Title: School of Engineering and Architecture
1School of Engineering and Architecture
LEBANESE AMERICAN UNIVERSITY
- Location of Transmission Lines Faults
- presented by Mr. Mohamad Haidar
- Supervised by
- Dr. Raymond Ghajar
- Final Year Project
2Table of Contents
- Introduction
- Faults
- Types of faults
- Fault Location Techniques
- Derivation of Single Line-to-Ground distance
equation - Tested Data
- Future Work
- Conclusion
3Introduction
4Faults
- What is a fault?
- Causes of Faults(Lightning strikes, sabotage, car
accidents, wind damage,etc) - History
- Digital Fault Recordershave voltage triggers,
record 32 or more analogue or digital
channels,and 720 samples/sec
5One-Terminal DFR
6Two-Terminal DFR
7Types of Faults
- Single Line-to-Ground faults(SLG)
- Double Line-to-Ground faults(DLG)
- Line-to-Line faults(LL)
- Three Phase faults
8Single Line-to-Ground(SLG)
- SLG whenever any one phase touches
- the ground.
9Double Line-to-Ground (DLG)
- DLG Whenever any two phases touches
- the ground.
10Line-to-Line (LL)
- LL Whenever any two phases touches
- each other.
11Three Phase
- Three Phase fault Whenever all phases touches
the ground.
Phase A
Ifa
Zf
Phase B
Ifb
Zf
Phase C
Ifa
Zf
12Fault Location Techniques
- One-Terminal Data Algorithm
- What effects the accuracy?
- Load current in presence of high fault resistance
- Mutual effects on zero-sequence components
- Untransposed Lines and line charging
- Inaccurate fault type identification
- Uncertainty of line parameters, particularly zero
sequence components
13Two-Terminal Data Algorithm
14Benefits of Fault Location and Analysis
- Help us to identify
- Causes of both permanent and temporary faults
- Weak spots in the transmission network
- Tower footing resistance , this helps to reduce
future faults in the network, providing other
benefits such as - Improved service reliability
- Reduced maintenance and operating costs
- Optimized equipment purchases (such as surge
arrestors)
15Comparison between One-Terminal and Two-Terminal
Algorithms
16Comparison between One-Terminal and Two-Terminal
Algorithms Graphically
17Derivation of SLG fault Distance Equation
- Description of the system
18Assumptions takes into consideration
- Three phases of a transmission line are assumed
to be transposed - Synchronization between the two terminals not
needed - No shunt capacitances
- No Load
- Mutual coupling between phases is ignored
- Source impedances, distribution factors, and
prefault currents are not needed by the
estimation procedures
19Sequence Network Diagram for phase A-to-ground
fault
20Derivation of the equations
- Vax V1x V2x V0x _at_ bus X ..(1)
- Vay V1y V2y V0y _at_ bus Y ..(2)
- by KVL
- V1x Z1xfI1xf V1f (3) V1y Z1yfI1yf
V1f (6) - V2x Z2xfI2xf V2f (4) V2y Z2yfI2yf
V2f (7) - V0x Z0xfI0xf V0f (5) V0y
Z0yfI0yf V0f (8) - Substituting eq.(3) to eq(8) in eq.(1) and eq(2)
and knowing that Z1xf Z2xf and Z1yf Z2yf - And Iaxf I1xf I2xf I0xf (9)
- Iayf I1yf I2yf I0yf (10)
21Final Equation
- Lx L Im(Z1xf) / Im(Zxy)
- Ly L Im(Z1yf) / Im(Zxy)
- Where Zxy Z1x Z1y and L length of the
transmission line and Lx and Ly are the distances
to the fault from buses X and Y respectively.
22Simulation of the Program
23Future Work
- Expanded to other types of faults
- Identifying type of faults
- Building up a network
- Will be tested on ElectroMagneticTransients
Program
24Conclusion
- In conclusion, Ive talked about the major
aspects of a power system. - Personally, Ive learned a lot throughout this
project, such as the different fault location
techniques, and learning a new computer language
(Visual Basic)