US 11,885,843 B2 · Method, system and apparatus for fault detection

Abstract

A method, system and apparatus for fault detection in line protection for a power transmission system. The method includes: obtaining a sampled value of voltage at a measurement point, at which a protection device for the line protection is installed, on an electrical line; obtaining a sampled value of current at the measurement point; calculating an instantaneous measurement point voltage value specified by operation criterion of a protection device from the sampled value of voltage at the measurement point and the sampled value of current at the measurement point by using measurement differential equation according to a time domain lumped parameter model for the electrical line; calculating an instantaneous comparison voltage value specified by operation criterion of a protection device from the sampled value of voltage at the measurement point and the sampled value of current at the measurement point by using comparison differential equation according to a time domain lumped parameter model for the electrical line; and performing the fault detection based on the comparison result of the instantaneous measurement point voltage value and the instantaneous comparison voltage value. The method transfers the distance relay to the format of voltage comparison, calculate the voltage using differential equation instead of vector, and compare the amplitude of calculated voltages. It designs a time-domain distance protection which has strong ability to resist DC components and harmonics including high frequency harmonic and low frequency harmonic.

A method for a fault detection in line protection for a power transmission system, comprising:

obtaining a sampled value of a voltage at a measurement point on an electrical line, wherein the measurement point corresponds to a location at which a protection device for the line protection is installed;
obtaining a sampled value of a current at the measurement point;
calculating an instantaneous measurement point voltage value specified by an operation criterion of the protection device, wherein the instantaneous measurement point voltage value is calculated by:
{
u
q
-
⁢
p
⁢
1
⁢
p
⁢
2
-
⁢
k
=
u
p
⁢
1
⁢
p
⁢
2
-
⁢
k
-
(
R
·
i
p
⁢
1
⁢
p
⁢
2
-
⁢
k
+
L
·
di
p
⁢
1
⁢
p
⁢
2
-
⁢
k
dt
)
u
q
-
⁢
p
⁢
1
-
⁢
k
=
u
p
⁢
1
-
⁢
k
-
[
R
·
(
i
p
⁢
1
-
⁢
k
+
k
R
·
3
⁢
i
0
-
⁢
k
)
+
L
·
d
⁡
(
i
p
⁢
1
-
⁢
k
+
k
L
·
3
⁢
i
0
-
⁢
k
)
dt
]
k
R
=
R
0
-
R
1
3
⁢
R
1
k
L
=
L
0
-
L
1
3
⁢
L
1
wherein p1 and p2 represent first and second phases, respectively, of a three-phase transmission line of the power transmission system, uq_p1p2_k represents the instantaneous measurement point voltage value between phase p1 and phase p2 at instant k, uq_p1_k represents the instantaneous measurement point voltage value of phase p1 at instant k, up1p2_k, ip1p2_k respectively, represent the sampled value of the voltage and the sampled value of the current between phase p1 and phase p2 at the measurement point at instant k, up1_k, ip1_k, respectively, represent the sampled value of the voltage and the sampled value of the current of phase p1 at the measurement point at instant k, R and L, respectively, represent a resistance value of a resistor and an inductance value of an inductor in a time-domain lumped parameter model,
di
p
⁢
⁢
1
⁢
p
⁢
⁢
2
⁢
_
⁢
⁢
k
dt
represents a differential value of the current ip1p2_k,
d
⁡
(
i
p
⁢
⁢
1
⁢
_
⁢
⁢
k
+
k
L
·
3
⁢
i
0
⁢
⁢
_
⁢
⁢
k
)
dt
represents a differential value of the value ip1_k+kL·3i0_k, R0 represents a zero sequence resistance of the three-phase transmission line, R1 represents a positive sequence resistance of the three-phase transmission line, L0 represents a zero sequence inductance of the three-phase transmission line, L1 represents a positive sequence inductance of the three-phase transmission line, and i0_k represents a zero sequence current at instant k;
calculating an instantaneous comparison voltage value specified by the operation criterion of the protection device, wherein the calculating the instantaneous comparison voltage value is based on the sampled value of the voltage and the sampled value of the current in accordance with a comparison differential equation corresponding to the time-domain lumped parameter model;
comparing the instantaneous measurement point voltage value specified by the operation criterion of the protection device and the instantaneous comparison voltage value;
and
tripping the electrical line based on a result of the comparison of the instantaneous measurement point voltage value specified by the operation criterion of the protection device and the instantaneous comparison voltage value indicating a fault on the electrical line.

203 more elements

Facts

Application

16/440,258Filed 13 Jun 2019 · continuation

Priority

15 Jun 2017

Published

US 2019/0293705 A126 Sep 2019

Granted

30 Jan 2024

Term ends

Not estimatedThe source records don’t support an estimate.

Classification4 codes

G01R 31/088
Locating faults in cables, transmission lines, or networks: aspects of digital computing
G01R 31/085
According to type of conductors: in power transmission or distribution lines, e.g. overhead
G01R 31/086
According to type of conductors: in power transmission or distribution networks, i.e. with interconnected conductors
G01R
Measuring electric variables

Method, system and apparatus for fault detection

Life of this patent

Method, system and apparatus for fault detection

Life of this patent

Abstract

Claims20