| 摘要 |
The invention relates to a method for identifying transient- type earth faults in an electrical network and for selectively tripping a faulty branch line (A/D). The absolute value (I0max) and its index (ind) in a zero-current buffer (BI) are retrieved from the samples of a zero-current sampling buffer, by means of which a value depicting the admittance-delta is calculated using the ratio DELTAl0 / DELTAU0 of the zero current l0 difference DELTAI0 and the residual voltage UC difference DELTAU0, A negative admittance-delta is classified as forward (FWD). A transient-type earth fault is detected in the branch line with the aid of at least one forward (FWD) spike during a selected time (FWDreset). |
