Page 660 - Industrial Power Engineering and Applications Handbook

Surge arresters: application and selection 18/625
Surge transference through a transformer V,,, = switching surge residual voltage of the arrester -
kV
(i) Electrostatic transference Z, = surge impedance of the affected line
T = travelling time of the switching surge in ,us
(1 8.7a) IZ = number of consecutive discharges
Surge protection of motors
Vi,. = voltage of surge transference
C,, = lumped capacitance between the primary and the For long-duration switching surges,
secondary windings
C, = lumped capacitance of the lower voltage side Surge frequency. f, = ~ 10' kHL (18.11)
V, = prospective voltage surge on the primary side 4t,
= a factor to account for the power frequency voltage r, = rise time of the FOW in pus
already existing when the surge occurs
Dampened \urge transference to account for the capa-
citance C of cables and terminal equipment. Further reading
V = CP V, ' I' (1 8.7b)
c,, + c, i C I ABB, India, Srlrctiori Guide ,%r ABB HV Suixe Awc.\fer.\.
Zinc Oxide Surge Arrester. Technical Information Publ. SESWG/
A 2300 E. Edition 2. 1991-02.
(ii) Electromagnetic transference 2 Brown. P.B. and Miske. S.A.. Jr. 'Application of zinc oxide
station class arresters', Missouri Valley Electric Association
Engineering Conference, Kansas City. Missouri, 13 April 1978.
( 18.8) 3 Cotton. H., 'The transmission and distribution of electrical
energy - protection against overvoltages'
11 = factor for power frequency voltage 1 Csuros L., Overvoltage protection.
q = response factor of the lower voltage circuit to the 5 Electricity Council (ed.). Power System Protection. Peter
arriving long-duration surges Peregrinus. Stevenage.
I' = a factor that will depend upon the transformer 6 General Electric Company. USA. ~r[r~i,\f/ti,\\;~~/i, October 197 1
(overvoltage protection).
connections 7 Greanwood, A,. Elecwiccrl Trufi.siuit,\ r/r Poiwt- SJ \tcwi,r, John
II = transformation ratio of the transformer ( V,/V2). Wiley. New York.
8 Lundquist. J., Stenstroni, L., Schei. A. and Hansen. B.. 'New
Selecting the protective level of an arrester method for measurement of the resibti\ e leakage currents 01
metal oxide surge arre\tern in service'. 89 SM 817-8 PWRD,
Protectihe distance IEEE ( 1989).
9 Ozawa. .I.. Mizukoshi, A,. Maruyaiiia. S.. Nakano. K.. Saito
v, = \',<, + s ' 2 T ( 18.9) K., St Jean, G., Latour. Y.. and Petit. A,. 'Pre5surc reliefdmign
and performance of metal oxide surge ai-resters'- IEEE- 1985.
V, = actual surge voltage at the equipment IO Sakahaug, E.C. and Kresge. J.S. and Miske. SA. Jr. 'A new
.S = r,r,r,v. of the incoming wave in kV/ps concept in station arrester desien'.
T = travelling time of the surge, to reach the equipment 11 Shirakawa. S., Endo, F., Kitajitna. H.. Kobayashi. S.. Kurita,
from the arrester terminals K.. Goto. K.. and Sakai. M.. 'Maintenance of surge arrester by
a portable arrater leakage current detector'. /E€€ Trcirirtrc/ioii.c
oti Poivrr De/iwn, 3. No. 3. July ( 1988).
Energy capability 17 Society of Power tngineers (India) Bomba! Chapter. Seininar
on EHV Substations, 24 June 1994.
8. IO) 13 Thoren B., 'Insulation coordination for \y\tem \(>Itage.: of -57
to 800 kV', All India EHV Forum 1979.
13 Walsh, G.W.. 'A review of lightning protection and grounding
CV = energy absorbed in kW-s or kJ practices', IEEE 7ruti.vrrc~tion.s or? /irdit,\ft-\ App/i<,u/ioii \. 1 A-9,
V, = prospective s*itching surgc crest voltage - kV No. 2. March/April (1973)