Page 902 - Industrial Power Engineering and Applications Handbook

Power reactors 27/853
Grid bus
I
I
Generator
Transformer 1 kVA, 11 kV
2500
5000 kVA, 33/11 kV 4, = 25%
Z,, = 7.1 5% 8 T (Reactive)
(Reactive)
Z,, = 7.15% z,, = 50%
(Reactive) (Reactive)

Series
reactor x%
f

3-phase loads Fault
(a) Location of fault (b) Equivalent circuit

Figure 27.13 Application of a series reactor

where qq = equivalent p.u. impedance of the combined power If the fault level is required to be limited to 50 MVA, a series
system at the point of fault. reactor of reactance, XY0 may be introduced into the
Consider the base level as 5000 kVA, 11 kV transformer circuit, as illustrated in Figure 27.13(b),
:. Generator reactance at the new base The new - 5000
eq - 50 x 1000
5000
~25~- (equation (13.1)) = 0.1 p.u.
2500
1
= 50% and the new reactance - = +- 1
1=- 0.1 0.0715 + X 0.5
1
and +- (0.0715 + X) (0.5)
Z,, 0.0715 0.5 or 0.1 =
0.571 5 + X
or Zes = 0.0625 X = 0.0535 p.u. or 5.35 YO
or
:. Fault level = - (equation (13.6)) at 5000 kVA base and 11 kV
5000
0.0625
:. A series reactor of reactance 5.35% may be used to limit
= 80 MVA the fault to the required level.
Relevant Standards
ZEC Title zs BS

60289/1988 Reactors 5553 (1 to 8) BS EN 60289/1995
Relevant US Standards ANSVNEMA and IEEE
IEEE 62/1995 Guide for field testing of electric power apparatus insulation. Part I - oil filled reactors

Notes
1 In the tables of Relevant Standards in this book while the latest editions of the Standards are provided, it is possible that revised editions
have become available. With the advances of technology andor its application, the updating of Standards is a continuous process by
different Standards organizations. It is therefore advisable that for more authentic references, readers should consult the relevant
organizations for the latest version of a standard.
2 Some of the BS or IS standards mentioned against IEC may not be identical.
3 The year noted against each standard may also refer to the year of its last amendment and not necessarily the year of publication.