The resistances for cables, transmission lines and busways for maximum short-circuit current calculations are based on the conductor temperature at 20☌. Impedance correction factors are applied for network or utility ( K Q), generators ( K G), power stations units with on-load tap changer ( K S), power stations units without on-load tap changer ( K SO), and two- and three-winding transformers ( K T). The short-circuit impedances for electrical equipment are modified using impedance corrections factors that are calculated based on section 3. The values can be displayed in magnitude, magnitude and angle, or in real and imaginary quantities.įigure 2: Short-circuit currents decaying over time MethodologyĮasyPower uses the equivalent voltage source at the short-circuit location, symmetrical components impedance network, and the voltage factor c as described in section 2.3 of the standard. Corresponding voltages can be displayed at the buses. You can view the currents in various formats such as phase currents for A, B and C phases or in symmetrical components: positive sequence, negative sequence, zero sequence and the 3I0 value (3 times the zero sequence current). Steady-state short-circuit current ( I k)įigure 1: Display of short-circuit currents.DC component ( i dc) of short circuit-current at breaking times.Symmetrical short-circuit breaking current ( I b) at 0.02s, 0.05s, 0.1s and 0.25s.
Initial symmetrical short-circuit current ( I k ”).You can obtain the following values of short-circuit currents at the fault location for both maximum and minimum short circuit currents: Line-to-line short circuit with earth connection (double line-to-earth).The IEC standard terminology is used in the user interface and reports.ĮasyPower supports the following four types of short-circuit conditions as per IEC 60909: The results meet requirements of IEC-60909 and match the example provided in IEC TR 60909-4 section 6.
You can enter equipment data and parameters via user friendly interface. IEC-60909 Short-Circuit in EasyPower IntroductionĮasyPower offers a complete and accurate solution to short-circuit calculations in three-phase AC systems using the IEC-60909 standard.
0 kommentar(er)
