Method for identifying type of fault on power line

Patent metadata

Field	Value
Publication number	US-10141736-B2
Application number	US-200913380538-A
Country	US
Kind code	B2
Filing date	Jun 26, 2009
Priority date	Jun 26, 2009
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

A method for identifying the type of faults occurred on a power line, characterized in that it comprises: calculating a fault point voltage on fault points based on terminal voltage and fault locations of the power line; adopting the fault point voltage corresponding to a maximum transition resistance as a setting value; comparing the fault point voltage on fault points with the setting value; and identifying the type of fault as a permanent type or a transient type based on the result of the comparison.

First claim

The invention claimed is:

1. A method for identifying a fault that occurred on parallel double-circuit power lines on a same tower transmitting power, comprising:
calculating a first fault point voltage of a first fault point on a first fault phase of a first circuit multiphase power line of the parallel double-circuit power lines using a first terminal voltage;
calculating a second fault point voltage of a second fault point on a second phase of a second circuit multiphase power line of the parallel double-circuit power lines using a second terminal voltage;
calculating a voltage difference between the first fault point voltage and the second fault point voltage, wherein one of the first fault phase and the second fault phase are in a non-open configuration;
adopting the first fault point voltage corresponding to a maximum transition resistance as a setting value;
first comparing the first fault point voltage with the setting value;
identifying the fault includes a permanent ground type or a transient ground type based on a result of the first comparison;
second comparing the calculated voltage difference with a fault-type-dependent voltage threshold value;
identifying the fault includes a permanent inter-phase type if the voltage difference is less than a voltage difference threshold value or a transient inter-phase type if the magnitude of the voltage difference is greater than the voltage threshold value;
in response to the identifying the fault includes the transient ground type fault, sending commands that reclose fault phase breakers according to the transient inter-phase type fault; and
wherein the steps are performed by one or more digital processors.

2. The method according to claim 1 , wherein in a case of a same-name phase fault across the first circuit power line and the second circuit power line, one of the faulty phases is an open phase and the other faulty phase is a reclosed phase.

3. The method according to claim 1 , wherein in a case of a different-name phase fault across the first circuit power line and the second circuit power line, both of the faulty phases are an open phase.

4. The method according to claim 1 , wherein the fault is identified as a permanent type only when the fault point voltage is less than the setting value; and
identifying the type of fault as a transient type only when the fault point voltage is higher than the setting value.

5. The method according to claim 1 , wherein the voltage difference threshold value is calculated based on voltages and currents on faulty and sound phases and a coefficient matrix of a homogenous power line equation.

6. A non-transitory storage media comprising a computer program for identifying a type of faults that occurred on a power line, wherein, the computer program is loaded into an internal memory of a digital processor and comprises computer program code, which, when executed by the digital processor, causes the digital processor to execute the method according to claim 1 .

7. The method according to claim 1 , wherein the voltage difference threshold value is calculated based on voltages and currents on faulty and sound phases and a coefficient matrix of a homogenous power line equation.

8. The method according to claim 2 , wherein the voltage difference threshold value is calculated based on voltages and currents on faulty and sound phases and a coefficient matrix of a homogenous power line equation.

9. The method according to claim 3 , wherein the voltage difference threshold value is calculated based on voltages and currents on faulty and sound phases and a coefficient matrix of a homogenous power line equation.

10. The method according to claim 4 , wherein the voltage difference threshold value is calculated based on voltages and currents on faulty and sound phases and a coefficient matrix of a homogenous power line equation.

11. The method according to claim 1 , wherein the fault in the parallel double-circuit power lines on the same tower includes at least one of a group consisting of:
an interphase fault in one line;
a same-name fault in two lines;
an interphase fault between a phase of one line and a different phase of a second line;
an interphase fault between a first and second phases of one line and a first phase of a second line and the first phases are the same;
an interphase fault between two phases of a first line and a different phase of a second line; and
an interphase fault between a first and a second phase of a first line and a first and a second phase of a second, and the second phase of the first line and the first phase of the second line are the same.

12. The method according to claim 1 , further comprising:
sending at least one permanent fault command for the type of fault identified as the permanent type.

13. A fault type identifying controller for identifying a type of fault that occurred on parallel double-circuit power lines on a same tower transmitting power, comprising:
a calculating unit that includes one or more digital processors configured to calculate a first fault point voltage of a first fault point using a first terminal voltage on a first fault phase of a first circuit multiphase power line of the parallel double-circuit power lines on the same tower, to calculate a second fault point voltage of a second fault point using a second terminal voltage on a second fault phase of a second circuit multiphase power line of the parallel double-circuit power lines, and to calculate a voltage difference between the first fault point voltage and the second fault point voltage, wherein one of the first fault phase and the second fault phase are in a non-open configuration;
a setting value setup unit that includes the one or more digital processors configured to adopt the first fault point voltage calculated corresponding to a maximum transition resistance as a setting value;
a comparing unit that includes the one or more digital processors configured to first compare the first fault point voltage with the setting value and to second compare the calculated voltage difference with a fault-type dependent threshold; and
an identifying unit that includes the one or more digital processors configured to identify a permanent ground type fault or a transient ground type fault based on a result of the first comparison and to identify a permanent inter-phase type fault if the voltage difference is zero or a transient inter-phase type fault if the voltage difference is greater than zero, and in response to the identified fault including a transient interphase type fault, sending commands that reclose fault phase breakers according to the transient inter-phase type fault.

Assignees

• Li Yongli
• Li Botong
• Chen Li
• Su Bin
• Abb Research Ltd

Inventors

• Li Yongli
• Li Botong
• Chen Li
• Su Bin

Classifications

• G01R31/085

  in power transmission or distribution lines, e.g. overhead · CPC title

• H02H7/267 Primary

  for parallel lines and wires · CPC title

• H02H1/00

  Details of emergency protective circuit arrangements · CPC title