1. Rocky Mountain Power 2011 Clinic Project Dynamic Line Rating Preliminary Design Review
Project Advisor: Dr. Thomas Schmid
Clinic Team Members: Skyler Kershner, Benjamin Sondelski, Trevor Nichols, Shayan Barzagari, Zhao Qi

2. Presentation Overview
Project Background
Goals
Proposed Solution
Additional Considerations
System Implementation
Model
Expected Results
Budget / Timeline

3. Project Background Overhead Conductor Sag
National Electrical Safety Code specifies minimum clearance
As conductor heats, sag increases
Environmental, power considerations
Dynamic line rating system needed
[1] Clearance Levels

4. [2] Line Sag Illustration
Project Goals
Develop dynamic line rating system
Combine best characteristics of commercially available models
Simple design
Implement system in a model
Validate collected data
[2] Line Sag Illustration

5. Proposed Method: Thermal Imaging
Directly measures sag and line temperature
Non-contact measurement
[4] Configuration
[5] Camera View

6. Proposed Method: Thermal Imaging
Provides high contrast images, temperature measurement
Image processing tracks lowest point in line
[6] Thermal Image

7. Proposed Method: Thermal Imaging
Limitation: Cost
Model
Price
$19,500
FLIR T620
[7]
$13,500
FLIR SC325
[8]
FLIR E60
$7,500
[9]

8. Conclusion Need for dynamic line rating Goals
Thermal imaging as potential solution
Limitations of thermal imaging
Other methods needed

9. Overview Sag – Tension rating and calculation Tension as a solution
Tension as a problem
Design Problems/Solutions**
Conclusion

10. Tension as a Possible Solution
All-Inclusive Measurement
line temperature, environment temperature, solar absorption
Accuracy
Simplicity
Low-Power Draw

11. Sag-Tension Rating and Calculations
D – Vertical sag
S – Horizontal length of the span
W – Unit weight of the conductor
Tr – Resultant conductor tension
Th – Horizontal component of tension
Fig. 1 Parabolic Sag Curve
[10]

12. Tension as a Possible Problem
Cost
Actual implementation
Required line outage for installation
Ice and wind loading
Length of Conductor
Stretching and high temperatures

13. Design Problems/Solutions
Ice loading
Wind loading
For structures below 60 feet:
For structures exceed 60 feet:
Resultant ice and wind loading

14. Conclusion Overview of Tension Tension pros Tension cons
Solutions to tension cons

15. Overview Magnetic Field Sensing Implementation difficulties
Build a model - advantages
Conclusion

16. Magnetic Field Sensor [11] Three Axis Magnetic Field Sensor
MAGNETOMETER RS232 W/CASE
High Accuracy, <0.5% Full Scale
10 to 154 Sample/Sec
Low Power consumption
Input voltage range 6 to 15 (VDC)
[11]

17. Magnetic Field Measurement Difficulties

18. Build a Model Test wide range of aspects
Control experiment variables and environment
Develop realistically implementable solutions
Retain a low budget

19. Conclusion
Magnetic Sensing
Magnetic Difficulties
Advantages of Model

20. Overview Proposed Solution Math defining model requirements
Measuring Temperature
Conclusion

21. Proposed Solution Mock thermal imaging system
[12] [13]
Build a model scaled down to 1:30 ratio
Approximately 600 feet scaled to 20 feet
Measure sag in a controlled environment
Clinic Lab – Merrill Engineering Building 2350
Develop an effective dynamic line rating system

22. Math defining model
Tension in the line – direct effect of line temperature
Temperature – direct effect of amount of line current
Amperage – controlled system input

23. MEASURING TEMPRATURE

24. MEASURING TEMPRATURE

25. Conclusion Mock thermal imaging Proposed Solution
Characteristics of model
Mock thermal imaging
IR thermometer
IR video camera

26. Physical Model: Introduction
benefits of in-house scale model
power supply
electrical diagram
conductor span
expected model performance

27. Benefits of In-House Scale Model
communications
controlled environment
simple comparison to IEEE 738
no exposure to weather
verification of thermal time constant
test bed for future clinics

28. Power Supply need 480V, 3 phase 208V 3 phase is available 2kVA each
power supply losses

29. Model Electrical Diagram
National Electrical Code:
bonding and grounding
conductor sizing
overcurrent protection
ground detector

30. Conductor Span 1½″ PVC structure (FORMUFIT connectors)
transparent covering (acrylic or polycarbonate)
dead-end attachments

31. Expected Model Performance
20′ span
200lbs tension at 25°C
Sparrow ACSR

32. Physical Model: Conclusion
benefits of in-house scale model
power supply
electrical diagram
conductor span
expected model performance

33. Budget Qty Description Cost Total Total: $1566 1 Transformer $0 2
Cable
Transformer Pad
$20
$40 4
Various lugs, clamps, connectors
$80
Circuit breaker
$300 3
Locking plug
$42
$126
Tension meter
$1000
Total:
$1566

34. Timeline

35. CONCLUSION Measure Sag Build a Model Desirable:
Measure Conductor Temperature
Due to budget, use Temp Sensor and IR Camera
Validate Measurement
Measuring Tension
Magnetic Sensor

36. Contact Info / References
Rocky Mountain Power Clinic Team
University of Utah
Electrical and Computer Engineering Department
References
[1] “Clearance Levels”, Oct. 3, [Online]. Available:
[2] “Line Sag Illustration”, Oct. 3, [Online]. Available:
[3] “Tension Illustration”, Oct. 3, [Online]. Available:
[4] “Configuration”, Oct. 3, [Online]. Available:
[5] ”Power Line View”, Oct. 3, [Online]. Available:
[6] “Thermal Image”, Oct. 3, [Online]. Available:
[7] “FLIR T620”, Oct. 3, [Online]. Available:
[8] “FLIR SC325”, Oct. 3, [Online]. Available:
[9] “FLIR E60”, Oct. 3, [Online]. Available:
[10] “Sag and Tension”, Sep. 20, [Online]. Available:
[11] “Smart Digital Magnetometer HMR2300”, Sep. 30, [Online]. Available: documents/Missiles-Munitions/HMR2300.pdf.
[12] “IR Thermo Gun”, Sep. 29, [Online]. Available:
[13] “IR Security Camera”, Sep. 29, [Online]. Available: