Reconductoring and Voltage Upgrading of Transmission Lines
Power transmission owners and operators need to develop new line designs and to find ways of increasing the capacity of existing lines that are acceptable to the public, reliable, and which re-quire only modest capital investment. Long lead times for new lines, limited availability of right-of-way, and increasingly complex procedures for applications and permits justify increased sophistication in making lines that are more compact yet capable of higher power flow levels.
COURSE OBJECTIVE AND SUMMARY
This course addresses traditional and novel methods and materials for maximizing power flow on new and existing transmission lines. It explores the tradeoffs between reducing visual impact and operational reliability, between capital investment and increased power flow. Both electrical and mechanical aspects of line design and modification are covered within a framework of making smart economic choices. Both experienced designers and beginning engineers can profit from the presentations. Some topics related to underground cables are included.
Expected Learning Objectives / Outcomes
PDC has identified learning objectives we expect each student to obtain on completion of this course. The student completing this course should be able to:
Identify the main components of an overhead power transmission line.
List and briefly describe the power system constraints that may apply to a transmission line.
Describe in general terms the relationships between sag, tension, line loading and operating temperature.
List the basic environmental issues associated with transmission lines.
Understand the basic requirements for overhead line ratings.
WHO SHOULD ATTEND
The course will be valuable to engineers responsible for planning, operating or designing transmission circuits.
An engineering degree in mechanical, electrical or civil engineering is desirable.
LINE DESIGN OVERVIEW
Introduction to Line Design
Historical Development of T Lines
Examples of Common Designs
Main Components of Lines
Uprating vs. New Line Design
Power System Constraints
Phase Shift Stability
Post and Tension Insulators
Porcelain and Non-ceramic Insulators
In-Span Insulating Spacers
Power Frequency Insulation
Clearances to Structures
Design of Insulator Skirts
Coupling of Shield and Phase Conductors
Aluminum, Copper and steel wires
Stranded Conductor Designs
ACSR Stranding Alternatives
Trapezoidal Aluminum Wires
Phase Conductor Selection
Shield Wire Choices
CATENARIES, RATINGS & WIND
The catenary: sag vs. tension
Conductor Length & Slack
Wind & Ice Loads
Sag at high temperature
Unloaded Tension Limits
Standard Tension Limits
Extreme Loading Limits
Ruling span concept
Coupled suspension spans
Ruling span definition
Stringing sag tables
Ruling Span Errors
Wind-Induced conductor Motions
Ice galloping & control methods
Conductor Heat Balance
Steady State Normal Ratings
Transient Emergency Ratings
Annealing of Copper and Aluminum
Sag clearance at high temperature
High temperature creep elongation
DESIGN & UPRATING
Criteria, Prediction and Evaluation
Field at Conductor Surface and Corona
Field at Ground Level and Coupling
Unperturbed and Perturbed Fields
Safety, Annoyance and Perception
Maximum and Resultant Field
Problems Comparing Calculation to Measurement
Corona: Noise and Losses
Radio and Television Noise
Signal to Noise Ratio
New Line Design Cost Issues
Present Worth of Electrical Losses
Conductor Material & Labor
Cost of Structures
Detailed Review of 115kV Line Design
Blowout & ROW width
Calculating high temperature sag
Choosing a pole length
Selecting a pole strength
Electric & Magnetic Fields
Noise & Interference
Power System Inputs
Normal vs. emergency power flow
Dynamic Rating Methods
Use of higher conductor temperature
Typical classroom hours are 8:30AM to 4:30PM, with a continental breakfast starting a half hour before class time. The instructors will take an informal survey of students on the first day to see if the classroom hours should be adjusted to accommodate travel schedules or other activities outside of class.
The three-day course will be held at the Alden Beach Resort, 5900 Gulf Boulevard, St. Pete Beach, Florida 33706. A special rate is available to those attending PDC's course. The rooms generally have two double beds, living room, and kitchenette. Please contact the Alden Resort directly at 1-800-237-2530. Mention the PDC course to obtain the lower rate. Reservations must be made by 30 days in advance to insure the special rate. Map of Area
Dr. Dale A. Douglass , Principal Engineer, with Power Delivery Consultants, has over 30 years experience with overhead line design, analysis, uprating and R&D. Dr. Douglass will be the primary instructor for the course.
Dr. James R. Stewart, P.E., Consultant, has over 30 years experience with overhead lines, focusing on research and development projects including development of the first 6 and 12 phase transmission lines. Dr. Stewart will present information on the electrical parameters of lines, environmental factors (fields, noise), and lightning.
Continuing Education Units
PDC will issue students a course certificate indicating the number of Continuing Education Units for the course completed based on national guidelines and the number of classroom hours. 1.8 Continuing Education Units (CEUs) will be awarded for successful completion of this course. The CEU is the nationally recognized unit for recording participation in noncredit educational programs. One CEU is equal to ten classroom hours.
Tuition and Enrollment:
The tuition covers the cost for this three-day course and includes extensive course notes, continental breakfast and lunch. Each participant will be furnished a bound set of notes. Included will be an extensive bibliography and selected technical papers. Lodging, transportation, and other meals are not included.