Parameter free traveling wave based fault location for power transmission lines
A method can be used for fault location in a power transmission line connecting a first terminal with a second terminal. Arrival times of a first peak and a second peak of travelling waves are detected from measurements carried out at the first and second terminals. a rough location of a fault is identified based on a comparison of the arrival times obtained for the travelling waves detected from the measurements carried out at the first terminal, and the arrival times obtained for the travelling waves detected from the measurements carried out at the second terminal. The fault location is estimated based the rough location, the arrival times of the first and second peaks of the travelling waves detected from measurements carried out at the first and second terminals, and a length of the power transmission line.
1. A method for fault location in a power transmission line connecting a first terminal with a second terminal, wherein the method is implemented with a processor of a device associated with the power transmission line, the method comprising:
obtaining arrival times of a first peak and a second peak of travelling waves detected from measurements carried out at the first and second terminals;
identifying one of a first half, a second half, and a mid-point of the power transmission line as having the fault, based on a comparison of (tn2−tm1) with (tm2−n1), wherein tm1 and tm2 are the arrival times of the first and second peaks obtained for the travelling wave detected from the measurements carried out at the first terminal, and tn 1 and tn 2 are the arrival times of the first and second peaks obtained for the travelling wave detected from the measurements carried out at the second terminal;
estimating the fault location based on the identification of the first half, the second half, and the mid-point, as having the fault, the arrival times of the first and second peaks of the travelling waves detected from measurements carried out at the first and second terminals, and a length of the power transmission line, wherein estimating the fault location is not based on capacitance, inductance, or propagation velocity of the power transmission line; and
repairing the power transmission line based on the estimated fault location, wherein:
the fault is identified as being in the first half when (tn2−tm1) is greater than (tm2−tn1) and the fault is identified as being in the second half when (tm2−tn1) is greater than (tn2−tm1), and the fault location in the first half of the line
(
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
4
(
tn
2
-
tm
1
)
)
;
or
the fault location in the second half of the line is estimated from
(
L
-
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
4
(
tm
2
-
tn
1
)
)
,
wherein L is the length of the power transmission line, or
the fault is identified as being in the first half when (tn 2 - tm 1 ) is greater than (tm2−tn1) and the fault is identified as being in the second half when (tm2−tn1) is greater than (tn2−tm1), and the mid-point of the power transmission line is identified as having the fault when a difference between (tn2−tm1) and (tm2−tn1) is less than a threshold value, or
the fault location in the first half of the line is estimated from
(
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
4
(
tn
2
-
tm
1
)
)
,
wherein L is the length of the power transmission line, or the fault location in the second half of the line is estimated from
(
L
-
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
4
(
tm
2
-
tn
1
)
)
,
wherein L is the length of the power transmission line, or
the mid-point of the power transmission line is identified as having the fault when the difference between (tn2−tm1) and (tm2−tn1) is less than a threshold value.
2. The method of claim 1 , wherein the fault location is estimated by taking an average of first and second fault locations, wherein the first fault location is estimated for a fault in the first half of the line and the second fault location is estimated for a fault in the second half of the line.
3. A method for fault location in a power transmission line connecting a first terminal with a second terminal, the method comprising:
measuring voltages or currents at the first terminal;
measuring voltages or currents at the second terminal;
calculating arrival times of a first peak and a second peak of travelling waves at the first terminal based on the measurements of the voltages or currents carried at the first terminal;
calculating arrival times of the first peak and the second peak of the travelling waves at the second terminal based on the measurements of the voltages or currents carried at the second terminal;
identifying a rough location of a fault based on a comparison of (tn2−tm1) with (tm2−tn1), wherein tm1 and tm2 are the arrival times of the first and second peaks obtained for the travelling wave detected from the measurements carried out at the first terminal, and tn1 and tn2 are the arrival times of the first and second peaks obtained for the travelling wave detected from the measurements carried out at the second terminal, the rough location being one of a first half of the power transmission line, a second half of the power transmission line, or a mid-point of the power transmission line;
estimating the fault location based on the rough location, the arrival times calculated based on the measurements at the first terminal, the arrival times calculated based on the measurements at the second terminal, and a length of the power transmission line, wherein estimating the fault location is not based on capacitance, inductance, or propagation velocity of the power transmission line; and
repairing the power transmission line based on the estimated fault location, wherein:
the fault is identified as being in the first half when (tn2−tm1) is greater than (tm2−tn1) and the fault is identified as being in the second half when (tm2−tn1) is greater than (tn2−tm1), and the fault location in the first half of the line is estimated from
(
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
4
(
tn
2
-
tm
1
)
)
)
,
or
the fault location in the second half of the line is estimated from
(
L
-
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
4
(
tm
2
-
tn
1
)
)
,
wherein L is the length of the power transmission line, or
in the first half when (tn2−tm1) is greater than (tm2−tn1) and the fault is identified as being in the second half (tm2−tn1) is greater than (tn2−tm1), and the mid-point of the power transmission line is identified as having the fault when the difference between (tn2−tm1) and (tm2−tn1) is less than a threshold value, or
the fault location in the first half of the line is estimated from
(
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
4
(
tn
2
-
tm
1
)
)
,
wherein L is the length of the power transmission line, or
the fault location in the second half of the line is estimated from
(
L
-
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
(
tm
2
-
tn
1
)
)
,
wherein L is the length of the power transmission line, or
the mid-point of the power transmission line is identified as having the fault when a difference between (tn2−tm1) and (tm2−tn1) is less than a threshold value.
4. The method of claim 3 , wherein the fault location is estimated by taking an average of first and second fault locations, wherein the first fault location is estimated for a fault in the first half of the line and the second fault location is estimated for a fault in the second half of the line.
5. A device for fault location in a power transmission line connecting first and second terminals, the device including a processor and a receiver, the receiver configured to:
receive measurements carried out at the first terminal of the power transmission line; and
receive measurements carried out at the second terminal of the power transmission line;
the processor configured to:
obtain arrival times of a first peak and a second peak of travelling waves detected from the received measurements carried out at the first and second terminals;
identify one of a first half, a second half, and a mid-point of the power transmission line as having the fault, based on a comparison of (tn2−tm1) with (tm2−tn1), wherein tm1 and tm2 are the arrival times of the first and second peaks obtained for the travelling wave detected from the received measurements carried out at the first terminal, and tn 1 and tn 2 are the arrival times of the first and second peaks obtained for the travelling wave detected from the received measurements carried out at the second terminal; and
estimate the fault location based on the identification of the first half, the second half or the mid-point as having the fault, the arrival times of the first and second peaks of the travelling waves detected from the measurements carried out at the first and second terminals, and a length of the power transmission line, wherein estimating the fault location is not based on capacitance, inductance, or propagation velocity of the power transmission line; and
repair the power transmission line based on the estimated fault location, wherein:
the fault is identified as being in the first half when (tn2−tm1) is greater than (tm2−tn1) and the fault is identified as being in the second half when (tm2−tn1) is greater than (tn2−tm1), and the fault location in the first half of the line is estimated from
(
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
4
(
tn
2
-
tm
1
)
)
,
or
the fault location in the second half of the line is estimated from
(
L
-
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
(
tm
2
-
tn
1
)
)
,
wherein L is the length of the power transmission line, or
the fault is identified as being in the first half when (tn2−tm1) is greater than (tm2−tn1) and the fault is identified as being in the second half when (tm2−tn1) is greater than (tn2−tm1), and the mid-point of the power transmission line is identified as having the fault when a difference between (tn2−tm1) and (tm2−tn1) is less than a threshold value, or
the fault location in the first half of the line is estimated from
(
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
4
(
tn
2
-
tm
1
)
)
,
wherein L is the length of the power transmission line, or
the fault location in the second half of the line is estimated from
(
L
-
(
(
tm
2
-
tm
1
)
+
(
tn
2
-
tn
1
)
)
×
L
(
tm
2
-
tn
1
)
)
,
wherein L is the length of the power transmission line, or
the mid-point of the power transmission line is identified as having the fault when the difference between (tn2−tm1) and (tm2−tn1) is less than a threshold value.
6. The device of claim 5 , wherein the device is an intelligent electronic device associated with the first terminal.
7. The device of claim 6 , wherein the device is configured to receive the measurements carried out at the corresponding terminal from measurement equipment associated with the first terminal, and to receive the measurements carried out at the second terminal over a communication channel from a device associated with the second terminal of the power transmission line.
8. The device of claim 5 , wherein the device is a server connected with intelligent electronic devices associated with the first and second terminals, respectively.
9. The device of claim 8 , wherein the server is configured to receive travelling wave parameters obtained by the intelligent electronic devices from the measurements carried out at the respective terminals.