Single Ended Location of Faults
SELF (Single-Ended Location of Faults) is an impedance-based method applied to Low Voltage power system cables.
What is SELF?
- Allows pre-location of fault even without customer interruptions
- Easy to use – simply select the circuit cable details
The term “Single-ended” refers to the fact that the impedance estimation is based on the measurement of current and voltage at one point on the faulted phase. Unlike TDR it does not care about the number of joints on the network.
Single Phase SELF only measures one point at the substation using a REZAP FAULTMASTER
3 Phase SELF measures all 3 phases voltage and current simultaneously using a combination of auto-reclosing Devices from KELVATEK.
How SELF works
- Based on voltage and current recordings
- Identify fault half-cycles
- Input Network cable details
- SELF outputs pre-location distance in meters.
- Fault can change mode - PP, PN, PPN, 3P, 3PN
- Often changes mode within a half-cycle