Fault location detection and distance protection apparatus and associated method

Patent metadata

Field	Value
Publication number	US-10746779-B2
Application number	US-201615570612-A
Country	US
Kind code	B2
Filing date	Apr 28, 2016
Priority date	Apr 30, 2015
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

An apparatus for determining a fault location distance or distance protection in a multi-phase power transmission medium, configured to; determine a set of line fault parameters based on a measurement of voltage and current at a point of said power transmission medium and a fault type, the line fault parameters determined at a plurality of sample times determine a derivative with respect to time of a line fault parameters representative of an inductive part of measured faulty phase current; determine a set of phasors using a Fourier transformation of the derivative and of the remaining line fault parameters at the plurality of sample times and use said set of phasors to determine a fault location distance or distance projection distance along the power transmission medium; wherein, the determination of the fault location distance or the distance protection distance is based on the line equation;

U
.

P

=

U
.

F

+

[

R
1

⁢

I
.

PR

+

X
1

ω
0

⁢

I
.

PX

]

⁢

D
F

.

First claim

What is claimed is:

1. An apparatus for determining a fault location distance or a distance for distance protection in a multi-phase power transmission medium, the apparatus configured to;
determine a set of line fault parameters u p , i PR , i PX and i P0 based on a measurement sample of voltage and current values at a measurement point for phases of a multi-phase current of said power transmission medium and a fault type, the set of line fault parameters determined at a plurality of sample times, n;
determine a derivative with respect to time of one of the line fault parameters i PX representative of an inductive part of measured faulty phase current;
determine a set of phasors {dot over (U)} P (n), İ PR (n), İ PX (n), and İ P0 (n), using a Fourier transformation of the derivative and of the remaining line fault parameters at the plurality of sample times and use said set of phasors to determine a fault location distance or distance projection distance along the power transmission medium;
wherein, the determination of the fault location distance or the distance protection distance is based on the line equation;

U
.

P

=

U
.

F

+

[

R
1

⁢

I
.

PR

+

X
1

ω
0

⁢

I
.

PX

]

⁢

D
F

where {dot over (U)} P , İ PR , and İ PX comprise the Fourier transforms of the line fault parameters u p , IPR and the derivative i PX , {dot over (U)} F is a Fourier transform of the voltage at the fault location, R 1 is a positive sequence resistance of the power transmission medium per length (ohm/km), D F is the fault location distance, X 1 is a positive sequence reactance of the power transmission medium per length (ohm/km) and ω 0 is the fundamental angular frequency where ω 0 =2πf 0 and f 0 is the fundamental frequency of the current of the power transmission medium; and
clearing a fault by tripping a breaker adjacent to a protective zone determined based at least in part on the determination of the fault location distance or the distance protection distance.

2. The apparatus according to claim 1 , wherein the apparatus is configured to;
determine a fault location distance for one or more of the following fault conditions or for distance protection;
i) a phase-to-phase fault and/or phase-to-phase-to-ground fault and/or three-phase fault in which;

D
F

=

imag
⁡

[

U
.

P

]

imag
⁡

[

R
1

⁢

I
PR

+

X
1

ω
0

⁢

I
PX

]

where the function imag[y] defines taking the imaginary part of the term y;
ii) a single-phase-to-ground fault in which;

D
F

=

imag
⁡

[

U
.

P

⁢

I

P
⁢

⁢
0

]

imag
⁡

[

(

R
1

⁢

I
_

PR

+

X
1

ω
0

⁢

I
.

PX

Assignees

• General Electric Technology Gmbh

Inventors

• Ha Hengxu
• Sri Gopala Krishna Murthi Sankara Subramanian

Classifications

• H02H3/405

  using phase sequence analysing arrangements · CPC title

• H02H3/042

  combined with means for locating the fault (locating faults in cables G01R31/08) · CPC title

• Y04S10/52

  Outage or fault management, e.g. fault detection or location · CPC title

• H02H1/0092

  concerning the data processing means, e.g. expert systems, neural networks · CPC title

• G01R31/088 Primary

  Aspects of digital computing · CPC title