning arresters at both ends of the cable will limit the overvoltages at these ends; however, dangerous overvoltages may develop along the length of the cable, away from the lightning arresters.
- OSTI ID:
- 7188792
- Report Number(s):
- CONF-9102205--
- Journal Information:
- Journal of the Tennessee Academy of Science; (United States), Journal Name: Journal of the Tennessee Academy of Science; (United States) Vol. 67:1-2; ISSN JTASAG; ISSN 0040-313X
- Country of Publication:
- United States
- Language:
- English
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