Short-Circuit Current Definition
According to TEC60909-0:2016 (shown as Fig.1 below), the definitions of Ip, I’, and Ik is used for the calculation of the maximum short-circuit current of power generators.
Short-circuit current definition as per TEC60909-0:2016
Where: I, is the steady-state short-circuit current which could be measured for 5 cycles (100ms). It is the RMS value of the short-current which remains after the decay of the transient phenomena.
For inverters, I am the max output current (Imax). because during faults, the max reactive current is Iscmax Which is controlled by the firmware. Normally short circuit contribution means Ik.
I”, is the initial symmetrical short circuit current. It is the RMS value of AC symmetrical component of a prospective short circuit current applicable at the instant of short circuit if the impedance remains at zero-time value.
In the inverter, we take the first 20ms RMS value as I’’,.I, is the peak short-circuit current. It is the maximum possible instantaneous value of the prospective short-circuit current.
According to IEC 60909-0:2016, the short-circuit current of SUN2000-185KTL-H1 is declared as below:
