PROT 407: Transmission Line Protection

Course Length: 5 Days (PDHs: 38)
Course Based Fees: $3,000*
* Plus Applicable Tax


PROT 407 provides an in-depth study of the principles and schemes for protecting high-voltage power transmission lines. The course provides advanced guidelines for relay application and settings for transmission lines, including series-compensated lines, and reviews time-domain ultra-high-speed line protection principles. Additional topics include the application and settings of power swing blocking and out-of-step tripping functions, an overview of power system faults, and instrument transformers.


This course is intended for engineers who need a comprehensive understanding of the design concepts and methods used in protecting high-voltage power transmission lines.


Day 1

  • Power System Faults
  • Class Exercise: Autotransformer High-Voltage Side Single-Phase-to-Ground Fault Calculation
  • Class Exercise: Autotransformer Tertiary Winding and Neutral Fault Current Calculation
  • Power Line Overview

Day 2

  • Relaying Fundamentals
  • Class Exercise: Relaying Fundamentals
  • Instrument Transformers
  • Class Exercise: Current Transformers
  • Line Directional Overcurrent Protection

Day 3

  • Class Exercise: Line Directional Overcurrent Protection
  • Line Distance Protection
  • Class Exercise: Line Distance Protection Settings Calculation

Day 4

  • Line Directional Comparison Protection
  • Line Current-Based Protection
  • Time-Domain Line Protection

Day 5

  • Series-Compensated Line Protection
  • Power Swing Blocking and Out-of-Step Tripping
  • Class Exercise: Power Swing Blocking Element Setting Calculation

Note: This course teaches fundamental knowledge but does not provide hands-on experience with SEL relays.

Learning Outcomes

At the conclusion of this course, students can:

  • Describe transmission line protection problems and identify solutions using digital relays.
  • Select the appropriate transmission line protection schemes for various applications.
  • Calculate settings for transmission line protection schemes, including directional overcurrent, distance, and pilot protection schemes.
  • Specify current transformers for protective relay applications.
  • Describe the various pilot protection schemes for transmission lines.
  • Discuss the advantages of line current differential protection.
  • Describe time-domain ultra-high-speed transmission line protection.
  • Identify the challenges and solutions to series-compensated transmission line protection.
  • Identify and apply power swing blocking and out-of-step tripping.

Student Background and Knowledge

A degree in electrical engineering or equivalent experience is recommended. In addition, we recommend that you complete PROT 401: Protecting Power Systems for Engineers OR have the following:

  • Familiarity with transmission line characteristics.
  • A basic knowledge of protective relay design, symmetrical components, fault analysis, and power system protection.
  • A working knowledge of trigonometry, basic calculus, complex numbers, and phasor concepts.

Click here to view our recommended reading on these topics:

  • Electric circuit analysis
  • Power systems that cover symmetrical components, fault analysis, power lines, and electrical transients in power systems

Additional information is on the Course Policies and FAQ pages.

Available Courses

Request onsite training for your company.