FOREWORD
1 General
1.1 Scope and object
1.2 Reference documents
1.3 Application of the factors
1.3.1 Factor c
1.3.2 Factors K[G] and K[S] of K[SO]
1.3.3 Factors K[G,S], K[T,S] or K[G,SO], K[T,SO]
1.3.4 Factor K[T]
1.3.5 Factors [kappa]
1.3.6 Factors [mu], [lambda] and [q]
1.3.7 Factors [m] and [n]
1.3.8 Contribution of asynchronous motors to the
initial symmetrical short-circuit current
1.4 Symbols, subscripts and superscripts
1.4.1 Symbols
1.4.2 Subscripts
1.4.3 Superscripts
2 Factors used in IEC 60909-0
2.1 Voltage factor c for the equivalent voltage source
at the short-circuit location
2.1.1 General
2.1.2 Calculation methods
2.1.3 Equivalent voltage source at the short-circuit
location and voltage factor c
2.1.4 A simple model illustrating the meaning of the
voltage factor c
2.2 Impedance-correction factors when calculating the
short-circuit impedances of generators, unit
transformers and power-station units
2.2.1 General
2.2.2 Correction factor K[G]
2.2.3 Correction factors for power station units with
on-load tap changer
2.2.4 Correction factors for power station units without
on-load tap changer
2.2.5 Influence of the impedance correction factor for
power-station units when calculating short-circuit
currents in meshed networks and maximum
short-circuit currents at worst-case load flow
2.3 Impedance correction factor K[T] when calculating the
short-circuit impedances of network transformers
2.3.1 General
2.3.2 Example for a network transformer S[rT] = 300 MVA
2.3.3 Statistical examination of 150 network transformers
2.3.4 Impedance correction factors for network
transformers in meshed networks
2.4 Factor [kappa] for the calculation of the peak short-circuit
current
2.4.1 General
2.4.2 Factor [kappa] in series R-L-circuits
2.4.3 Factor [kappa] of parallel R-L-circuits
2.4.4 Calculation of the peak short-circuit current i[P]
in meshed networks
2.4.5 Example for the calculation of [kappa] and i[P] in
meshed networks
2.5 Factor [mu] for the calculation of the symmetrical
short-circuit breaking current
2.5.1 General
2.5.2 Basic concept
2.5.3 Calculation of the symmetrical short-circuit breaking
current I[b] with the factor [mu]
2.6 Factor [lambda] (lambda[max], lambda[min]) for the calculation
of the steady-state short-circuit current
2.6.1 General
2.6.2 Influence of iron saturation
2.7 Factor [q] for the calculation of the short-circuit breaking
current of asynchronous motors
2.7.1 General
2.7.2 Derivation of factor [q]
2.7.3 Short-circuit breaking currents in the case of
unbalanced short circuits
2.8 Factors [m] and [n] for the calculation of the Joule integral
or the thermal equivalent short-circuit current
2.8.1 General
2.8.2 Time-dependent three-phase short-circuit current
2.8.3 Factor [m]
2.8.4 Factor [n]
2.8.5 Factor [n] in IEC 60909-0, figure 22
2.9 Statement of the contribution of asynchronous motors or groups
of asynchronous motors (equivalent motors) to the initial
symmetrical short-circuit current
2.9.1 General
2.9.2 Short circuit at the terminals of asynchronous motors
2.9.3 Partial short-circuit currents of asynchronous motors
fed through transformers
2.9.4 Sum of partial short-circuit currents of several
groups of asynchronous motors fed through several
transformers
Bibliography
Figures and Tables