Download presentation

Presentation is loading. Please wait.

1
**Fault Location EE 526 Venkat Mynam Senior Research Engineer Schweitzer Engineering Laboratories**

2
**Accurate Fault Location is Critical**

Expedite Service Restoration Reduce outage times Identify insulator problems Prevent potential recurring faults Verify Protective Relay Performance

3
**Permanent Fault Need Immediate Attention**

We need accurate fault location

4
**Temporary Faults Needs Attention Too**

Identify & Fix Damaged Insulators-Minimize Fault Recurrence

5
**Hard to Find a Flashed Insulator**

Fault location investigations

6
Finding Faults

7
Visual Methods

8
**Estimate Location From Current**

“JM Drop” circa 1936 Approximate fault location was calculated based on system and line parameters

9
**Methods in Use Line impedance Based Traveling Wave Based**

Measure impedance to fault Compare it to the actual line impedance Traveling Wave Based Measure wave arrival time

10
**System One-Line and Circuit Representation of System Fault**

11
**Modified Takagi Method-Single Ended (Negative Sequence)**

Multiply by I2 and save Imaginary part Zero For: Rf=0 or system is homogeneous

12
**IEEE Guide Defines Homogeneous System**

“A transmission system where the local and remote source impedances have the same angle as the line impedance”

13
**Single End Impedance Method**

Accuracy of zero-sequence line impedance Effect of zero-sequence mutual coupling from parallel lines Time synchronization Communication Radial topology Fault resistance System nonhomogeneity Accuracy of measurements Accuracy of positive-sequence line impedance

14
**SE Impedance Fault Location Phase-Ground Faults**

𝑚𝐴𝐺= 𝐼𝑚 𝑉𝐴𝐺∙ 𝐼 2 𝑎 ∗ 𝐼𝑚 𝑍1𝐿∙ 𝐼𝐴𝐺+𝑘0∙𝐼𝐺 ∙ 𝐼 2 𝑎 ∗ 𝑚𝐵𝐺= 𝐼𝑚(𝑉𝐵𝐺∙ 𝐼 2 𝑏 ∗ ) 𝐼𝑚(𝑍1𝐿∙(𝐼𝐵𝐺+𝑘0∙𝐼𝐺)∙ 𝐼 2 𝑏 ∗ ) 𝑚𝐶𝐺= 𝐼𝑚 𝑉𝐶𝐺∙ 𝐼 2 𝑐 ∗ 𝐼𝑚 𝑍1𝐿∙ 𝐼𝐶𝐺+𝑘0∙𝐼𝐺 ∙ 𝐼 2 𝑐 ∗ 𝐼 2 𝑏 =𝑎∙𝐼 2 𝑎 𝐼 2 𝑐 = 𝑎 2 ∙𝐼 2 𝑎

15
**SE Impedance Fault Location Multi-Phase Faults**

𝑚𝐴𝐵= 𝐼𝑚 𝑉𝐴𝐵∙ 𝑗∙𝐼 2 𝑐 ∗ 𝐼𝑚 𝑍1𝐿∙𝐼𝐵𝐶∙ 𝑗∙𝐼 2 𝑐 ∗ 𝑚𝐵𝐶= 𝐼𝑚 𝑉𝐵𝐶∙ (𝑗∙𝐼 2 𝑎 ) ∗ 𝐼𝑚 𝑍1𝐿∙𝐼𝐵𝐶∙ (𝑗∙𝐼 2 𝑎 ) ∗ 𝑚𝐶𝐴= 𝐼𝑚 𝑉𝐶𝐴∙ (𝑗∙𝐼 2 𝑏 ) ∗ 𝐼𝑚 𝑍1𝐿∙𝐼𝐶𝐴∙ (𝑗∙𝐼 2 𝑏 ) ∗ 𝑚3𝑃= 𝐼𝑚 𝑉∅∅∙ 𝐼∅∅ ∗ 𝐼𝑚 𝑍1𝐿∙𝐼∅∅∙ 𝐼∅∅ ∗ 𝐼 2 𝑏 =𝑎∙𝐼 2 𝑎 𝐼 2 𝑐 = 𝑎 2 ∙𝐼 2 𝑎

16
**Fault Loop Selection and Reporting**

Select appropriate Fault Loop Report a single fault location value Select a window of data from the fault data Provide the average value of fault location computed from the selected window

17
**Modified Takagi Method-Multi Ended (Using Remote terminal current)**

Multiply by I2 and save Imaginary part THIS IS ZERO

18
**Multi-End I2 Total Current**

Fault resistance System nonhomogeneity Accuracy of measurements Accuracy of positive-sequence line impedance Accuracy of zero-sequence line impedance Effect of zero-sequence mutual coupling from parallel lines Time synchronization Communication

19
**ME_I Impedance Fault Location Phase-Ground Faults**

𝑚𝐴𝐺= 𝐼𝑚 𝑉𝐴𝐺∙ 𝐼 2𝑇 𝑎 ∗ 𝐼𝑚 𝑍1𝐿∙ 𝐼𝐴𝐺+𝑘0∙𝐼𝐺 ∙ 𝐼 2𝑇 𝑎 ∗ 𝑚𝐵𝐺= 𝐼𝑚(𝑉𝐵𝐺∙ 𝐼 2𝑇 𝑏 ∗ ) 𝐼𝑚(𝑍1𝐿∙(𝐼𝐵𝐺+𝑘0∙𝐼𝐺)∙ 𝐼 2𝑇 𝑏 ∗ ) 𝑚𝐶𝐺= 𝐼𝑚 𝑉𝐶𝐺∙ 𝐼 2𝑇 𝑐 ∗ 𝐼𝑚 𝑍1𝐿∙ 𝐼𝐶𝐺+𝑘0∙𝐼𝐺 ∙ 𝐼 2𝑇 𝑐 ∗ 𝐼 2𝑇 𝑏 =𝑎∙𝐼 2𝑇 𝑎 𝐼 2𝑇 𝑐 = 𝑎 2 ∙𝐼 2𝑇 𝑎 𝐼2𝑇=𝐼2𝐿𝑜𝑐𝑎𝑙+𝐼2𝑅𝑒𝑚𝑜𝑡𝑒

20
**ME Impedance Fault Location Multi-Phase Faults**

𝑚𝐴𝐵= 𝐼𝑚 𝑉𝐴𝐵∙ 𝑗∙𝐼 2𝑇 𝑐 ∗ 𝐼𝑚 𝑍1𝐿∙𝐼𝐵𝐶∙ 𝑗∙𝐼 2𝑇 𝑐 ∗ 𝑚𝐵𝐶= 𝐼𝑚 𝑉𝐵𝐶∙ (𝑗∙𝐼 2𝑇 𝑎 ) ∗ 𝐼𝑚 𝑍1𝐿∙𝐼𝐵𝐶∙ (𝑗∙𝐼 2𝑇 𝑎 ) ∗ 𝑚𝐶𝐴= 𝐼𝑚 𝑉𝐶𝐴∙ (𝑗∙𝐼 2𝑇 𝑏 ) ∗ 𝐼𝑚 𝑍1𝐿∙𝐼𝐶𝐴∙ (𝑗∙𝐼 2𝑇 𝑏 ) ∗ 𝑚3𝑃= 𝐼𝑚 𝑉∅∅∙ 𝐼∅∅𝑇 ∗ 𝐼𝑚 𝑍1𝐿∙𝐼∅∅∙ 𝐼∅∅𝑇 ∗ 𝐼 2𝑇 𝑏 =𝑎∙𝐼 2𝑇 𝑎 𝐼 2𝑇 𝑐 = 𝑎 2 ∙𝐼 2𝑇 𝑎 𝐼2𝑇=𝐼2𝐿𝑜𝑐𝑎𝑙+𝐼2𝑅𝑒𝑚𝑜𝑡𝑒 𝐼∅∅𝑇 =𝐼∅∅𝐿𝑜𝑐𝑎𝑙+𝐼∅∅𝑅𝑒𝑚𝑜𝑡𝑒

21
**Multi Ended Negative Sequence Using Remote terminal voltage and current**

ref V2F +

22
**Use Synchronized Measurements to Calculate Voltage at Fault Point**

23
** Double End With V2 and I2**

Fault resistance System nonhomogeneity Accuracy of measurements Accuracy of positive-sequence line impedance Accuracy of zero-sequence line impedance Effect of zero-sequence mutual coupling from parallel lines Time synchronization Communication

24
**Multi-End Fault Location That Does Not Require Data Alignment**

Each Relay Receives: Magnitude and Angle of Z2R ½I2R½

25
**Local and Remote Data Necessary for Fault Location**

Rearrange Above Equation to Form a Quadratic Equation Solve Quadratic for Fault Location m Download Paper

26
**Multi-End Methods Needs Time Synchronized Data**

Synchrophasors Synchronized samples Devices with data acquisition synchronized to a common time source Fixed sampling rate

27
**Series Compensated Lines**

Line Side PT Bus Side PT Challenges Steady State Transient (phasor estimate is not stable) Subsynchronous MOV and bypass breaker switching Download Paper

28
Three-Terminal Line

29
**Reduce From Three-Terminal Line to Two-Terminal Equivalent**

V2_SP = V2S – Z2L_SP • I2S V2_TP = V2T – Z2L_TP • I2T Same Result V2_UP = V2U – Z2L_UP • I2U

30
**Use Two-Terminal Equivalent to Solve for m**

I2_Eq = I2T + I2U V2_Eq = V2_TP Solve for m using SE or Multi-terminal (ME_I, ME) ME_I

31
**Mutually Coupled Lines**

Download Paper

32
**Composite Lines Identifies faulted line section**

Calculates distance to fault

33
**Intersection of Voltage Profiles Identifies Faulted Section**

34
**Calculate Distance to Fault Within Faulted Section using ME method**

Download Paper

35
**Impedance Method Approach Summary**

Measure VA, VB, VC, IA, IB, IC Extract fundamental components Determine phasors and fault type Apply impedance algorithm

36
**Impedance Fault Location Methods**

Single-End Method using local voltage and currents SE Multi-End Method using local voltage and currents, and remote currents MEI Multi-End Method using local and remote voltage and currents ME

37
**Some of the Challenging Situations for Z based Fault Location Methods**

Short faults: faster relays and breakers- phasor estimate is not stable Faults associated with time-varying fault resistance-phasor estimate is not stable Series compensation

38
**Short Duration Faults Raw-Blue, Cosine Filtered-Green**

Magnitude of Filtered Quantity-Red

39
**Lightning and Faults Launch Traveling Waves**

tL tR Download Paper

40
**Double Ended TW Fault Location**

41
**Single-End TW Fault Locator**

42
**Image courtesy of Google**

Results From Field 117.11km, 161 kV line 18 sections with 4 different tower configurations Challenges with existing impedance based fault location methods Image courtesy of Google

43
**Fault Location Results (161kV, 117.11km long line)**

TW Patrol SE_Z ME_Z_I ME_Z CG 109.74 109.29 105.44 106.24 106.56 BG 61.12 61.41 54.75 60.69 60.70 108.23 107.60 101.59 106.43 98.85 98.98 95.20 98.37

44
**Temporary Fault Due to Insulator Flashover**

45
Insulator Flashover

Similar presentations

Presentation is loading. Please wait....

OK

Topic 1: DC & AC Circuit Analyses

Topic 1: DC & AC Circuit Analyses

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Download ppt on motion sensing technology Ppt on operating system concepts Ppt on op amp circuits analysis Ppt on central nervous system Download ppt on lcd tv Ppt on review writing sample Ppt on idiopathic thrombocytopenia purpura genetic Ppt on sustainable tourism practices Ppt on cse related topics of psychology Ppt on natural numbers and whole numbers