CE1 IEC (Première édition – ) (First edition – ) Courants de court-circuit dans les réseaux Short-circuit currents in three-phase. IEC Edition INTERNATIONAL. STANDARD. NORME. INTERNATIONALE. Short-circuit currents in three-phase a.c. systems –. Buy IEC SHORT-CIRCUIT CURRENTS IN THREE-PHASE A.C. SYSTEMS – PART 0: CALCULATION OF CURRENTS from SAI Global.
|Published (Last):||16 February 2015|
|PDF File Size:||14.61 Mb|
|ePub File Size:||17.33 Mb|
|Price:||Free* [*Free Regsitration Required]|
These values cannot be used when calculating the aperiodic component id. This fault is beyond the scope of, and is therefore not dealt with in, this standard. The effect of series capacitors can be neglected in the calculation of short-circuit currents, if they are equipped with voltage-limiting devices in parallel, acting if a short circuit occurs.
IEC | IEC Webstore
For other ,values of minimum time delay, linear interpolation between curves is acceptable. A,,, may be obtained from figures 18 or 19 for cylindrical rotor generators or salient-pole generators.
For per unit or other similar unit systems, no transformation is necessary if these systems are coherent, i. Impedances between a starpoint and earth shall be introduced without correction factor. All other static converters are disregarded for the short-circuit current calculation according to this standard. With these impedances the corrected equivalent impedances Isc, z B K and ZCKshall be calculated using the procedure given in equation i i.
The zero-sequence system impedance Z,, of the motor shall be given by the manufacturer, if needed see 4. The effective resistance per unit length RL of overhead lines at the conductor temperature 20 “C may be calculated from the nominal cross-section qn and the resistivity p: If ifc operation of the power station unit is expected at some time for instance to a large extent especially in pumped storage plantsthen only when calculating unbalanced short- circuit currents with earth connection see figures 3c and 3d the application of Ks according to equation 22 may lead to results at the non-conservative side.
Transformer secondary short circuits. Connection of a Motor The value should be obtained from the manufacturer. Calculation of a Cable 8. The resistance iev to be 609009-0 if the peak short-circuit current ip or the d.
Phasor diagram of a 6909-0 generator at rated conditions Short-circuit current of a far-from-generator short circuit with constant a.
E” Subtransient voltage of a synchronous machine f Frequency 50 Hz or 60 Hz Ib Symmetrical short-circuit breaking current r.
Rated voltage, line-to-line r.
Electric and magnetic circuits IEC 15 1: Nominal system voltage, line-to-line r. Characterization of short circuits and their currents I 1 unacceptable, marketing specialist other 609090 two-winding transformers with and without on-load tap-changer, an impedance correction factor KT is to be introduced in addition to the impedance evaluated according to equations 7 to 9: The capacitances of lines overhead lines and cables of low-voltage networks may be neglected in the positive- negative- and zero-sequence system.
CE1 TR2– Instead of: This part of IEC does not 60909–0 with the calculation of short-circuit currents in installations on board ships and aeroplanes.
Calculate the Impedance 8. Short-circuit impedances of a three-phase a. In the case of high-voltage direct-current transmission systems, the capacitor banks and filters need special considerations, when calculating a.
Depending on the application of the results, it is of interest to know the r. The symbols represent physical quantities possessing both numerical values and dimensions that are independent of units, provided a consistent unit system is chosen, for example the international system of units SI. Within the accuracy of this standard, it is often sufficient to determine the short-circuit current at the short-circuit location F as being the sum of the absolute values of the individual partial short- circuit currents.
Short Circuits in Power Systems: A Practical Guide to IEC 60909-0, 2nd Edition
Transformers in Parallel Short-circuit current of a near-to-generator short circuit with decaying a. All network feeders, synchronous and asynchronous machines are replaced by their internal impedances see clause 3.
For the short-circuit impedances of synchronous generators in the negative-sequence system, the following applies with KG from equation 1 8: Supply to a Factory For higher temperatures than 20 OC, see equation 3.
660909-0 the short circuit is a far-from-motor short circuit i. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. Normally, the steady-state short-circuit current Ik 6099-0 smaller than the symmetrical short-circuit breaking current 1.
If the Joule integral or the thermal equivalent short-circuit current shall be calculated for unbalanced short circuits, replace I: The equivalent voltage source is the only active voltage of the system. Log In Sign Up. Investigations of non-simultaneous short circuits, which may lead to higher aperiodic components of short-circuit current, are beyond the scope of this standard.
Factors f o r the calculation of short-circuit currents in three-phase a. For the examples in figures 1Ib and 1 IC, the initial symmetrical short-circuit current is calculated with the corrected impedances of the generator and the power station unit see 3.
The zero-sequence short-circuit impedance at the short-circuit location F is obtained according to figure 5c, if an a.