Wide area fault detection method using PMU data

Patent metadata

Field	Value
Publication number	US-10132853-B2
Application number	US-201615095266-A
Country	US
Kind code	B2
Filing date	Apr 11, 2016
Priority date	Apr 10, 2015
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

The embodiments herein are directed to monitoring in real time, power system data so as to provide insights into global operation of a power grid. Such a scheme disclosed herein utilizes rules, which are created by analyzing PMU measurement data, in order to detect the fault location (bus and line) and fault type. Three common types of faults in a power grid, single-line-to-ground (SLG), line-to-line (LL), and three phase faults, can be detected using the methods herein.

First claim

We claim:

1. A method for wide-area real time line fault detection in a power grid system, the power grid comprising a plurality of phasor measurement units (PMUs) and other sensors individually coupled to various system components of the power grid and supervisory control and data acquisition facilities, the method comprising:
(a) using the PMUs to measure one or more current phasors and one or more voltage phasors at a monitored bus of a load center of the supervisory control and data acquisition facilities, wherein the supervisory control and data acquisition facilities include a logic processor device; and
(b) using the logic processor device of the supervisory control and data acquisition facilities to:
take out transmission lines without a stable steady-state positive sequence current value;
acquire the measured one or more current and voltage phasors obtained from the PMUs;
identify an event as one or more faulted buses in the power system via calculating a maximum three phase total average voltage deviation (ΔV i ), wherein a magnitude of the one or more measured voltage phasors is utilized to calculate the maximum three phase total average voltage deviation (ΔV i );
determine the event as one or more fault types using at least one methodology selected from: a first method that uses the magnitude of the one or more voltage phasors and a second method that uses both the magnitude and a phase angle of the measured one or more voltage phasors, wherein the first method and the second method enables determination of the one or more fault types with at least one fault type selected from: single line-to-ground faults (SLG), line-to-line faults (LL), and three-phase faults;
detect the one or more faulted lines using the magnitude of positive sequences of the one or more current phasors as the parameter; and
issue an auditory and/or user interface warning concerning the one or more faulted lines detected.

2. The method of claim 1 , wherein calculation of the maximum three phase total average voltage deviation (ΔV i ) to identify the event further comprises:
calculating a voltage sag (V sag ) at a bus;
determining a voltage deviation of each phase using (ΔV i )=V ssi −V sagi ; and
thereafter calculating the three phase total average voltage deviation ΔV i , using:

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3. The method of claim 1 , wherein the first method that uses the magnitude of the one or more voltage phasors to determine the one or more faulted lines further comprises:
determining the single line-to-ground faults (SLG) via a threshold that requires a first phase to have one or more voltage sag values to be less than 0.95 per-unit (p.u.) with a second and a third phase to have one or more voltage sag values to be above 0.95 per-unit (p.u.).

4. The method of claim 1 , wherein the first method that uses the magnitude of the one or more voltage phasors to determine the one or more faulted lines further comprises:
determining the line-to-line faults (LL) via a threshold that requires one or more voltage sag values from two of the three phases selected from a first phase, a second phase, and a second phase to be in a range between 0.35 per-unit (p.u.) and 0.95 per-unit (p.u.).

5. The method of claim 1 , wherein the first method that uses the magnitude of the one or more voltage phasors to determine the one or more faulted lines further comprises:
determining the three-phase faults via a threshold that requires all three phases selected from a first phase, a second phase, and a second phase to have one or more voltage sag values to be in a range between 0.0.0 per-unit (p.u.) and 0.8 per-unit (p.u.) and wherein all voltage sags among the three phases have a value within 10% of a defined unbalanced threshold using:

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%

=

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.

Assignees

• Liang Xiaodong
• Wallace Scott Andrew
• Zhao Xinghui
• Univ Washington State

Inventors

• Liang Xiaodong
• Wallace Scott Andrew
• Zhao Xinghui

Classifications

• H02H7/26

  Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured (locating faults in cables G01R31/08) · CPC title

• G01R31/086 Primary

  in power transmission or distribution networks, i.e. with interconnected conductors · CPC title

• H02H1/0092

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

• Y02E60/728

  Cross-Sectional Technologies · mapped topic

• Y04S10/522

  Cross-Sectional Technologies · mapped topic