Distance Protection Calculation PDF
Distance Protection Calculation PDF
Distance Protection Calculation PDF
ZONE SETTINGS:
Zone 1 = 80% of Protected Line
Zone 1B = 100% of Protected Line
Zone 2 = 100% of Protected Line + 20% of Adjacent Shortest Line
Zone 3 = 100% of Protected Line + 150% of Adjacent Longest Line
Zone 4 = 200% of Protected Line
CALCULATIONS:
1. CT / PT RATIO :
2. Positive Sequence Resistance ={ Line Length * Positive Sequence
Resistance* 80 % of Protected Line}
3. Positive Sequence Reactance = {Line Length * Positive Sequence
Reactance* 80 % of Protected Line}
4. Arc Resistance (Secondary) for Phase to Phase Fault =
{ * Primary Arc Resistance * CT / PT Ratio}
5. Tower Footing Resistance ( Secondary ) for Phase to Ground Fault
= {Tower Footing Resistance (Primary) * CT / PT Ratio}
6. Positive Sequence Resistance 100% of Line ={Line Length* Positive
Sequence Resistance / Km}
7. Reactance per Unit Length= {Positive Sequence Reactance / Line
Length}
8. Positive Sequence Reactance 100% of Line = {Line Length * Positive
Sequence Reactance / Km}
9. Zero Sequence Resistance 100% of Line = {Line Length * Zero
Sequence Resistance / Km}
10. Zero Sequence Reactance 100% of Line = {Line Length * Zero
Sequence Reactance / Km}
11. Phase to Phase Resistance (Reactance) = {R1(X1) +Arc Resistance
Ph to Ph}
12. Phase to Ground Resistance (Reactance) = {R1(X1) +Arc Resistance
Ph to Ph+Tower Footing Resistance Ph to Gnd}
13. Zero Sequence Compensation:
RE / RL = {1/3 * Zero Sequence Resistance 100% of Line / Positive
Sequence Resistance 100% of Line 1}
XE / XL = {1/3 * Zero Sequence Reactance 100% of Line / Positive
Sequence Reactance 100% of Line 1}
X/R = {Positive Sequence Reactance 100% of Line /
Positive Sequence Resistance 100% of Line}
Line Angle () = tan1 {X / R}
14. R load Primary = {Vmin / 1.732 * IL max}
R load Secondary = {(NCT / NVT) * R load Primary}
15. R load (ph to ph) Sec ={R load Primary * Security Margin (%) }(=)
= {R load Secondary Above value (=)}
TESTING PROCEDURE:
1. Measurement :
2. Zone Reach Test :
3. Carrier Send :
Create zone 1 fault within Teleprotection Element Enabled.
4. Carrier Received :
Create zone 2 fault within Teleprotection Element Enabled.
Initiate receive signal, it will trip at Z1 B time instantly.
5. SOTF ( SWITCH ON TO FAULT ) :
SOTF Protn should be enabled, give the current settings.
Trip L123 should be Configured.
Given 1 or 3 (ct or volt) with manual close BI at the
Same Time).
Create zone 2 fault & give manual close signal, it will trip
at Z1 time instaneously.
6. DTT ( Direct Transfer Trip ) :
Given 3 Trip will go to other end.
7. A/R ( Auto Reclosure ) :
Configured with Trip and action times.
For 1 trip we configured in power system data 2, Relay
Trip Command L1L2L3 (507, 8, 9) & Distance trip 1 trip Z1 at
Distance General Settings (3811, 3823). CB1 ready signal should be
configured in power system data 2.
Dead Time:
It is the time b/w after bkr tripping time to reclosing
Pulse initiating time.
Reclaim Time:
Reception of reclosing pulse time to the time taken by
The system comes to Normal Condition.
- Within reclaim time we are trying to give another pulse, it
Will go to Lockout.
- Create Z2 fault with Carrier Failure and A/R Enabled, the
1 fault Convert into 3 fault.
- Create Z2 fault with Carrier Receive and A/R Enabled,
Auto Reclosure with attempt and give the close command.
8. PSB(D) [Power Swing Blocked (Detection)] :
It is created by Ramping in OMICRON kit. We want to
Vary the voltage & current simultaneously.
9. Back up O/C and E/F protection :
It is Back up Directional O/C for distance protection.
10.VT Fuse Failure :
Apply 3 voltage and Remove one phase.
11.Broken Conductor:
Give 3 voltage and 2 current, less amount of current
in 3rd phase. Whenever the CT jumper is open at the
Time it will operate.